PHOSPHORUS MANAGEMENT FOR THE GREAT LAKES

TASK FOR-

TO THE IMfDIFINARONM - --'S GREAT LAKES WmER QwuKY BOAR0 Am GREAT LAKES SC-E AW8SUW BOARD

PHOSPHORUS MANAGEMENT FOR THE GREAT LAKES

FINAL REPORT OF THE PHOSPHORUS MANAGEMENT STRATEGIES TASK FORCE

TO THE INTERNATIONAL JOINT COMMISSION'S GREAT LAKES WATER QUALITY BOARD AND GREAT LAKES SCIENCE ADVISORY BOARD

JULY, 1980 WINDSOR, ONTARIO

INTERNATIONAL JOINT,COMMISSION GREAT LAKES SCIENCE ADVISORY AND WATER QUALITY BOARDS

100 OUELLETTE AVENUE, 8TH FLOOR, WINDSOR, ONTARIO N9A 6T3

F i l e : 3000-6 c / r : 2000-6

J u l y 8, 1980

I n t e r n a t i o n a l J o i n t Commission Great Lakes Science Adv isory Board Great Lakes Water Q u a l i t y Board

Gentlemen:

T ransmi t ted he rew i t h i s t h e f i n a l r e p o r t o f t h e Phosphorus Management S t r a t e g i e s Task Force. Th is r e p o r t i s submi t ted i n f u l f i l m e n t o f t h e requi rements s p e c i f i e d i n t h e Terms o f Reference p rov ided t o t h e t ask f o r c e by t h e Boards.

As requested by t h e Commission i n i t s l e t t e r o f September 13, 1979 t o t h e Secre ta ry o f t h e Science Adv isory Board, t h e r e p o r t i s be ing submi t ted t o b o t h Boards and t h e Commission i n a form s u i t a b l e f o r p u b l i c r e l ease by t h e Commission i f i t so des i res.

The task f o r c e members are p leased t o have had t h i s o p p o r t u n i t y t o c o n t r i b u t e t o t h e impor tan t task o f enhancing water q u a l i t y i n t h e Great Lakes. Wi th t h e submission o f t h i s r e p o r t , t h e task f o r c e cons iders i t s assignment t o be completed. However, we would be p leased t o p rov ide any c l a r i f i c a t i o n o f t he f i n d i n g s o r f u r t h e r exp lana t i on o f t h e bas i s f o r any o f t h e recommendations con ta ined i n t h e r e p o r t which t h e Commission o r i t s Boards may request .

R e s p e c t f u l l y submit ted,

6&atAu.@* Gerard A. Roh l i ch

a.6cd Donald J. O'Connor

Co-Chairman Co-Chai rman Phosphorus Management S t r a t e g i e s Task Force

PREFACE

This r e p o r t presents t he f i nd ings o f the Phosphorus Management S t ra teg ies Task Force. The task fo rce was appointed i n t h e s p r i n g of 1978 by t h e Great Lakes Science Advisory Board ( a t t h a t t ime t h e Great Lakes Research Advisory Board) w i t h i n s t r u c t i o n s t o i n v e s t i g a t e a1 t e r n a t i v e s t r a t e g i e s f o r managing phosphorus i npu ts t o t he Great Lakes. Subsequently, t h e task fo,rce membership was expanded t o become a j o i n t task f o r c e r e p o r t i n g t o both t h e Science Advisory Board and the Water Qu.a l i t y Board o f t he I n t e r n a t i o n a l J o i n t Commission.

The Terms o f Reference and membership o f t h e task f o r c e are g iven i n Appendices 1 and 2.

As p a r t o f i t s e f f o r t s t o o b t a i n t he l a t e s t in format ion, t h e task f o r c e arranged a conference on "Phosphorus Management S t ra teg ies f o r t h e Great LakesM sponsored by t h e I n t e r n a t i o n a l J o i n t Cnmmission and Corne l l Un i ve rs i t y . Presentat ions a t t h e conference were made by i n v i t e d speakers recognized as exper ts on t o p i c s dea l ing w i t h p o i n t and nonpoint phosphorus i n p u t s t o t h e Great Lakes, phosphorus avai 1 ab i 1 i ty, model i n g approaches, c e n t r a l ob jec t i ves , and techn i ca l , economic, and i n s t i t u t i o n a l aspects of management s t ra teg ies .

The proceedings o f t he conference together w i t h var ious r e p o r t s o f t h e I n t e r n a t i o n a l J o i n t Commission and o ther sources have been o f g rea t va lue t o t he task f o r c e i n i t s d e l i b e r a t i o n s . The major documents used by t h e task f o r c e inc lude:

1. Proceedings o f t he IJC/Cornel l U n i v e r s i t y Conference on "Phosphorus Management S t ra teg ies f o r t h e Great Lakes" h e l d i n Rochester, N.Y., A p r i l 1979.

2. Report o f Task Group I11 - A Technical Group t o Review Phosphorus Loadings F i f t h Year Review o f Canada - Un i ted States Great Lakes Water Q u a l i t y Agreement, February 1978.

3 . Report on D i f f e rences i n t he Great Lakes Phosphorus Load Est imates - Report t o P o l l u t i o n f rom Land Use A c t i v i t i e s Reference Group, February 1979.

4. Review o f Models - prepared by t h e Model 1 i n g Group o f t he Phosphorus Management S t ra teg ies Task Force, J u l y 1980.

I

The statements and views presented i n t h i s r e p o r t are those o f t h e task fo rce members and do no t necessa r i l y r e f l e c t t h e views o r p o l i c i e s o f t h e Great Lakes Water Qua1 i ty Board, t h e Great Lakes Science Advisory Board, nor t h e I n t e r n a t i o n a l J o i n t Commission.

TABLE OF CONTENTS

CHAPTER Page

.......................................................... PREFACE . . .

LIST OF FIGURES ...................................................... LIST OF TABLES ................................................... ABBREVIATIONS AND SYMBOLS ........................................

..................................................... 1.0 1:NTRODUCTION 1.1 Eco log ica l Perspect ives .....................................

. 1.2 Phosphorus as Related t o Great Lakes Eu t roph i ca t i on ......... 2.0 DEVELOPMENT OF 1978 GREAT LAKES WATER QUALITY AGREEMENT

PHOSPHORUS TARGET LOADS ........................................ 2.1 Tota l Phosphorus Target Loads ............................... 2.2 To ta l Phosphorus Concentrat ion Ob jec t i ves ................... 2.3 Mathematical Models ......................................... 2.4 Development o f S p e c i f i c Target Loads ........................ 2.5 Summary .....................................................

3.0 EVALUATION OF PHOSPHORUS INPUTS TO THE GREAT LAKES ............... 3.1 Present Load Est imates ...................................... 3.2 L i m i t a t i o n s and Imp1 i c a t i o n s o f xis sting Loading Est imates . .

3.2.1 T r i b u t a r y Loads ................................... 3.2.2 Shore1 i n e Eros ion ................................. 3.2.3 Bioavai 1 abi 1 i ty o f ~hosphorus ..................... 3.2.4 Primary Sources o f T o t a l Phosphorus

i n T r i b u t a r i e s .................................. . .

3.3 Fu tu re Load Est imates ....................................... 3.3.1 Po in t Sources ..................................... 3.3.2 T r i b u t a r i e s ......... .,. ............................ ................................ 3.3.3 . Repor t ing o f Loads .................................................. 3.4 Sumary .. ..

4.0 REVIEW AND EVALUATION OF MODELS ................................... .................... 4.1 Present S ta te o f Eu t roph i ca t i on Modeling ......................... 4.2 Models Used t o Develop Target Loads 4.3 Assessment o f R e l i a b i l i t y o f Target Loads ..................................... Establ i shed by Model s

4.3.1 Dif ference i n Target Loads Calcu lated by ................................... Various Models 4.3.2 Percent E r r o r Between Computed and Observed Values 4.3.3 Issues Not Addressed by t h e Models ................ ..................................................... 4.4 Summary

CHAPTER Page

5.0 COSTS AND TECHNOLOGIES OF PHOSPHORUS CONTROL ..................... . .5.1 Phosphorus Management f o r Po in t Sources .....................

5.1.1 Chemical Phosphorus Removal ....................... 5.1.2 B i o l o g i c a l and Bio logica l /Chemical Processes ...... 5.1.3 Land A p p l i c a t i o n f o r Phosphorus Removal ........... 5.1.4 Costs f o r Mun ic ipa l P o i n t Source Cont ro ls ......... 5.1.5 Phosphorus Detergent Cont ro ls ..................... 5.1.6 Summary ...........................................

5.2 Management of Nonpoint Sources o f Phosphorus ................ 5.2.1 Land Use A c t i v i t i e s o f Concern .................... 5.2.2. C h a r a c t e r i s t i c s o f Nonpoint Sources-Imp1 i c a t i o n s .................................. f o r Management 5.2.3 Remedial Measures ................................. ................ 5.2.4 Costs f o r Nonpoint Source Cont ro ls ........................................... 5.2.5 Summary

5.3 Other Considerat ions ........................................ 6.0 STRATEGIES FOR ASSESSING THE SOCIAL AND ECONOMIC IMPACTS .........

6.1 Background .................................................. ..................................... 6.2 Bas. i s f o r t h e Framework 6.3 Current Status o f Pol icy-Re1 evant I n fo rma t i on ............... 6.4 S p e c i f i c S t ra teg ies ..........................................

7.0 PHOSPHORUS MANAGEMENT STRATEGY ................................... .............................................. 7.1 Basic Premises 7.2 Staged. Approach ............................................. 7.3 Management o f P o i n t Sources ................................. 7.4 Management o f Nonpoint Sources ..............................

7.4.1 In format ion/Educat ion ............................. 7.4.2 Level 1 Remedial Measures ......................... ....................... 7.4.3 C r i t i c a l Area I d e n t i f i c a t i o n 7.4.4 Demonstration Watersheds ..........................

7.5 In fo rma t i on Needs ........................................... 7.6 Summary ......................................................

8.0 REFERENCES ......................................................... APPENDICES

1 . Terms o f Reference ...................................... .............................................. 2 . Membership

L I S T OF FIGURES

No. -

3.1

TITLE Page

General Re la t ionsh ips between Phosphorus .............................. Forms and Algae 28

Phosphorus Management Linkages ................. 71

Estimated Tota l Phosphorus t o Lake E r i e ......... 87

..... Estimated To ta l Phosphorus t o Lake Ontar io 88

Recommenddd r.?!lni c i pa l Poi n t Source Contro l Program ...................................... 94

Framework f o r a Nonpoi n t Source Management Program ...................................... 102

L I S T OF TABLES

No. - 2.1

TITLE Page

1978 Great Lakes Water Qua1 i t y Agreement To ta l Phosphorus Target Loads ............... 13

T o t a l ~ h o s p h o r u s Ob jec t i ves w i t h Est imated Leve ls o f Ch lo rophy l l - a, Secchi Depth, and Troph ic S t a t e ........................... 14

"Best Est imate" o f 1976 T o t a l Phosphorus Loads ....................................... 22

Shore1 i n e Eros ion as a Sorlrce o f Lake-Wide T o t a l Phosphorus ............................ 26

Phosphorus Removal by Land Treatment Systems ..................................... 5 0

Mun ic ipa l P o i n t Source Treatmen,t Opt ions ...... 5 7

Remedi a1 Measures f o r A g r i c u l t u r a l Nonpoint Sources ............................ 6 5

Remedi a1 Miasures f o r Urban Nonpoint Sources ..................................... 6 6

Phosphorus Cont ro l Program f o r t h e Great Lakes 84 .................................

ABBREVI AT1 ONS AND SYMBOLS

cu m - cubic metres

d - day

g ~ d / s q ft - - gal lons per day per square foot

ha - hectare

l b - pounds

m - metres

MGD - m i 11 ions o f gal lons (U. S. ) per day

mg/L - mil l igrams per l i t r e

NI/L - micro grams per 1 i t r e

t / y r - metr ic tons per year

1 , O I N T R O D U C T I O N

I n 1970, t h e I n t e r n a t i o n a l J o i n t Commission repo r ted t o the Governments o f

Canada and the Un i ted States1 t h a t :

o "Lake Erie, particularly its Western Basin, is in an advanced state of eutrophication and accelerated eutrophication is occurring in Lake Ontario. The accelerated eutrophication of these waters is due to the presence of nutrients which have been and are being added to these waters. The resultant biological productivity is proportional to the annual rate of input of these nutrients. Of the nutrients involved, phosphorus is the only one that is both growth-limiting .in the lakes .qn(q controllable effectively by man with present technology.

o The major source of phosphorus is municipal sewage. ,

In the United States 70 percent of the phosphorus in sewage originates from detergents, most of the remainder from human excreta. In Canada approximately 50 percent originates from each sewage source. Apart from municipal sewage, the other significant sources of phosphorus are agricultural runoff,and some industrial wastes.

o The input of phosphorus can be reduced by widespread improvement in the treatment in existing plants of municipal and industrial wastes containing phosphorus. An over-all programme to achieve this is essential if eutrophication is to be ha1 ted.

o Because of the practical difficulties in implementing the municipal programme contemplated in the preceding conclusion within the reasonable future, it is essential that both countries reduce the phosphorus content of detergents to the maximum practicable extent at the earliest possible time.

o The inputs to the waters of the basin of phosphorus, nitrogen and other nutrients from agricultural ,operations are difficult to control but methods must be found to diminish them."

and recommended tha t :

"The Governments of Canada and the United States enter into agreement on an integrated programme of phosphorus control to include:

(a) the immediate reduction to a minimum practicable level of the phosphorus content of detergents and the total quantities of phosphorus-based detergents discharged into the Great Lakes System with the aim of complete replacement of all phosphorus in detergents with environmentally less harmful materials by December 31, 1972;

(b) further reduction, as a matter of urgency, of the remaining phosphorus in municipal and industrial waste effluents discharging to Lake Erie, Lake Ontario and their tributaries and to the International Section of the St. Lawrence River, with a view to achievingat least an 80 percent reduction by 1975 and thereafter additional reduction to the maximum extent possib.1e by economically feasible processes;

(c) the reduction of phosphorus discharged to these waters from agricultural activities."

On A p r i l 15, 1972 a Great Lakes Water q u a l i t y ~ g r e e m e n t ~ was signed by

Canada and the Un i ted States wherein t hey agreed t o implement the f o l l o w i n g

programs and o ther measures t o c o n t r o l the inpu ts o f phosphorus:

1. "Programs. Programs shall be developed and implemented to reduce inputs of phosphorus to the re at Lakes System. ~hese progr-ams shall include:

(a) Construction and operation of waste treatment facilities to remove phosphorus from municipal sewage;

(b) Regulatory~measures to require industrial dischargers to remove phosphorus from wastes to be discharged into the Great Lakes System:

(c) Regulatory and advisory measures to control inputs of phosphorus through reduction of waste discharges attributable to animal husbandry operations.

In addition, programs may include regulations limiting or eliminating phosphorus from detergents sold for use within the basin of the Great Lakes System.

2. Effluent Requirements. The phosphorus concentrations in effluent from municipal waste treatment plants discharging in excess of one million gallons per day, and from smaller plants as required by regulatory agencies, shall not exceed a daily average of one milligram per litre into Lake Erie, Lake Ontario and the International Section of the St. Lawrence River.

3. Industrial Discharges. Waste treatment or control requirements for .a11 industrial plants discharging wastes into the Great Lakes System shall be designed to achieve maximum practicable reduction of phosphorus discharges to Lake Erie, Lake Ontario and the International Section of the St. Lawrence River.

4. Reductions for Lower Lakes. These programs are designed to attain reductions in gross inputs of phosphorus to Lake Erie and Lake Ontario of the quantities indicated in the following tables for the years indicated.

The r e s p o n s i b i l i t y f o r mon i t o r i ng progress i n implement ing these programs

and assessing t h e i r impact on Great Lakes water q u a l i t y was assigned t o t h e

I n t e r n a t i o n a l J o i n t Commission. Based on t he r e p o r t s o f i t s p r i n c i p a l adv i so r

under t h e Agreement, t h e Great Lakes Water q u a l i t y Board, t h e IJC has repo r ted

annua l l y t o t he Governments w i t h recommendations f o r changes i n t he programs

o r t h e i r implementat ion.

I n 1978, a r e p o r t t o t he IJC by t he I n t e r n a t i o n a l Reference Group on

P o l l u t i o n o f t he Great Lakes f rom Land Use ~ c t i v i t i e s ~ proposed programs t o

c o n t r o l phosphorus i n p u t s f rom nonpoint sources and suggested a d d i t i o n a l

c o n t r o l s f o r p o i n t sources. A lso i n 1978, t h e Governments reviewed progress

under t he 1972 Agreement, and signed a new Agreement4 i n which t h e y

t e n t a t i v e l y agreed t o new t a r g e t loads and suggested f u r t h e r programs as

f o l l o w s :

1. "The purpose of the following programs is to minimize eutrophication problems and to prevent degradation with regard to phosphorus in the boundary waters of the Great Lakes System. The goals of phosphorus control are:

(a) Restoration of year-round aerobic conditions in the bottom waters of the Central Basin of Lake Erie;

(b) Substantial reduction in the present levels of algal biomass to a level below that of a nuisance condition in Lake Erie;

(c) Reduction in present levels of algal biomass to below that of a nuisance condition in Lake,Ontario including the International Section of the St. Lawrence River;

Maintenance of the oligotrophic state and relative algal biomass of Lakes Superior and Huron;

Substantial elimination of algal nuisance growths in Lake Michigan to restore it to an oligotrophic state; and

The elimination of algal nuisance in bays and in other areas wherever they occur'.

(.

The following programs shall be developed and implemented to reduce input of phosphorus to the re at Lakes:

Construction and operation of municipal was& treatment facilities in all plants discharging more than one million gallons per day to achieve, where necessary to meet the loading allocations to be developed pursuant to paragraph 3 below, or to meet local conditions, whichever are more stringent, effluent concentrations of 1.0 milligram per litre total phosphorus maximum for plants in the basins of Lakes Superior, Michigan, and Huron, and of 0.5 milligram per litre total phosphorus maximum for plants in the basins of Lakes Ontario and Erie.

Regulation of phosphorus introduction from industrial discharges to the maximum practicable extent.

Reduction to the maximum extent practicable of phosphorus introduced from diffuse sources into Lakes Superior, Michigan, and Huron; and reduction by 30 percent of phosphorus introduced from diffuse sources into Lakes Ontario and Erie, where necessary to meet the loading allocations to be developed pursuant to paragraph 3 below, or to meet local conditions, whichever are more stringent. .

Reduction of phosphorus in household detergents to 0.5 percent by weight where necessary to meet the loading allocations to be developed pursuant to paragraph 3 below, or to meet local conditions, whichever are more stringent.

Maintenance of a viable research program to seek maximum efficiency and effectiveness in the control of phosphorus introductions into the Great Lakes.

The following table establishes phosphorus loads for the base year (1976) and future phosphorus loads. The Parties, in cooperation with the State and Provincial Governments, shall within eighteen months after the

date' of entry into force of this Agreement confirm the future phosphorus loads, and based on these establish load allocations and compliance schedules, taking into account the recommendations of the International Joint Commision arising from the Pollution from Land Use Activities Reference. Until such loading allocations and compliance schedules are established, the Parties agree to maintain the programs andother measures specified in Annex 2 of the Great Lakes Water Quality Agreement of 1972.

Future 1976 Phosphorus Phosphorus Load

Load in Metric Tomes in Metric Tonnes Basin Per Year Per Year

Lake Superior Lake Michigan Main Lake Huron Georgian Bay North Channel Saginaw Bay Lake Erie Lake Ontario

* These loadings would result if all municipal plants over one million gallons per day achieved an effluent of 1 milligram per litre of phosphorus.

** These loadings are required to meet the goals stated in paragraph 1 above."

Several quest ions were r a i s e d w i t h r espec t t o t he v a l i d i t y o f the models

used t o e s t a b l i s h t he proposed t a r g e t loads, d i f ferences i n r e p o r t e d est-iniates

of phosphorus inpu ts , and t he e f f e c t i v e n e s s and r e l a t i v e cos ts o f a v a i l a b l e

techno log ies t o f u r t h e r reduce phosphorus i npu t s . The Phosphorus Management

S t r a t e g i e s Task Force was e s t a b l i s h e d by t he I J C t s Science Adv isory Board t o

rev iew t h e a v a i l a b l e data and o the r in fo rmat ion i n an at ter r~pt t o p rov ide

answers t o these s c i e n t i f i c and t e c h n i c a l quest ions. The task f o r c e was

subsequent ly expanded i n membership and became a j o i n t task , fo rce o f bo th t h e

Science Adv isory Board and t he Water Q u a l i t y Board and i t s terms o f re ference

(Appendix 1) expanded t o i n c l u d e development o f recommendations f o r

a l t e r n a t i v e phosphorus management s t r a t e g i e s f o r t he Great Lakes.

I n the remainder of t h i s chapter, the task f o r c e prov ides some

perspect ives on the ecology of t h e Great Lakes and the r e l a t i o n s h i p between

phosphorus and eu t roph i ca t i on . - I n subsequent chapters, the task f o r c e reviews

the phosphorus t a r g e t loads proposed i n t h e 1978 Great Lakes Water Q u a l i t y

Agreement, discusses the est imates o f phosphorus i npu ts t o the lakes,

evaluates t h e mathematical models used t o e s t a b l i s h t a r g e t loads, rev iews

ava i l ab le technologies t o reduce both p o i n t and nonpoint source inputs,

recommends a staged phosphorus management s t ra tegy , and i d e n t i f i e s a d d i t i o n a l

in fo rmat ion needed t o f u r t h e r r e f i n e the proposed st rategy.

1.1 ECOLOGICAL PERSPECTIVES

The Great Lakes represent a conl. i : iuously changi \~g, dynamic system.

Geo log i ca l l y t he St. Lawrence drainage system i s r e l a t i v e l y young.

I n s u f f i c i e n t t ime has elapsed f o r the evo lu t i on o f many endemic species and

the species t h a t occur i n t h e Great Lakes are the ones t h a t cou ld adapt t o

these l a rge bodies o f water. Several marine forms occurred i n t he p r o g l a c i a l

lakes and some o f these " g l a c i a l r e l i c t s " remained i n the e a r l y Great Lakes as

the g l a c i e r s re t rea ted . Today some Great Lakes1 species have c lose marine

a f f i n i t i e s w h i l e o thers have gained access t o t h e lakes f rom o ther drainage

systems. I n t he pas t 200 years man has ass is ted the establ ishment o f

a d d i t i o n a l species through d i r e c t i n t r o d u c t i o n s o f carp, brown t r o u t , rainbow

t r o u t , smelt, and salmon o r by p r o v i d i n g access t o the Great Lakes through

canals, such as t h e E r i e and New York Barge canals, f o r t he sea lamprey, wh i te

perch, and a lewi fe . Each o f the new species has r e s u l t e d i n some s t ress on

the system and as a consequence the b i o t a o f t h e St. Lawrence Great Lakes has

been changing and evo l v ing long be fore recent concerns f o r p o l l u t i o n and

eu t roph ica t ion .

The case f o r major environmental change r e s t s on data f rom water -intakes

and a Tew e a r l y surveys o f t h e lakes. The h i s t o r i c a l r eco rd shows long term

in'creases i n t o t a l d isso lved so l ids , ch lo r i de , s u l f a t e , and combined sodium

and potassium i n a l l t h e Great Lakes except Superior, and increases i n ca lc ium

i n Lakes E r i e and .0ntar io. ' 'These observat ions are based on data f o r open

lake cond i t i ons f rom i n - l a k e surveys o r f rom water i n takes which had been

demonstrated t o take i n open lake water^.^ Data are a v a i l a b l e f o r some o t h e r substances such as n i t r a t e s and i r o n , b u t i n general the e a r l y methods

are i n doubt and such v a r i a b i l i t y e x i s t s i n t he da ta t h a t no t r e n d can be

es tab l i shed . The excep t ions are n i t r o g e n da ta f rom Milwaukee, which show a

l ong te rm decrease i n n i t r a t e as the o rgan ic f r a c t i o n (a lbumino id n i t r o g e n )

increased; presumably t h e consequence o f increased b i o l o g i c a l uptake o f t h e

i no rgan i c f r ac t i on .= Some da ta f o r western Lake E r i e appeared t o be

r e l i a b l e and showed increases i n n i t r o g e n and phosphorus, a l though t h e exac t

e x t e n t o f t h e inc rease remains i n doubt.7 The f r e e ammonia content o f Lake

O n t a r i o water a t t he Toronto i n t a k e doubled between 1923 and 1961.'

The d i sso l ved oxygen content o f most o f the Great Lakes waters i s near

s a t u r a t i o n a t a l l depths. The exceptions arz i n Lake E r i e , Green Bay of Lake

Michigan, Saginaw Bay o f Lake Huron, and i n o the r smal l bays and/or harbors.

Oxygen d e p l e t i o n i n Lake E r i e , i n t he c e n t r a l and occas iona l l y western bas ins,

has become more ex tens ive over the years and i n d i c a t e s a s u b s t a n t i a l l y changed

environment s ince t he 1930's. Th is gradual d e p l e t i o n of oxygen has r e s u l t e d

i n major changes i n t he n a t u r e and abundance of t he b i o ta . Extens ive surveys

of t h e bottom waters o f t h e c e n t r a l bas in have shown t h a t about 70 percent o f

t h e bottom waters develop a pronounced oxygen d e f i c i e n c y each year.

We1 1 documented changes have occur red i n t h e species composi t ion and

abundance o f ben th i c communities i n western .Lake ~ r i e ~ and southern Green

Bay1' where organisms assoc ia ted w i t h c lean water c o n d i t i o n s have been

rep laced by more p o l l u t i o n t o l e r a n t forms. For example, t h e former1.y abundant

mayf ly, Hexagenia, disappeared from these environments as w e l l as f rom Saginaw

Bay, Lake Huron. The opossum shrimp, Mysis r e l i c t a , which i s c l o s e l y

assoc ia ted w i t h t h e ben th i c environment, as w e l l as t he plankton, has dec l i ned

f rom i t s former abundance and wide d i s t r i b u t i o n i n ~ a k e E r i e so t h a t i t i s now

captured i n f r e q u e n t l y o n l y i n t h e eas te rn .bas in .

F i s h popu la t ions have undergone and are c o n t i n u i n g t o undergo changes

throughout t h e Great Lakes. Many ~ h o i c e ~ ' f o r m e r 1 . y abundant, commercial

species such as lake t r o u t , b l ue p ike , w h l t e f i s h , sauger, and lake h e r r i n g

have d r a s t i c a l l y dec l i ned iwabundance. o r disappeared f rom t h e i r former

h a b i t a t s i n t he lakes. Other species, such as the sea lamprey, a lewi fe,

smelt, and salmon, which have found t h e i r way i n t o the lakes o r been

introduced, have prospered.

Changes i n p lankton have been observed i n Lakes Er ie, Michigan, and

Ontar io. Plankton data from the levela and, l1 chicago12 and or onto' water in takes show long term increases i n p lankton abundances f o r Lakes Er ie,

Michigan, and Ontar io, a1 though some s tud ies suggested t h a t the increases a t

Chicago may r e f l e c t l o c a l condition^.'^"^ The t rends seen i n the lakes

have shown a s h i f t i n t he diatom popu la t ions towards the dominance o f species

favored by n u t r i e n t r i c h condi t ions. I n Lake E r i e a major increase occurred

i n the abundance o f blue-green algae.

Extensive growths o f the attached alga, Cladophora, have been a problem i n

Lakes E r i e and Ontar io s ince .the e a r l y 1930's and Cladophora i s now a major

problem along much o f the Lake Michigan shorel ine. . I n recent years a red

alga, Bangia, appeared i n the lakes and has become abundant i n Lakes Er ie,

Huron and Michigan, e s p e c i a l l y around harbors. The s i g n i f i c a n c e o f t h i s new

a lga has n o t been establ ished.

I n terms o f developing s t r a t e g i e s t o deal w i t h eu t roph ica t ion , i.e.

increased n u t r i e n t loading, i t i s important t o i d e n t i f y those changes which

are good i nd i ces o f eu t roph ica t i on and those which are not, o r may be due t o

o ther pe r tu rba t i ons o f the environment. Increases i n n u t r i e n t concentrat ions

and decreases i n dissolved-oxygen content are accepted i nd i ces o f

eutrophicat ion.13 The increases i n d isso lved sol ids, o r i n c e r t a i n ions

such as ch lo r ide , have been observed i n o ther lakes undergoing eut roph ica t ion ,

such as Lake rich'^ and i t has been assumed t h a t increases i n the major

ions probably r e f l e c t what has happened t o the n u t r i e n t s . Nevertheless, t he

increases i n major ions may be more app rop r ia te l y ca l l e d environmental

changes, which might n o t i n d i c a t e eu t roph ica t ion .

Some o f the changes i n the b i o t a o f the Great Lakes have considerable

s ign i f i cance as i nd i ces o f eu t roph ica t ion , e s p e c i a l l y t he increases i n

abundance and changes i n the composit ion o f plankton. Extensive growths of

Cladophora are known t o occur i n o ther lakes undergoing eu t roph ica t ion . l 5 A

dramatic dec l i ne and even disappearance o f salmonid f i s h e s has occurred i n a

number of lakes.16 It i s l i k e l y t h a t environmental changes i n c l u d i n g those

def ined as eu t roph i ca t i o n have a f fec ted f i s h stocks. Nevertheless, i t i s

u n l i k e l y t h a t we w i l l be able t o a t t r i b u t e any changes i n f i s h stocks d i r e c t l y

t o eu t roph ica t ion , s ince we must a lso consider t he e f f e c t o f o ther s t resses

such as the successful establ ishment o f popu la t ions o f var ious e x o t i c species

and t h e i r impact on n a t i v e species: over e x p l o i t a t i o n by commercial and

r e c r e a t i o n a l f i she r i es , p redat ion by the sea lamprey, phys ica l chanqes i n

important h a b i t a t s f o r spawning, and t h e i n t r o d u c t i o n o f t o x i c substances i n t o

the aquat ic environment. Some changes i n the benth ic communities may be due

t o eu t roph i ca t i on where increased organic product ion has l e d t o chanqes i n the

organic content o f the sedimentary environment and the d isso lved oxygen

content o f t h e o v e r l y i n g waters. Some changes i n t he benth ic communities i n

lake sediments , e s p e c i a l l y i n dominant midge species, are w e l l documented and

have been use fu l f o r i n d i c a t i n g eu t roph ica t ion . l 7 The disappearance of the

mayfly, Hexagenia, f rom t h e bottom o f Lake E r i e has been associated w i t h

decreasing oxygen level^.^ Nevertheless, o ther changes i n the benthos of

Lake E r i e occurred i n a r e l a t i v e l y sho r t time, which may i n d i c a t e s t resses

o the r than those o f eu t roph i ca t i on . Also, t he c l o s e l y s i m i l a r changes t a k i n g

p lace i n Green Bay, Saginaw Bay, and western Lake E r i e dur ing the same t ime

pe r i od could be due t o p a r a l l e l t rends i n eu t roph i ca t i on o r some o ther

s t ress . It i s important t o recognize t h a t major changes i n t he ben th i c

communities took p lace du r i ng the l a t e 1940's and through the 19501s, a pe r i od

du r i ng which t o x i c m a t e r i a l s such as ClDT were f i r s t used e x t e n s i v e l y and

entered the environment.

1.2 PHOSPHORUS AS RELATED TO GREAT LAKES EUTROPHICATION

Phosphorus has been shown t o be a major n u t r i e n t c o n t r o l l i n g phytoplankton

growth i n t he Great ~ a k e s . ~ ~ Experiments w i t h n a t u r a l phytoplankton

assemblages have shown phosphorus t o be t h e growth l i m i t i n g n u t r i e n t and t h a t

a d d i t ions o f phosphorus w i 11 acce le ra te t he growth o f diatoms prov ided

supp l ies o f s i l i c a are maintained. ley 1 9 y 2 0 Increases i n phosphorus

concentrat ions i n t he lakes w i 11 c rea te blooms o f phytoplankton and increase

t h e s tand ing crop.21 Th is r e l a t i o n s h i p between phosphorus and phytop lankton

growth a l l ows t o t a l phosphorus t o be used as an i n d i c a t o r o f t h e t r o p h i c

s t a t u s o f t h e water.22

Changes i n t o t a l phosphorus concen t ra t i on w i t h t ime have n o t been observed

i n t h e Upper Great Lakes, b o t h because t h e r e i s l i t t l e h i s t o r i c a l d a t a 2 j and

because phosphorus concen t ra t i ons appa ren t l y have never been v e r y la rge . The

present accepted average t o t a l phosphorus concen t ra t i on i n Lake Michigan i s

o n l y 8 p g / ~ . ~ ~ Year t o year changes i n t h e t o t a l phosphorus

concent ra t ions f o r Lake Michigan may be as smal l as 0.2 pg/L d u r i n g

acce le ra ted e u t r o p h i c a t i o n and would be d i f f i c u l t t o detect . " I n add i t i on ,

t h e non-conservat ive na tu re o f phosphorus and i t s ex tens i ve i n t e r a c t i o n w i t h

b i o l o g i c a l popu la t i ons make i t ve ry (liff i c u l t t o t r a c e phosphorus

concent ra t ion changes i n t h e Great Lakes.

The o n l y h i s t o r i c a l t r e n d f o r n u t r i e n t s i s t he decrease i n s o l u b l e

r e a c t i v e s i l i c a t h a t was observed i n data c o l l e c t e d a t t h e Chicago Water

F i 1 t r a t i o n P lan t . 2 5 These da ta i n d i c a t e t h a t s-i 1 i c a concen t ra t ions

decreased over a p e r i o d o f f o r t y years f rom l e v e l s o f up t o 6.0 mg/L. More

recen t da ta i n d i c a t e a decrease i n t h e over -w in te r concen t ra t ions of s i l i c a

f r om 4.0 t o 1.4 mg/L between 1955 and 1970.26 This s i l i c a d e p l e t i o n i s

i n d i r e c t l y r e l a t e d t o phosphorus enr ichment s ince inc reased phosphorus w i l l

s t i m u l a t e t h e growth o f diatoms i n t h e presence o f s i l i c a . 2 7

With in t h e Great Lakes system, t h e concen t ra t i on o f phosphorus i s v a r i a b l e

as shown i n t he pub l i shed l i t e r a t u r e . Th is v a r i a b i l i t y i n concen t ra t i on can.

be examined i n d i f f e r e n t perspec t i ves which i nc l ude ch rono log i ca l , seasonal,

and s p a t i a l d i f f e rences .

Chrono log ica l l y , a conc lus ive upward o r downward t r e n d has n o t been shown

f o r phosphorus~concentrat ions i n t h e Great Lakes. L i t t l e h i s t o r i c a l da ta e x i s t

p r i o r t o . t h e 1960 's f o r t r ends t o be i d e n t i f i e d t h a t encompass more than about

ten years. The pub l i shed l i t e r a t u r e makes re fe rence t o smal l t rends, b u t a

c l o s e r examinat ion o f t h e data g e n e r a l l y show t o o much v a r i a b i l i t y between

y e a r l y concen t ra t ions t o be s i g n i f i c a n t . '

E a r l y data i n the 1 i t e r a t u r e comes p r i m a r i l y f rom water in takes. Weekly water samples from Lake Michigan a t an o f f sho re i n take a t Oak Creek, Wisconsin - 3 showed a poss ib le t r end from 1961 t o 1968. Average concentrat ions of PO -P

4 ranged f rom 10 pg/L i n 1961 t o 20 pg/L i n 1968; however, values of 20

and 30 pg/L were recorded randomly f o r the i n t e r i m years 1962 t o 1967.28

Indiana Harbor data averages f o r 1965 through 1968 showed extensive v a r i a t i o n - 3

concent ra t ions of 36, 23, 96, and 24 pg/L o f PO -P r e s p e c t i v e l y over the 4

f o u r years.28 A comprehensive rev iew o f ava i l ab le data f o r t o t a l

phosphorus i n Lake Michigan up t o 1974 showed no s i g n i f i c a n t t rends towards an

increase o r decrease i n phosphorus i n sample se ts spanning 2-4 year

per i ods . 2 8

On a sho r te r t ime scale and f o r Lake Ontar io, a smal ler lake, decreases i n

the t o t a l phosphorus concent ra t ions o f approximately 1 pg/L f o r each year

s ince 1973 have been r e p ~ r t e d . ~ ' S i m i l a r l y i t has been repor ted3 ' t n a t

w i n t e r averages f o r t he t o t a l phosphorus concentrat ions i n Lake Ontar io were

2-3 pg/L lower i n 1977 than concentrat ions repor ted i n 1974.31 uata t rom

1967 t o 1974 on the Niagara River were i n t e r p r e t e d by the I n t e r n a t i o n a l J o i n t

C o m m i ~ s i o n ~ ~ as showing a s i g n i f i c a n t reduc t ion i n the t o t a l phosphorus

concent ra t ions which was a t t r i b u t e d t o a reduc t ion i n the phosphorus

loadings. However, the l a rge v a r i a b i l i t y o f these data suggest t h a t no r e a l

t r end i s ev ident f o r t h i s t ime pe r i od which spans the pre- and post-phosphate

detergent con t ro ls .

Data have been presented t o demonstrate changes i n the phosphorus

concentrat ion o f o f f sho re samples on a seasonal b a s i s . 2 3 y 3 3 For Lake

Michigan, the t rends i n d i c a t e h igher concent ra t ions o f t o t a l phosphorus i n t he

l a t e f a l l and winter . 3 4 Physica l phenomena such as wind, waves, o r

increased r u n o f f may cause m ix ing i n nearshore s t a t i o n s and may be causing the

peak i n phosphorus concent ra t ions i n A p r i l and ~ a y . ~ ~ ' ~ ~ Data on

f l u v i a l discharges t o Lake Michigan show t h a t sp r i ng concentrat ions o f t o t a l

phosphorus a t the r i v e r mouth were h igher than concentrat ions a t the same

s t a t i o n i n Ju ly . The Grand River had a t o t a l phosphorus concentrat ion of 160

pg/L a t i t s mouth i n A p r i l and approx-imately 100 pg/L i n Ju ly . I n the

nearshore r e g i o n off t he Grand R i ve r , t o t a l phosphorus concen t ra t i ons are a l s o

h i ghe r i n t h e spr ing . 3 6

S p a t i a l l y , e x t e r n a l i n p u t s o f phosphorus v i a t r i b u t a r i e s c r e a t e h i gh

concent ra t ions a t t h e mouths of t h e r i v e r s b u t g e n e r a l l y show t h a t t h i s

i n c r e a s e i s q u i c k l y d ispersed w i t h i n t h e f i r s t 0.5 km o f f s h o r e o f t h e r i v e r

mouths. Data on ma jo r f l u v i a l i n p u t t o Lake Mich igan show t h a t open l a k e

concent ra t ions o f t o t a l phosphorus on t h e o rder of 7-8 pg/L a re ma in ta ined

a t d is tances o f 13 km o f f s h o r e o f t he r i v e r mouths.36 I n A p r i l , t h e

concen t ra t i on o f t o t a l phosphorus a t t h e mouth o f t h e St. Joseph R i v e r was 125

pg/L b u t r a p i d l y decreased t o l e s s than 10 pg/L 13 km o f f s h o r e f rom t h i s

r i v e r . S i m i l a r r e s u l t s were noted f o r t h e Kalamazoo R iver , Grand R iver ,

Muskegon R iver , Pere Marquet te R i ve r , and t h e Mani tou ~ i v e r . ~ ~ The ex ten t

o f t h e decrease i n phosphorus concen t ra t i an v a r i e d w i t h t h e o r i g i n a l

concen t ra t ions o f t o t a l phosphorus a t t h e mouth o f t he r i v e r . Inshore t o t a l

phosphorus concent ra t i ons f o r t he Grand R i v e r were 160 pg/L, whi 1 e i nsho re

concent ra t ions f o r t h e Muskegon R i v e r were o n l y 50 pg/L a t i t s mouth and

decreased r a p i d l y t o 15 pg/L a t 0.2 km o f fshore . 3 6

Offshore f rom a1 1 e leven r i v e r s sampled, t o t a l p h o s p h o r ~ ~ s concent ra t ions

were l e s s than 10 pg/L a t s t a t i o n s rep resen t i ng t h e open water reg ion.

These va lues agree c l o s e l y w i t h o the r da ta r e p o r t e d on open l a k e t o t a l

phosphorus concen t ra t i ons o f 8 pg/L f o r samples c o l l e c t e d i n 1971 and

1 9 7 ~ ~ ~ and 7 pg/L f o r samples c o l l e c t e d i n 1 9 6 5 . ~ ~

Nearshore v a r i a b i l i t y appears t o be more ex tens i ve i n Lake Mich igan w i t h

t h e t o t a l phosphorus concen t ra t i on o f i nsho re sample rang ing f rom 20 t o 200

pg/L o f f t he Kalamazoo R i v e r and t h e S t . Joseph R i v e r r e s p e c t i v e l y . Th is

v a r i a t i o n may be a t t r i b u t a b l e t o r i v e r d ischarge s i nce c o n d i t i o n s o f f t h e

Sa in t Joseph R i v e r were g r e a t l y i n f 1 uenced by t h e r i v e r plume. 3 6

DEVELOPMENT OF 1978 GREAT LAKES WATEK QUALITY AGREEMENT . . PHOSPHORUS TARGET LOADS

With t h e s i g n i n g . of t h e 1978 Great Lakes Water Q u a l i t y ~ g r e e m e n t , ~ the'

U n i t e d S ta tes and Canada reaf f i rmed t h e i r i n t e n t i o n s t o r e s t o r e and m a i n t a i n

the,chemica l , phys ica l , and b i o l o g i c a 1 . i n t e g r i t y o f t h e Great Lakes bas in

ecosystem. A s . p a r t of t h i s Agreement, t h e P a r t i e s es tab l i shed t e n t a t i v e t o t a l

phosphorus t a r g e t loads which,. i n coopera t ion w i t h t h e S t a t e and Pro'v inci a1

Governments, a re t o be conf i rmed w i t h i n e igh teen months o f t h e s i g n i n g o f t h e

Agreement. and, i f confirmed, be used as t h e bas i s f o r l oad a1 l o c a t i o n s and

compliance schedules f o r t h e two coun t r i es .

2.1 TOTAL PHOSPHORUS TARGET 10AQS

The t e n t a t i v e t o t a l phosphorus t a r g e t loads, presented i n Table 2.1, were

developed by Task Group 111, a b i n a t i o n a l group o f U.S. and Canadian

s c i e n t i s t s organ'ized as p a r t o f t he f i f t h - y e a r rev iew o f t h e 1972 Great Lakes

Water Qua1 i t y Agreement t o formul a t e updated phosphorus l oad ing ob jec t i ves , o r

t a r g e t loads, f o r t h e lakes. D e t a i l s o f t h e development o f t h e t a r g e t loads

a re descr ibed i n t h e r e p o r t o f Task Group 111. The bas i c approach used by

Task Group I 1 1 was t o e s t a b l i s h d e s i r a b l e i n - l a k e water q u a l i t y c o n d i t i o n s and

then determine t h e phosphorus loads which would produce these cond i t ions .

- TABLE 2.1 1978 GREAT LAKES WATER QUALITY AGREEMENT

TOTAL PHOSPHORUS TARGET LOADS

Basin

Lake Super io r

Lake Mich igan

Main Lake Huron

Georgian Bay

No r th Channel

Sagi naw Bay

Lake E r i e

Lake O n t a r i o

Target Load ( t /yr )

3,400

5,600

2,800

600

520

440

11,000

7,000

2.2 TOTAL PHOSPHORUS CONCENTRATION OBJECTIVES

While phosphorus i s considered a major cause o f accelerated eu t roph ica t i on

i n the Great Lakes, i t i s d i f f i c u l t t o i n t e r p r e t concentrat ions o f t h i s

element d i r e c t l y as a measure of t he t r o p h i c s ta tus o f a lake. A more

e f f e c t i v e i n t e r p r e t a t i o n can be obta ined by re1 a t i n g the t o t a l phosphorus

ob jec t i ves t o parameters t h a t more d i r e c t l y measure a lga l biomass, d isso lved

oxygen, and water transparency, as has been done by Chapra and ~ o b s o n . ~ ~

The background t o the development o f the t o t a l phosphorus ob jec t i ves i s

f u l l y described i n t h e rev iew o f phosphorus c o n t r o l ob jec t i ves presented a t

the IJC/Cornel l U n i v e r s i t y Conference. 3' These object ives, as we1 1 as the

expected water q u a l i t y t h a t would r e s u l t i f they are met, are presented i n

Table 2.2.

The bas is f o r t h e s e l e c t i o n o f these ob jec t i ves i s found i n t h e 1972

Agreement2 as f o l lows :

TABLE 2.2 TOTAL PHOSPHORUS OBJECTIVES WITH ESTIMATED LEVELS OF CHLOROPHYLL a, SECCHI DEPTH, AND TROPHIC STATE3'

(1 ) s t a b i l i z a t i o n o f Lake Superior, Lake Huron and Lake Michigan i n t h e i r

present 01 i g o t r o p h i c s tate.

Lake Basin

super i or

Michigan

Huron

Sagi naw Bay'

Western E r i e

Central E r i e

Eastern E r i e

Ontar io

Tota l Phosphorus

(vg/L)

5

7

5

15

15

10

10

10

Chl oro- Secchi p h y l l a Depth (vg/L)-- (m)

1.3 8.0

1.8 6.7

1.3 8.0

3.6 3.9

3.6 3.9

2.6 5.3

2.6 5.3

2.6 5.3

Trophic S ta te

O l i go t roph ic

O l i go t roph ic

01 i g o t r o p h i c

Mesotrophi c

Mesotrophic

Oligomesotrophic

01 igomesotrophic

01 i gomesotrophic

( 2 ) Saginaw Bay, Lake On ta r i o and Western and, Eastern Lake' E r i e waters

should be f r e e f r o m n u t r i e n t s . e n t e r i n g t he k i te ; as a ' r e s u l t o f human

a c t i v i t i . e s i n concen t ra t ions . t h a t . c rea te nu i sance growth .of aqua t i c . , , ( '

, we.eds and a.lgae. :

( 3 ) Cent ra l Lake E r i e - ' ' re 'storat ion. o f year-round aerob ic c o n d i t i o n s i n

t h e . bottom watersM,;-

2.3 MATHEMATICAL MODELS . ,

To es t imate lake responses t o changes i n phosphorus loads, Task Group I 1 1

used t he var ious mathematical models developed by V ~ l l e n w e i d e r , ~ ~ C h a ~ r a , ~ '

~homann, 4 1 ~ i ~ o r o ~ ~ and Bierman. 4 3 The mode I s used ranged from simple,

comple te ly mixed systems w i t h s e t t l i n g o f phosphorus, t o complex mechan is t i c

models which i nvo l ved dynamic c a l c u l a t i o n s f o r the major phys i ca l , chemical,

and b i o l o g i c a l processes. The s i m p l i f i e d models e m p i r i c a l l y c o r r e l a t e d t he

t o t a l phosphorus concen t ra t i on t o the var ious response parameters no ted above.

Task Group I11 developed t h e t a r g e t loads f o r t he Lower Great Lakes by

c a l i b r a t i n g t he models t o " e x i s t i n g c o n d i t i o n s i n each lake" and re - runn ing

t h e models w i t h reduced phosphorus' loads .in o rder t o es t imate t he responses o f

t h e water bodies.

2.4 DEVELOPMENT* OF SPECIFIC TARGET LOADS ,

( 1 ) Upper Great Lakes (Lakes Superior, M.ichigan and Huron, except f o r

Saginaw Bay) - the phosphorus t a r g e t loads were a r e a f f i r m a t i o n t h a t

"present water q u a l i t y " should be ma in ta ined i n these lakes. Hence,

no mathematical models were needed t o de r i ve t he loads. Rather, t he

p resen t t o t a l phosphorus concent ra t ions were judged acceptable. And

i t was assumed t h a t phosphorus load reduct ions, which would be

achieved when a l l mun ic ipa l wastewater t rea tment p l a n t s d i scha rg ing - more than 3800 cu m/d ( 1 MGD) have no more than 1 mg/L t o t a l

phosphorus i n t h e i r e f f l u e n t s , would be adequate t o ma in ta i n these

concent ra t ions .

( 2 ) Saginaw Bay - the mathematical models o f V ~ l l e n w e i d e r , ~ ~ DiToro e t - a1 4 2 ~hapra, '" and Bierman e t a1.43 were used t o de r i ve the -* -- Saginaw Bay t a r g e t load. The pr imary c r i t e r i o n used was t a s t e and

odor problems a t t he Whitestone Po in t Water F i l t r a t i o n P lan t i n inner

Saginaw Bay (which processes approximately 85 percent o f t h e water

drawn from Saginaw Bay f o r human use). The degree o f degradat ion o f

t h e inner bay ecosystem, as w e l l as f i l t e r - c l o g g i n g and t a s t e and

odor problems i n the Pinconning and Bay City Water F i l t r a t i o n P lan ts

were secondary c r i t e r i a .

The models i nd i ca ted t h a t a t o t a l phosphorus load o f 440 t / y r would

correspond t o an annual average t o t a l phosphorus concentrat i .on o f

approximately 15 pg/L. This load would be expected t o reduce the

t a s t e and odor problems noted above and should reverse some o f t he

inner bay ecosystem degradation,, p l a c i n g Saginaw Bay i n a

" t r a n s i t i o n " s t a t e between n u t r i e n t - d e f i c i e n t and n u t r i e n t - r i c h

condi t ions.

'The phosphorus loading ob jec t i ve recommended by Task Group I 1 1 f o r

Saginaw Bay was based on the average t o t a l phosphorus r e s u l t s f o r a l l

four models and on the r e s u l t s o f the Bierman model f o r t a s t e and

odor i n te r fe rences t o the p r i n c i p a l municipal water supply.

( 3 ) Lake E r i e - as w i t h the other lakes, phosphorus and ch lo rophy l l - a

concentrat ions corresponding t o a number o f phosphorus loads were

ca l cu la ted f o r each o f the three Lake E r i e sub-basins by Task Group

1 1 1 , ~ ~ us ing the models o f , ~ o l l e n w e i d e r , ~ ~ DiToro -- e t a1.,42 and

~ h a p r a . ~ " To r e l a t e the model r e s u l t s more d i r e c t l y t o ac tua l

c e n t r a l bas in condi t ions, DiToro -- e t a1. , 4 2 c o r r e l a t e d t h e i r model

ou tpu t f o r d isso lved oxygen concentrat ions t o t h e area l ex ten t o f

anoxic cond i t i ons i n the c e n t r a l basin. The model i nd i ca ted t h a t a

90. percent reduc t ion i n t he anoxic area and e l i m i n a t i o n o f "any

subs tan t i a l amount" o f phosphorus being re leased from the lake bottom

sediments could be a t ta ined w i t h a phosphorus load o f approximately

11,000 t/yr.

( 4 ) Lake O n t a r i o - the models o f V ~ l l e n w e i d e r , ~ ~ Thomann e t al . ,41 -- and Chapra4' were used t o de r i ve t he Lake On ta r i o lo'ad. The p r ima ry c r i t e r i o n was degradat ion o f t h e l ake ecosyskem, w i t h t h e

p r i n c i p a l i n d i c a t o r parameter be ing annual average t o t a l phosphorus

concent ra t ion . The average r e s u l t of t h e t h r e e models i n d i c a t e d t h a t

a t o t a l phosphorus concen t ra t i on o f 10 pg/L corresponded t o a

phosphorus l oad o f approx imate ly 7,000 t/yr; which would p lace Lake

,On. tar io a t t he " lower ' th resho ld f o r t he undes i rab le consequences o f

p h o s p h o r ~ ~ s enrichment", i.e. a t t he 'o l i ~go t roph i c /meso t roph i c 'boundary. . ;. , .

, . I . '

2.5 SUMMARY , . - , . - . . . .

. - , . . .

. . . .

The development o f t e n t a t i , ? phosphorus loading o b j e c t i v e s i n t he 1978

Water Q u a l i t y Agreement was t h e f i r s t occasion i n which t he r e s u l t s o f

d i f f e r e n t mathematical models were synthes ized and used as a bas i s f o r

management recommendations. These l oad ing o b j e c t i v e s should be cons idered

b e s t es t imates based on s t a t e - o f - t h e - a r t research, i.e. t h e models used i n

t h e i r development should be regarded as p l ann ing t o o l s and n o t p r e d i c t i v e

techniques as discussed i n Chapter 4. I n perspec t i ve , t he models have

p rov ided a q u a n t i t a t i v e framework f o r o rgan i z i ng and i n t e r p r e t i n g t he e x i s t i n g

data.

As descr ibed i n Chapter 3, an impor tan t unresolved research i ssue i s t he

ques t ion o f t h e b i o l o g i c a l a v a i l a b i l i t y o f va r i ous forms o f phosphorus i n p u t s

and poss ib l e t r ans fo rma t i ons i n t h e lakes. A c e r t a i n f r a c t i o n of t h e

b i o l o g i c a l l y unava i l ab le forms o f phosphorus becomes a v a i l a b l e i n a g iven

system depending p r i m a r i l y on t he r e l a t i v e magnitudes o f t he n e t

t ransfo.rmat ion r e a c t i o n and t h e n e t s e t t 1 i n g f l u x o f unavai l a b l e phosphorus t o

t h e sediments.

A d i s t i n c t i o n should be made between r e s o l u t i o n o f t he s c i e n t i f i c

ques t ions concern ing phosphorus b i o a v a i l a b i l i t y and t h e i m p l i c a t i o n s o f a

r e s o l u t i o n t o these ques t ions i n a management con tex t . The Vol lenweider and

~ h a p r a ~ i iodels cons idered o n l y t o t a l phosphorus and t h e Thomann, DiToro, and

Bierman models i nc l uded e x p l i c i t d i s t i n c t i o n s between b i o l o g i c a l l y a v a i l a b l e

and unava i lab le phosphorus forms i n t he ex te rna l loads as w e l l as i n t he water

column,. I n s p i t e o f u n c e r t a i n t i e s i n desc r i b ing the dynamics o f unava i lab le

phosphorus forms, these l a t t e r 'models reasonably descr ibed the present data

f o r b i o l o g i c a l l y a v a i l a b l e and unava i lab le phosphorus concent ra t ions i n t he

1 akes.

An eva lua t ion of the models and a d iscussion o f the conf idence which can

be p laced i n t h e t a r g e t loads p red i c ted by them i s presented i n Chapter 4.

The task f o r c e accepts the t a r g e t loads presented i n Table 2.1 as reasonable

goals, w i t h the-degree of u n c e r t a i n t y discussed i n Chapter 4, f o r achiev ing

water q u a l i t y ob jec t i ves , and be l ieves t h a t they prov ide the bas is f o r

developing a phosphorus management s t r a t e g y f o r t h e Great Lakes.

EVALUATION OF PHOSPHORUS'' INPUTS TO THE GREAT LAKES

Various es t imates of t he t o t a l phosphorus i n p u t s t o the Great Lakes have

been made employing s ta te -o f - t he -a r t technology and i n severa l ins tances

advancing t he understanding o f s i g n i f i c a n t processes and phenomena which

i n f l u e n c e t h e t r a n s p o r t o f phosphorus t o t he lakes. I n t he con tex t o f

d e f i n i n g t h e l e v e l of dec i s i on making t h a t can be supported by t he technology

and ana l ys i s c u r r e n t l y ava i l ab le , t h i s chapter addresses issues t h a t are

s i g n i f i c a n t i n terms o f phosphorus l oad ing es t imates used i n c a l i b r a t i n g

e u t r o p h i c a t i o n models and t he impact on s p e c i f i c t a r g e t loads developed w i t h

these models and t he types o f loads t o be c o n t r o l l e d .

3.1 PRESENT LOAD ESTIMATES

Since 1973, t h e I n t e r n a t i o n a l J o i n t Commission ' s Great Lakes Water qua1 i t y

Board has been p u b l i s h i n g annual es t imates o f t he t o t a l phosphorus loads t o

t he Great Lakes. These values are comprised o f es t imates o f the p r imary

sources o f phosphorus i n terms o f p o i n t sources f r om mun ic ipa l and i n d u s t r i a l

i n p u t s d i r e c t l y t o t he lakes, i n p u t s v i a moni tored t r i b u t a r i e s , atmospheric

load ings and loads t r anspo r ted between lakes v i a the connect ing channels.

Since 1976, r e p o r t i n g o f the i n d i r e c t p o i n t source d ischargers has p e r m i t t e d

an es t imate t o be made o f t h e nonpo in t source^.^" Inpu ts f rom unmonitored

areas were a l so est imated. Phosphorus c o n t r i b u t e d through s h o r e l i n e e ros ion

has a l s o been est imated, a l though t h i s i n p u t i s n o t inc luded i n t he t o t a l l ake

loads because i t i s be l i eved t o be v i r t u a l l y unava i l ab le f o r u t i l i z a t i o n by

phytoplankton. Regenerat ion o f phosphorus f r om lake bottom sediments i s

acknowledged, b u t i t has never been q u a n t i f i e d by t h e Water q u a l i t y Board.

These annual es t imates have been used by t he Water q u a l i t y Board and t h e

I n t e r n a t i o n a l J o i n t Commission t o assess progress made i n c o n t r o l l i n g

phosphorus i n p u t s t o the Great Lakes.

The d i f f i c u l t i e s i n accu ra te l y measuring and e s t i m a t i n g phosphorus i n p u t s

f rom the l a rge number o f phosphorus sources i n t h e Great Lakes b a s i n have been

recognized. Indeed, t h e Water Q u a l i t y Soard's e f f o r t s have undergone con-

t i n u a l r e v i s i o n and ref inement. The h igh va r i ance assoc ia ted w i t h t h e

est imates f o r some of t h e load est imates i s i l l u s t r a t e d by a decrease o f

approx imate ly ha l f of t h e 1977 i n te r connec t i ng channel l oad f rom Lake E r i e t o

Lake Ontar io , an inc rease of approx imate ly 6000 m e t r i c tons i n t h e 1978 Lake

E r i e es t imate (due p r i m a r i l y t o a s i g n i f i c a n t inc rease i n t h e s t a t e of Ohio

t r i b u t a r y l oad est imate) , and an inc rease o f about 2500 m e t r i c tons iln t h e

1978 Lake Super ior atmospheric load. Th is annual comp i l a t i on of l oad ing da ta

From t h e va r i ous Great Lakes' j u r i s i d i c t i o n s i s t h e o n l y bas in-wide e f f o r t t o

q u a n t i f y t h e Great Lakes t o t a l phosphorus i n p u t on a c o n t i n u i u g bas is .

. . . .

Separate est imates o f t he .1976 t o t a l phosphorus load ings t o t h e Great

Lakes were a l so made: by Task Group 1 1 1 3 ' and t h e I J C ' s P o l l u t i o n From .Land

Us:: A c t i v i t i e s Reference Group (PLUARG) .3

There were cons iderab le d i f f e r e n c e s among t h e Water Q u a l i t y Board, Task

Group 111, and PLUARG 1976 phosphorus l oad ing est imates f o r some o f t h e

lakes. The t h r e e est imates were compared i n cons ide rab le d e t a i l as p a r t o f

t h e PLUARG

To a l a r g e degree, t h e basi; da ta used f o r t h e t h r e e est imates were

s ~ ~ p p l i e d by t h e same j u r i s d i c t i o n s respons ib l e f o r t h e i r c o l l e c t i o n i n t h e

Great Lakes b a s i n . . The Water Q u a l i t y Board i s t h e source of m o s t . o f , t h e

mun ic ipa l and i n d u s t r i a l p o i n t source phosphorus l oad ing data. The Water

Q u a l i t y Board da ta a r e der i ved p r i n c i p a l l y f rom da ta submi t ted by t h e var ious

s t a t e s i~ t h e Great Lakes bas in and t h e Prov ince o f Ontar io . Some

m o d i f i c a t i o n s o f t h e p o i n t source da ta were made by PLUARG and Task Group 111,

t o r e f l e c t what t h e y be l i eved were more accura te es t imates o f t h e phosphorus

i ~ p r ~ t s from s p e c i f i c sources, e s p e c i a l l y t o Saginaw Bay and Lake Er ie .

The t r i b u t a r y load ing da ta a r e based p r i n c i p a l l y on i n f o r m a t i o n submi t ted

by t h e s t a t e s and t h e Prov ince o f On ta r i o t o t h e Water Q u a l i t y Board.

A d d i t i o n a l da ta f o r some t r i b u t a r i e s were ob ta ined i n t h e PLUARG s tud ies3 .

and ex tens ive da ta f o r some t r i b u t a r i e s t o Lake E r i e were c o l l e c t e d i n t h e

U.S. Army Corps o f Engineers Lak,e E r i e Wastewater Management S t ~ d y - . " ~

The PLUARG atmospheric est imates were based ' on PLUARG atmospheric

s tudies. The Water Q u a l i t y Board est imates were based on Canadian studies,

genera l ized t o t he e n t i r e Great Lakes basin, except f o r Lake Michigan, f o r

which U.S. EPA data, from i t s extensive, r e c e n t l y completed Lake Michigan

study, were used. Task Group I 1 1 used the atmospheric est imates from the

Water Q u a l i t y Board.

The PLUARG in te rconnec t ing channel loads, i .e. upstream lake loads f o r

Lakes Huron and E r i e were taken 'from t h e Water q u a l i t y Board. The PLUARG Lake

On ta r i o est imate was based on Niagara River s tud ies conducted a t the r i v e r

mouth by Environment Canada. The Water q u a l i t y Board est imates f o r Lakes

Huron and E r i e were taken f rom the Upper Lakes Reference ~ roup ' " wh i l e the

Lake Ontar io va lue was based on a 1974 study on phytoplankton i n Lake Ontar io,

conducted f o r the Water q u a l i t y Board by Hydroscience, ~ n c . " '

De ta i l ed d iscussion o f the var ious sources o f da ta used by each group and - ,

t h e d i f f e rences i n t h e load ing est imates f o r each lake can be found i n the

PLUARG repo r t . 45 The t o t a l phosphorus load est imates f o r a l l lakes exce'pt

Lake E r i e are w i t h i n 15 percent o f each other . The d i f f e rences are due

p r i n c i p a l l y t o the s l i g h t l y d i f f e r e n t sources of data.

The Lake E r i e load est imates are t h e most d iverse. The Task Group I 1 1

est imate, based on the Lake E r i e Wastewater Management Study o f the U.S. Army

Corps o f ~ n ~ i n e e r s , i s h ighes t a t about 19,500 t l y r , wh'i le t he Water q u a l i t y

Board est imate i s lowest a t about 15,500 t /yr. The PLUARG est imate of 17,450

t /yr i s about midway between the Water q u a l i t y Board and Task Group I 1 1

est imates. The main d i f f e r e n c e between the PLUARG and Task Group I 1 1 loads i s

t he h igher es t imate o f t h e U.S. d i r e c t mun ic ipa l load used by the Task Group.

The major d i f f e rence between the PLUARG and water qua1 i ty Board loads i s a

lower t r i b u t a r y es t imate used by t h e Water Q u a l i t y Board.

Based on a comp le te~~rev iew o f the a v a i l a b l e in format ion, t he task f o r c e "

has made "best est imates" o f t he 1976 phosphorus loads t o the var ious Great

Lakes as shown i n Table 3.1.

It should be noted t h a t there i s no r i g i d s c i e n t i f i c o r s t a t i s t i c a l bas is

f o r these est imates, nor can such a bas is be presented w i thou t a major e f f o r t

i n v o l v i n g reeva lua t ion of v i r t u a l l y a l l the raw data submitted t o the th ree

groups, a task ou ts ide the resources o f t h i s task force. However, t he task

fo rce considers t h a t the ''best est imatesM o f the t o t a l phosphorus load f o r

each lake i s w i t h i n p lus o r minus 15 percent o f the ac tua l load f o r t he

sources inc luded i n the estimates.

A coordinated c o l l e c t i o n o f phosphorus load ing data, and a standardized

and s c i e n t i f i c a l l y sound methodology f o r c a l c u l a t i n g phosphorus loads w i 11

he lp t o reduce the unce r ta in t y i n f u t u r e estimates.

*consis ts o f i n d i r e c t p o i n t sources and nonpoint sources i n t r i b u t a r y basin

-...

TABLE 3.1 "BEST ESTIMAIEM OF 1976 TOTAL PHOSPHORUS LOADS ( m e t r i c tons per year)

It should be noted t h a t more "accurate" loads w i l l n o t necessa r i l y a f f e c t

the phosphorus reduct ions requ i red under t h e 1978 Great Lakes Water Q u a l i t y

Agreement. For the Upper Lakes (Lakes Superior, Michigan and Huron, except ing

Saginaw Bay) t h e recommended reduct ions are those which w i l l r e s u l t from

achievement o f a 1 mg/L t o t a l phosphorus concentrat ion i n e f f l u e n t s from

munic ipal wastewater treatment p l a n t s d ischarging i n excess o f 3800 cu mld

( 1 MGD). Therefore, t he requ i red phosphorus reduct ions f o r these lakes are

n o t dependent upon est imates o f t h e present phosphorus loads.

Lake

SUPERIOR

MICHIGAN

HURON

ERIE

ONTAR I 0

D i r e c t Munic ipal

7 2

1,041

126

6,292

2,093

D i r e c t I n d u s t r i a l

103

38

38

275

8 2

T r i bu ta ry * Tota l

2,455

3,596

2,901

9,960

4,047

Upstream Load

- -

657

1,080

4,769

Tot a 1

4,212

6,357

4,867

18,425

11,803

Atmosphere

1,566

1,682

1,129

774

488

Urban D i r e c t

16 -

16

44

324

For Lakes E r i e and On ta r i o and Saginaw Bay, t h e 1976 phosphorus load

est imates were used i n d i r e c t l y i n the development o f t he phosphorus t a r g e t

loads. A "base year" load was der ived on the bas is o f t he 1976 load from

d i r e c t p o i n t sources and t h e atmosphere, and t r i b u t a r y loads based on an

"average" hydro log ic year. Hence, t he 1976 es t imate can i n p a r t a f f e c t t he

u l t i m a t e t a r g e t load es tab l i shed through t h e lake modeling exerc ise. The

i m p l i c a t i o n s o f the present loads as they a f f e c t t h e lake modeling r e s u l t s are

discussed below.

3.2 LIMITATIONS AND IMPLICATIONS OF EXISTING LOADING ESTIMATES

The t a r g e t loads were developed, i n pa r t , cons ider ing measures o f

eu t roph i ca t i on and employing or?e o r more water q u a l i t y models i n combination

w i t h t h e measured t o t a l phosphorus i n t h e Great Lakes. Four aspects o f t he

t o t a l phosphorus load est imates are discussed i n t he contex t o f t h i s use and

the i rnp l i ca t ions on water q u a l i t y management decis ions. The f o u r aspects

considered are t r i b u t a r y loads, sho re l i ne erosion, b i o a v a i l a b i l i t y of var ious

forms o f phosphorus, and assignment o f t r i b u t a r y loads t o p r imary sources such

as p o i n t sources, r u n o f f f rom a g r i c u l t u r a l land, stream bank erosion, and

urban r u n o f f . The u n c e r t a i n t y i n est imated t o t a l phosphorus loads as r e l a t e d

t o ana lys is o f e x i s t i n g data on the loads f rom p o i n t sources, atmospheric

sources, and connect ing r i v e r s between lakes, has been discussed i n Sect ion

3.1. The f o l l o w i n g i s a d iscussion o f a d d i t i o n a l u n c e r t a i n t i e s which may

i n f l uence management decis ions.

3.2.1 T r i b u t a r y Loads

T r i b u t a r y loads are gene ra l l y measured a t upstream loca t i ons which are n o t

s i g n i f i c a n t l y i n f l uenced by the lake backwater. Por t ions of t h e measured

t r i b u t a r y loads are associated w i t h p a r t i c u l a t e s . Many streams are character-

i z e d by increases i n t o t a l phosphorus concent ra t ions du r i ng t h e h igh runoff

per iods associated w i t h storm events. Data f rom sampling du r i ng runoff events

i n seven o f ten streams moni tored on the U.S. s i de o f Lake E r i e i n d i c a t e d t h a t

phosphorus f l u x increased w i t h i nc reas ing f low. 49 These streams are

sometimes r e f e r r e d t o as event response streams. The phosphorus associated

w i t h h igher f l o w per iods can be a s i g n i f i c a n t percentage o f the t o t a l annual

load. The Corps of ~ n g i n e e r s ~ ~ has developed a technique f o r event sampling

of t r i b u t a r i e s and f o r es t ima t i ng the annual t o t a l phosphorus f l u x t o Lake

E r i e us ing these data and a phosphorus load ing model. The t o t a l phosphorus

l oad es t imate f o r Lake E r i e us ing the phosphorus model t o e x t r a p o l a t e Corps

data i s 79 percent and 49 percent l a r g e r than est imates us ing h i s t o r i c a l data

f o r c e r t a i n U.S. and Canadian t r i b u t a r i e s , respec t i ve l y . 'These d i f fe rences

are f o r est imated loads summed over var ious per iods and t r i b u t a r i e s . It may

be concluded t h a t event sampling o f t r i b u t a r y loads can increase s i g n i f i c a n t l y

t he est imated t o t a l phosphorus e n t e r i n g a lake f rom t r i b u t a r i e s . The increase

i n phosphorus loads du r i ng h igh r u n o f f events i s p r i m a r i l y asociated w i t h

p a r t i c u l a t e phosphorus. The documented e f f e c t s o f event sampling on t r i b u t a r y

load est imates were obta ined i n t he Lake E r i e basin, which has s i g n i f i c a n t

reg ions w i t h h igh c l a y content s o i l s . Other areas o f the Great Lakes, w i t h

more sandy s o i l s , would tend t o have phosphorus f l u x e s l ess s e n s i t i v e t o h igh

flows. Some event data were a l s o a v a i l a b l e f o r t r i b u t a r i e s t o o ther lakes,

however, t he re i s no cons i s ten t o r comprehensive Great Lakes-wide data base

w i t h associated analyses t h a t considers t h i s phenomenon. T r i b u t a r y l oad ing

es t imates f o r lakes o ther than Lake E r i e may be low due t o t h i s - l a c k o f data.

Employing Lake E r i e as a guide, t he underestimate could range f rom 10 t o 30

percent o f t r i b u t a r y loads. Since no a d d i t i o n a l data have been c o l l e c t e d i t

i s n o t poss ib le t o determine i f the loads have a c t u a l l y been underestimated

f o r i n d i v i d u a l lakes no r t he magnitude o f any underestimate.

The event response phenomena suggests t h a t a problem may e x i s t i n terms of

t r a n s p o r t i n g t r i b u t a r y loads t o t he main body o f t he lakes. The t r i b u t a r y

loads are est imated from measurements made i n streams above the i n f l uence o f

t he backwater o f t he lake. 'These are stream segments u s u a l l y charac ter ized by

h ighe r v e l o c i t i e s du r i ng h igh f l o w events. The ex is tence o f event response

streams suggests t h a t s e t t l i n g and subsequent scour o f p a r t i c u l a t e phosphorus

are s i g n i f i c a n t inst ream processes c o n t r o l 1 i n g the magnitude and t ime of

d e l i v e r y o f phosphorus loads f rom t r i b u t a r i e s . The i n f l uence o f the lake

backwater tends t o lower stream v e l o c i t i e s and t h i s tendency i s accentuated by

bays, de l tas , and i n the nearshore reg ion o f the lakes. It would appear t h a t

the t o t a l phosphorus loads f rom t r i b u t a r i e s may be s e t t l i n g i n the bays,

de l tas , and nearshore areas o f t h e lake. Th i s s e t t l i n g would tend t o reduce t h e es t imates of t o t a l phosphorus loads t h a t impact l ake e u t r o p h i c a t i o n

processes. The phosphorus which s e t t l e s can u l t i m a t e l y e n t e r lakewide

processes b u t t h e t ime frame over which t h i s occurs would be long and much of

t h e m a t e r i a l may be e f f e c t i v e l y removed f rom t h e system. The mathematical

models o f e u t r o p h i c a t i o n each con ta in terms t h a t account f o r s e t t l i n g o f t o t a l

phosphorus. The va lues o f these s e t t l i n g terms are made t o compensate f o r t he

processes discussed above.

The t a r g e t phosphorus loads were es tab l i shed i n t h e con tex t o f c o n t r o l l i n g

e u t r o p h i c a t i o n on a lakewide sca le and t h e es t imates o f phosphorus loads f rom

i r i b u t a r i e s are n o t comple te ly c o n s i s t e n t between lakes.

3.2.2 Shore 1 i ne Eros ion

The load es t imates o f t o t a l phosphorus a l l exc lude cons ide ra t i ons o f t h e

c o n t r i b u t i o n o f s h o r e l i n e e ros ion . Th i s exc lus ion i s based on t h e observa t ion

t h a t t h i s source o f phosphorus has a h i gh percentage o f unava i l ab le phos-

phorus. The problem assoc ia ted w i t h t h i s assumption i s t h a t t a r g e t loads have

been developed us ing mass balance models and es t imated t o t a l phosphorus loads,

i n con junc t i on w i t h measurements of t o t a l phosphorus ob ta ined i n t h e lakes, t o

d e f i n e model c o e f f i c i e n t s and parameters. 'Therefore, f r om t h e s tandpo in t of

develop ing t a r g e t loads, t h e t o t a l phosphorus l oad ing es t imates should con ta in

a1 1 sources o f t o t a l phosphorus which cou ld i n f l u e n c e i n - l a k e measurements of

t h i s substance. Table 3.2 p resen ts es t imates o f t h e s h o r e l i n e e ros ion

c o n t r i b u t i o n o f t o t a l phosphorus and i t s r e l a t i v e magnitude compared t o t h e

o the r sources o f phosphorus.

The s i gn i f icance o f t h e p a r t i c u l a t e t o t a l phosphorus r e 1 ated t o shore1 i n e

e ros ion and t o event loads i n t r i b u t a r i e s would be lessened if t h e m a t e r i a l

s e t t l e s r a p i d l y . There appear t o be s i g n i f i c a n t percentages o f c l a y and s i l t ,

r ang ing f rom 25 t o 80 percen t i n t h e eroded m a t e r i a l f r om shore l ines . Much of

t h e phosphorus i n t r i b u t a r y loads t r anspo r ted d u r i n g s torm events i s

assoc ia ted w i t h p a r t i c l e s o f t h i s s i z e range. A l a r g e percentage o f t r i b u t a r y

p a r t i c u l a t e t o t a l phosphorus may be assoc ia ted w i t h c l a y s i z e p a r t i c l e s . It

i s probable t h a t some p o r t i o n o f t he loads f rom these sources, p a r t i c u l a r l y

t h a t assoc ia ted w i t h t h e l a r g e r p a r t i c l e s , s e t t l e s and does n o t e n t e r

lake-wide processes. Un fo r tuna te ly , t h e da ta base does n o t e x i s t t o determine

what percentage o f these loads s e t t l e s .

The ana l ys i s employed t o o b t a i n t h e t a r g e t loads assumes:

t

TABLE 3.2 SHORELINE EROSION AS A SOURCE OF LAKE-WIDE TOTAL PHOSPHORUS

1. ' A l l o f t h e t r i b u t a r y t o t a l phosphorus en te r s t h e lake. Some o f t h e

p a r t i c u l a t e phosphorus i n these loads i s c a l c u l a t e d t o s e t t l e and

does n o t e n t e r lake-wide processes. The d i sso l ved p o r t i o n s . o f t h e

t r i b u t a r y loads do e n t e r lake-wide processes.

Lake

Super ior

Michigan

Huron

E r i e

On ta r i o

2. A l l t h e t o t a l phosphorus f rom s h o r e l i n e e ros ion s e t t l e s ve ry r a p i d l y

and does n o t en te r lake-wide processes.

The tendency o f these assumptions i s t o e l i m i n a t e cons ide ra t i on o f t h e

e f fec ts o f p a r t i c u l a t e phosphorus f r om sho re l i ne e ros ion and t o assign

b e n e f i t s t o c o n t r o l o f p a r t i c u l a t e phosphorus loads f rom t r i b u t a r i e s .

Therefore, t h e p r o j e c t e d b e n e f i t s a t t r i b u t e d t o t he c o n t r o l o f p a r t i c u l a t e

Notes: 1. U.S. load o n l y 2. PLUARG r e p o r t s on U.S. and Canadian sho re l i ne e r ~ s i o n . ~ 3. Canadian es t imate f o r s h o r t term used (1972-1973) @ 9512 t / y r -

Canadian long te rm es t imates (1953-1973) @ 5912 t /yr.

Shore 1 i n e Eros i on ( t o t a l sediment)

( t / ~ r )

11,279,000

21,778,000

1,763,000

11,131,000

3,206,000

T o t a l Phosphorus Shore 1 i n e 2

Eros ion ( t / ~ r )

3,800 ' 3,700

794

10,536

1,280

1976 To ta l Phosphorus

A l l Other Sources ( t / y r )

4,212

6,357

4,867

18,425

11,803

phosphorus from t r i b u t a r i e s and o the r sources may be overest imated. The s i g n i f i c a n c e o f t h i s poss ib l e .ove res t imat ion o f b e n e f i t s cannot be determined

f r om t h e e x i s t i n g in fo rmat ion .

3.2.3 B i o a v i l a b i l i t y o f Phosphorus

H i s t o r i c a l l y , management p r a c t i c e s f o r c o n t r o l l i n g l ake e u t r o p h i c a t i o n

have been d i r e c t e d towards t o t a l phosphorus. Recent s tud ies have r a i s e d

ques t ions as t o t he re levance o f t h i s parameter.

Phosphorus i n surface waters i s made up o f so lub le and p a r t i c u l a t e forms.

It i s w ide l y accepted t ha t , w i t h i n t he so lub le f r ac t i on , orthophosphate i s

r e a d i l y a v a i l a b l e f o r a l g a l p ~ o d u c t i v i t y . I'he p a r t i c u l a t e f r a c t i o n may be

chem ica l l y def ined as non -apa t i t e i no rgan i c phosphorus, a p a t i t e i no rgan i c

phosphorus, and o rgan ic phosphorus. Non-apat i te i no rgan i c phosphorus i s

cons idered t o be t h e p o t e n t i a l l y and u l t i m a t e l y a v a i l a b l e form. A p a t i t e

i no rgan i c phosphorus i s cons idered v i r t u a l l y unavai l ab le . A p o r t i o n o f

o rgan ic phosphorus 1-1 k e l y becomes a v a i l a b l e over t ime. ques t ions remain as t o

t h e a c t u a l u t i l i z a t i o n o f these forms i n t h e aquat i c environment. L i m i t e d .

s t ud ies are underway t o r e l a t e these chem ica l l y de f i ned forms t o t he

phosphorus used by algae. F igure 3.1 shows a genera l r e l a t i o n s h i p among these

forms o f phosphorus and t h e i r u t i 1 i z a t i o n by algae.

A rev iew o f t h e most r ecen t s tud ies concerned w i t h phosphorus a v a i l a b i l i t y

have been p rov ided by Lee -- e t a l . 5 0 a t t he IJC/Corne l l U n i v e r s i t y Conference

on Phosphorus Management S t ra teg ies f o r Lakes and t h e Great Lakes Science

Adv isory Board's Exper t Committee on the Engineer ing and Technolog ica l Aspects

o f Great Lakes Water ~ u a l i ty. 5 1 E x i s t i n g eva lua t i ons of phosphorus

a v a i l a b i l i t y have been p red i ca ted ma in l y on chemical e x t r a c t i o n s which measure

a v a i l a b l e phosphorus as orthophosphate. The r e s u l t s obta ined w i t h t he

chemical methods p r e s e n t l y used are r e l a t i v e l y comparable. Stud ies are

p r e s e n t l y be ing conducted i n an e f f o r t t o compare chemical and b i o l o g i c a l

methods. Nevertheless, t h e r e s t i l l remains a p a u c i t y o f da ta f o r making such

comparisons. The c o r r e l a t i o n between a l g a l b ioassay da ta and lake biomass

response i s s t i 11 unresolved.

.FIGURE 3 . 1 GENERAL RELATIONSHIPS BETWEEN PHOSPHORUS FORMS AND ALGAE

Soluble Orthophosp hate

T o t a l Phosphorus

Organic Phospate Soluble Orthophosp h a t e

Note: (Th is i s not a complete n u t r i e n t c y c l i n g diagram - r a t h e r a schematic showing t h e paths between t o t a l phosphorus inputs and a lgae . )

Chemical analyses of t h e a v a i l a b i l i t y o f t r i b u t a r y p a r t i c u l a t e phosphorus

across t h e b a s i n p rov ides two est imated ranges. PLUARG s t u d i e s 3 u s i n g a

s i n g l e chemical method t o es t ima te non-apa t i te phosphorus found a range o f 14

t o 40 percen t depending upon t h e t r i b u t a r y sampled. The Lake E r i e Wastewater

Management s tudyb6 u s i n g two chemical e x t r a c t i o n s t o es t imate non-apat i t e

phosphorus showed a range o f 43 t o 89 percen t i n se lec ted Lake E r i e

t r i b u t a r i e s . It remains unc lea r how e i t h e r o f these procedures used t o

es t ima te non -apa t i t e phosphorus r e l a t e s t o t h e phosphorus a c t u a l l y used b y

algae.

S o i l m a t e r i a l s f r om b l u f f e ros ion and wastewater d ischarge represen t t h e

ex3tremes o f t h e a v a i l a b i l i t y issue. W i l l i ams -- e t a1.s2 and Armstrong -- e t

. bo th - . f i nd t h a t b l u f f m a t e r i a l s have b i o l o ! j i c a l l y a v a i l a b l e phosphorus i n t h e

range o f a few percent . The r e l a t i v e b i o l o g i c a l a v a i l a b i l i t y o f phosphorus i n

wastewater i s n o t as c l e a r cu t . Recent EPA s t u d i e s s 4 i n d i c a t e t h a t t h e

b i o l o g i c a l l y a v a i l a b l e f r a c t i o n o f phosphorus mun ic ipa l wastewater t o be on

t h e o rde r o f 60 t o 75 percent. The percentages f o r a g iven wastewater remain

r e 1 a t i v e l y cons tan t r ega rd less o f b i o l o g i c a l wastewater t reatment w i t h

supplemental t rea tment i n c l u d i n g chemical a d d i t i o n f o r phosphorus removal.

The b i o l o g i c a l a v a i l a b i l i t y o f phosphorus ques t i on i s one r e q u i r i n g f u r t h e r

research.

Another f a c t o r i n d e f i n i n g t h e a v a i l a b i l i t y o f , phosphorus i s t h e p r o x i m i t y

o f t h e phosphorus source t o t h e r e c e i v i n g water. I n i t i a l s t ud ies by Carlson

e t a1. 5 5 suggest t h a t streams have a n a t u r a l a b i l i t y t o reduce t h e -- p r o p o r t i o n o f a v a i l a b l e phosphorus f rom upstream sources. Whi le t h i s

c a p a b i l i t y i s d i f f i c u l t t o measure i n l a r g e systems, i t s i n c l u s i o n i n t h e

f i n a l equat ion used t o d e f i n e t h e impacts o f phosphorus f rom var ious sources

may be o f s u b s t a n t i a l importance.

The foregoing d i scuss ion unde r l i nes t h e importance o f cons ide r i ng

phosphorus av.ai 1 a b i 1 i ty i n formu l a t i ng management s t r a t e g i e s f o r t h e Great

Lakes. It i s u n f o r t u n a t e t h a t t h e o n l y e x i s t i n g comprehensive da ta base i s

t o t a l phosphorus. Therefore, a l though p resen t management s t r a t e g i e s must

con t i nue t o be p red i ca ted on cons ide ra t i on o f t o t a l phosphorus, work should

con t inue t o o b t a i n t h e l oad ing and o the r aspects o f phosphorus a v a i l a b i l i t y

and t h e i r . . i m p l i c a t i o n f o r phosphorus management f o r t h e Great Lakes.

3.2.4 Pr imary Sources o f T o t a l Phosphorus i n T r i b u t a r i e s

I n o rder t o assess t h e f e a s i b i l i t y and p r a c t i c a l i t y o f managing t o t a l

phosphorus i n p u t s t o t h e Great Lakes, i t i s necessary t o ass ign t he measured

t r i b u t a r y loads t o p r imary sources such as p o i n t discharges, r u n o f f f r om

a g r i c u l t u r a l , urban, and o the r land uses, and stream bank e ros ion .

The genera l procedure employed was t o de f i ne t o t a l t r i b u t a r y loads f r om

measured f l ows and t o t a l phosphorus concen t ra t i on data. I n t he PLUARG Study

independent es t imates o f t o t a l phosphorus f rom pr imary sources on t r i b u t a r i e s

were developed. The sum o f t he pr-imary sources o f phosphorus on t r i b u t a r i e s

was compared t o t h e t r i b u t a r y load es t imates developed f r om t h e r i v e r mouth

measurements. I n some cases s i gn if i c a n t adjustments i n p r imary t o t a l

phosphorus source loads were requ i red . These adjustments cou ld o f t e n be

r e l a t e d t o s p e c i f i c watershed o r t r i b u t a r y c h a r a c t e r i s t i c s . I n o the r cases

t h e agreement between t he two c a l c u l a t i o n s was reasonable. Th is procedure

p rov ides some b a s i s f o r d e f i n i n g p r imary sources o f t o t a l phosphorus on

t r i b u t a r i e s .

There i s evidence t h a t t o t a l phosphorus d ischarged by upstream mun ic ipa l

and i n d u s t r i a l p o i n t sources undergoes t r ans fo rma t i ons and removals f r om t h e

water column. Phosphorus f rom these sources i s i n d i s t i n g u i s h a b l e f rom t h a t

assoc ia ted w i t h o the r sources a t t h e mouth o f t h e t r i b u t a r y . Phosphorus f rom

t reatment p l a n t s cou ld be removed i n t he downstream reaches o f t r i b u t a r i e s .

Th is removed phosphorus i s most p robab ly assoc ia ted w i t h s o l i d p a r t i c u l a t e s

which s e t t l e . The t r a v e l t ime of t h i s p a r t i c u l a t e phosphorus t o t he l a k e i s

l a r g e compared t o t h e average h y d r a u l i c t r a v e l t ime o f t h e s t reamf low and may

be i n t h e range o f severa l years. The storm event r e l a t e d increases i n

t r i b u t a r y phosphorus are p robab ly assoc ia ted w i t h s e t t l i n g and subsequent

scour o f p a r t i c u l a t e phosphorus. Th is process a l so can i n f l u e n c e phosphorus

discharged by p o i n t sources on t r i b u t a r i e s .

The exe rc i se of c a l c u l a t i n g t h e p r imary sources o f phosphorus i s an

approx imat ion which appears t o i nco rpo ra te some type o f long term equ i 1 i br ium

assumption i n terms of e x i s t i n g loads. The e f f e c t i v e n e s s o f phosphorus

c o n t r o l a t p o i n t sources on t r i b u t a r i e s i s s u b j e c t t o some u n c e r t a i n t y . As an i l l u s t r a t i o n o f these u n c e r t a i n t i e s t he f o l l o w i n g quest ions should be

considered:

1. How much o f t h e p o i n t s'ource phosphorus d ischarged t o t r i b u t a r i e s

reaches t h e open lake and i n what t ime frame?

2. How much o f t he p o i n t source phosphorus f rom t r i b u t a r i e s t h a t reaches

t h e open lake i s b i o l o g i c a l l y a v a i l a b l e and i n what t ime frame?

The same general issues o f t r a n s p o r t and a v a i l a b i l i t y appear t o be

assoc ia ted w i t h p o i n t and nonpo in t sources on t r i b u t a r i e s . The s i g n i f i c a n c e

of ques t ions w i t h regard t o p o i n t sources inc rease w i t h i nc reas ing d i s tance

f r om t h e lake and f o r l a r g e r d e l t a o r bay systems a t t h e mouth o f t h e

t r i b u t a r y .

3.3 FUTURE LOAD ESTIMATES

The task f o r c e be l i eves t h a t severa l changes are necessary t o improve t he

es t imates o f phosphorus loads. Improvements are r e q u i r e d i n t he es t imates

f rom p o i n t sources and t r i b u t a r i e s and t he types o f r e p o r t i n g .

3.3.1 P o i n t Sources

Areas i n which p o i n t source es t imates can be improved are t o i n c l u d e an

es t ima te f o r wastewater t rea tment p l a n t bypasses and combined sewer

over f lows. A measure o f t o t a l f l o w and a f l o w p ropo r t i oned sample are needed

f o r each bypass event. Regu la to ry agencies should r e q u i r e t h i s i n f o r m a t i o n t o

be c o l l e c t e d and repor ted. The es t imates o f annual t rea tment p l a n t loads

should con t inue t o be based on d a i l y load est imates, i .e . d a i l y f l o w t imes t h e

phosphorus concent ra t ion i n a d a i l y con~posi t e d saap le .

3.3.2 Tributaries

In order to obtain a reasonable estimate of total loads to the lakes from event response rivers, sampling during high flow events is necessary.

Aproximately two to three of the largest events must be sampled for a yearly estimate, with 15 to 20 grab samples collected over the hydrograph. An additional 5 to 10 samples should be collected during steady flow periods. This program should yield a loading estimate with an error estimate of 1 0 to

20 percent .

The above program wi 1 1 result in annual estimates for tributaries which are reliable and estimates which can also be used to detect differences in annual loads. However, this program will likely lot be sufficient to detect progress made in control of diffuse sources. Annual variations in the frequency and duration of high flow events as well as basin conditions, such as soil moisture and cover, make any simple evaluation of change in phosphorus

loads impossible. If changes in phosphorus loads are to be measured, continuous records of rainfall, streamflow, water quality, soil moisture, and

cover will be needed as well as improved methodologies for relating this information. A few watersheds should be selected for such studies.

Reporting of Loads

Total phosphorus loads are needed for two reasons: calibration and

validation of lake models and measurement of progress in reducing inputs to the lakes.

For the purpose of lake modeling, an estimate of the total phosphorus load

from all sources is needed. Estimates are needed for all point sources, not

just those with flows greater than one million gallons per day. An event

sampling program for the tributaries as described above is needed as well'as

estimates of loads from connecting. channels and the atmosphere.

Reporting of annual and comparison total lake phosphorus loads is not the

best way to measure progress in controlling phosphorus. Rather, only

munic ipa l sources w i t h f l ows grea ter than 3800 cu m/d (1 MGD) and ' i n d u s t r i a l

sources should be repo r ted annual ly ' and compared t o s p e c i f i c t a r g e t loads f o r

these p o i n t sources as a measure o f progress.

. .

Progress i n d.iffuse source c o n t r o l can bes t be assessed.through -moni tor ing . t

the implementation of conservat ion measures i n the a g r i c u l t u r a l community and

stormwater management c o n t r o l s i n t h e urban areas. I n tens i ve mon i to r i ng

programs t o accura te ly measure r i v e r loadings cou ld be c a r r i e d out on se lec ted

r i v e r s as descr ibed above. Implementation of conservat ion measures can be

used as i n p u t t o models o r t oo l s , such as the Un iversa l S o i l Loss Equation, t o

es t imate progress based on reduc t ions i n p o t e n t i a l gross eros ion.

3.4 SUMMARY

It appears t h a t the t o t a l phosphorus load ing est imates developed f o r the

Great Lzkes were based on a se t o f assumptions which were cons i s ten t w i t h

a v a i l a b l e data and the degree o f understanding o f the processes c o n t r o l l i n g

t r a n s p o r t o f t o t a l phosphorus. The var ious analyses used cou ld be viewed as

being a t the lead ing edge o f the s ta te -o f - t he -a r t . From the standpoint o f

phosphorus management i n t h e Great Lakes basin these analyses have prov ided

important in fo rmat ion and i n s i g h t . As discussed, t he re are a number o f gaps

i n our knowledge o f load iog which should be considered i n developing a

phosphorus management s t ra tegy f o r the Great Lakes. I n general they are

associated w i t h t h e a b i l i t y t o charac ter ize the t o t a l load t o a lake o r lake

segment cons is ten t w i t h t h e methods employed t o de f ine t a r g e t loads; s e t t l i v g

o f t o t a l phosphorus i n t r i b u t a r i e s , bays, de l tas , and near-shore areas; and

d e f i n i n g the b e n e f i t s associated w i t h t reatment o f p o i n t and nonpoint sources

on t r i b u t a r i e s . The task f o r c e has suggested ways t o improve t h e f u t u r e

est imates o f phosphorus loads.

The present gaps i n fundamental knowledge associated w i t h est imates of

t o t a l phosphorus loads are n o t s u f f i c i e n t t o r e q u i r e major mod i f i ca t i ons i n

t he proposed management programs f o r c o n t r o l o f eu t roph i ca t i on i n the Great

Lakes. The i r ex is tence suggests t h a t t h e c e r t a i n t y o f ob ta in ing b e n e f i t s f rom

c o n t r o l ac t ions va r i es w i t h t he type and l o c a t i o n o f the pr imary source. The

most certain benefits are associated with control of point sources discharging directly to the Great Lakes. The certainty of obtaining the anticipated benefits is reduced for controls on point sources discharging to tributaries. The greatest uncertainty of obtaining anticipated benefits is associated with the control of particulates from nonpoint agricultural sources.

REVIEW AND EVALUATION OF MODELS

As no ted i n Chapter 2, severa l mathematical models were used t o e s t a b l i s h

t h e 1978 Great Lakes Water Q u a l i t y Agreement t e n t a t i v e phosphorus t a r g e t loads

f o r Saginaw Bay and t he lower Great Lakes. A major p a r t o f t h i s task f o r c e ' s

charges was t o rev iew these models and eva lua te t h e i r a b i l i t y t o p r e d i c t t h e

l i m n o l o g i c a l e f f e c t s o f changes- in phosphorus load ings and comment on t he

v a l i d i t y o f t h e t a r g e t loads.

The task f o r c e e s t a b l i s h e d a model ing sub-group t o rev iew the s c i e n t i f i c

and t e c h n i c a l bases f o r t h e models and assess t h e i r a b i l i t y t o p r e d i c t

reasonable t a r g e t loads. Based on the model i ~ ~ g sub-group's d e t a i l e d rev iew o f

t h e modelss6 t h e task force, i n t h i s chapter, p rov ides some general

observa t ions on t h e na tu re o f t h e model ing process, a b r i e f d e s c r i p t i o n and

e v a l u a t i o n o f t he models, and an assessment o f the r e l i a b i l i t y o f the t a r g e t

1 oads.

4.1 PRESENT STATE OF EUTROPHICATION MODELING

Mathematical models have severa l impor tan t f unc t i ons . One main f u n c t i o n i s

t o inc rease t h e s c i e n t i f i c i n s i g h t and understanding o f r e a l wo r l d processes.

A second i s t o p rov ide a q u a n t i t a t i v e t o o l f o r assessing p l ann ing and

management a l t e r n a t i v e s . The f i r s t f u n c t i o n i s cha rac te r i zed by the

express ion o f fundamental ideas i n mathematical form, l ead ing t o equat ions,

graphs, etc., whi-ch c o r r e l a t e and synthes ize s c i e n t i f i c observa t ions and

data. The second. func t ion i s . t h e a p p l i c a t i o n o f these equat ions i n t h e

e v a l u a t i o n o f a l t e r n a t i v e s f o r p l ann ing design and management purposes.

The a n a l y s i s by which t h e Great Lakes t a r g e t loads were determined

represen t t he p resen t s ta te -o f - t he -a r t o f model ing t h e e u t r o p h i c a t i o n

process.. Over t h e p a s t few decades a b e t t e r understanding o f the phenomena

assoc ia ted w i t h e u t r o p h i c a t i o n has been achieved and, more i m p o r t a n t l y

q u a n t i t a t i v e means have been developed f o r assessing va r i ous a1 t e r n a t i v e s f o r

c o n t r o l 1 i n g eu t roph i ca t i on , such as reduc ing phosphorus inpu ts . However, t he

approaches are s t i l l ve ry new and, as ye t , t he re i s l i t t l e d i r e c t and

emp i r i ca l evidence o f t h e i r v a l i d i t y i n p r o j e c t i n g responses o f t he Great

Lakes t o reduced n u t r i e n t inpu ts .

Most environmental problems are charac ter ized by components which vary

over t ime, are three-dimensional, and respond i n a non l i nea r manner, i .e. t h e

e f f e c t s do n o t correspond t o the environmental d is turbances o r s t resses i n a

1:l manner. Assuming our s c i e n t i f i c . knowledge o f the r e a l s i t u a t i o n i n

systems-such as the Great Lakes i s complete, a t . l e a s t i n p r i n c i p l e , an

abs t rac t i on o r "model" o f t he r e a l system i s developed, i n which the

s i g n i f i c a n t f a c t o r s are inc luded and i r r e l e v a n t f ea tu res are omi t ted o r

modi f ied.

A f te r development o f the model, whether- i n equat ion form o r i n the form o f

graphs o r p l o t s , i t must then be " c a l i b r a t e d " and "va l ida ted" . The process o f

c a l i b r a t i o n invo lves comparing model p r e d i c t i o n s w i t h observed o r measured

data, and i s done t o i nsu re t h a t t h e r e l e v a n t f a c t o r s i n t he model have been

inc luded and r e a l i s t i c a l l y character ized. The v a l i d a t i o n i s usual l y done by

comparison o f p red i c ted data w i t h measured o r observed data f rom prev ious

years i n the water body be-ing modeled, o r by us ing data from a complete ly

d i f f e r e n t water body. When such a comparison i s sa tTs fac to ry , t he model i s

sa id t o be va l ida ted . What c o n s t i t u t e s " s a t i s f a c t o r y " depends on the na ture

o f t he problem, t he s t r u c t u r e of t he model,,the ex ten t o f a v a i l a b l e data, and

most important, t h e purpose o f the analys is . The h ighest l e v e l of v a l i d a t i o n

i s achieved when the model p r e d i c t i ons i d e n t i c a l l y reproduce the observed r e a l

wor ld cond i t ions . This type o f v a l i d a t i o n is , i n any p r a c t i c a l sense, almost

impossible t o achieve i n environmental modeling because of t he t ime l a g

invo lved between the use o f a c o n t r o l o r remedial measure and the r e s u l t a n t

response o f a lake, and because o f random f a c t o r s which a f f e c t hyd ro log i ca l

and meteoro log ica l events and n u t r i e n t inpu ts .

Water q u a l j t y models, i n general , should be considered p lann ing and/or

management t o o l s r a t h e r than p rec i se p r e d i c t i v e techniques. As such, they are

best used t o examine the spectrum o f lake responses which may occur as a

r e s u l t o f var ious management a l t e rna t i ves , as w e l l as t o increase our

understanding o f l ake systems. V a l i d a t i o n o f e u t r o p h i c a t i o n models should be

viewed i n t h i s con tex t . I n many cases, extreme accuracy i s n o t r e q u i r e d f o r

management dec is ions, b u t r a t h e r t rends and ranges may be s u f f i c i e n t t o answer

ques t ions r e l a t e d t o t h e c o n t r o l o f e u t r o p h i c a t i o n i n t h e Great Lakes bas in .

It i s noted t h a t w i t h e u t r o p h i c a t i o n models, e s p e c i a l l y t he more complex

ones, t h e components o f t h e models are outweighed by t h e number o f r a t e

c o e f f i c i e n t s these components may have, by f a c t o r s of 2 t o 10. That i s , a

model component o r process may have seve ra l poss ib l e values, a1 1 o f which a re

v a l i d under app rop r i a te cond i t i ons . Based on t he present s c i e n t i f i c knowledge

o f a q u a t i c ecosystems, however, t h e r e are u s u a l l y 1 i m i t e d ranges w i t h i n which

t h e va lues o f these components l i e . The v a l i d i t y of t he model as a r e a l i s t i c

r ep resen ta t i on o f a system as cornplex as t h e Great Lakes i s based on t h e

i n t e r n a l cons is tency o f these c o e f f i c i e n t s over a wide v a r i e t y o f

env i ronmenta l cond i t i ons .

The n a t u r e o f t he problem, and s p e c i f i c a l l y t h e t ime and space sca les o f

t h e problem, d i c t a t e how s imple o r complex t h e ana l ys i s w i l l be. Given o r

assuming these scales, a s p e c i f i c ques t ion i s posed, and t he purpose o f t he

a n a l y s i s should be t o answer t h i s ques t ion i n t h e s imp les t , most e f f i c i e n t and

r e a l i s t i c manner. The r e l a t i v e complex i t y of t h e model i s an impor tan t f a c t o r

i n i t s v a l i d a t i o n -- t h e more complex, t h e g rea te r t he degree o f v a l i d a t i o n

requ i red . The complex i t y o f a model i s determined by t he number o f i t s

components. The models descr ibed i n t h e f o l l o w i n g sec t i on cover t h e spectrum

f rom r e l a t i v e l y s imple t o complex, and each has a p a r t i c u l a r u t i l i t y .

4.2 MODELS USED TO DEVELOP TARGET LOADS

'The c h a r a c t e r i s t i c s o f t h e t r a n s p o r t ( s p a t i a l d i s t r i b u t i o n ) o f n u t r i e n t s

w i t h i n a g iven water body are accounted f o r i n va r i ous ways -- f rom t h e most

s i m p l i f i e d concept o f a comple te ly mixed system t o t he more complex systems

which v a r y s p a t i a l l y I n one o r more dimensions. 'The v a r i a t i o n s i n a water

body over t ime can a l s o be descr-ibed i n severa l ways -- f rom the s teady-s ta te

cond i t i on , t o t h e dynamic mode over a d i u r n a l , weekly, seasonal, o r annual

t ime scale. As noted above, t h e necessary degree of complex i t y o f a given

model i s u s u a l l y d i c t a t e d by t he n a t u r e o f t h e a n a l y s i s and t he answers be ing

sought. 37

Models may, there fo re , be ca tegor ized on the basis o f t he f o l l o w i n g

c r i t e ra :

1. Steady-state o r dynamic.

2. Completely m i x e d o r s p a t i a l l y va r i ab le .

3. S ing le reac tan ts w i t h s i m p l i f i e d k i n e t i c s o r m u l t i p l e reac tan ts w i t h

complex k i n e t i c s .

The models which were app l i ed t o t he ana lys is o f the eu t roph i ca t i on

problem i n t he Great Lakes have been reviewed by Task Group 111. A , .

' . slmmary o f t h i s review, w i t h a b r i e f eva lua t i on added by t h i s committee, i s , . . , . . I

presented below.

1. Steady-state, S ingle Const i tuen t ( V ~ l l e n w e i d e r ~ ~ )

The Vol lenweider model, based on a r a t i o n a l approach, i s an emp i r i ca l

c o r r e l a t i o n between phosphorus load and i n - lake concentrat ions o f

phosphorus and c h l o r o p h y l l - a, parameter ized by depth and h y d r a u l i c

de ten t ion t ime. I n developing the co r re la t i ons , data were used f rom s i x t y

temperate-zone lakes which represented a range o f cond i t i ons f rom

o l i g o t r o p h i c t o eutrophic . Conceptually, the model o r i g i n a t e d f rom the

s o l u t i o n s o f a s i m p l i f i e d m a s s balance model o f a complete ly mixed r e a c t o r

f o r the e q u i l i b r i u m o r steady s t a t e cond i t ion .

2. Dynamic, S ing le Const i tuen t (Chapra40)

The Chapra model i s a simple dynamic mass balance model w i t h phosphorus

concent ra t ion as the p r i n c i p a l var iab le . To ta l phosphorus i s considered

t o be a non-conservat ive substance which i s removed by s e t t l i n g t o the

bed. The model has been app l ied t o the Great Lakes as a coupled dynamic

system of basins. Given phosphorus load, volume, and depth, t he i n - l ake

phosphorus concent ra t ions are c a l c u l a t e d as a f u n c t i o n o f time, f o r a l l o f

t h e major Great Lakes basin. An emp i r i ca l component i s inc luded which

a l lows c o r r e l a t i o n s t o be made between the ca l cu la ted t o t a l phosphorus

concentrat ions and r e l a t e d parameters such as c h l o r o p h y l l - a and d i sso l ved

oxygen concent ra t ions and, ' i n t h i s respect , i s simi1a.r t o t he above. Th is model has been c a l i b r a t e d w i t h Great Lakes data, w h i l e t h e above used da ta

f r om many 1 akes.

3. Dynamic, M u l t i p l e Cons t i tuen ts , S ing le Phytoplankton (Thomann,"

~ i ~ o r o ~ 2,

The Manhattan Col lege groups (Thomann, D iToro4* ) has developed models

f o r Lake Ontar io , t h e Lake Huron-Saginaw Bay system, and Lake E r i e . These

are dynamic mass balance analyses which c a l c u l a t e bo th phosphorus and

n i t r o g e n concent ra t ions and t h e r e l a t e d parameters, c h l o r o p h y l l g concent ra t ion , zooplankton concent ra t ion , and, f o r Lake Er ie , d i sso l ved

oxygen concent ra t ion . The p h y t o ~ l ankton g ~ ~ o w t h i s a f u n c t i o n o f

phytop lankton concen t ra t i on and temperature. The same bas i c conceptual

framework has been a p p l i e d t o Lake On ta r i o and t o t h e Lake Huron-Saginaw

Bay system.

4. Dynamic, M u l t i p l e Cons t i tuen ts , M u l t i p l e Phytoplankton ( ~ i T o r o , ~ ~

Bierman, Thomann )

These models are concep tua l l y s i m i l a r t o the- Manhattan models i n t h a t a

dynamic mass balance i s used t o d i r e c t l y c a l c u l a t e phosphorus, n i t r ogen ,

phytop lankton, and zooplankton concentrat ions. The ph,ytoplankton biomass

i s p a r t i t i o n e d i n t o 2 c lasses o f diatoms and non-diatoms i n t h e DlToro and

Thomann models and a p p l i e d i n Lakes E r i e and Ontar io . The former a l s o

i nc l udes sediment n u t r i e n t r e l ease under anaerobic cond i t i ons . The

Bierman model i nco rpo ra tes f i v e d i f f e r e n t f u n c t i o n a l groups: diatoms,

greens, blue-greens (N2 - f i x i n g and non-N2f i x i n g ) , and "o thers " . More

d e t a i l e d mechanisms a re a l s o used t o descr ibe phosphorus and n i t r o g e n

i n t e r a c t i o n s w i t h t h e phytoplankton. The Bierman model has been app l i ed

o n l y t o Saginaw Bay.

4.3 ASSESSMENT OF RELIABILITY OF TARGET LOADS ESTABLISHED BY MODELS

As presented i n Chapter 2, t h e models descr ibed above were used t o de-

termine t he e f f e c t s o f changes i n phosphorus i n p u t loads on t h e concent ra t ion

o f var ious water q u a l i t y cons t i tuen ts . The models were used t o c a l c u l a t e

phosphorus i n p u t loads t o ma in ta in l e v e l s o f phosphorus and/or c h l o r o p h y l l and

d isso lved oxygen which were considered t o be i n d i c a t i v e o f acceptable water

qua1 i t y .

The f a c t o r s which are considered i n assessing the r e l i a b i l i t y o f t he

t a r g e t loads computed by the models, may be categor ized as f o l l o w s : (1) d i f f e rences i n loads ca l cu la ted by var ious models, ( 2 ) r e 1 i a b i l i t y o f models

i nd i ca ted by t h e ana l ys i s of res idua ls , and ( 3 ) cons idera t ion o f those

elements, which are n o t e x p l i c i t l y inc luded i n the models, b u t which may have

some e f f e c t on t h e t a r g e t loads. It i s ev ident t h a t w i t h respec t t o the f i r s t

two fac to rs , t h e u n c e r t a i n t y may be q u a n t i f i e d t o some degree, b u t o n l y a

q u a l i t a t i v e assessment may be made concerning t h e t h i r d .

4.3.1 ' D i f ference i n Target Loads Calcu lated by Various Models

Assuming t h a t each o f t h e models are o f comparable v a l i d i t y f o r t h i s

purpose, a measure o f conf idence i n t he t a r g e t loads es tab l i shed may be

der ived by comparing the di f ferences i n loads computed by the var ious models.

The models were used t o determine the e f f e c t s o f phosphorus i n p u t loads on

t h e concent ra t ion o f se lec ted water q u a l i t y cons t i t uen ts - p r i n c i p a l l y t o t a l

phosphorus and ch lo rophy l l . For Lake E r i e only, hypo1 imnion d isso lved oxygen

was a l so included. Resu l t i ng lake water q u a l i t y concentrat ions were

ca l cu la ted f o r an a r r a y o f phosphorus loads corresponding t o loadings which

would r e s u l t f rom var ious l e v e l s o f c o n t r o l . Target loads were se lec ted as

those which would achieve a se lec ted concent ra t ion o f phosphorus, considered

t o be an acceptable water q u a l i t y c r i t e r i o n . The c o r r e l a t i o n between t h e

phosphorus concent ra t ion and the r e s u l t i n g c h l o r o p h y l l and d isso lved oxygen

l e v e l s were es tab l i shed e i t h e r e m p i r i c a l l y o r causa l l y .

Comparison o f t he d i f f e rences i n model c a l c u l a t i o n s showed tha t , i n

general, t he re was agreement among t h e responses o f the f o u r models.56 For

a g iven i n p u t load, ca l cu la ted phosphorus concentrat ions were w i t h i n a range

of about 5 t o 25 percent, w i t h an approximate average o f about 20 percent.

Resu l t i ng ' ch lo rophy l l concent ra t ions f o r a given load were c a l c u l a t e d w i t h i n . .

about 35 percent f o r Lake Ontar io, al though absolute d i f f e rences were o n l y 1

o r 2 pg/L. For t he above, t he responses may be i n t e r p r e t e d as being

comparable. Calcu lated c h l o r o p h y l l responses i n Lake E r i e are a no tab le

except ion, i n t ha t , w h i l e i n agreement on phosphorus leve ls , the models d i f f e r

r a d i c a l l y i n t he c h l o r o p h y l l l e v e l s p red ic ted .

If, on the o the r hand, a s p e c i f i c concentrat ion i s adopted as a des i red

l eve l , t h e d i f ference i n i n p u t ioads ca l cu la ted by d i f f e r e n t models t o achieve

i t i s greater . or example, loads de f ined by the models t o achieve a s p e c i f i c

phosphorus concent ra t ion i n Lake Ontar io d i f f e r by about 30 percent; f o r lower

concent ra t ions i n Lake Er ie , ca l cu la ted loads d i f f e r by more than 50 percent.

4.3.2 Percent E r r o r Between Computed and 9bserved Values

I n t he determinat ion of load response re la t i onsh ips , t he models were used

t o p r o j e c t t o cond i t i ons beyond those f o r which they were formulated and

ca l i b ra ted . The quest ion regard ing the v a l i d i t y o f such an e x t r a p o l a t i o n

which immediately a r i ses i s : What i s the accuracy o f such p r o j e c t i o n s ?

Although no accepted methodology i s p r e s e n t l y a v a i l a b l e t o answer t h i s

quest ion, i t i s ev ident t h a t a q u a l i t a t i v e and v i s u a l comparison o f

computation and observat ion i s bas ic t o the degree o f acceptance o f the

v a l i d i t y o f t h e model. I n general, t he re was reasonable agreement between the

ca l cu la ted and observed values f o r each o f t he models.

A more q u a n t i t a t i v e measure o f t h e d i f f e r e n c e between the computed and

observed values o f t he var ious cons t i t uen ts has been determined by s t a t i s t i c a l

ana lys is o f t he r e s i d u a l e r ro rs , as descr ibed above. The median percent e r r o r

f o r Lake Ontar io ranged f rom 26 percent t o 41 percent, w i t h an average ~f 22

percent f o r a l l var iab les . The median percent e r r o r f o r t h e d isso lved oxygen

i n t h e Centra l Basin o f Lake E r i e i s i n t he range 5 t o 15 percent. A l low ing

f o r t h e f a c t t h a t 50 percent o f t he sediment oxygen demand was assigned would

j u s t i f y inc reas ing t h i s value, say i n t he order o f 20 percent.

The e f f e c t on t h e t a r g e t loads may be assessed i n an approximate manner by

use of t he above. Although the c a l i b r a t i o n e r r o r i s n o t equ iva len t t o the

p r e d i c t i o n e r ro r , i t may be used t o assign some measure o f r e l i a n c e t o the

loading. Assuming t h a t t h e c a l i b r a t i o n e r r o r c a r r i e s through t o comparable

e r r o r i n load ing and t h a t there i s a l i n e a r r e l a t i o n between load ing and

concentrat ion ( b o t h o f which assumptions are r a t h e r tenuous), t h e range i n

t a r g e t loads would be about 20 o r 25 percent.

The percent e r r o r i n t h e Lake Ontar io model appears t o have an annual

consistency: t h e model t y p i c a l l y undercalculates the sp r ing bloom, u s u a l l y

overca lcu la tes t h e summer mix, and occas iona l l y misses the f a l l bloom. The

l a r g e s t component o f t he e r ro r , however, l i e s i n the sp r ing bloom.

Furthermore, a regression ana lys is o f t h e observed and ca l cu la ted values

indic 'ated t h a t t he rev i sed k i n e t i c s did, i n f a c t , improve the f i t bu t produce

no s i g n i f i c a n t change -in t h e i n t e r c e p t o r res idua l e r r o r s as measured by the

square o f t he c o r r e l a t i o n c o e f f i c i e n t . 5 6 There appears t o be a systematic

b ias i n t h e model, which undercalculates t h e ch lo rophy l l f o r lower

concentrat ions and overca lcu la tes f o r h igher l eve l s . A1 though i t i s d i f f i c u l t

t o r e l a t e these s t a t i s t i c s t o t h e p r e d i c t i o n e r r o r o f loading, i t may be

concluded t h a t there i s some e f f e c t and f o r present purposes, these

observat ions are o f f e r e d as a f u r t h e r bas is f o r viewing the t a r g e t loads

w i t h i n the 25 percent range as i nd i ca ted above.

While t h e Lake E r i e ana lys is has a lesser r e s i d u a l e r ro r , t he assignment

o f 50 percent o f the benthal demand should be an add i t i ve ' f a c t o r i n t he

s p e c i f i c a t i o n o f t he range of t a r g e t loads. It i s p e r t i n e n t t o no te t h a t t he

p ro jec t i ons tend t o be on the conservat ive s ide i n each case.

4 .3 .3 Issues Not Addressed by the Models

The issues discussed i n t h i s sec t ion r e l a t e t o f a c t o r s which were n o t

inc luded i n t h e models and about which o n l y meager q u a l i t a t i v e conclusions can

be drawn from the present analys is . The p r i n c i p a l unaddressed issues r e l a t e

t o t h e d i s t i n c t i o n between t h e l i t t o r a l and pe lag i c zones o f t h e lakes and t o

the de l i nea t i on o f phytoplankton species, some o f which are considered

b e n e f i c i a l o r des i rab le and others not . It i s be l ieved t h a t these issues are

o f s u f f i c i e n t fundamental s i g n i f i c a n c e and of s u f f i c i e n t p r a c t i c a l value t o

warrant some discussion.

The f i r s t issue concerns the l i t t o r a l and pe lag i c zones. A l l o f the ava i l a b l e models are s t r u c t u r e d t o analyze p r i m a r i l y the pe lag i c segments o f

t he lakes, o r a t leas t , an o v e r a l l average of lake cond i t ions . None o f them

d i r e c t l y address water q u a l i t y cond i t i ons i n t h e l i t t o r a l areas. The

p r a c t i c a l importance of t h i s issue i s ev ident s ince the p u b l i c response i s

most i n f l uenced by t h e c o n d i t i o n s i n these areas. Furthermore, these areas

are gene ra l l y charac ter ized by d i f f e r e n t environmental condi t ions, w i t h

respec t t o such va r i ab les as l i g h t , c i r c u l a t i o n , and n u t r i e n t concentrat ions.

It i s l i k e l y they e x h i b i t d i f f e r e n t species con~pos i t ion and responses. I n

general, l i t t o r a l areas respond more q u i c k l y t o p o l l u t i o n stresses, bu t by t he

same token, w i l l improve more r a p i d l y due t o c o n t r o l and reduc t ion o f n u t r i e n t

discharges. It i s recognized t h a t these areas are n o t as amenable t o modeling

as are t h e c e n t r a l zones, p r i m a r i l y because o f the hydrodynamic t r a n s p o r t

w i t h i n t h e l i t t o r a l zone and because o f t he exchange w i t h t he pe lag i c zone.

Both of these fea tu res w i l l be unique t o each l i t t o r a l area examined. How

these areas respond t o n u t r i e n t c o n t r o l remains t o be seen. One cou ld

a n t i c i p a t e t h a t improvements would be more q u i c k l y f e l t w i t h a commensurate

p u b l i c response. It i s p e r t i n e n t t o no te t h a t present research a c t i v i t i e s a re

d i r e c t e d t o an ana lys is o f a more f i n e l y segmented lake, i n which both the

l i t t o r a l and pe lag i c zones are ca lcu la ted .

The second issue concerns the d i f f e r e n t i a t i o n o f species. It i s a mat te r

of r eco rd t h a t seasonal successib;l o f species occurs t o some extent , and more

important, t h a t long term eco log i ca l changes have occurred over the pas t few

decades. A s i m i l a r phenomenon has been observed i n es tua r i es subjected t o

inc reas ing discharges o f munic ipa l and i n d u s t r i a l discharges, as was repo r ted

f o r t h e Potomac Estuary. The s t a t e o f t he a r t o f eu t roph i ca t i on modeling has

n o t y e t developed t o the degree which permi ts adequate d e f i n i t i o n o f t h i s

phenomenon. The models which were used f o r t he t a r g e t loads f o r Lake On ta r i o

and E r i e incorpora ted two species, diatoms and "others", i n t he seasonal

analysis'. The long term t r a n s i t i o n s are y e t t o be addressed i n t he modeling

framework. These issues are r a i s e d n o t t o r e f u t e the bas ic v a l i d i t y and

u t i l i t y o f t h e present models, b u t t o o f f e r a perspec t ive f rom which t o view

the proposed l e v e l s f o r the t a r g e t loads.

4.4 SUMMARY - . , . . . I.. . . . . . . . . . .

. , .

,% .

Based on the analysis presented above, i t i s appropriate to interpret the target loads as a range within a specified percent of the values which are presently proposed. The principle of establishing a range rests on the uncertainties of our abi 1 i t y to reproduce mathematical ly biological phenomena.

. .

The models were then used' to project phosphorus and chlorophyll responses to' reduced' nutrient inputs. In general, there was agreement between and among

. . the responses of the four models for various projections of phosphorus

'loading. The differences in the allowable loads predicted by the various , '.

model's for a given' water quality objective had .a range of about 25 percent depending on the model selected. 'I! this sense, the target load may be interpreted as having a comparable range. hi's i s predicated on the assumption that the loads used' for validating the models were identical. If there were differences, such would & reflected in an increased range of uncertainty in the target loads.

The quantitative specification of the range i s based primari ly on three factors: (1) the s ta t is t ical analysis of the residual errors between observed and computed values, ( 2 ) the differences in target loads projected by the various models, and (3 ) the elements which were not included in the models, b u t which may have an effect on the target loads. Given the evaluation of the models, presented in this report, a range of plus or minus 30 percent i s suggested for the target load of 11,000 t/yr for Lake Erie and plus or minus 20 percent for the 7,000 t /y r , target load for Lake ,Ontario.

, I

. .

The concept of interpreting the target loads as a range i s one of the bases upon which the task force has developed i t s proposed phosphorus management strategies. As discussed in subsequent sections, a principal feature of the various strategies i s a staged approach. This approach permits assessment of the control achieved in each stage on water quality and, equally important, the opportunity t o refine the models t o minimize the range and t o provide a more reliable basis for establishing future controls.

COSTS AND TECHNOLOGIES OF PHOSPHORUS CONTROL

A v a r i e t y of t reatment technologies are ava i l ab le t o c o n t r o l both p o i n t

and nonpoint source i npu ts of t o t a l phosphorus. I n add i t ion , t he re are severa l non -s t ruc tu ra l opt ions, such as r e s t r i c t i n g the phosphorus content o f

detergents and r e g u l a t i n g f e r t i 1 i z e r app l i ca t i on , which can be used t o reduce

the amounts o f phosphorus which cou ld en te r the lakes as a r e s u l t o f man's

a c t i v i t i e s . Th is chapter prov ides an overview o f both t he s t r u c t u r a l and

non -s t ruc tu ra l op t ions and some perspec t ive on the r e l a t i v e cos ts o f

implementing d i f f e r e n t c o n t r o l opt ions.

5.1 PHOSPHORUS MANAGEMENT FOR POINT SOURCES

A major component of t he t o t a l phosphorus i n p u t s t o t he lakes i s domestic

wastewater, o f which 20 t o 35 percent may be der ived from phosphate based

detergents. E f f o r t s t o reduce the phosphorus content o f munic ipa l wastewater

discharged i n t he Great Lakes basin began i n the l a t e 1960's and e a r l y

1970's. Both phosphate detergent c o n t r o l s and a d d i t i o n a l t reatment a t

munic ipa l wastewater t reatment p l a n t s were p a r t o f t h i s e f f o r t .

Considerable resources have been devoted t o t he 'development and

app l i ca t i on o f cos t e f f e c t i v e technologies f o r meeting the 1973 and 1975

dead1 ines f o r phosphorus c o n t r o l a t munic ipa l wastewater t reatment p l a n t s i n

t h e lower Great Lakes basin. Faced w i t h a l a rge number o f e x i s t i n g t reatment

f a c i 1 i t i e s , e f f o r t s were concentrated on i n t e g r a t i n g chemical p r e c i p i t a t i o n

i n t o these f a c i l i t i e s . Today, chemical p r e c i p i t a t i o n i s the most w ide ly used

method f o r reducing t h e t o t a l phosphorus concent ra t ion i n munic ipa l e f f l u e n t s

t o below 1 mg/L.

O f t he niunicipal t reatment p l a n t s i n the Great Lakes basin us ing chemical

p r e c i p i t a t i o n f o r phosphorus removal about h a l f are us ing aluminum s a l t s and

h a l f use i r o n s a l t s and a few use l ime.54 Low cos t a l t e r n a t i v e p r e c i p i t a n t s

such as waste p i c k l e l i q u o r and "red mud" have a l so been s tud ied as have

var ious combinations o f chemicals and polymers. As a r e s u l t , waste p i c k l e

1 i quo r now has widespread acceptance where p l a n t processes permi t .

I n t he search fo r cos t e f f e c t i v e a l t e r n a t i v e s capable o f producing t o t a l

phosphorus e f f l uen t concent ra t ions i n t h e 0.1 mg/L t o 1 mg/L range, o ther

t reatment p rac t i ces , such as land a p p l i ~ a t i o n ' ~ and m o d i f i c a t i o n o f t he

a c t i v a t e d sludge process t o promote l uxu ry b i o l o g i c a l uptake6' o f phosphorus

have rece i ved more c r i t i c a l a t t e n t i o n i n recen t years.

Another a l t e r n a t i v e i n phosphorus management cons i s t s o f reduc ing the

t o t a l phosphorus conten t i n household detergents and s u b s t i t u t i n g i t w i t h

o the r b u i l d e r ma te r i a l s .

Chemical Phosphorus Removal

Chemicals which are used i n phosphorus removal inc lude f e r r o u s and f e r r i c

c h l o r i d e and sulphate sa l t s , alum and lime.63'6"hey are sometimes

used i n cornbination o r through separate i n j e c t i o n a t d i f f e r e n t p o i n t s i n t h e

t reatment process, and have been coupled w i t h polymers t o improve

c l a r i f i c a t i o n .

Alum o r f e r r i c s a l t s can be added ahead o f p r imary treatment, i n t o t he

ae ra t i on basin o r i n t h e ae ra t i on basin e f f l u e n t channel, prov ided adequate

m ix ing i s ava i lab le . Ferrous sa l t s , which are a v a i l a b l e as waste p i c k l e

l i q u o r , r e q u i r e conversion t o t h e f e r r i c form before p r e c i p i t a t i n g phosphorus

and gene ra l l y are n o t e f f e c t i v e when added t o pr imary c l a r i f i e r s . Although

p i c k l e l i q u o r i s e f f e c t i v e when added t o t h e aera t ion sec t i on o f a c t i v a t e d

sludge p l a n t s and i s low i n cost, i t has a number o f drawbacks. P i c k l e l i q u o r

v a r i e s i n q u a l i t y , u t i l i z e s oxygen, depresses t h e pH of wastewater,

c o n t r i b u t e s heavy meta ls and conta ins suspended m a t e r i a l which can p lug

chemical pumps and feed l ines .

It has been demonstrated t h a t phosphorus removal t o 1 mg/L can be

c o n s i s t e n t l y achieved through chemical p r e c i p i t a t i o n i n convent ional and

mod i f i ed a c t i v a t e d sludge p lan ts . I nc reas ing chemical dosage i n w e l l operated

and h y d r a u l i c a l l y underloaded p l a n t s has been repo r ted t o a t t a i n t o t a l

phosphorus e f f l uen t l e v e l s i n t he range o f 0.5 mg/L.'" However, i n o rder t o

achieve e f f l uen t phosphorus concent ra t ions below 0.5 mg/L c o n s i s t e n t l y a t most

a c t i v a t e d sludge p l a n t s i t would be necessary t o prov ide a d d i t i o n a l f i n a l

c l a r i f i e r capac i t y o r e f f l u e n t f i l t r a t i o n , and increase coagulant dosages and

p o s s i b l y add polymers.

A v a r i e t y of proven process technologies us iog l ime f o r phosphorus removal

e x i s t . E f f l u e n t t o t a l phosphorus concentrat ions as low as 0.05 mg/L have been . .

repor ted. 6 5 . .

The e f f i c i ency o f phosphorus removal depends on many fac to rs . Three o f

t he most important are t he degree of m ix ing of t he chemical w i t h t h e

wastewater, t h e p o i n t of chemical i n j e c t i o n , and the a b i l i t y o f the process t o

remove suspended s o l ids. Sign i f i c a n t reduc t ions i n t he chemical dosages

requ i red have been poss ib le through increasi1:g the i n t e n s i t y o f m ix ing a t the

p o i n t of chemical i n j e c t i o n and by r e l o c a t i n g t h e p o i n t o f a d d i t i o n f rom t h e

raw sewage condu i t t o the ae ra t i on basin o r secondary c l a r i f i e r i n l e t . 6 1

Ef f luent phosphorus l e v e l s l e s s than 1 mg/L are c o n s i s t e n t l y achieved w i t h

designed c l a r i f i e r over f low r a t e s o f less than 32.6 m/d (800 gpd/sq f t ) a t

peak f low. Corresponding e f f l u e n t suspended s o l i d s i n the range o f 15-20 mg/L

are obtained. Hydrau l i c load ing problems are most apparent i n pr imary p l a n t s

where h igh peak loads reduce phosphorus removal e f f i c i e n c i e s . Pr imary p l a n t s

meeting t h e 1 mg/L c r i t e r i a gene ra l l y have c l a r i f i e r s w i t h low overf low r a t e s

and are t r e a t i n g a sewage which i s compatible w i t h chemical t reatment.

Polymers are sometimes used t o a i d i n s o l i d s capture but, because of t h e i r

h igh cost, are considered t o be o n l y a temporary s o l u t i o n f o r o f f s e t t i n g

excessive h y d r a u l i c loadings.

High l e v e l s o f t o t a l phosphorus removal, through chemical add i t ion , have.

a1 so been achieved a t a1 1 ' types o f munic ipa l wastewater t reatment lagoons.

While l ime has n o t been found t o be e f f e c t ' i v e i n achiev ing 1 mg/L when added

t o e i t h e r con t inuous ly o r seasonal ly d ischarg ing lagoons, bo th alum and f e r r i c

c h l o r i d e are Continuous chemical a d d i t i o n can produce

. e f f l u e n t phosphorus l e v e l s i n t h e range o f 1 mg/L w i t h e f f l u e n t BOD and

suspended s o l i d s a t l e v e l s o f about 30 mg/L. On the o ther hand, batch

t reatment o f storage lagoon contents can produce an e f f l u e n t w i t h l ess than 10

mg/L BOD, 20 mg/L s ~ s ~ e n d e d ' s o l i d ; and 0.5 mg/L t o t a l phosphorus prov ided the

e f f l u e n t i s discharged w i t h i n 10-12 days a f t e r t reatment. Cap i ta l cos ts f o r

batch dosage are minimal compared t o cont inuous chemical dosage which r e q u i r e s

chemical s torage and feed equipment. Manpower costs are minimal i n bo th cases

and chemical dosages are s i m i l a r t o those requ i red f o r t reatment i n a c t i v a t e d

sludge p lan ts .

.5.1.2 B i o l o g i c a l and Bio logica l /Chemical Processes

B i o l o g i c a l removal o f phosphorus, w i t h o u t chemical t reatment, t o . l e v e l s . . . .

b e i i w l 'mg /L have a l so been repo r ted i n p i - i o t . s t ~ d i e s . ' ~ " ~ . , ~ h & e , , ,, . . . . . . . ,

processes . operate . . . .. on t h e p r i n c i p l e t h p t . . removal, ' takes p lace through wastage of p h d s p h ~ i u s ~ i c h . sludge. . . anaerobic basin , i s . h t i l i ' z e d ahead o f the ae ra t i on

tanks . , . 'wh&bkin .. t h e 's ludge becomes phosphoCus d e f i c i e n t ' f o l lowing which, i n an . . . . I

, . aerobic"environment, l u x u r y uptake o f 'phosphorus occurs. The sludge must be

. ( 1

dewatered r a p i d l y t o prevent t he ' re lease o f the phosphorus. Advantages . . over .

convent idna l che'micai p r e c i p i t a t i o n i nc lude : l e s i sludge, no chemicals, an,d . .

s i g n i f i c a n t l y . . l o w e r bpe ra t i ng costs. ~owevb i , t he b i o l o g i c a l system mey . .. . .

r e q i i ' r e more . . c a r e f u l ' ope ra t i ona l . con t ro l . . ~ u r t h e r eva lua t ion i s needed t o ', . . . . . . . ,

v e r i f y . p r o c k s s r e l i , d b i l i t y , . . . . . . i n c o l d c l imates. T h e p o t e n t i a t l l y s i g n i f i c a n t cos t

advantages . . , of b i o l o g i c i l . phosphorus remova l , 1 uxury uptake, m e r i t rap i 'd and

d l l i g e h t . . assessment o f . t he process r ' e l i a b i 1 i t y f o r ~ r e d t ~ a k e s . . a p p l i ca t ions . , ,

~ e c e n ' t technology employing a combination o f b i o l o g i c a l and chemical

processes has a l s o been success fu l l y demonstrated. 7 0 One example i s the

PhoStr ip process71 which i nvo l ves phosphorus uptake by mircroorganisms i n an

a c t i v a t e d sludge ae ra t i on basin, w i t h subsequent phosphorus concent ra t ion and

re lease i n the supernatant o f an anaerobic s t r i p p e r tank. When coupled w i t h

l ime t reatment o f t h e supernatant, t h e re leased phosphorus can be success fu l l y

p r e c i p i t a t e d and removed, w i t h t he phosphorus d e f i c i e n t sludge being re tu rned

t o t h e ae ra t i on sec t ion . Advantages of t h e PhoStr ip process over convent ional

chemical p r e c i p i t a t i o n inc lude lower chemical usage, lower sludge produc t ion

and, through o f f - 1 i n e sludge storage, p r o t e c t i o n o f t h e a c t i v a t e d sludge

process against shock loads. E f f l u e n t phosphorus l e v e l s o f l ess than 1 mg/L

are repo r ted a t cos ts which are about 35 percent lower than those repo r ted f o r

convent ional chemical p r e c i p i t a t i o n . " 1t would appear t h a t a t p l a n t s izes

greater t h a n about 20,000 cu m/d ( 5 MGD) the economies of this process become advantageous over conventional technology. 7 2

5.1.3 Land Application for Phosphorus Removal

Land application has been utilized as a method of wastewater treatment and

management for many decades. In the nineteenth century, i t became relatively common for municipalities t o use this process t o dispose of their wastes. As urban expansion encroached upon available land and technological interests turned t o sewage treatment plants, other approaches replaced many land

application systems. There has been a renewed interest in this form of

wastewater treatment with over 600 municipalities in the United States currently using land applicat i t 1 1 1 systems. The majority of these are crop irrigation systems located in western states. In Canada, only a limited number of municipalities treat wastewaters by l a n d application methods. The report on "Land Treatment of Municipal Wastewaters in the Great Lakes basin"73 summarizes the use of land treatment in the Great Lakes basin and

the potential of land treatment t o remove contaminants entering the Great Lakes and their tributaries.

Land treatment of municipal wastewater invol.ves the use of plants and soil t o remove many wastewater constituents. The three principal land treatment processes are known as slow rate, rapid infiltration, and overland flow. In the slow rate process the wastewater t o be treated i s applied t o the land by

flooding or spray irrigation. The wastewater is treated as i t flows through the soil matrix and a portion of the flow percolates t o groundwater. Crop irrigation is an integral part of this system.

In rapid infiltration, the wastewater is applied a t a high rate, and most of the applied wastewater percolates through the soil with the treated effluent eventually reaching the groundwater or collecting in under drains. The wastewater is applied t o highly permeable soils, such as sands or loamy

sands, and crops are not usually used. In overland flow land treatment, wastewater is applied over the upper reaches of sloped terraces and allowed t o flow across the vegetated surface t o runoff collection. ditches. The waste-

water i s t r e a t e d by physical , chemical and b i o l o g i c a l means as i t flows, ,

through the e x i s t i n g vegeta t ion i n a t h i n f i l m down the r e l a t i v e l y impermeable

slope.

Slow r a t e systems are those most 'widely used. Table 5.1 summarizes the

phosphorus removals t h a t have occurred a t land a p p l i c a t i o n s i t e s . The

d i f f e rences noted i n t he c h a r a c t e r i s t i c s o f the renovated wastewater are due

t o t h e d i f f e r e n t reac t i ons t h a t OCCIJ*~ w i t h each type o f land treatment process.

. . . . .' . . , . . .

A t mqst r a p i d i n f i l t r a t i o n ' s i tes, t he . , does n o t reach $ur face

waters i n s izab le q u a n t i t i e s and genera l l y moves through loams and c lays

before en te r i ng a surface stream. 'Thus, ql though the groundwater a t the r a p i d . . '

i n f i l t r a t i b n s i . . t b s may cbnta in h isher . phosphorus , co"centrat ions than a t . $ l o w

r a t e s i t es , such groundwater may n o t be a major source o f phosphorus o f . . . .. .

streams o r lakes. " . . . .

, < . . . . !: ,. :

. . . . . . . . . .

~t o v e r l a n d f l o w s i tes , .. t h e . s o i .. 1 i s : o n l y s l i g h t l y and a n y ,

treatment occurs , by ... r eac t i ons a t the s o i l surface. A la rge p o r t i o n o f t h e , . .

TABLE 5.1 PHOSPHORUS REMOVAL BY LAND TREATMENT SYSTEMS" . . . .

*Analyses of. samples,,of groundwater .under the site,, groundwater a t t he s i t e boundary, o r r u n o f f ' f rom an over land 'f 1 ow system.

. . . % I ' . .

. .,

To ta l 'Ph'osphor'us Appl ied

Wastewater . .

. , . 4.8-15.8 . .

> .

1-12.4

. . , . 5-15 . . . ,

. .

. . . .

., . Type

Slow rat.e . . .

. . ., , .

Concentrat ion (mg/L) Renovated : .

Wastewater*

0.04-0,. 5 . . .

0.02-5.6 . .

,. . 1-10

. .

. Range o f ' '

System Sizes; ( 1,000 cu m/d)

. .

.. 08-213.

. .

Rapid i n f i l t r a t i o n 1-49

. . . . . . . , .. '

Over , !and f !.ow

. . . .

. .

. % 16-27.4 . .

' . .

app l i ed wastewater i s c o l l e c t e d as t r e a t e d r u n o f f a t t he bottom o f t he

over land f low s lope f o r e i t h e r r e a p p l i c a t i o n o r discharge. Since t h e

wastewater f low i s on the s o i l surface, wastewater con tac t w i t h t he s o i l i s

l e s s than f o r slow r a t e and r a p i d i n f i l t r a t i o n systems, and phosphorus removal

i s l ess w i t h over land f low systems. Chemical a d d i t i o n t o t he wastewater

before appl i c a t i o n can enhance t h e phosphorus removal a t over land f l o w s i t e s .

The renovated wastewater from w e l l designed, operated, and managed slow

r a t e o r r a p i d i n f i 1 t r a t i o n s i t e s perco la tes t o groundwater r a t h e r than

discharged t o a stream. Where these processes can be used, t he phosphorus

load ing o f sur face waters such as t h e Great Lakes i s less than would occur

w i t h o the r p o i n t source phosphorus c o n t r o l a1 t e r n a t i ves.

Land t reatment systems represent a v i a b l e a l t e r n a t i v e f o r phosphorus

c o n t r o l where s i t e spec i f i c cond i t ions , such as s o i l c h a r a c t e r i s t i c s , geology,

a v a i l a b l e area, s u i t a b l e crops, and t ransmiss ion cos ts make t h i s process

compet i t i ve w i t h o the r wastewater t reatment a l t e r n a t i v e s .

I n a d d i t i o n t o phosphorus removal, land t reatment can have a d d i t i o n a l

b e n e f i t s such as: ( a ) reduced sludge product ion f o r hand1 ing, t reatment, and

u l t i m a t e d isposal ; ( b ) r e c y c l e o f n u t r i e n t s and organics t o t h e s o i l - c r o p

system; and ( c ) removal o f t o x i c and o ther contaminants. However, some

disadvantages may a l so occur such as: a) acc i~mulat ion o f metals, t o x i c

organic substances, and o ther contaminants i n t he s o i l ; and b) poss ib le

contaminat ion o f groundwater w i t h low molecular weight organic substances.

5.1.4 Costs f o r Munic ipa l Po in t Source Cont ro ls

Costs o f phosphorus removal t o achieve e f f l uen t l e v e l s on t h e order o f 1.0

mg/L through chemical p r e c i p i t a t i o n i n p r imary and secondary p l a n t s va r i es

w i t h p l a n t s i z e and d is tance f rom t h e source o f chemicals. To ta l c a p i t a l and

annual opera t ing cos ts (1975 d o l l a r s ) f o r a t y p i c a l 4,500 cu m/d p l a n t are

est imated a t $14,000 and $1,600 respec t i ve l y , exc lus i ve of chemical

S im i l a r l y , t o t a l c a p i t a l and annual opera t ing cos ts f o r a t y p i c a l

45,000 cu m/d p l a n t are est imated a t $52,000 and $5,400 respec t i ve l y . The

average chemical cos t i s given as $5 per 1,000 cu m o f sewage t reated, a f a c t , . . .

which i s meaningful o n l y i n the broadest sense o f cos t comparisons. 6 ' 4

No l e v e l o f munic ipal p o i n t source c o n t r o l alone i s l i k e l y t o achieve the

'mean'target load est imates f o r Lake Er ie. If t h e mean t a r g e t load f o r Lake . .

E r i e i s met, t he t a r g e t load f o r Lake o n t a r l o could be met i f munic ipal . , . . .

discharges had an e f f luent concentrat ion o f - 0.15 m g / ~ t o t a l phosphorus.

An e f f l u e n t requirement of 0.5 mg/L- t o t a l phosphorus f o r munic ipal t reatment

f a c i l i t i e s w i t h f lows greater than 3,800 cu m/d ( 1 MGD) cou ld achieve 24

percent and 34 'percent o f t he l o a d reduct ions requ i red t o achieve the mean

t a r g e t loads fo r Lakes E r i e and Ontar io r e s p e c t i v e l y (see a l so Table 7.1).

This l e v e l o f a d d i t i o n a l munic ipal p o i n t source c o n t r o l would increase the

annual treatment costs f o r p l a n t s i n t h e LOW&- Great ~ a k e s basins by 92

percent from $38 m i l l i o n t o $73 m i l l i ~ n . ' ~

These cos t p r o j e c t i o n s are est imated w i t h a computer program based on the

uniform. a p p l i c a t i o n o f chemical add i t i on technology f o r t he 1.0 mg/L e f f l u e n t . . . .

l e v e l p l u s dual media f i l t r a t i o n f o r the 0.5 mg/L e f f l u e n t l e v e l . 'The ' u n i t

cos ts f o r these technologies were app l i ed t o t h e s i ze d i s t r i b u t i o n o f t he

e x i s t i n g munic ipal f a c i l i t i e s w i t h 'known o r est imated i n f l u e n t pho'sphorus . . . .

l eve ls . . The . cos t o f t h e in te rmed ia te technology i s based on doubl ing t h e . . . . . .

c l a r i f i e r capac i ty t h u s reducing the over f low r a t e from . 28.5 . t o 14.3 m/d (700

t o 350 & d / s q f t ) , add ing 10 percent more chemical and associated sludge

d isposal costs. ' It is 'ex t reme ly d i f f ' i c u l t t o make accurate cos t p r o j e c t i o n s

f o r p h o ~ p h 6 r ~ ~ .. . removal technologies because o f t he v a r i a t i o n . . i n p l a n t

performance associated w i t h a given c o n t r o l technology. This i s p a r t i c u l a r l y

t r u e w i t h the suggestion t o double the c l a r i f i e r capaci ty . Because of t he

economies of scale associated w i t h each technology i t i s ' poss ib le t o achieve

some l i m i t e d savings i n o v e r a l l cos ts by app ly ing d i f f e r e n t technologies t o I, . . I . .

d i f f e r e n t s izes o f p l a n t s t o achieve t h e lowest u n i t c o s t s f o r a given t o t a l . I

l o a d reduction. These ' p o t e n t i a l cos t savings are n o t expected t o be dramatic. . . . . .

3 .

. . . . .

. . .

I f the' . . . . a p p l i c a b i l i t y and r e 1 i a b i :. . . . 1 . it$ of proces{ 'modif i ca t i 'ons

, ; ' . . .

u t i l i z i n g b ib loc j i ca l ' l u~u ry uptake o f phosdhorus' are demonstrated, i t i s

poss ib le tha t .phosphbru i kemovbl to t h e 1.0 h b / ~ , l e v e l . c 8 n be , . achieved . a t ~. . , . , . . . I ( . . .

costs equivalent to those for conventional activated sludge treatment. The avai 1ab.i 1 ity of an essentially no cost option for reducing the phosphorus

content of municipal wastewater discharges to 1.0 mg/L would have a

significant impact on the overall phosphorus management strategies.

Land treatment of wastewater, where applicable, can provide excellent

phosphorus control 0.1 mg/L. This technology was not included in the cost estimates because reliable cost estimates are highly site specific and sparse.

Emerging technologies for municipal point source control, such as the

magnetic separator and adsorption contactor offer the promise of lower

phosphorus residuals and reduced 1 and area requirements. Development of these technologies, as well as the 3,ttainment of improved reliability and better

performance from current technologies, can contribute to the goal of

preserving Great Lakes water quality.

5.1.5 Phosphorus Detergent Controls

Phosphorus removal at n~unicipal wastewater treatment faci 1 i ties was

preceded in many areas of the Great Lakes basin by legislation to reduce the

phosphorus content of household laundry detergents. In the early to

mid-19701s, whi le institutional mechanisms were developed, most jurisdictions

in the United States and Canada implemented detergent phosphorus control s to

effect immediate reductions in municipal phosphorus inputs in the Great Lakes.

At the present time Canada limits the phosphate content of laundry

detergent to 2.2 percent as phosphorus measured by weight. In the United

States, all of the Great Lakes states except Ohio and Pennsylvania have

legislative controls 1 imi ting the phosphorus content of laundry detergents to

0.5 percent. The existing controls are generally less restrictive or exempt

formul ations for automatic dishwashers and certain commerci a1 and industri a1

uses. In those jurisdictions not covered by legislative controls, the soap

and detergent industry has reduced the phosphorus content of household laundry

detergent from about 11 percent to 5.5 percent thus providing some reduction

in detergent related phosphorus discharges in those areas.

. . . D i r e c t . < , * . and, , i n d i r e c t . municipal . phosp,horus: . d ischarges . i n , the Lake E r i e basin i n , O h i o a n d ~ennsy lvan ia , ,were est imated f o r 1978"to. be ',441 and 158 t / y r ,

. . . . ;. , respec t ' i ve ly . I n those areas hav ing . no c o n t r o l s i t i s est imated tha t ,

. .

de te rgent , phosphorus accounts . fo r 20 t o . 3 5 percent o f the phosphorus. i n , :

mun ic ipa l wastewater discharges. The detergent phosphorus c o n t r i b u t i o n t o

municip,al discharges ,may the re fo re be. es,t imated f o r . 0hi,o and. Pennsylvania t o

be 490 t o 850,and 30 t o 55 t / y r , , respec t i ve l y . . . . , . ,

, , . . . . , . ; . . . .

Phosphate, as t h e major p recon t ro l b u i l d e r i n detergents has th ree major

replacements; n i t r i l o t r i a c e t a t e (NTA), c i t r a t e , and carbonate. NTA i s , t h e . , . . . . p r imary b u i l d e r s u b s t i t u t e used .in Canada. .. There has been some, controversy

,. . and. concern i n terms of . t h e . h e a l t h and. environmental, effect.^ o f NTA. 'The, IJC,

through the Science Advisory Board, has evaluated s tud ies .address ing these . . .

concerns and concluded the e f f e c t s are Nevertheless,,.

because o f these concerns NTA was n o t used i n t h e Uni ted States and carbonates

have become t h e dominant replacement b u i l d e r . C i t r a t e s are n o t i n general

use. Recent ly t h e U.S. Environmental P ro tec t i on Agency, a f t e r rev iewing t h e

a v a i l a b l e in fo rmat i o n on the eco log i ca l . and human h e a l t h efficts of NTA a t

l e v e l s expected t o be re leased t o t h e environment f rom i t s use i n laundry

detergents, h a s announced t h a t i t "sees no reason t o take r e g u l a t o r y act ion.

aga ins t resumed produc t ion .and use" o f NTA. . , , ,,

Studies have been c a r r i e d out t o assess the impact o f replacement b u i l d e r s . .

on t h e phosphorus . , removal . . e f f i c i e n c i e s o f e x i s t i n g t reatment systems and t h e

environment. It i s gene ra l l y concluded t h a t t he re are no adverse long term

e f f e c t s . c,aused .by t h e t h r e e .major s u b s t i t u t e b u i l d e r s . on phosphorus removal e f f i c i e n c y . . o r . t he sur face water environment. ,

. . . . . . . , . . . . . .. .~ . .

, Comparative c o s t s associated w i t h .detergent phosphorus cont ro ls . and . ' . . . . . . . . .

wastewater t reatment are d i f f i c u l t t o determine because o f the range . of .

va r i ab les invo1,ved.. The Soap and Detergent Associat ion considers cos ts

associated . , w i t h . phosphorus c o n t r o l s t o inc lude addit i .ona1 wear. o n m a t e r i a l s

, . .and equipment .and addit iona.1 product use i n c l u d i n g supplemental c l ean ing a ids , . . , . . . . , . .

.and f a b r i c , . softeners, used t o . , enhance c lean ing e f f i c i e n c y . Hardness . , o f l o c a l

water supp l ies i s a . major , . v a r i a b l e i m p a c t i n g these incremental : costs. . , 8 . .

P r o p r i e t a r y p r o t e c t i o n precludes an est imate o f . t h e d i r e c t costs t o the

i n d u s t r y f o r reformulat ion.

Determinat ion of the magnitude and impact o f t h e cos ts d i r e c t l y r e l a t e d t o

re formula t ion i s d i f f i c u l t because o f t h e many sub jec t i ve consumer judgements

t h a t must be made. D i r e c t comparison t o the incremental cos t increases i n

detergent phosphorus removal a t wastewater treatment f a c i l i t i e s i s d i f f i c u l t

because o f inadequate accounting and recordkeeping. Recognizing these shor t -

comings, t h e Soap and Detergent Associat ion est imates t h a t t he annual cos t per

f a m i l y f o r carbonate detergents i s $13 t o $62 i n 1978 d o l l a r s . The range i s a

f u n c t i o n o f veh i c le water hardness, b u t has a median value of about $29. Use o f NTA and 2.2 percent phosphorus has made the economic impact of detergent

re fo rmula t ions on the Canadian corlsumers very z r i~a l l . Estimates of t h e annual

cos t o f removing detergent associated phosphorus t o a l e v e l o f 1.0 mg/L by

waste treatment range from $2 t o $20 per f a m i l y (1978 d o l l a r s ) depending upon

the assumptions used i n the analys is .

Detergent con t ro l s t h a t are no t i n p lace have accrued b e n e f i t s f o r which

economic values have not been assigned. Cont ro ls p rov ide a measure of

treatment f o r those f a c i l i t i e s under 3,800 cu m/d ( 1 MGD) t h a t have no

phosphorus e f f 1 uent 1 i m i t s , f o r communities with. combined sewer o v e r f 1 ows and

f o r unsewered areas. Cont ro ls p rov ide some p r o t e c t ion from increased

phosphorus discharges caused by c o l l e c t i o n system and treatment p l a n t

malfunct ions. I n addi t ion, a reduc t ion i n requ i red treatment prov ides energy

and chemical savings and reduces t h e volume o f sludge r e q u i r i n g u l t i m a t e

d isposal .

It i s general l y be1 i eved t h a t detergent phosphorus c o n t r o l s have he1 ped

reduce t h e r a t e of eu t roph ica t i on o f t he Great Lakes. While the re i s some

quest ion as t o the e f f i c a c y o f t h i s c o n t r o l s t rategy, i t i s suggested t h a t

extension of c o n t r o l s t o uncon t ro l l ed areas should have a p o s i t i v e e f f e c t on

t h e Great Lakes wh i l e munic ipal wastewater treatment f a c i l i t i e s are being

brought i n t o compliance w i t h phosphorus reduct ion requirements.

While there are b e n e f i t s t o detergent phosphorus cont ro ls , t he re are

c l e a r l y costs. , Unfor tunate ly the costs.are n o t we l l de f ined so , t h a t . a n : -. " . . , . . . accurate cos t -benef i t ana lys is i s n o t possib le. . ,

Summary , ' , .

A v a r i e t y o f proven treatment and management opt ions are ava i l ab le t o

reduce the phosphorus content of munic ipal wastewaters. The major opt ions are

compared i n Table 5.2 w i t h respect t o e f f l u e n t q u a l i t y t o t a l phosphorus and,

r e l a t i v e costs. The most c o s t - e f f e c t i v e op t ion f o r a given m u n i c i p a l i t y can

on l y be es tab l ished on a s i t e - s p e c i f i c basis consider ing such f a c t o r s as

e x i s t i n g f a c i l i t i e s , f i n a l e f f l u e n t requirements, loca t ion , a v a i l a b i l i t y and

cos ts o f chemicals, and sludge .d isposal . . . . . ' . . . .

5.2 MANAGEMENT . . OF NONPOINT SOLIRCES . . OF PHOSPHORUS . .

I n t e r e s t i n nonpoint sources of phosphorus w i t h i n the Great Lakes basin

has been focused through f o u r major programs: the I n t e r n a t i o n a l Reference

Group on Great Lakes P o l l u t i o n from Land Use A c t i v i t i e s (PLUARG) 3; the

Llni t e d States Federal Water P o l l u t i o n Contro l Act Amendments o f 1972,

PL92-500, p a r t i c u l a r l y Sect ion 108 on " P o l l u t i o n Contro l i n t he Great Lakes"

i nc lud ing the L1.S. Army Corps o f Engineers, Lake E r i e Wastewater Management

Study46 and Sect ion 208 "Areawi de Waste Treatment Management" ; and i n

Ontario, r i v e r basin s tud ies such as the Thames R iver Implementation S t ~ d y . ~ '

Each of these programs represent an experrd i t u r e o f considerable resources

on a v a r i e t y o f s tud ies and has r e s u l t e d i n the c o l l e c t i o n o f a subs tan t i a l

data base on the sources o f nonpoint p o l l u t i o n . However, what has been

l ack ing i n most o f t he studies w i t h the except ion o f the PL92-500 Sect ion 108

study on Black Creek i n A l l en County, Ohio7' and the Sect ion 108 Red Clay

p r o j e c t on Lake ~ u p e r i o r , ~ ~ has been a r i go rous assessment of the

e f fec t iveness o f nonpoint remedial measur,es i n reducing the movement of

phosphorus t o the Great Lakes. Work has begun i n the , Lake . E r i e Wastewater

Management Study t o eva,l uate the e f fec t iveness o f conservat ion t i 1 lage

p rac t i ces on phosphorus bu t t h i s work i s i n i t s e a r l y stages and

d e f i n i t i v e r e s u l t s are n o t y e t ava i lab le . E f f o r t s are a.lso underway . i n t he , .

TABLE 5.2 MUNICIPAL POINT SOURCE TREATMENT OPTIONS

Note: Care must be taken i n comparing cos ts f o r va r ious t reatment op t ions . Of ten phosphorus removal can be in tegra ted i n t o e x i s t i n g f a c i l i t i e s . Costs o f abandoning e x i s t i n g f a c i l i t i e s must be considered where t h i s op t ion i s proposed. N/A - Not Appl icable.

Process E f f l u e n t u u a l i t y T o t a l Phosphorus

(mg/L) Incremental Costs

A-S/Chemical A c t i v a t e d Sludge

plus

alum o r f e r r i c c h l o r i d e , f e r r o u s s a l t s

o r l ime

plus polymer

Physical/Chemical

Pr imary

plus alum o r f e r r i c c h l o r i d e , f e r r o u s s a l t s ,

o r l ime

plus

polymer

AWT/Chemical Advanced Waste Treatment ( AWT)

plus alum o r f e r r i c ch lo r ide . f e r r o u s s a l t s o r l ime

Lagoons/Chemical Aerated o r

F a c u l t a t i v e

plus alum o r f e r r i c ch lo r ide .

f e r r o u s s a l t s . o r l ime

B i o l o g i c a l Bardenpho A/O Process

Bio logical /Chemical PhoStr ip

Land A p p l i c a t i o n Slow Rate

Rapid I n f i l t r a t i o n Overland Flow

Comments

(A-S)

0.6-1.0 0.6-1.0

1.0

1.0 N/A

1.0

0.3-0.5 N/A

0.3-0.5

0.5-1.0

N/A 1-0

1.0 1.0

0.5

0.04-0.5

0.02-6 1-10

1

I

C a p i t a l - $3.500 per 1000 cu m/d capac i t y .

Chemicals - $5 p e r 1000 cu m t rea ted .

0 & M - $80/yr p e r 1000 cu m/d capaci ty .

These waste s a l t s are low cost .

Expensive f o r con- t i nuous use.

S i m i l a r t o A-SIChemical. N/A

S i m i l a r t o A-S/Chemical.

Expensive f o r con- t i nuous use.

N/A

N/ A N/A --

Expected t o be s i g n i f i c a n t l y lower than A-S/Chemi c a l and cou ld be equ iva len t t o con-1 A-5 alone.

34-37 percent lower than A:S/Chemical.

Compet i t ive w i t h A-S/ Chemical.

I) In ,, N/A

Peak f l o w c l a r i f i e r over f low r a t e 32.6 m/d (800 gpd/sq f t ) essen t ia l .

F e r r i c conversion i n aera t ion sec t ion . Poor q u a l i t y can cause problems.

Used i n p r imary sect ion only . L i m i t i n q pH l e v e l s may make i t d i f f i c u l t t o achieve 1.0 mq/L.

Temporary s o l u t i o n t o p e r i o d i c h y d r a u l i c over 1 oads.

Peak f l o w c l a r i f i e r over f low r a t e 32.6 m/d (800 gpd/sq f t ) e s s e n t i a l .

Cannot he used unless conver ted t o f e r r i c s a l t s .

E f f l u e n t needs pH adjustment. Lime feed ing i s d i f f i c u l t .

Temporary s o l u t i o n t o p e r i o d i c h y d r a u l i c overloads.

Using e f f l u e n t f i l t e r and chemical. N /A

Using upf low c h a r i f i e r and chemical. -

Continuous chemical feed produces a 1 mq/L e f f l u e n t . Batch dosage and seasonal d ischarqe q ives 0.5 mq/L.

N/A D i f f i c u l t t o handle.

A d d i t i o n a l development work requi red.

Lime t reatment o f waste sludge sidestream reduces chemical requirements and sludge product ion,

A p p l i c a b i l i t y dependent upon s o i l cond i t i ons . h e a l t h r i s k s , c o s t compet i t iveness and p u b l i c acceptance.

App l i cab le o n l y where impermeable so i 1s are ava i lab le .

Thames R ive r basin78 t o implement remedial measures, bu t t h i s a l so i s i n t h e

e a r l y stages o f implementation. . .

A1 1 o f these s t u d i e s . have concluded t h a t t h e phosphorus t ranspo r ted t o

surf ace waters f rom nonpoi n t sources i s predomi nant l y c a r r i e d i n assoc ia t i on

w i t h eroded sediment. This i s i n c o n t r a s t t o t h e phosphorus i n p o i n t source

discharges which conta ins more soluble, r e a d i l y a v a i l a b l e forms o f phosphorus.

5.2.1 Land Use A c t i v i t i e s o f Concern

There a re a number o f procedures a v a i l a b l e f o r rank ing t h e r e l a t i v e

phosphorus c o n t r i b u t i o n from i n d i v i d u a l land use a c t i v i t i e s . The most u s e f u l

means o f assessing c o n t r i b u t i o n s o f ghosphorus, :, UIII a remedial measure

perspect ive, i s t h e i d e n t i f i c a t i o n o f those land use a c t i v i t i e s which

c o n t r i b u t e t h e h ighes t loading per u n i t area o f land. It i s assumed t h a t

resources are b e t t e r invested i n t r e a t i n g those areas where t h e problem i s

most concentrated. A g r i c u l t u r a l and urban land use a c t i v i t i e s have been

i d e n t i f i e d as t h e most important c o n t r i b u t o r s o f phosphorus. Most u n i t

area loads o f t o t a l phosphorus range f rom 0.1-9.1 and 0.3 -2.1 kg/ha-yr f o r

a g r i c u l t u r a l and urban areas, respec t i ve l y . I n comparison, f o r e s t e d areas

gene ra l l y e x h i b i t u n i t area loads o f 0.02-0.67 kg/ha-yr .e2se3

Ag r i cu l t u re :

U n i t area loads o f phosphorus from a g r i c u l t u r a l areas inc rease w i t h t h e

p ropo r t i on o f c l a y i n t h e s o i l , t h e degree of slope, and t h e stream and

dra inage d i t c h network densi ty . Maximum sheet e ros ion i s a lso associated w i t h

areas where t h e r e has been a h igh p r o p o r t i o n of cont inuous c u l t i v a t i o n of row

crops, such as corn and beans. These crops p rov ide t h e l e a s t s o i l cover

du r i ng t h e growing season and a re t r a d i t i o n a l l y preceded by f a1 1 p lowing and

extensive seed bed prepara t ion which leaves t h e s o i l exposed t o e ros ion dur ing

t h e c r i t i c a l February-Apr i l snowmelt and sp r i ng r u n o f f per iod.

I n t h e PLUARG s t ~ d i e s ~ " ~ ~ ~ i t was est imated t h a t r u r a l sources o f

phosphorus occurred i n t h e f o l l o w i n g propor t ions : cropland - 70 percent;

l i v e s t o c k operat ions - 20 percent; streambank eros ion - 5 percent, and

unimproved a g r i c u l t u r a l ' land - 5 percent.

Urban :

Var ia t ions i n u n i t area loads from developed urban areas were found t o be

p r i m a r i l y a f u n c t i o n of t h e type of conveyance system (separate o r combined

sewers), popul a t i o n densi ty , occurrence o f medium and h igh dens i t y i n d u s t r i a l

a c t i v i t y , and t h e area of contiguous urban development. Developing urban

areas have been character ized as having t h e h ighes t u n i t area loadings o f

suspended s o l i d s due t o t h e o f t e n severe s o i l eros ion o f exposed s o i l s .

Although t h e range o f u n i t area loads from urban areas was comparable t o some

a g r i c u l t u r a l areas, t h e t o t a l area o f land i n urban uses i s on l y about 5

percent o f t h e t o t a l Great Lakes bas in area as compared t o 35 percent f o r

a g r i c u l t u r a l uses.

Phosphorus loadings from urban areas must no t be looked a t i n i s o l a t i o n ,

s ince t h e heavy metal loadings from these areas exceed t h e background l e v e l s

measured i n r u n o f f from a g r i c u l t u r a l areas. 'Thus, remedial programs

implemented i n urban areas could r e s u l t i n reduced metal as w e l l as phosphorus

loadings.

5.2.2 Charac te r i s t i cs o f Nonpoint Sources-Impl icat ions f o r Management

Despi te t h e r a t h e r l i m i t e d na ture o f t h e research completed t o date on

nonpoint sources, i t has become apparent t h a t t h e approaches t o p o i n t source

c o n t r o l are not s u i t e d t o t h e s o l u t i o n o f nonpoint problems. A number of

f a c t o r s have been i d e n t i f i e d w h i c h no t o n l y a f f e c t t h e k i n d of remedial

measures which 'can be considered, bu t a lso t h e means by which successsful

implementation c a n be achieved. ~ h e s e f a c t o r s are discussed below.

Annua 1

Great Lakes t r i b u t a r i e s serve as the p r i n c i p a l conveyance system fo r

5 9

t r a n s p o r t i n g phosphorus from nonpoi n t sources t o the 1 akes. Mon i to r ing o f phosphorus loads c a r r i e d by most t r i b u t a r i e s has, a t best, been inadequate and

thus our understanding o f phosphorus load ing v a r i a b i l i t y i s suspect.

Estimates of t r i b u t a r y phosphorus loads are based on simple a r i t hme t i c

r e 1 a t i ons h i ps between measured f l o w values and concent ra t ion data. Measured

f lows o f Great Lakes t r i b u t a r i e s genera l l y e x h i b i t a much greater range than

t h e concent ra t ion data, and it i s l i k e l y t h a t wide ranges i n f l ows w i l l

descr ibe s i m i l a r changes i n loads.

An assessment o f t h i s v a r i a b i l i t y i n t r i b u t a r y f l ows f o r t h e 15 year . -

period, 1962-1976 was r e c e n t l y conducted. 8 6 Flows i n Canadian t r i b u t a r i e s

t o Lake E r i e va r ied - + 38 percent w h i l e U. S. t r i b u t a r i e s va r ied + 49 percent

over t h e same 15 year period. Given t h i s wide ranging na tu ra l v a r i a b i l i t y , i t

w i 11 be extremely d i f f i c u l t t o j u s t i f y expenditures on nonpoint remedi a1

programs i f measurable shor t term improvements i n t r i b u t a r y phosphorus , ,

loadings are expected.

Seasonal

I n a number o f t h e studies conducted under PLUARG, a d i s t i n c t seasona l i t y

i n t h e d e l i v e r y o f sediment was i d e n t i f i e d . I n t h e Maumee River basin, t h e

s i x months f rom December t o May accounted f o r 92 percent o f t h e t o t a l sediment load de l i ve red t o Lake E r i e by t h e r i v e r dur ing t h e pe r iod July, 1975 - June, 1977." Ca lcu la t ions made f o r t h e 11 a g r i c u l t u r a l watersheds studied i n

Ontar io revealed t h a t 75 percent o f t h e t o t a l annual suspended sediment load l e f t t h e watersheds dur ing t h e months o f February through ~ p r i 1.

Thus, remedial measures d i r e c t e d towards reducing sediment del i v e r y t o t h e

lakes must necessar i l y p rov ide maximum p r o t e c t i o n dur ing t h e l a t e w i n t e r and

e a r l y sp r i ng pe r iod o f t h e year. For instance, t h e t r a d i t i o n o f f a l l -

moldboard ploughing o f t h e bas in 's heavier s o i l s when used f o r row crops w i l l

have t o be reevaluated if b e n e f i c i a l reduc t ions i n sediment loadings a re t o be

achieved.

S p a t i a l V a r i a b i l i t y

Macro Sca le

The r e l a t i v e importance of t h e c o n t r i b u t i o n o f i n d i v i d u a l land use

a c t i v i t i e s v a r i e s f rom l ake bas in t o l a k e basin. For example, i n t h e Lake Super io r bas in f o r e s t e d areas c o n t r i b u t e 74 percen t o f t h e t o t a l nonpoint

source phosphorus load, w h i l e i n t h e Lake E r i e bas in t h i s land use a c t i v i t y

o n l y accounts f o r 1 percen t o f t h e load.3

Therefore, remedia l a c t i o n d i r e c t e d t o c o n t r o l l i n g nonpoint sources o f

phosphorus w i l l r e q u i r e a d i f f e r e n t focus i n each l ake bas in and w i l l r e c e i v e

d i f f e r e n t p r i o r i t i e s based on t h e i r r e l a t i v e importance and c o n t r o l l a b i l i t y .

W i th i n i n d i v i d u a l l a k e basins, marked v a r i a t i o n s a l so e x i s t w i t h r espec t

t o t h e r e l a t i v e s i g n i f i c a n c e o f land areas c o n t r i b u t i n g t o t h e nonpoint

problem. D i f f e rences i n s o i l s , geomorphology, c l imate , and land use

a c t i v i t i e s r e s u l t -in cons ide rab le ranges i n 'nonpoint loadings. 'The most

impor tan t f a c t o r s i d e n t i f i e d i n t h i s r ega rd have been t h e co-occurrence o f

areas o f f i n e t e x t u r e d s o i l s be ing used f o r row c rop a g r i c u l t u r e . These areas

generate h igher loadings o f sediment du r i ng r u n o f f i n r e l a t i o n t o t h e i r slope,

i n f i 1 t r a t i o n ra tes , and suscep t i b i 1 i t y t o sediment suspension and t r anspo r t .

The implementors o f nonpoint remedia l measure programs w i l l have t o t a k e

cognizance o f these f a c t o r s i f program resources a r e n o t t o be d i s s i p a t e d by

t r e a t i n g a l l areas o f a g i ven bas in t o t h e same l e v e l . A program s t r u c t u r e d

on a p r i o r i t y area bas i s would channel resources i n t o thos'e areas where t h e

g rea tes t and most r a p i d reduc t i ons can be achieved a t l e a s t cost . Adopt ion of

t h i s approach does r a i s e some concern about t h e c r e a t i o n o f i n e q u i t i e s between

those bas in r e s i d e n t s who w i l l need t o implement remedia l measures f i r s t and

those who' w i l l be i nvo l ved t o a l esse r ex ten t and a t a l a t e r t ime. Given t h e

pe renn ia l problem o f l i m i t e d f i s c a l resources, adop t ion o f t h e a l t e r n a t e more

e q u i t a b l e approach o f r e q u i r i n g un i f o rm compl iance would r e s u l t i n a

c o n t i n u a t i o n of p resen t p r i o r i t i e s and i n a smal l e r l oad ing reduc t ion . , . . .

Micro Scale

Although est imates of gross p o t e n t i a1 s o i 1 e ros ion a re use fu l . in. determing

t h e impact of ~ r o s i o n on a g r i c u l t u r a l p r o d u c t i v i t y , t h e i r va lue i n assessing

' impacts on water q u a l i t y i s l im i ted . O f more concern from a water q u a l i t y

perspec t ive i s t h e de termina t ion o f t h e sediment d e l i v e r y r a t i o , o r t h e

p r o p o r t i o n o f t h e gross p o t e n t i a l e ros ion which i s a c t u a l l y d e l i v e r e d t o a

stream. Th i s i s t h e f r a c t i o n whichamay exe r t an impact on water q u a l i t y .

Logan has noted, t h a t i n t h e Maumee R ive r basin, t h e annual sediment de l i v e r y

r a t i o l i e s somewhere between 4.2 percent and 14.9 percent." S o i l s w i t h t h e

f i n e s t t ex tu res had t h e h ighes t d e l i v e r y r a t i o s and y e t e x h i b i t some of t h e

lowest gross eros ion r a t e s as est imated by t h e Un iversa l S o i l Loss Equation; a

s i t u a t i o n which cou ld be overlooked i n t h e design o f a remedia lmeasure

program i f gross eros ion r a t e s a re t h e o n l y c r i t e r i o n used t o determine

prob 1 em areas.

The f i n e p a r t i c l e s i z e c l a y f r a c t i o n s associated w i t h most s o i l s have.a

g rea te r sur face area and c a t i o n exchange capaci ty , and w i l l remain i n

suspension longer and thus t r a v e l f a r t h e r than t h e coarser sand and s i l t s o i l

f r ac t i ons . Typ i ca l l y , f i n e tex tu red s o i l s w i t h h igh c l a y contents a re more

l i k e l y t o have lower i n f i l t r a t i o n r a t e s r e s u l t i n g i n more sur face r u n o f f f rom

areas w i t h such s o i l s . Conventional remedial measures, w h i l e e f f e c t i v e i n

c o n t r o l l i n g gross erosion, may be l ess e f f i c i e n t i n c o n t r o l 1 i n g t h e d e l i v e r y

o f t h e c l a y s i z e f r a c t i o n .

When viewed from a management perspec t ive i t i s important t o determine no t

o n l y what p r o p o r t i o n o f t h e gross eroded s o i l i s reaching a watercourse b u t

a l sa t h e s p a t i a l d i s t r i b u t i o n o f t h e source areas. I n f a c t , t h e sediment

d e l i v e r y r a t i o i s no t a constant f o r a g iven s o i l t ype across t h e area of a

watershed. I n s tud ies c a r r i e d o u t by Van V l i e t -- e t a1.88 i n two PLUARG

a g r i c u l t u r a l watersheds, i t was revealed t h a t on t h e average o n l y about 10

percent and 15 percent o f t h e respec t i ve watershed areas had t h e p o t e n t i a l f o r

c o n t r i b u t i n g t o stream sediment loads du r i ng t h e year. The s i z e of these

c o n t r i b u t i n g areas o r h y d r o l o g i c a l l y a c t i v e areas i s determined by s o i l .

tex tu re , slope, drainage c h a r a c t e r i s t i c s , and land management. What i s now

l a c k i n g from a management pe rspec t i ve i s a method f o r d e f i n i n g these areas. i n

t h e f i e l d . Once those respons ib l e f o r implementat ion can s y s t e m a t i c a l l y

i d e n t i f y t hese areas on t h e land, t h e a p p l i c a t i o n o f remedia l measures w i l l

become more e f f i c i e n t and e f f e c t i v e .

Impor tant concerns a1 so remain w i t h respec t t o de te rmin ing what p r o p o r t i o n

o f t h e t o t a l suspended s o l i d s found i n t h e headwaters of t r i b u t a r i e s i s

a c t u a l l y t r anspo r ted t o t h e lakes. Some o f t h i s m a t e r i a l may be t rapped by

dams and o the r o b s t r u c t i o n s o r t h e sediment assoc ia ted n u t r i e n t s may be used

i n s i t u by t h e b i o l o g i c a l community i n t h e streams. --

5.2.3 Remedial Measures

Agencies i n bo th c o u n t r i e s w i l l need t o rede f ine t h e i r p o l l u t i o n c o n t r o l

programs t o be more respons ive t o t h e management of nonpoint sources.

E x i s t i n g and planned urban stormwater conveyance systems, which have been

designed t o move runoff away from urban cen t res as q u i c k l y as poss ib le , w i l l

need t o be redes igned t o make them more respons ive t o reduc ing urban

stormwater p o l l u t i o n . I n a g r i c u l t u r a l areas, many o f t h e remedia l measures

t e s t e d and adopted over t i m e as e f f e c t i v e f o r reduc ing gross s o i l e ros ion have

no t been adequately eva luated t o determine t h e i r s u i t a b i l i t y f o r reduc ing t h e

d e l i v e r y o f f i n e g ra ined sediments t o t h e water course. For example, i n t h e

Corps o f Eng ineer ' s Lake E r i e Wastewater Management est imates of

nonpoint phosphorus l oad ing reduc t i ons have o n l y been based on t h e conc lus ions o f two s imu la ted r a i n f a l l p l o t s t ud ies and one f i e l d analys is . S i m i l a r l y , t h e

PLUARG est imates o f r educ t i ons achievable a re s u b j e c t t o a 50 percen t marg in

o f e r ro r .

Al though t h e exact r educ t i ons which can be achieved by these programs

under Great Lakes bas in c o n d i t i o n s a re uncer ta in , s i g n i f i c a n t r educ t i ons i n

a g r i c u l t u r a l r e 1 ated phosphorus loadings can be achieved. I n many cases these

reduc t i ons may be r e a l i z e d w i t h o u t t h e imp1 ementat ion o f expensive and

d i s r u p t i v e remedia l measures.

Studies t o evaluate t h e actual e f fec t iveness o f remzdi a1 measures under

Great Lakes bas in cond i t i ons must be conducted, be fore commitments t o f u l l

sca le imp1 ement a t i o n are made. However, considerable progress can be made

immediately through t h e use o f t echn ica l assist-ance, education, and p i l o t

demonstration programs.

'The remedial measures i d e n t i f i e d i n Tables 5.3 and 5.4 a r e those which

genera l l y show some promise f o r reducing p o l l u t i o n from a g r i c u l t u r a l and urban

nonpoint sources. It should be noted t h a t when several o f these measures are

combined i n a comprehensive land t reatment system, t h e load ing reduct ion

achieved o f t e n exceed t h e sum o f t h e par ts . Although cos ts o f remedial

measure op t ions are a key considerat ion, they vary markedly according t o t y p e

o f farming system o r urban area, c l imate, and s i t e phys ica l c h a r a c t e r i s t i c s ,

such as s o i l type, drainage, and slope.

Selected Measures - A g r i c u l t u r e

It has been demonstrated t h a t sediment i s t h e pr imary v e h i c l e f o r moving

phosphorus from a g r i c u l t u r a l 1 ands. Therefore, t h e p r i n c i p a l focus o f

remedial measures has been towards min imiz ing t h e d is turbance o f t h e s o i l

sur face and s t a b i l i z i n g a p r o t e c t i v e vegeta t ive cover t o reduce t h e p o t e n t i a l

f o r s o i l detachment. Changes t o conservat ion t i l l a g e p rac t i ces have received

t h e most a t ten t i on . (See Table 5.3).

Selected Measures - Urban

Measures f o r reducing po l l u t i o n i n urban stormwater have p r imar i l y been

d i rec ted towards c o n t r o l a t source, c o n t r o l i n t h e c o l l e c t o r system, and

storage w i t h treatment.

While implementation o f measures t o c o n t r o l t h e q u a n t i t y o f urban r u n o f f

are e a s i l y accompl ished i n developing urban areas, important quest ions remain

w i t h respect t o how these measures can be e f f e c t i v e l y implemented i n

establ ished urban areas.

TABLE 5.3 REMEDIAL MEASURES FOR AGRICULTURAL NONPOINT SOURCES

Conservat ion T i l l a g e - inc ludes no t i l l , d isk p l a n t . and c h i s e l p low

NO T i l l - w i t h t h e excep t ion of a narrow s t r i p pene t ra ted by a f l u t e d c o u l t e r (5-8cm) t h e r e i s no d i s tu rbance of t h e r e s i d u e cover o r t h e s o i l p r o f i l e . U s u a l l y seeding, f e r t i l i z i n g and h e r b i c i d e a p p l i c a t i o n a re a l l c a r r i e d ou t i n one opera t ion .

Reductions i n s o i l l o s s of up t o 90 percent over convent ional t i l l a g e have been a t t r i b u t e d t o t h i s technique w i t h no s a c r i f i c e i n c rop y i e l d s on some s o i l s and i n some areas o f the basin. Sediment phosphorus reduc t ions have been r e p o r t e d t o f a l l anywhere between 10-90 percent when evaluated on a watershed bas is .

Disk P l a n t - may c o n s i s t of one o r two passes over t h e f i e l d fo l l owed by a p l a n t i n g opera t ion . The system loosens t h e e n t i r e s o i l sur face t o a shal low depth (IOcm), breaks up c rop r e s i d u e and mixes t h i s w i t h t h e t o p su r face s o i l . Reductions i n s o i l l o s s o f between 70-90 percent have been r e p o r t e d on some s o i l s .

Ch ise l Plow - r e s u l t s i n t h e break up o f s o i l t o a depth o f 20 cm, b u t does no t r e s u l t i n a t u r n over o f t h e s o i l sur face l a y e r . Consequently a l a r g e p o r t i o n o f c rop r e s i d u e i s mainta ined on t h e surface. Ch ise l p low ing i s no rma l l y f o l l o w e d by a t l e a s t one d isk ing . Sediment l o s s reduc t ions between 30 and 90 percent have been r e p ~ r t e d . ~ ' > ~ ~

Vege ta t i ve Buf fer S t r i p s - when mainta ined adjacent t o water courses prove e f f e c t i v e i n reduc ing the r a t e o f ove r land f l ow and t r a p p i n g sediment i n suspension. A 50 f o o t wide s t r i p may remove up t o 50 percent o f sediment load." Level of u t i l i t y i s a f fected by t h e i r width, v igour , h e i g h t o f vege ta t ion and s lope. I n a d d i t i o n t o t h e cos ts f o r developing and m a i n t a i n i n g these s t r i p s , t h e o the r l ong term opera t ing cos t i s t h e l o s s o f p r o d u c t i v e a g r i c u l t u r a l land.

Contour C u l t i v a t i o n - t h i s technique r e q u i r e s t h a t c u l t i v a t i o n be done p a r a l l e l t o t h e n a t u r a l contours o f the land. Surface r u n o f f which no rma l l y f l o w s down t h e f a l l l i n e i s now d i v e r t e d l a t e r a l l y , and more g e n t l y t o t h e base. Average s o i l losses can be reduced by 50 percent on moderate s lopes (3-7 pe rcen t ) .g0

Cross Slope T i l l a g e - as opposed t o contour c u l t i v a t i o n t h i s approach o n l y r e q u i r e s t h a t c u l t i v a t i o n proceed a t r i g h t angles t o d i r e c t i o n o f s l o e. Probably more e a s i l y adopted than con tour ing a l though sediment r e d u c t i o n s may o n l y be one h a l f as much."

S t r i p Cropping - by a1 t e r n a t i n g s t r i p s o f c l o s e grown crops (hay and g r a i n s ) w i t h row crops (co rn ) across the slope, t h e l e n g t h o f t h e s lope i s e f f e c t i v e l y broken. Increases t h e absorp t ion o f ove r land f l o w and reduces i t s v e l o c i t y . Th is technique i s a l s o e f f e c t i v e i n reduc ing wind eros ion. S t r i p c ropp ing may reduce sediment y i e l d s up t o 85 percent . I t encourages c rop r o t a t i n g by farmers.

F e r t i l i z e r A p p l i c a t i o n - poor t i m i n g and placement o f f e r t i l i z e r can inc rease the l e v e l s o f s o l u b l e ino rgan ic phosphorus l e a v i n g a watershed. Genera l l y these l e v e l s are low, l e s s than 9 percent , however, t h i s form of phosphorus i s the most r e a d i l y a v a i l a b l e t o algae. I n c o r p o r a t i o n o f a p p l i e d f e r t i l i z e r i n t o t h e s o i l p r o f i l e a t a t ime when crops can maximize t h e i r use o f i t , w i l l a s s i s t i n reduc ing t h e loss o f f e r t i l i z e r n u t r i e n t s due t o su r face r u n o f f .

Subsurface ( T i l e ) Dra inage - i n many areas where s o i l s are c h a r a c t e r i z e d as p o o r l y drained, t h e c o n s t r u c t i o n o f subsur face d r a i n s can reduce r u n o f f and subsequent s o i l loss. On these s o i l s , t h e i n s t a l l a t i o n o f subsur face d ra ins may a l s o improve c rop y i e l d s when f o l l o w i n g conserva t ion t i l l a g e p r a c t i c e s .

Management o f L i ves tock Manure - a l though t h i s source i s o f l e s s importance when t o t a l l oad ings a re examined (20 percent o f the a g r i c u l t u r a l nonpoint phosphorus l o a d i n g i n the Great Lakes bas in ) cons ide rab le improvements can be made i n e x i s t i n g opera t ions . Fac to rs such as l o c a t i o n o f feed ing opera t ions r e l a t i v e t o water courses, t h e s i z e and design o f manure s to rage f a c i l i t i e s , f requency o f w i n t e r spreading, and d is tance o f spreading f rom streams and open d i t c h e s a re some o f t h e many f a c t o r s which u l t i m a t e l y a f f e c t t h e d e l i v e r y of manure r e l a t e d phosphorus t o streams.

-

TABLE 5.4 REMEDIAL MEASURES FOR URBAN NONPOINT SOURCES

Source Cont ro l Measures f o r reduc ing p o l l u t i o n i n urban stormwater have p r i m a r i l y been d i r e c t e d towards c o n t r o l a t source, c o n t r o l i n the c o l l e c t o r system and storage w i t h t reatment . I n most l o c a l i t i e s water q u a l i t y problems i d e n t i f i e d w i t h urban stormwater have o n l y been associated w i t h combined s a n i t a r y and storm systems. Stormwater a lone has been considered t o be of a r e l a t i v e low p r i o r i t y . Con t ro l a t source may be accomplished us ing a v a r i e t y o f approaches which inc lude:

S t r e e t Sweeping - t h e e f f i c i e n c y o f s t r e e t sweepers i n reducing t h e t o t a l p o l l u t a n t load' i s dependent on a number of f a c t o r s i n c l u d i n g f requency o f sweeping. , c o n d i t i o n o f pavement, t ype o f equipment used (vacuum o r mechanical sweepers), frequency o f r a i n f a l l and pub1 i c a t t i t u d e s . Re1 iab le . p r e d i c t i o n s o f the e f f e c t i v e n e s s o f these measures a r e g e n e r a l l y not ava i lab le , however, est imates i n d i c a t e t h a t removal l e v e l s f o r phosphorus may range f rom 4 t o 44 percent f o r vacuum sweepers and 5 t o 16. percent f o r brush sweepers dependingon t h e f requency o f operat ion.

Catchment Basin Cleaning - now performed o n l y about once o r t w i c e a year. A more regu la r . program combined w i t h s t r e e t sweeping may improve q u a l i t y - 25-50 percent .

Urban Runof f Con t ro l A reduc t ion i n the q u a n t i t y and an increase i n the r u n o f f p e r i o d ' o f urban stormwater w i l l a l so reduce the t o t a l l oad ing o f p o l l u t a n t s f r a n urban areas. This can be accomplished e i t h e r through a r e d u c t i o n i n t h e t o t a l f l o w which might u l t i m a t e l y reach a sewer system and/or a r e d i r e c t i o n o f f l o w over land thereby inc reas ing the t ime a v a i l a b l e f o r n a t u r a l i n f i l t r a t i o n be fo re i n t r o d u c t i o n t o t h e a r t i f i c i a l conveyance system. Measures a v a i l a b l e inc lude:

Roof Top Pondi ng Detent+on/Retent ion Ponds Temporary Check Dams I n f i l t r a t i o n Basins Drainage Swal es Porous Pavements

Stormwater Treatment Measures are a v a i l a b l e t o t r e a t urban stormwater r u n o f f . These op t ions are g e n e r a l l y ve ry 'expensive and would p robab ly on ly be cos t e f f e c t i v e where severe l o c a l water q u a l i t y problems were being experienced and where more than one p o l l u t a n t parameter was o f concern. Measures a v a i l a b l e inc lude :

Physical-Chemical Systems Swi r l Concentrators S t a t i o n a r y Screens Hor izon ta l and/or V e r t i c a l Shaf t Ro ta ry Screens Treatment Lagoons A i r F l o t a t i o n T r i c k l i n g F i l t e r s Contact S t a b i l i z a t i o n

Urban Cons t ruc t ion The most important source o f sediment i n urban areas i s der i ved f rom developing urban lands where y i e l d s may be 1000 t imes g rea te r than on comparable a g r i c u l t u r a l land. There are a v a r i e t y o f proven measures a v a i l a b l e f o r dea l ing w i t h t h i s problem. What seems t o be l a c k i n g i n a Great Lakes con tex t i s the a d m i n i s t r a t i v e w i l l t o implement them..

Sedimentat ion Ponds M a t t i n g and N e t t i n g f o r Slope S t a b i l i z a t i o n Organic Mulch Temporary Mulch and Ssed Chemical S o i l S t a b i l i z e r s Staged Land C l e a r i n g . . .

Re ta in ing Wal ls Hydro Seeding

5.2.4 Costs f o r Nonpoint Source Cont ro ls

The cos ts f o r ag r i cu 1 t u r a l norlpoi n t source c o n t r o l s t o reduce phosphorus

loadings range from almost no cos tb6 t o a range of f rom $15 t o $58 annua l ly

per watershed hectare." The types o f measures which should be implemented

are very s i t e - s p e c i f i c and ve ry l i t t l e data are a v a i l a b l e t o determine t h e i r

cos t -e f fec t i veness over t h e long term. As discussed prev ious ly , t h i s i s a

major i nformat ion need i d e n t i f i e d by t h e task fo rce . Demonstration p r o j e c t s

need t o be c a r r i e d out.

5.2.5 Summary

A g r i c u l t u r a l and urban land use a c t i v i t i e s have been i d e n t i f i e d as t h e

most important nonpoint sources o f phosphorus. U n l i k e t h e i npu ts f rom p o i n t

sources, nonpoint loadings are charac ter ized by c ~ ~ l s i d e r a b l e temporal and

s p a t i a l v a r i a b i l i t y . Major changes i n annual load ing r a t e s r e s u l t f rom

na tu ra l f l u c t u a t i o n s i n t h e hydro log ic c y c l e and considerable v a r i a t i o n w i t h i n

a s i n g l e year can be a t t r i b u t e d t o t h e irrlportance o f t h e sp r i ng r u n o f f per iod.

Viewed from a, s p a t i a l perspect ive, t h e r e a re major d i f f e rences i n t h e

r e l a t i v e importance o f nonpoint sources t o t h e t o t a l n u t r i e n t budget o f

i n d i v i d u a l lakes. W i th in i n d i v i d u a l l ake drainage basins the re a re areas

which c o n t r i b u t e a d i sp ropo r t i ona te share o f t h e t o t a l nonpoint source load.

These inheren t c h a r a c t e r i s t i c s o f nonpoint sources w i l l have t o be

considered i n t h e design o f an e f f e c t i v e management program. Nonpoint source

management p lans are a1 so hampered by a lack o f knowledge about t h e

e f fec t i veness o f remedial measures i n reducing loadings and t h e importance o f

t h e ques t ion o f r e l a t i v e b i o l o g i c a l a v a i l a b i l i t y o f phosphorus f rom p o i n t and

nonpoi n t sources.

Given t h e complex i ty o f t h e nonpoint problem, t h e f o l l o w i n g represent some

o f t h e important cons idera t ions which must be taken i n t o account i n t h e design

o f a nonpoint management program:

(1) Those areas which account f o r t h e d e l i v e r y o f t h e greates t p ropo r t i on

of n u t r i e n t s must be sys temat i ca l l y i d e n t i f i e d , i n order t o make t h e

appl i c a t i o n of remedial measures more e f f i c i e n t and ef fect ive.

(2 ) Remedial measures must be e f f e c t i v e i n reducing t h e d e l i v e r y of t h e

f ine-gra ined s o i l p a r t i c l e s , especia l l y dur ing t h e c r i t i c a l

l a te -w in te r ear ly -spr ing r u n o f f per iod.

(3) Implementation of remedial measures must proceed on a p r i o r i t y area

bas is t r e a t i n g those areas where t h e l a rges t and most r a p i d

reduc t ions can be achieved a t l e a s t cost.

5.3 OTHER CONS I DERATIONS

'The implementation o f measures t o reduce the phosphorus inputs t o t h e

Great Lakes has several a n c i l l a r y b e n e f i t s and detr iments which, al though no t

q u a n t i f i a b l e a t t h i s time, can be described qua1 i t a t i v e l y .

Chemical a d d i t i o n f o r phosphorus removal a t e x i s t i n g pr imary and secondary

municipal wastewater treatment p lan ts w i l l reduce t h e suspended s o l i d s and BOD

and i s l i k e l y t o reduce t h e amounts o f t o x i c organic substances and heavy

metals i n t h e i r ef f1ue"ts. The n u t r i e n t content o f sludges produced a t these

p l a n t s w i l l be increased. However, the,amounts o f s ludge t o be t rea ted and

disposed o f w i l l a l so increase s i g n i f i c a n t l y . I n addi t ion, t h e poss ib le

increased content o f heavy metals and t o x i c organic substances i n these

sludges may r e q u i r e a r e s t r i c t i o n i n a p p l i c a t i o n ra tes f o r land d isposal and

l i m i t o ther d isposal opt ions. I nc lud ing requirements f o r phosphorus removal

a t munic ipal wastewater treatment p lan ts in t roduces more complex technology

which requ i res h igher operator s k i 11s.

Because o f t h e biochemical, physical , and chemical removal mechanisms

associated w i t h s o i l systems, many cons t i t uen ts a re removed by land

treatment. Removal of t o x i c and hazardous cons t i t uen ts i s a r e l a t i v e l y new

p o l l u t i o n c o n t r o l i n t e r e s t , and t h e r e are few data t o de f i ne t h e removals t h a t

occur a t land t reatment s i t es . However, t h e l i m i t e d a v a i l a b l e data i n d i c a t e

t h a t land treatment systems can reduce contaminants such as pes t ic ides ,

herb ic ides, cadmium, z inc, and 2,4-0 concentrat ions i n t h e app l ied wastewater

t o essent i a1 l y background groundwater concentrat ions.

I n a d d i t i o n t o t h e phosphorus and other contaminants removal bene f i t s ,

land treatment has f u r t h e r environmental b e n e f i t s such as: reduced sludge

product ion f o r treatment and u l t i m a t e disposal, and recyc le o f n u t r i e n t s and

organics t o t h e s o i 1-crop system. Potent i a1 disadvantages, which i nc lude t h e

poss ib le accumulation o f contaminants such as heavy metal, t o x i c organic

compounds, and pathogenic organisms i n s o i 1 systems, must a1 so be recognized.

The magnitude o f t h i s remains t o be quan t i f i ed .

6 .0 , STRATEGIES FOR ASSESS1 NG THE SOCIAL AND ECONOMIC IMPACTS

I n t h e preceding chapters o f t h i s r e p o r t t h e task f o r c e has i d e n t i f i e d

both a range of phosphorus t a r g e t loadings f o r t h e lakes and t h e remedial

measure opt ions which can be implemented t o achieve f u r t h e r phoshorus loading

reduct ions.

I n consider ing t h e s t r a t e g i e s t o be used, cons idera t ion must be g iven t o

t h e system l i n k i n g phosphorus management, water q u a l i t y , and water use as

shown i n F igu re 6.1. It i s c l e a r from our examination t h a t t he l inkages

between phosphorus management and r e s u l t i n g water q u a l i t y remain uncer ta in.

To t h e ex ten t possible, t h i s task force has attempted t o q u a n t i f y t h e range of

v a r i a b i l i t y t h a t e x i s t s thus reducing t h i s l e v e l o f uncer ta in ty . Add i t i ona l

e f f o r t w i 11 be requ i red t o f u r t h e r r e f i n e these estimates.

FIGURE 6.1 PHOSPHORUS MANAGEMENT LINKAGES

Qua1 i t y w I n t h e context o f phosphorus management t h e task f o r c e has a lso i d e n t i f i e d

an important gap i n our understanding o f t h e l inkage which e x i s t s between

Great Lakes water q u a l i t y and t h e use o f t h i s resource. To date, o n l y minimal

a t t e n t i o n has been d i rec ted towards developing an understanding i n t h i s

important area.

The task f o r c e has not had s u f f i c i e n t t ime nor resources t o p rov ide an

assessment of t h e consequences t h a t changes i n water q u a l i t y ho ld f o r t h e use

of t h e water resource. Therefore, i t i s o f c r i t i c a l importance t h a t governments

n o t o n l y con t inue t h e i r present commitments t o improve t h e knowledge o f t h e

1 inkages between phosphorus management and r e s u l t a n t water qua1 i ty bu t a1 so t o

undertake new programs d i r e c t e d towards assessing t h e i m p l i c a t i o n s which

changes i n water q u a l i t y h o l d f o r users o f t h i s resource.

Given t h i s s i t u a t i o n t h e task f o r c e i n t h i s sec t i on proposes a conceptual

framework o u t l i n i n g t h e commitments requ i red over t h e long term t o p r o p e r l y

assess t h e s o c i a l and economic consequences o f managing t h e Great Lakes. Once

t h i s knowledge i s es tab l i shed governments w i 11 have a more reasonable bas i s

f o r developing p o l i c y and f o r determi n i ng whether t h e consequences, i n c l u d i n g

bo th p o s i t i v e and negat ive impacts, warrant t h e commitment o f a d d i t i o n a l

expenditures f o r phosphorus removal.

6.1 BACKGROUND

The de termina t ion of des i red water q u a l i t y o b j e c t i v e s i n t h e lakes has

l a r g e l y been t h e purview of 1 imnologis ts . Thus, these ob jec t i ves - - t he

des i rab i 1 i t y of r e s t o r i n g year round aerobic cond i t i ons i n t h e bottom waters

of t h e Cent ra l Basin of Lake E r i e and reducing nuisance growths o f algae,

weeds, and s l imes t h a t a re o r may become i n j u r i o u s t o any b e n e f i c i a l water

use--have been expressed w i thou t f u l l cons ide ra t i on o f ba lanc ing t h e i r

b e n e f i t s and costs. Moreover, pas t dec is ions t o spend b i l l i o n s of do1 l a r s t o

reduce phosphorus i n p u t s have been taken w i thou t t h e b e n e f i t o f q u a n t i f i c a t i o n

o f t h e impacts o r consequences these ac t i ons ho ld f o r s o c i e t y i n general and

i n p a r t i c u l a r , t h e users o f t h e resource (such as commercial f ishermen,

t o u r i s t s , and those depending on t h e lakes f o r a po tab le water supply) .

However, today, most o f us a re aware o f t h e s c a r c i t y o f resources

a v a i l a b l e t o apply t o t h e s o l u t i o n o f water q u a l i t y problems.

Pa r t o f t h e reason f o r t h e ex is tence o f t h i s s i t u a t i o n was t h e ex ten t of

p u b l i c a t t e n t i o n commanded by environmental issues i n t h e e a r l y sevent ies.

Th is focus o f i n t e r e s t encouraged p o l i t i c a l i n i t i a t i v e s t o deal w i t h

s i t u a t i o n s which had pu rpo r ted l y reached c r i s i s p ropor t ions . ''

Today, a1 though environmental problems are s t i 11 o f concern t o soc iety , 9 2 ' 9 3 ' 9 4

economic issues have become preeminent. Without a c l e a r a r t i c u l a t i o n of t h e

b e n e f i t s and cos ts o f f u r t h e r programs aimed a t management o f t h e Great Lakes,

1 i tt l e support w i 11 be forthcoming.

I n t h e Un i ted States a r e p o r t by t h e Comptro l ler ~ e n e r a l ' ~ rev iewing

water qual i t y management p lann ing concluded t h a t , t o "accornpl i s h t h e

l e g i s l a t i v e goals o f c lean water requ i res t h e development o f sound water

qual i t y management plans. The p lans should consider t h e general publ i c ' s

percept ion o f s i g n i f i c a n t water q u a l i t y problems and understanding of what t h e

water qual i ty management e f f o r t i s t r y i n g t o accomplish".

Since t h e s ign ing o f t h e f i r s t Great Lakes Water Qua1 i t y Agreement i n

1972, t h e r e have been a number o f i s o l a t e d and r e l a t i v e l y unre la ted attempts

t o determine t h e publ i c ' s goals f o r t h e Great Lakes and t h e i r assessment of

t h e need f o r and t h e d i r e c t i o n o f f u r t h e r

Unfortunately, these e f fo r t s have f a l l e n sho r t o f p r o v i d i n g p o l i t i c i a n s

and managers a l i k e w i t h a c l e a r enunc ia t ion o f t h e expected s o c i a l and

economic consequences o f t a k i n g f u r t h e r a c t i o n t o manage t h e Lakes.

6.2 BASIS FOR THE FRAMEWORK

The conceptual framework presented i n t h i s chapter descr ibes an approach

f o r t a k i n g a c t i o n i n t h e face o f these economic and s o c i a l u n c e r t a i n t i e s

whi le , a t t h e same time, generat ing t h e necessary i n fo rma t i on t o reso l ve these

unce r ta in t i es .

The framework recognizes t h a t t h e r e a re four p ieces o f in fo rmat ion needed

be fore i n t e l l i g e n t p o l i c y dec is ions can be made. These are:

I

1. A knowledge o f t h e "s tate-of - the-wor ldn, n o t o n l y as i t i s b u t as i t

would be as a r e s u l t o f any p o l i c y changes.

2. A c l e a r idea o f t h e des i red o b j e c t i v e s of t h e p o l i c y .

3 . An understanding of t h e . s t a t u s o f e x i s t i n g p o l i c y t h a t may c o n f l i c t

w i t h o r support p o l i c y ob jec t i ves .

4. An understanding o f t h e l i k e l y s o c i a l cos t of making a mis take- - tha t

i s , choosing t h e wrong p o l i cy .

C e r t a i n l y t h e t o o l s of limnology,. hydrology, etc'. a re c r u c i a l t o t h e f i r s t

p iece o f in fo rmat ion . It i s quest ionable, however, whether these s c i e n t i f i c

d i s c i p l i n e s o r any o ther d i s c i p l i n e such as economics and p o l i t i c a l science

can, by i t s e l f , shed much l i g h t on t h e o ther t h r e e pieces. Unfor tunate ly ,

t h e r e has been a tendency t o ask t h e phys i ca l s c i e n t i s t t o do too much. The

s c i e n t i s t has been asked, f o r example, t o spec i f y " t a r g e t loads" as i f these

t a r g e t s have a t o t a l l y " s c i e n t i f i c " basis. He o r she may be ab le t o r e l a t e

t h e l i k e l y phys i ca l cond i t i ons of t h e lakes t o loadings, b u t t h e r e i s no

p u r e l y s c i e n t i f i c way o f determin ing what phys i ca l cond i t i ons would be i n t h e

bes t i n t e r e s t s o f soc iety .

On t h e o the r hand, t h e p o l i t i c a l s c i e n t i s t can a s s i s t i n p r o v i d i n g

in format ion on t h e second and t h i r d p iece o f i n fo rma t i on and t h e economist,

knowledgeable i n t h e t o o l s o f c o s t - b e n e f i t analys is , can he lp w i t h the,

f ou r th . However, conduct ing p o l i t i c a l , economic, cost-benef it, and p o l i c y

analyses are impossib le w i thou t t h e t e c h n i c a l i n fo rma t i on prov ided by t h e

phys i ca l and b i o l o g i c a l s c i e n t i s t s . Yet t h i s information, w h i l e necessary, i s

no t s u f f i c i e n t . I tem four , espec ia l l y , r e q u i r e s i n fo rma t i on on s o c i a l and

p o l i t i c a l preferences t h a t cannot be generated s o l e l y by a n a l y t i c a l methods.

I n shor t , a p o l i c y framework t h a t recognizes t h e f o u r elements of

i n t e l l i g e n t p o l i c y dec is ion needs a balanced mix o f i n fo rma t i on from t h e

phys i ca l s c i e n t i s t , t h e s o c i a l s c i e n t i s t , and t h e general public. '

6.3 CURRENT STATUS OF POLICY -RELEVANT INFORMATION

The f o l l o w i n g i s a b r i e f summary o f what i s known regard ing t h e f o u r

pieces o f i n fo rma t i on r e l e v a n t t o t h e issue o f phosphorus management i n t h e

Great Lakes.

1. Knowledge of t h e State-of-the-World

Since most of t h i s r e p o r t covers t h i s f i r s t area, a summary w i l l not be

presented. It i s probably safe t o conclude t h a t wh i l e much i s known about

t h e phys ica l r e l a t i o n s h i p between phosphorus loading and t h e qua1 i ty of

t h e Lakes, t h e knowledge i s not s u f f i c i e n t l y p rec i se t o j u s t i f y s t r a t e g i e s

r e q u i r i n g attainment of p r e c i s e l y def ined ta rge ts .

2. Clear Idea o f Object ives

While t h e cu r ren t q u a l i t y ob jec t i ves appear unambiguous, improvement may

s t i l l be needed. For example, w h i l e t he re i s a des i re t o reduce

"nuisance" growths of algae, "nuisance" has no t been p r e c i s e l y def ined.

F a i r l y h igh concentrat ions o f algae may not be perceived as a nuisance t o

f ishermen i f t h e n u t r i e n t s serve t o increase c e r t a i n f i s h y ie lds .

S im i l a r l y , t h e goal o f ma in ta in ing naerobicl' bottom cond i t ions may have t o

be replaced w i t h a more s p e c i f i c d isso lved oxygen goal. A t t a i n i n g aerobic

condi t ions, w i t h very low d isso lved oxygen, may not be considered worth

t h e t r o u b l e i f c e r t a i n f i s h species cannot be supported.

3. , Understanding o f Status o f Current P o l i c y

The issue here i s no t what i s o r i s not mandated by cu r ren t t r e a t i e s and

laws, bu t r a t h e r by t h e s t a t u s o f implementation o f these t r e a t i e s and

laws. Knowledge o f what treatment technology i s i n p lace as t h e r e s u l t o f

these laws i s poor, e s p e c i a l l y i n t h e Uni ted States. Even less i s known

about t h e imp l i ca t i ons fo r phosphorus loadings t h a t w i l l r e s u l t f rom t h e

soon t o be rev i sed Best Avai lab1 e Technology and i n d u s t r i a1 pretreatment

regu la t ions . A1 though these new regu la t i ons are p r i m a r i l y ta rge ted

towards t o x i c chemicals, t h e recommended technologies may have profound

e f f e c t s on both i n d u s t r i a l and munic ipal phosphorus discharges.

It i s d i f f i c u l t t o determine t h e ex ten t t o which implementation o f t h e

e x i s t i n g U.S. l e g i s l a t i o n , f o r example t h e 1977 Clean Water Act, t he

Resource Conservation and Recovery Act, and t h e past l e g i s l a t i o n embodied

i n t h e 1972 Water P o l l u t i o n Cont ro l Act Amendments, w i l l c o n t r i b u t e t o

at ta inment of t h e c u r r e n t l y s ta ted phosphorus t a r g e t loads. New p o l i c y

i ncen t i ves may o r may n o t be requi red.

4. Soc ia l Cost o f P o l i c y E r ro r

To asce r ta in t h e l i k e l y s o c i a l cos ts o f making a p o l i c y e r r o r requ i res an

ana lys is o f t h e costs, bene f i t s , d i s t r i b u t i o n a l imp l i ca t i ons , and

implementat ion p o s s i b i l i t i e s o f va r i ous p o l i c y a l t e r n a t i v e s - - i n c l u d i n g t h e

a l t e r n a t i v e o f doing nothing. Current knowledge o f these areas seems

r a t h e r weak. Whi le t h e u n i t cos ts o f c e r t a i n munic ipa l and a g r i c u l t u r a l

phosphorus t reatment technologies have been est imated (see Chapter 5),

t o t a l incremental p o l i c y costs, which account f o r t h e cu r ren t s ta tus o f

in -p lace t reatment technology, have no t been estimated. There appear t o

have been no e f f o r t s t o p rov ide q u a n t i t a t i v e est imates o f b e n e f i t s o r o f

cos t and b e n e f i t d i s t r i b u t i o n s among i nd i v i dua l s , households, o r

geographical regions. Analyses o f implementation s t r a t e g i e s appear

nonexistent.

As a r e s u l t , w h i l e a g r i c u l t u r a l s t r a t e g i e s appear t o be l eas t - cos t

approaches t o c u r r e n t l y s ta ted ta rge ts , i t i s unclear whether such

s t r a t e g i e s can be r e a l i s t i c a l l y implemented. I n add i t ion , t h e equ i ty , of

p lac ing t h e burden on a g r i c u l t u r a l populat ions r a t h e r than on more urban

populat ions has. n o t been assessed. . .

It does appear t ha t , a t cu r ren t phosphorus load ing leve ls , t h e

eu t roph i ca t i on o f t h e Great Lakes has s t a b i l i z e d and t h e process may even

be reve rs ib le . This s i t u a t i o n i s f o r t u n a t e f o r i t permi ts t h e caut ious

approach embodied i n t h e conceptual framework. If necessary, more r a d i c a l

p o l i c i e s can be app l i ed a t a l a t e r date w i thou t t h e delay lead ing t o

ser ious consequences.

6.4 SPECIFIC STRATEGIES

The above conceptual framework$ and t h e c u r r e n t s t a t e o f knowledge suggest

t h e f o l l o w i n g t h r e e s p e c i f i c act ions:

1. Urge t h e implementation o f cu r ren t laws and t r e a t y agreements and

reassess t h e s i t u a t i o n a f t e r a pe r iod o f one year. ,

2. Assemble data, when ava i lab le , f rom e x i s t i n g sources, o r develop new

data cover ing t h e fo l l ow ing b e n e f i t categor ies:

Munic ipal Water Suppl ies (Potable Water)

The Great Lakes serve as an important source o f d r i n k i n g water f o r t h e m a j o r i t y o f bas in res iden ts (35 m i l l i o n people). To what ex ten t have water qual i t y cond i t i ons r e l a t e d t o phosphorus add i t ions r e s u l t e d i n increas ing cos ts both c a p i t a l and opera t ing a t water treatment p lan ts? From t h e consumer's perspect ive can p e r i o d i c t a s t e and odor problems be l i n k e d t o phosphorus r e l a t e d water q u a l i t y cond i t i ons? Do p u b l i c percept ions o f d i f f e rences i n t h e t r o p h i c character o f i n d i v i d u a l lakes r e s u l t i n t h e adopt ion o f more c o s t l y water supply opt ions, e.g. London and Kitchener/Waterloo?

I n d u s t r i a l Water Supply ( D i r e c t Users)

Many i n d u s t r i e s i n t h e Great Lakes bas in u t i l i z e technologies which r e q u i r e l a r g e q u a n t i t i e s o f water f o r both consumptive and nonconsumptive uses. Do i n d u s t r i a l users o f Great Lakes water r e a l i z e economic pena l t i es due t o d i f f e rences i n t h e t r o p h i c c o n d i t i o n o f water supp l ies? Does water q u a l i t y ac t as an important l o c a t i o n a l f a c t o r ? Do i n d u s t r i e s which have nonconsurnptive uses o f water, e.g. c o o l i n g water f ace a d d i t i o n a l cos ts fo r pretreatment i n some areas as opposed t o o thers?

Hydro E l e c t r i c Power Generation

I n an i nc reas ing l y energy power world, conversion o f Great Lakes water power t o e l e c t r i c i t y , about 50 b i l l i o n k i lowat t -hours each year, makes an important c o n t r i b u t i o n t o t h e r e g i o n ' s energy budget. Have a d d i t i o n a l cos ts been i ncu r red e i t h e r by a l t e r a t i o n s t o standard p l a n t design o r through changes i n ope ra t i ona l procedures t o accommodate changing water qual i t y cond i t i ons r e s u l t i n g from increas ing phosphorus loadings?

Property Values

Decaying aquat ic vegeta t ion washed up on Great Lakes shore l ines has o f t e n been i d e n t i f i e d as one of t h e most obvious l i a b i l i t i e s associated w i t h eutrophic waters. Has t h e occurrence o f t h i s phenomenon af fected . sho re l i ne proper ty values? Have areas which have not experienced s i m i l a r problems exh ib i t ed para1 l e l o r d ivergent p r i c i n g t rends? To what extent a re t h e l o c a t i o n a l preferences o f buyers a f fec ted by r e a l o r perceived not ions o f water q u a l i t y ?

Tourism & Recreat ion

Ontar io earnings from tour ism and rec rea t i on account f o r $9.34 b i l l i o n o r 11 percent of t h e Gross Nat ional Product. Have pa t te rns and i n t e n s i t y of t ou r i sm and r e c r e a t i o n a c t i v i t y been a f f e c t e d by t h e changing t r o p h i c character of t h e Great Lakes?

Swimming

Swimming i s one of t he most popular rec rea t i on a c t i v i t i e s based on an ana lys is o f user day p a r t i c i p t i o n leve ls . Are those invo lved i n d i r e c t water contac t r e c r e a t i o n a c t i v i t i e s af fected i n t h e i r p u r s u i t o f these a c t i v i t i e s by changes i n t r o p h i c cond i t i ons? What are t h e costs o f keeping beaches c lean of decaying aquat ic vegetat ion? Have t h e r e been changes i n t h e focus o f marina operat ions t o areas w i t h h igher q u a l i t y water?

Sport F ish i .ng .

The expression coarse and u r~des i rab le i s o f t e n used t o descr ibe t h e f i s h species normal ly found i n eutrophic waters. To what ex ten t has t h e change f rom so c a l l e d h igh q u a l i t y stocks t o t h e coarser v a r i e t i e s a f fec ted t h e spo r t f i s h e r y ? I s t h e q u a n t i t y o f catch as important o r more important than t h e qua1 i t y ?

Recent s tock ing o f anadromous f i s h has r e s u l t e d i n a new focus fo r t h e spo r t f i s h e r y . Do t r o p h i c cond i t ions a f f e c t t h e s u r v i v a l o f these 'f,i s h?

Aesthet ics

Shore1 i ne v i s t a s and spark1 i n g waters are c red i ted w i t h ho ld ing important i n t r i n s i c values f o r v i s i t o r s t o t h e lakes. To what extent do eutrophic cond i t i ons d e t r a c t from these va lues? ' Have there-been measurable d i f f e rences i n t h e number o f v i s i t o r s t o sho re l i ne r e c r e a t i o n s i t e s i n areas subjected t o eutrophic cond i t ions as opposed t o those which have no t? I s t h e recent upsurge i n development of new sho re l i ne rec rea t i on f a c i l i t i e s l i n k e d w i t h chaGging t r o p h i c cond i t i ons?

Waterfowl Hab i ta t

Important popu 1 a t ions o f waterfowl i n h a b i t Great Lakes coas ta l regions. They a lso serve as an important f l yway f o r m ig ra t i ng waterfowl. What are t h e e f f e c t s o f eu t roph ica t ion on waterfowl h a b i t a t and m ig ra t i on pa t te rns? What i s t h e e f f e c t on waterfowl hunt ing and i t s support ing i n f r a s t r u c t u r e ?

Commercial F i s h i n g

Over t h e l a s t 50 years the re has, been a marked change i n t h e composit ion o f t h e commercial f i s h catch, ( f rom lake t r o u t and b l u e

p i c k e r e l t o perch). by changing t r o p h i c t r o p h i c cond i t i ons t h e i n t r o d u c t i o n o f

Has t h e Great Lakes commercial f i s h e r y been damaged cond i t i ons? I s i t poss ib le t o i s o l a t e t h e impact o f

from o the r problems which a f f e c t t h e f ishery, such as tox' ic contaminants and o v e r f i sh ing?

3. Es tab l i sh a v a r i e t y o f mechanisms t o o b t a i n in fo rmat ion on s o c i a l

b e n e f i t s and cos ts associated w i t h changing t r o p h i c cond i t i ons i n t h e

Great Lakes. A number o f these mechanisms are presented below:

a) Es tab l i sh an Advisory Committee comprised o f members o f t h e p u b l i c t o

p rov ide an i n p u t t o d e t a i l e d program design a t t h e e a r l i e s t stage.

Since many o f t h e parameters being examined i n t h e study d i r e c t l y i n v o l v e the measurement o f p u b l i c values through one way and two way communication, i t w i l l be a d e f i n i t e advantage t o i nvo l ve t h e p u b l i c i n p rov id ing study d i r e c t i o n . 'This i s important f o r two reasons: f i r s t , i t avoids poss ib le c r i t i c i s n i t h a t p u b l i c values were not f a i r l y o r adequately assessed and second, i nnova t i ve and c o n s t r u c t i v e i n s i g h t s can o f t e n be o f f e r e d by those no t burdened w i t h preconceptions and d o c t r i n a i r e l i n e s o f reasoning. Es tab l i sh c l e a r l y de f ined ob jec t i ves f o r t h i s committee w i t h i n t h e o v e r a l l s tudy framework and prov ide s u f f i c i e n t f i s c a l resources.

b) I n s t i t u t e a coord ina t ion mechanism between Canada and t h e Uni ted

States t o ensure development o f a comprehensive study design.

'The Great Lakes represent a major shared resource between Canada and the Uni ted States. So lu t ions t o whole l ake problems must be considered i n a comprehensive fash ion by bo th countr ies; there fore , impacts must be assessed from a comparable data base. This w i l l avoid l a t e r problems when e f f o r t s a re made t o assess t h e r e l a t i v e conseqlrences f o r each count ry o f d i f f e r e n t phosphorus management s t ra teg ies .

c ) Develop a s o c i a l p r o f i l e o f t h e Great Lakes bas in t o i d e n t i f y : - t h e var ious pub l i cs t o be involved; - t h e l e v e l o f knowledge and b e l i e f s about t h e sub jec t matter; - t h e leadership and organizat ions; and -

' t he media coverage and ef fect iveness.

Complet.ion o f t h i s f i r s t step w i l l he lp t o avoid l a t e r problems o f having overlooked segments. o f t h e popu la t ion who have a use fu l c o n t r i b u t i o n t o make. The in fo rmat ion gathered w i l l a lso f a c i l i t a t e communication w i t h t h e var ious p u b l i c s i d e n t i f i e d .

d) Undertake a program of publ i c in fo rmat ion i nvo l v ing : - development of f a c t sheets on remedial measure op t ions and water

q u a l i t y impacts;

- media presentat ions;

- p u b l i c meetings; and

- audio v i sua l in format ion.

The conduct o f an in format ion program w i l l ensure. t h a t those pub l i cs invo lved are informed about t h e issues and thus ab le t o make a. more cons t ruc t i ve input . Pub1 i c meetings can serve t h e dual purpose o f i d e n t i f y i n g i n d i v i d u a l s who are i n te res ted i n p a r t i c i p a t i n g i n a more i n t e n s i v e program of publ i c consul t a t i o n as we1 1. as - f a c i 1 i t a t i n g t h e co! l e c t i o n o f concerns from a wider audience.

e) Assess t h e a t t i t u d e s and percept ions o f Great Lakes res iden ts through

soc ia l surveys and informant i nte rv iew i rig.

Through t h e uses o f some o f these techniques, those who are unable/or u n w i l l i n g t o become invo lved i n a more p u b l i c d iscussion o f issues w i l l have an oppor tun i t y t o cont r ibu te .

In fo rmat ion c o l l e c t e d i n surveys w i l l c o n t r i b u t e t o t h e process of understanding broad based publ i c a t t i t u d e s and percept ions. Sound water p lanning and management must consider how people perce ive t h e lakes and what aspects of t h i s resource they are concerned about. Users and nonusers a l i k e must be considered.

f ) Provide f o r more i n depth involvement o f t h e pub l i c . - e s t a b l i s h a p u b l i c consu l ta t i on program on a reg iona l bas i s w i t h

representa t ion from e lec ted o f f i c i a l s ( a l l t h r e e l e v e l s o f

government), i n d u s t r i a l i n t e r e s t s a f fec ted by changing water

qua1 i t y , o ther i n t e r e s t groups, e.g. anglers clubs, co t tager

associat ions, educators, commercial fisherman...

- use "nominal group", and o ther p u b l i c p a r t i c i p a t i o n techniques

as means o f determining t h e b e n e f i t s from i d e n t i f i e d management

approaches.

- prov ide ob jec t ives , t i m e frame, and ensure techn ica l support

where requi red.

Use o f t h i s approachprovides an oppor tun i t y f o r an i n t e n s i v e i n t e r a c t i o n w i t h those most a c t i v e l y invo lved i n a c t i v i t i e s which may be affected by changes i n water q u a l i t y . Through t h e use o f techniques such as t h e nominal group, t h e r e i s a r e a l oppor tun i t y t o determine o v e r a l l p u b l i c percept ions and t o descr ibe reg iona l va r i a t i ons .

g ) Survey t h e s ta tus o f in -p lace treatment technology f o r municipal,

i n d u s t r i a l , and a g r i c u l t u r a l f a c i l i t i e s .

In fo rmat ion o f t h i s s o r t i s essen t i a l f o r ascer ta in ing t h e t r u e incremental costs of a l t e r n a t i v e s t ra teg ies .

h) Undertake one o r two case studies.

Probably one o f t h e more manageable ways o f assessing t h e s o c i a l and economic imp l i ca t i ons o f eu t roph ica t ion w i l l be t o begin w i t h a s tudy cover ing a more r e s t r i c t e d area than t h a t o f t h e e n t i r e Great Lakes basin. Along both o f t h e Canadian and American shore l ines the re are a number o f embayments which would be su i tab le . These embayments are already eutrophic due t o h igh n u t r i e n t loadings and r e s t r i c t e d c i r c u l a t i o n w i t h whole l ake waters.

A study o f t h e soc ia l and economic issues o f concern t o res idents and v i s i t o r s a l i k e cou ld be r e a d i l y compared t o those found i n areas immediately adjacent which are not located on eutrophic waters. I n Canada, t h e Bay of Quinte, and t o a lesser ex ten t Bu r l i ng ton Bay i n Lake Ontar io a re areas where problems associated w i t h eutrophic cond i t i ons a l ready ex i s t . I n t h e Uni ted States, Saginaw Bay i n Lake Huron and Green Bay i n Lake Michigan prov ide para1 l e l oppor tun i t ies .

It i s be l ieved t h a t these steps w i l l p rov ide a sens ib le approach g iven t h e

present s t a t e o f in fo rmat ion and t h e needs f o r f u t u r e in format ion. I n

addi t ion, t h i s approach w i l l p rov ide a more balanced response t o the four

bas ic in format ion needs i d e n t i f , i e d i n t h e conceptual framework.

I n t h e preceding chapters, t h e task f o r c e has prov ided a d iscussion o f

phosphorus t a r g e t loads, phosphorus inputs, models used t o develop ta rge ts ,

and techniques and costs o f phosphorus con t ro l . On t h e basis o f t h i s

in format ion, t he task force i s proposing a staged approach t o f u r t h e r

phosphorus management f o r t h e Great Lakes. I n addi t ion, t h e task f o r c e has

concluded tha t , i n order t o es tab l i sh p o l i c y t h a t w i l l be e f f e c t i v e over t h e

long term, i t w i l l be necessary t o c a r r y o u t a program t o ob ta in in format ion

t h a t can be used t o p rope r l y assess t h e s o c i a l and economic consequences o f

managing phosphorus inputs t o the Great Lakes. . % .

Chapter 6, e n t i t l e d "St ra teg ies f o r Assessing t h e Socia l and Economic I

Impacts o f Great Lakes Phosphorus Management", prov ides a conceptual framework

o u t l i n i n g t h e commitments r e q l ~ i r e d t o i n i t i a t e a -ptograni which should be

undertaken immediately t o p rov ide t h e knowledge hse 'needed t o develop and

implement p o l i c y i n para1 l e l w i t h the staged :approach t o phosphorus management

g iven i n t h e fo l l ow ing discussion.

7.1 BASIC PREMISES

The phosphorus management s t ra tegy and recommendations t h a t f o l l ow , a re

based on t h e evaluat ions and observat ions made by var ious members and

subcommittees o f t h e task force. These evaluat ions and observat ions have

prov ided t h e framework w i t h i n which t h e f o l l o w i n g bas ic premises have been :I :

i d e n t i f i e d .

e The f i n d i n g s o f t h e task f o r c e w i t h respect t o present phosphorus

loads t o each o f t h e Great Lakes, eu t roph ica t ion c o n t r o l ob jec t i ves

and t a r g e t loads, and estimated f u r t h e r reduc t ion i n phosphorus loads

which may be requ i red t o meet t he t a r g e t loads, are summarized i n

Table 7.1.

9 The t e n t a t i v e t o t a l phosphorus t a r g e t loads proposed i n t h e 1978

Great Lakes Water Q u a l i t y Agreement represent t h e best s c i e n t i f i c

TABLE 7.1 PHOSPHORUS CONTROL PROGRAM FOR THE GREAT LAKES

Lake

SUPERIOR

MICHIGAN

HURON

ERIE

ONTARIO

2 .. ,u ,4: '..* * Present programs inc lude r e s t r i c t i o n s on the phosphorus cont6;t ofi detergents and a requirement t h a t ill p o i n t source disdR'arg,{s g rea te r than - . . . 3,800 cu m/d ( 1 MGO) con ta in not more than 1.0 mg/L of t o t a l :6hosfihorg.s. ;; + . . = rd - -2 C'

- . - ,-,a ;'.. ... i. .2. v1 -7 ,:$ "' t / y r - met r i c tons per year --' 5.'- 1.3 b

31 !\: :'?~ , . . ' .. ,-: 1.9 -? :a 5

, .- -. 3.. \ .-. L;3_.

& % - a 1 -. - . .. ,', 4

.".,. p; .. :j: .: ! ' .> ill i: =. . . 2. t

i. c>

. s 5 !,j --l .- c- - e: ' ' - "-? -- .? - a

q 4' ei : . C' --. . . - - 0 c . r . ' i' - L? :?&' ,

* .. - - .LC - ', :. . 9 2 t?} - +' . . ...,

!-G -- . . ;A> , L: <- i

: 1: u., . . . .: . ?. 7 . . . ; 1" .. . - .A 2.. . . -* ., -d. ?L <<, ?.b .

. . < L:. L.:. .-, .: ti .U L' , 2 . . : v .- : , -'+ 5: C. - . . . :. .- . .. . 2: L . . .:. c;. .*.. --. . -2

, -; ZI -2 :.; . . .... r , . I . . . . - -. ' :. r : 7 -. "<. <'C .'. L-: .c c,- .: -.>. 10 f C

- 3 . > .;* 3 -. L:. . L I '4. 7- .- -. :,, <<. r- ' . - ,

.: ... # .-. 0 '.:" . -. - , .. . .- . . . . ; : 1. ... KJ --- . - . . - .-- .:. I. . ", -.. d C. L) 2: . W. ',? q. KJ B-> . ' x. . > ,A ,.> . . . . > ,=- C>. - &, J > -' - . . - -.. 7: ':? ' . . rJ zz ?3 . . ... i. . . - 3 . .*^I !I,.. r? ,._. . c.-> >.-.< .".. ..: - 3 <.

-* . .

1976 ~ o t - a l ~ h o s ~ h o r u s ' Inpu t Load ( t l y r ) . . . . . ..

. . 4,200

6,400

. . 4,900

18,400

1 1', 800

. .

. . I. .:. '.> .

Eutrophicat ion. Contro l Object ives ' . ,;:Tot a1 Phosphorus

. . - Object ives Tanget .Load ( t / y r ) 7.1 .-. 1 ... .

:> <: Nondegradation:; ". 3,400

- ,- .I_ -2. .a*.

.; Nondegradationz g' 5,600 :+ .

Nondegradat) o$ 4., 400 .-. I:;

Improved qua1 i g y ~ , 1 1 , 0 0 0 . -.

. .:. i9 f.+ i.. :. Improved qua1 iicy T 7&000

.A is .2 ?

7 8 !$ -<

d. ," -

Estimated Tota l Phosphorus Loading A f t e r F u l l

Implementation O f Present .Programs* ( t l y r )

..

3,400' ' . . .,-

5,600 . ' t ; ,.?

. . ,

.. 4,400 . d

14,700 , .

. . . . ' . 9,600 .

- . .

1-

:; ~8 l i ti:bnal Reductions I n ' '

To ta l -Phosphorus Loadings $2 ~ G i c h - ~ a ~ Be Required ( t / y r )

B e i t E j t i m a t e .Range .4 - * . ..

.?-?. ;-Z .. ..

. - 1 L> "..'. ,a % . - -- .. - ... '77 :+ .. -". 3 r+ ,-:. - !,. '. r e L-5 . , 0 -i'

:e - -- . i*)

-- --a 2 .-. 3300 0 t o 9,400 ..+ t, " -2.

FJ " 2,$00 . 200 . to 5,400 < Q ---

L A .I'.. CD . . 9 - .

o p i n i o n as t o reasonable goals f o r ach iev ing water q u a l i t y ob jec t i ves

and p rov ide t h e bas is f o r developing a phosphorus management s t r a t e g y

f o r t h e Great Lakes.

A measure of u n c e r t a i n t y has been i d e n t i f i e d w i t h respect t o both t h e

t a r g e t loads and t h e e s t h a t e s o f t h e i n p u t loads.

Based p r i m a r i l y on an .assessment o f t h e models used t o develop t h e

t a r g e t loads, t h e task f o r c e est imates t h a t t h e t a r g e t loads f o r Lake

E r i e and Lake Ontar io have a range o f p l u s o r minus 30 percent and 20

percent, r espec t i ve l y .

A f te r rev iewing t h e data and assumptions used i n developing present

est imates o f t o t a l phosphorus i npu ts t o t h e lakes dur ing 1976, t h e

task f o r c e considers these est imates t o be w i t h i n p l u s o r minus 15

percent o f t h e ac tua l load f o r t h e sources included. , .

It i s recognized t h a t t r i b u t a r y phosphorus i npu ts a re a l so

charac ter ized by s i g n i f i c a n t annual v a r i a t i o n s due t o weather and

hydrology. This annual v a r i a t i o n can be as l a r g e as t h e reduc t ions

expected from implementat ion o f major c o n t r o l programs i n t h e

t r i b u t a r y watersheds.

The task f o r c e recognizes t h e ' f a c t t h a t o n l y f u r t h e r study o f t h e

f a c t o r s lead ing t o these u n c e r t a i n t i e s w i l l a l l ow a t i g h t e n i n g of

these ranges. This conclus ion g ives d i r e c t i o n t o f u r t h e r work. ' But

more impor tan t ly , t h e load ranges g i v e d i r e c t i o n f o k s t ra tegy

development.

0 Lakes E r i e and On ta r i o have undergone major changes i n water q u a l i t y

and b i o t a associated w i t h eu t roph ica t ion . The task f o r c e be l ieves

t h a t i t i s h i g h l y probable t h a t programs and remedial measures i n

a d d i t i o n t o those s p e c i f i e d i n t h e 1972 Great Lakes Water Q u a l i t y

Agreement w i 11 be requ i red t o reduce phosphorus inputs. The bes t

es t imate o f t h e a d d i t i o n a l load reduc t i on which may be ' requ i red i n

order t o meet t h e t a r g e t load o f 11,000 t / y r f o r Lake E r i e i s 3,700 -

t /yr and t o meet t h e t a r g e t o f 7,000 t l y r f o r Lake Ontar io a

reduc t i on of 2,600 t /yr may be requi red.

The est imates o f past, present, and fu tu re i n p u t phosphorus loads and

t h e i r r e l a t i o n s h i p t o t h e t a r g e t loads proposed by Task Group 111,

a re i l l u s t r a t e d i n F igu re 7.1 f o r Lake E r i e and i n F igu re 7.2 f o r

Lake Ontar io. The degree o f unce r ta in t y i n bo th t h e inputs and

t a r g e t loads determined by t h e task f o r c e are a lso shown i n F igures

7.1 and 7.2. Recognizing t h e unce r ta in t y i n - bo th t h e t a r g e t s and t h e

i npu t loads, f u t u r e load reduct ions which may be requ i red f o r Lake

E r i e vary from zero t o 9,400 t / y r and f o r Lake Ontar io from 200 t o

5,400 t / y r .

. .

a , The open waters o f Lakes Superior, Michigan, and Huron are considered

t o be o l i g o t r o p h i c and c o n t r o l ,o f anthropogenic i npu ts o f phosphorus

t o these lakes, as recommended i n t h e 1978 Great Lakes Water Q u a l i t y

Agreement, i s based on a concept o f nondegradation o r maintenance of

t h e present h igh q u a l i t y waters i n these lakes. The t a r g e t loads

shown i n Table 7.1 should be met w i t h f u l l implementation o f t h e

recommended c o n t r o l programs. However, s p e c i f i c p o r t ions o f t h e

upper lakes, such as Saginaw Bay, Green Bay and p o r t i o n s of Georgian

Bay, a re p resen t l y degraded and a d d i t i o n a l reduc t ions i n phosphorus

inputs t o these areas may be requi red.

a The present phosphorus and ch lo rophy l l ob jec t ives , developed by t h e

Science Advisory Board's Committee on t h e S c i e n t i f i c Basis f o r Water

Q u a l i t y C r i t e r i a and used by Task Group I 1 1 as t h e bas is f o r

es tab l i sh ing t h e t a r g e t loads, represent t h e bes t s c i e n t i f i c op in ion

of experts. However, these ob jec t i ves should be p r o p e r l y viewed as I

gu ide l ines and may change as our understanding and knowledge

increases.

The f i n a l s p e c i f i c a t i o n o f phosphorus and ch lo rophy l l ob jec t i ves can

not be f u l l y ascer ta ined w i thout a b e t t e r understanding o f t h e s o c i a l

b e n e f i t s t o be der ived from a reduc t i on i n eutrophicat ion.

FIGURE 7.1 ESTIMATED TOTAL PHOSPHORUS TO LAKE ERIE

1981 TARGET

PHOSPHORUS CONTROL PROGRAMS STATUS

TOTAL LOAD ( t / y r )

MUNICIPAL LOAD ( t / y r )

Note: Area of c i r c l e s i s p ropor t iona l t o t o t a l phosphorus load and hatched area i s p ropor t iona l t o municipal po in t source load.

Target. Load To Achieve Desired Water Q u a l i t y Condit ions

I 11; 000 i

No Programs P a r t i a l Implementation F u l l Implementation o f 1972 Agreement Programs I o f 1972 Agreement, Programs I

14,700

2,900

1

I 30,000 18,400

18,200 6,600

TARGET

PHOSPHORUS CONTROL PROGRAMS STATUS

P a r t i a l Implementation of 1972 Agreement Programs

F u l l Implementation of 1972 Agreement Programs

Target Load To Achieve Desired Water Q u a l i t y Condit ions

Note: Area of c i r c l e s i s p ropor t iona l t o t o t a l phosphorus load and hatched area i s propor t ional t o municipal po in t source load.

TOTAL LOAD ( t / y r )

MUNICIPAL LOAD ( t / y r )

19.400

11,600

o Contro l o f eu t roph i ca t i on o f t h e Great Lakes has been o f major

concern because o f t h e de le te r i ous changes i n q u a l i t y and b io ta .

Nevertheless, i t i s important t o recognize t h a t o the r stresses, e.g.

i n t r o d u c t i o n o f e x o t i c species, o v e r f i s h i ng, and t o x i c substances may

have c o n t r i b u t e d t o these changes. The r e l a t i v e importance of these

st resses has no t been determined, bu t i t i s poss ib le t h a t a s t r a t e g y

which addresses t h e eu t roph i ca t i on issue can c o n t r i b u t e t o r e s o l v i n g

t h e t o x i c substances problem.

0 The models, which were used t o c a l c u l a t e t h e t a r g e t loads, have been..

s t ruc tu red t o analyze cond i t i ons i n t h e pe lag i c zone o f a l ake o r t h e

l a k e as a whole, b u t do no t s p e c i f i c a l l y . a d d r e s s t h e l i t t o r a l zone.

This area, t o which t h e p u b l i c i s more s e n s i t i v e and o f which they

are more aware, may respond i n a d i f f e r e n t manner.

0 Given t h e present s t a t e o f knowledge, phosphorus management

s t r a t e g i e s must be based on c o n t r o l o f t o t a l phosphorus. However,

t h e ques t ion o f b i o l o g i c a l l y a v a i l a b l e versus t h e nonava i lab le

phosphorus i s an important concern and programs must be developed t o

permi t f o rmu la t i ng management s t r a t e g i e s based on c o n t r o l o f

b i o a v a i l a b l e forms o f phosphorus.

0 Chemical p r e c i p i t a t i o n technology f o r phosphorus removal t o 1.0 mg/L

i s being p r a c t i s e d a t many mun ic ipa l wastewater t reatment p l a n t s i n

t h e Great Lakes basin. As we1 1, proven technologies e x i s t which can

reduce t h e t o t a l phosphorus concent ra t ion o f munic ipa l waste waters

t o 0.3 mg/L and less. The cos t o f phosphorus removal f o r achiev ing

these l e v e l s v a r i e s considerably. This i s a t t r i b u t e d t o s i t u a t i o n s

which a1 low f o r add-on processes t o e x i s t i n g p l a n t s on one hand i n

con t ras t t o s i t u a t i o n s which r e q u i r e t h e design o f a new p lan t .

I n view o f t h e above premises, t h e task f o r c e concludes t h a t i t i s h i g h l y

probable t h a t programs i n a d d i t i o n t o those s p e c i f i e d i n t h e 1972 Agreement

w i 11 be requ i red t o f u r t h e r reduce both p o i n t and nonpoint source phosphorus

i npu ts t o the Great ~ a k e s . However, given t h e na ture o f t h e v a r i a t i o n s and

the degree o f the u n c e r t a i n t i e s i d e n t i f i e d i n these premises, t h e task force

proposes t h a t a phosphorus management s t ra tegy be developed as a cont inu ing

process encompassing a staged approach which inc ludes implementation programs,

study programs, eva lua t i on o f s tudies, and dec is ion making.

A s t a g e d app'roach w i 11 permi t the phosphorus management s t ra tegy t o

minimize t h e e f f e c t of these v a r i a t i o n s and u n c e r t a i n t i e s and be s u f f i c i e n t l y

f l e x i b l e t o incorpora te mod i f i ca t i ons as the management s t ra tegy i s

implemented.

The approach accepts ' the t a r g e t loads as gu ide l ines f o r p lanning

purposes. Target loads and c o n t r o l programs can be r e f i n e d and developed i n a

sequential , interdependent, and evo lv ing fashion, i .e. implement, measure and

evaluate, and plan. Analys is o f t he b e n f i t s gained and t h e knowledge der ived

as the s t ra tegy i s implemented w i l l p rov ide the bas is f o r making i n t e r i m

deci s i ons.

The task f o r c e ' s recommendations f o r t he proposed s t r a t e g y are presented

i n terms of : management o f p o i n t sources, management o f nonpoint sources, and

major in fo rmat iona l needs t o more p r e c i s e l y de f i ne an appropr ia te s t rategy.

7.3 MANAGEMENT OF POINT SOllRCES

A major component o f any s t r a t e g y f o r phosphorus management i s a program

t o con t ro l munic ipal wastewater p o i n t source inputs. Recommendations f o r

implementing such a program are presented below:

All municipal wastewater treatment plants discharging in excess

of 3,800 cu m/d (1 MGD) in the Great Lakes basin should be

designed and operated so that the total phosphorus concen-

trations in their effluents will not exceed a maximum of 1.0

mg/L. This objective should be pursued and accomplished as

quickly as possible.

F u l l implementation o f t h i s program w i l l achieve t h e t a r g e t loads fo r t h e

Upper Great Lakes and reduce t h e 1976 est imated t o t a l phosphorus loads t o

Lakes E r i e from 18,400 t / y r t o 14,700 t / y r and f o r Lake Ontar io from 11,800

t / y r t o 9,600 t / y r . Populat ion increases w i l l r e s u l t i n somewhat h igher loads

even w i t h p r o v i s i o n of adequate wastewater treatment.

I n t h e lower Great Lakes basin, adequate wastewater treatment f a c i l i t i e s

genera l l y ex i s t , o r are under construct ion. However, t h e r e i s s t i l l a g rea t

deal of noncompliance w i t h t h e phosphorus ob jec t ive . This can l a r g e l y be

a t t r ' i bu ted t o t h e inadequate opera t ion and maintenance o f e x i s t i n g

f a c i l i t i e s . Programs of f i n a n c i a l and techn ica l support t o m u n i c i p a l i t i e s may

be requ i red t o ensure f u l l achievement o f t h e 1.0 mg/L t o t a l phosphorus

c o n t r o l ob jec t ive .

The fundamental problem faced i n t h e development o f t h e s t ra tegy was t o

ga in i n s i g h t s i n t o t h e extent, urgency, and t i m i n g o f remedial measures. The

f a c t i s t h a t both Lakes E r i e and Ontar io do not p resen t l y meet t h e Agreement

water qua1 i t y ob jec t ives . The p a r t i a l implementation o f t h e program o f

phosphorus removal a t munic ipal sewage treatment p l a n t s has l e d t o an apparent

improvement i n water q u a l i t y and fu r the r improvement i s expected w i t h f u l l

implementation of t h e program. The task f o r c e t h e r e f o r e urges t h e

governments, as a mat te r o f h igh p r i o r i t y , t o f u l l y implement phosphorus

removal t o 1.0 mg/L a t a l l munic ipal sources w i t h f l ows g rea te r than 3,800 cu

m/d ( 1 MGD).

The next problem i s t o de f i ne what a d d i t i o n a l c o n t r o l s should be

implemented, i n what t ime frame, recogn iz ing t h e f a c t t h a t t h e extremes of t h e

ranges f o r t h e est imates o f t h e t a r g e t and i npu t loads f o r Lake E r i e over lap

(F igure 7.1) and nea r l y over lap ' f o r Lake Ontar io (F igu re 7.2). Should

governments await t h e r e s u l t s o f t h e p resen t l y agreed t o phosphorus c o n t r o l

program, recogniz ing t h a t phosphorus sources w i l l cont inue t o increase as

populat ions expand, o r implement a d d i t i o n a l measures leading t o f u r t h e r

phosphorus c o n t r o l ?

A f t e r f u l l achievement o f t h e present programs, t h e best est imate of t h e

expected t o t a l phosphorus load t o Lake Er ie, i s 14,700 t / y r . The present

est imate o f t h e t a r g e t load requ i red t o achieve t h e water q u a l i t y ob jec t i ves

i s 11,000 t/yr. Th is leaves a d i f f e r e n c e o f 3,700 t/yr t o be removed by

a d d i t i o n a l phosphorus c o n t r o l programs. PLuARG3 and LEwMS"~ e s t i ~ n a t e t h a t

nonpoint source c o n t r o l s i n t h e Lake E r i e bas in could remove f rom 1,800 t o

5,000 t lyr. I n t h e absence o f d e f i n i t i v e cos t performance r e l a t i o n s h i p s f o r

nonpoint source c o n t r o l s t h e task f o r c e judges t h a t 2,000 t /yr cou ld be

removed a t cos ts which are economical ly compet i t i ve w i t h a d d i t i o n a l p o i n t

source cont ro ls . Therefore, a d d i t i o n a l p o i n t source c o n t r o l s may be needed t o

remove t h e remain ing 1,700 t l y r (3,700 t / y r - 2,000 t l y r ) . This would mean

t h a t mun ic ipa l t reatment f a c i l i t i e s l a r g e r , t h a n 3,800 cu m/d would need t o

reduce t h e i r e f f l u e n t phosphorus concentrat ions t o about 0.3 mg/L.

The best es t imate o f t h e expected load t o Lake Ontar io, a f t e r f u l l

implementat ion o f present programs, i s 9,600 t/yr. The present es t imate f o r

t h e t a r g e t load i s 7,000 t/yr. This leaves an est imated 2,600 t/yr which may

have t o be removed t o meet water q u a l i t y ob jec t i ves . PLUARG est imates t h e

l i m i t e d nonpoint source c o n t r o l o p p o r t u n i t i e s i n t h e Lake Ontar io bas in t o be

200 t/yr. PLUARG a l so est imates t h a t t h e load t o Lake Ontar io w i l l be reduced

by 1,200 t/yr when t h e t a r g e t load o f 11,000 t / y r f o r Lake E r i e i s achieved.

This leaves 1,200 t /yr which may have t o be c o n t r o l l e d by a d d i t i o n a l t reatment

o f munic ipa l p o i n t sources i n d i c a t i n g an e f f l u e n t phosphorus requirement o f

about 0.3 mg/L.

E l i m i n a t i o n of a l l munic ipa l p o i n t discharges would reduce t h e phosphorus

loads t o Lake E r i e by 2,800 t/yr and t o Lake Ontar io by 1,800 t / y r . These

reduc t ions alone a re n o t s u f f i c i e n t t o meet p ro jec ted t a r g e t loads.

The above f a c t s c l e a r l y i n d i c a t e t h a t a combinat ion o f p o i n t and nonpoint

source c o n t r o l s w i 11 be requ i red i n bo th t h e Lake E r i e and Lake Ontar io basins

i n o rder t o meet t h e p ro jec ted t a r g e t loads. A l l approaches which can reduce

t h e phosphorus loads t o t h e Great Lakes should be considered f o r each

sub-basin and each l o c a l i t y . There undoubtedly w i l l be d i f f e r e n t se t s o f

c o s t - e f f e c t i v e approaches t h a t a re d e s i r a b l e i n d i f f e r e n t p a r t s o f t h e Great

Lakes basin.

Given a requirement f o r f u r t h e r removal o f phosphorus from p o i n t sources,

a program i s recommended which inc ludes eva lua t i on and study, add i t i ona l

t reatment a t e x i s t i n g m ~ n i c i . ~ a l wastewater t reatment f a c i 1 i t i e s , and

cons idera t ion of new and i nnova t i ve technologies i n c l u d i n g 1 and appl i c a t i o n .

This program i s summarized i n F igu re 7.3 and d e t a i l e d i n t he s i x f o l l o w i n g

recommendations:

RECOMMENDATION NO. 2 -

Governments should immediately evaluate the ability of

municipal wastewater treatment facilities in the lower Great

Lakes basin, currently required to meet an effluent limit of

1.0 mg/L total phosphorus, to be operated so as to produce

effluent concentrations below 1.0 mg/L. Those plants

identified which can achieve levels less than 1.0 mg/L should

be operated to achieve these levels as soon as possible.

E f f 1 uent phosphorus 'concentrat ions less than 1.0 mg/L cou ld be achieved a t

many e x i s t i n g p l a n t s by op t im iza t i on o f ' such operat ions as chemical dosing, pH

con t ro l , and f l o w con t ro l . The major goals o f t h e proposed study are: a) i d e n t i f i c a t i o n of e x i s t i n g f a c i 1 i t i e s where improvement i s poss ib le, b)

i d e n t i f i c a t i o n o f means o f fund ing and o ther issues o f implementation, and c )

opera t ion of t h e f a c i l i t i e s a t t h e lower leve ls .

Two a l t e r n a t i v e s are suggested t o p rov ide m u n i c i p a l i t i e s w i t h an economic

i n c e n t i v e t o de f ray t h e increased opera t ing cos ts t h a t t h i s recommendation

coul d i nvol ve:

(1 ) Approve cons t ruc t i on o f new f a c i l i t i e s t o achieve

t h e es tab l i shed optimum phosphorus removal f o r

t he t ype o f t reatment proposed a t t he same t ime

ensur ing t h a t t h e new f a c i l i t i e s are cons i s ten t

w i t h long term p lann ing ob jec t i ves t o achieve

phosphorus l e v e l s o f 0.3 mg/L o r less. This i s

b a s i c a l l y c a p i t a l i z a t i o n o f t he increased

opera t ing costs.

I ENSURE THAT ALL MUNICIPAL WASTEWATER DISCHARGES OF MORE THAN 3,800 cu m/d ( 1 MGD) CONTAIN NO MORE THAN 1.0 mg/L TOTAL I

I nearshore water q u a l i t y problems. I H I n i t i a t e p lann ing f o r - H Complete f a c i l i t y

remain inq f a c i l i t i e s . p l ann inq t o upgrade H Assess optimum phosphorus removal c a p a b i l i t y of e x i s t i n g mun ic ipa l t r ea tmen t f a c i l i t i e s more than 1 MGD i n Lake E r i e & Lake O n t a r i o bas ins t o achieve r e s i d u a l s l e s s than 1.0 mg/L P. S t a r t w i t h l a r g e s t f a c i l i t i e s demonst ra t ing p o t e n t i a l t o produce l e s s t h a n 1.0 mg/L P. Fund t e c h n i c a l suppor t a c t i v i t i e s .

PHOSPHORUS -

E s t a b l i s h l ong term p l a n n i n g o b j e c t i v e s f o r phosphorus c o n t r o l a t major m u n i c i p a l i t i e s i n

I n i t i a t e reassessment Complete H o f l o a d s / t a r g e t s and reassessment mun ic ipa l t r ea tmen t and make req /cos ts i n Lake E r i e a p p r o p r i a t e and Lake Ontar io . recommendations.

-

Lake E r i e and Lake O n t a r i o bas ins . Fund p lann ing s tud ies . . S t a r t w i t h f a c i l i t i e s hav ing

- 1 1 phosphorus removal. I

subs id ies or approve c a p i t a l improvements t o achieve l ess than 1.0 mg/L P i f c o n s i s t e n t . w i t h l ong term p lann ing

-

- Approve fund ing of c a p i t a l improvement o f f a c i l i t i e s hav ing

3

Time - Yrs.

Complete p lann ing f o r f a c i l i t i e s hav ing near shore water q u a l i t y problems.

.

B r i n g remain ing f a c i l i t i e s capable o f l e s s t h a n 1:0 mg/L

l i n e t h r u subs idy o r - approve c a p i t a l improvements t o achieve l ess than 1.0 mo/L.

Complete optimum phosphorus removal assessments.

Eva luate mun ic ipa l c o n t r o l a l t e r n a t i v e s t o c o s t e f f i c i e n t l y achieve P r e s i d u a l s f r o m 0.5 t o 0.1 mg/L such as t e r t i a r y s o l i d s con tac to rs , f i l t e r s , magnet ic separa tors o r adso rp t i on contac tors , and l and a p p l i c a t i o n .

nearshore water q u a l i t y problems.

-on

I

Complete a1 t e r n a t i v e eva luat ions . - - Continue a1 t e r n a t i v e

eva luat ions . Complete eva lua t i ons o f two a l t e r n a t i v e s .

Senior l e v e l s o f government could prov ide munici-

p a l i t i e s i n t h e lower Great Lakes bas in w i t h an

opera t ing subsidy f o r every k i logram o f phos-

phorus removed below t h e 1.0 mg/L requirement

dur ing t h e next f i v e years. A s i m i l a r subsidy

cou ld a lso be used t o p rov ide t h e same i n c e n t i v e

t o t h e nonpoint source c o n t r o l program

implementors. This would encourage f u r t h e r

reduc t ions i n phosphorus i npu ts a t cos ts

equivalent t o t h e cos ts o f cu r ren t programs.

RECCIMMENDATION NO. 3

It is recommended that all planning for future municipal point

source discharges in the lower Great Lakes basin should, for

planning purposes, consider future requirements for total

phosphorus removal to concentrations on the order of 0.1 to 0.5

w / L .

Future discharge objectives from municipal facilities should be

developed employing mass loading allocations. Mass loading

allocations are recommended to encourage the consideration of a

variety of managerial and other structural approaches to reduce

phosphorus inputs . These approaches may include :

o industrial pre-treatment requirements for phosphorus

o detergent phosphorus controls

o effluent fees

o user fees dependent on phosphorus inputs

o other treatment options such as land application

o combinations of the above

The planning should include detailed consideration of costs,

effectiveness, and possible implementation difficulties.

F a c i l i t y p lans t o meet t h e long term ob jec t i ves should be prepared.

Cap i ta l improvements which are i ncons i s ten t w i t h these p lans should not be

approved. These p lans should consider t h e decen t ra l i z i ng o f new capac i ty

investments t o p rec lude land area r e s t r i c t i o n s . f o r conterr~plated t e r t i a r y

f a c i l i t i e s a t e x i s t i n g s i t e s as w e l l as p rov ide oppor tun i t i es t o use land

t reatment f o r new capac i ty wherever poss ib le and cos t -e f fec t i ve .

As soon as p r a c t i c a l , w i t h i n t h e next 5 years, upgrade munic ipal c o n t r o l

f a c i l i t i e s i n t h e Lake E r i e and Lake Ontar io basins l a rge r than 3,800 cu m/d

(1 MGD) which a re capable o f ' achiev ing t o t a l phosphorus e f f l u e n t concen-

t r a t i o n s of less than 1.0 mg/L where j u s t i f i e d on t h e bas is o f nearshore o r

r e c e i v i n g stream water qua1 i ty cons idera t ions.

RECOMMENDATION NO. 4

It is recommended that existing laws and regulations to control

the phosphorus content of detergents in the Great Lakes basin be

retained and that controls be extended immediately to include

Pennsylvania and, in particular, Ohio. It is further

recommended that an independent study of direct and indirect

costs, benefits and disbenefits associated with detergent

phosphorus controls be carried out.

Phosphorus detergent con t ro l s were i n i t i a t e d i n t h e e a r l y t o mid 1970's as

a method o f removing phosphorus from wastewater w h i l e munic ipal wastewater

phosphorus. t reatment f a c i l i t i e s were b u i l t .

The e a r l i e s t c o n t r o l s were e f f e c t i v e i n reducing wastewater phosphorus

concentrat ions. Decreases o f 50 percent and more were achieved. Voluntary

reduct ions by t h e detergent i n d u s t r y i n areas where l e g i s l a t e d c o n t r o l s have

not been imposed,' have reduced t h e p ropo r t i on o f detergent phosphorus. . . p resent

i n munic ipal wastewater t o 20 t o 35 percent.

Immediate reduc t i on i n phosphorus loads t o t h e Great Lakes may s t i l l be

r e a l i z e d w i t h an extension o f detergent c o n t r o l s t o j u r i s d i c t i o n s which have

no such c o n t r o l s and whose waste t rea tment programs a re no t i n compliance. In p a r t i c u l a r , c o n t r o l s i n Ohio a t t h e 2.2 o r 0.5 percen t as phosphorus have t h e

p o t e n t i a l f o r ' reduc ing mun i c i pa l phosphorus d ischarges by 170 and 730 t / y r

r e s p e c t i v e l y . S i m i l a r r educ t i ons f o r Pennsylvania would range f rom 30 t o 50

t/yr. The impact of t h e Pennsylvania i n p u t i s smal l b u t t h e d ischarge o f

detergent phosphorus f r om Ohio f a c i l i t i e s i s s u b s t a n t i a l . P r i o r t o Ohio

coming i n t o t rea tment compliance, immediate b e n e f i t w i l l be r e a l i z e d by

implement ing detergent c o n t r o l s .

Con t i nua t i on o f e x i s t i n g de te rgen t phosphorus c o n t r o l s a re e s s e n t i a l as

t h e y p rov ide a measure of phosphorus c o n t r o l f o r :

o communit ies w i t h d ischarges o f l ess than 3,800 cu m/d f1 MGD) w i t h o u t

phosphorus removal,

o communit ies w i t h combined sewer over f lows,

o households which a r e unsewered,

o c o l l e c t i o n systems and t rea tment p l a n t s which ma l func t ion , and

o f o r t rea tment p l a n t s w i t h phosphorus removal, t h e y reduce t h e degree

o f t rea tment r equ i red , energy and chemical consumption, and s ludge

p roduc t ion .

E x i s t i n g de te rgen t c o n t r o l s appa ren t l y i n v o l v e consumer costs . The

de te rgen t i n d u s t r y suggests these cos t s a re l a r g e compared w i t h t h e

incrementa l cos t s o f phosphorus removal a t t h e wastewater t reatment

f a c i l i t i e s . A need e x i s t s t o v e r i f y these cos t s and i n v e s t i g a t e a l t e r n a t i v e

c o n t r o l measures t h a t may be used t o reduce de te rgen t phosphorus i npu t s t o t h e

Great Lakes. The f u t u r e e f f i c a c y o f such c o n t r o l s must be v e r i f i e d by

app rop r i a te s t u d i e s t h a t address economic and s o c i a l costs , b e n e f i t s and

det r iments , and a l t e r n a t i v e c o n t r o l s t r a t e g i e s . The r e s u l t s o f these s t u d i ~ s

should be used t o p r o v i d e an update o r m o d i f i c a t i o n o f t h e t ask f o r c e ' s

recommendat ions t h a t e x i s t i n g de te rgen t c o n t r o l programs i n t h e Great Lakes

b a s i n should be r e t a i n e d w i t h Ohio and Pennsylvania implement ing s i m i l a r

c o n t r o l s. 97

RECOMMENDATION NO. 5

It is recommended that the governments initiate a technology '

development and demonstration program for a1 term t ive and

innovative treaknt technologies which reliably and cost

effectively achieve various effluent total phosphorus residuals

down to .0.1 mgi/L. It is further recommended that governments . .

develop and evaluate, by field studies, alternative municipal

control technologies to reliably and cost-effectively achieve

reduced effluent residuals of phosphorus which can be used for

both new facilities and to upgrade existizq facilities.

Research and development e f f o r t s which focus on new o r i nnova t i ve

technologies should be cont inued and expanded i n both t h e . Uni ted . States and

Canada. These technologies should be implemented when they are found t o be

cos t -e f fec t i ve . Recent in fo rmat ion i nd i ca tes t h a t new technology used i n

Sweden i s capable o f achiev ing l ess than 0.3 mg/L t o t a l phosphorus a t cos ts

equivalent t o cu r ren t technology. S i t e s p e c i f i c evaluat ions o f f e a s i b l e and

cos t e f f e c t i v e technologies which cou ld be implemented a t major p o i n t sources

(over 38,000 cu m/d) should be c a r r i e d out.

RECOMMENDATION NO. 6

It is recommended that where cost-effective, land application

of wastewaters be utilized.

Increasing numbers o f s tudies have shown t h a t ' land a p p l i c a t i o n can b'e a

c o s t - e f f e c t i v e technology f o r t h e treatment o f m i ~ n i c i p a l and i n d u s t r i a l

wastes. his technology has been used pri'mar-i l y f o r t h e t reatment o f wastes

from small communities bu t a lso can be considered f o r l a r g e r communities. I f

a l l p l a n t s w i t h f l ows l ess than 38,000 cu m/d (10 MGD) were converted t o land

app l ica t ion , t h e t o t a l phosphorus load discharged by munic ipal sources i n t h e

Lake E r i e bas in would be decreased by 700 t/yr, and i n t h e Lake Ontar io basin

S i t e s e l e c t i o n and design guide1 ines r e c e n t l y have become a v a i l a b l e i n

bo th t h e Un i t ed States and Canada t o he lp communi't i e s , c o n s u l t i n g engineers,

and p u b l i c o f f i c i a l s i d e n t i f y t h e cos t -e f f ec t i veness o f land a p p l i c a t i o n i n a

s i t e - s p e c i f i c s i t u a t i o n . I n e v a l u a t i n g land a p p l i c a t i o n as a means t o ach ieve

ve ry low phosphorus i n p u t s t o su r f ace waters, f u l l cons ide ra t i on should be

g iven t o t h e p o s s i b l e adverse impacts o f s o i 1 and groundwater contaminat ion.

It is recommended that studies be initiated to quantify the

reductions. in toxic and hazardous, substances that occur concurrent

with phosphorus removal.

An a n c i l l a r y b e n e f i t o f phosphorus removal by chemical p r e c i p i t a t i o n o r

l and a p p l i c a t i o n i s l i k e l y t o he a r e d u c t i o n i n t h e amount o f t o x i c and

hazardous substances (heavy meta ls and t r a c e o rgan i cs ) d ischarged t o t h e Great

Lakes. The magnitude o f such reduc t i ons i s unknown. Concurrent s t ud ies

should eva lua te t h i s a n c i l l a r y b e n e f i t as w e l l as i t s poss ib- le impact on

s ludge d i s p o s a l / u t i l i z a t i o n s t r a t e g i e s .

7.4 MANAGEMENT OF NONPOINT SOURCES

Nonpoint source c o n t r o l s f o r urban and a g r i c u l t u r a l areas, p w t i c u l a r l y

e ros ion c o n t r o l on fa rm lands which a re i n t e n s e l y cropped and have medium t o

f i n e - g r a i n e d s o i l s , may be r e q u i r e d t o p r o v i d e a t l e a s t a p a r t of t h e I p r o j e c t e d a d d i t i o n a l l oad reduc t i ons needed f o r Lake E r i e and p o s s i b l y Lake ~ I Ontar io .

RECOMMENDATION NO. 8

, .

It is recommended that the nonpoint source component of

I comprehensive phosphorus management plans developed for each

country include the implementation of:

o ' a basin wide public information and education program; and

o where appropriate, those low cost measures which can result

in a reduction in nonpoint loadings based on a common sense

approach to problem solving (PWARGVS proposed Level 1

measures) ;

and the development of:

o a modelling capability for predicting phosphorus reductions

for critical areas within the basin; and

o demonstration watershed studies within these critical

problem areas to evaluate the cost effectiveness of a

variety of remedial measures, identify any problems

associated with their implementation, and provide examples

of implementation as incentives for other farm operators.

Implementation and Evaluat ion:

Both PLUARG and t h e Lake E r i e Wastewater Management Study have i d e n t i f i e d

nonpoint source c o n t r o l measures which can be -implemented c o s t - e f f e c t i v e l y .

The greates t bene f i t from nonpoint source c o n t r o l s i s l i k e l y be t o achieved i n

t h e areas d r a i n i n g i n t o t h e western and c e n t r a l basins o f Lake Er ie .

The ef fect iveness o f a nonpoint management program w i l l be pred ica ted on

t h e ex ten t t o which t h e r e l a t e d issues o f remedial measures and t h e

i n s t i t u t i o n a l arrangements requ i red f o r t h e i r implementation are brought

together . Without a c l e a r understanding o f how each in f luences t h e o t h e r ,

l i t t l e subs tant ive progress w i l l be made towards reducing nonpoint sources o f

phosphorus.

Important quest ions remain w i t h respect t o remedial measures. What

measires are opt imal f o r use under vary ing s o i l , c l imate, and land management

systems and what phosphor~~s load reduct ions can be expected g iven t h e wide,

range o f va r i ab les which w i l l u l t i m a t e l y a f f e c t these measures?

The implementat ion of a nonpoint source remedial measure program i s

complex. Which measures should be used, where 'should t hey b e implemented t o

achieve maximum reduc t ions f o r t h e money spent, how can farmers and

m u n i c i p a l i t i e s be encouraged no t o n l y t o adopt bu t a lso implement these

measures over t h e long term, and f i n a l l y how can t h e changes i n loadings which

u l t i m a t e l y occur be accura te ly assessed?

Answers t o these quest ions cannot be developed separa te ly bu t must be

approached h o l i s t i c a l l y . This s i t u a t i o n i s i n marked con t ras t t o t h e

s i t u a t i o n which preceded t h e imp1 ementat i o n o f t h e p o i n t source phosphorus

c o n t r o l program i n 1972. A t t h a t t ime t h e i n s t i t u t i o n a l means o f achiev ing

r a p i d implementat ion were i n place. However, t h e r e was considerable

unce r ta i n t y concerning which rerr~cdi a1 measures were t h e most appropr ia te.

To reso l ve these issues, Canada requ i red t h e adopt ion o f small p i l o t - s c a l e

s tudies. Regarding nonpoi n t p o l l u t i o n c o n t r o l , t h e unknowns are g rea te r and

t h e c o n t r o l which e x i s t i n g i n s t i t u t i o n s can exer t over 'implementation w i l l be

much less. Thus, t h e r e . i s even a g rea ter need f o r a s i m i l a r incremental

approach be fore widespread adopt i o n o f an extensive nonpoi n t source c o n t r o l

program.

The p r i n c i p a l ac t ions which should be undertaken t o achieve t h e necessary

implementation and eva lua t i on o f t h e nonpoi n t programs are discussed below and

a re i l l u s t r a t e d i n F igu re 7.4.

Concern about nonpoint sources o f phosphorus i n t h e Great Lakes began i n

t h e e a r l y 1970's and t h i s concern was l a r g e l y r e s t r i c t e d t o those persons

studying t h e lakes. Since t h e complet ion o f a number o f s tud ies which

addressed t h e nonpoi n t problem, concern over nonpoi n t sources has been

growing. General p u b l i c awareness o f t h e problem, however, s t i l l remains a t a

low po in t . The PLUARG a g r i c u l t u r a l surveys conducted i n Canada and t h e Un i ted

States under1 ined t h i s fact. ,

FIGURE 7.4 FRAMEWORK FOR A NONPOINT SOURCE ,MANAGEMENT PROGRAM . .

. .

I I I WORK CARRIED OUT I N DEW3NSTRATION I I I I 1 I GREAT LAKES B A S I N WATERSHEDS

A

o

DEMONSTRAT ION DEVELOP A WATER 1 1

-

BEGIN DEVELOPMENT OF AN DEVELOP ESTIMATES OF OVERVIEW MODELLING CAPABILITY CALIBRATE WITH COST EFFECTIVENFSS

CRIT ICAL AREA - TO ALLOW FOR PREDICTION OF P CONTINUE DATA FROM OF NONPOINT PROGRAM IDENTIF ICAT ION REDUCTIONS BASED ON EVALUATION DEVELOPMENT DEMO WATERSHEDS I N C R I T I C A L AREAS OF

WATERSHEDS MANAGEMENT STUDY PLAN SELECTION - 25K1100K DEVELOP WATER QUALITY MONITORING

ACRES I K S I Z E - BASELINE DATA

. .

CONTINUE -AND CONTINUE EVALUATE

PROGRESS

. .. . . .

INFORMATION/EDUCATION - BASINWIDE

I 1 . . - ALGAL ASSAY WORK I I

i IMPLEMENTATION

OF REMEDIAL MEASURES. I N

, DEMONSTRATION WATERSHEDS r

.

+

-

/ CONTINUE EVALUATION IMPLEMENTATION

AND EVALUATE F I N A L REPORT

I

I

IMPLEMENTATION - LEVEL 1 MEASURES - BASINWIDE,

WHERE APPROPRIATE

DECISION . POINT

1 2 5 4 5

CONTINUATION OF YEAR 1

-. .

+

. . T i m e - Y r s .

. . . . .

, :

CONTINUATION OF YEAR 1 + EVALUATION

+ M I D COURSE CORRECTION ( D e c i s i o n P o i n t )

-CONTINUATION OF YEAR 1

+

-b

CONTINUATION AND - CONTINUE AND EVALUATION CONTINUE EVALUATE

M I D COURSE CORRECTION . .

PROGRESS ( D e c i s i o n P o i n t )

A fundamental requirement of any program d i r e c t e d towards encouraging

i n d i v i d u a l s o r i n s t i t u t i o n s t o adopt a program o r measure i s t o develop an

awareness of t h e problem and i t s so lu t i on . Governments must be committed t o

beginning t h i s f i r s t s tep i n a comprehensive and dedicated manner if

widespread adopt ion and implementat ion are t o be achieved.

As a f i r s t p r i o r i t y t h i s program should be d i r e c t e d towards those who are

respons ib le f o r developing nonpoint source management programs. Once t h i s

task i s accomplished t h e program should be widened t o encompass t h e general

pub1 i c .

. . . . Re1 i ance on in format i o n programs t o accompl i sh i r r~pl ementat i o n w i 1 1 no t be

s u f f i c i e n t . Education. programs i n v o l v i n g components o f demonstration and

techn i ca l ass is tance w i l l a l so be requ i red i f widespread vo lun ta ry adopt ion of

improved management p r a c t i c e s i s t o be accompl ished.

Throughout t h e conduct o f t h e i n fo rma t i on and educat ion programs, t h e r e

must be an ongoing eva lua t i on o f t h e i r e f fec t i veness i n developing a h igh

l e v e l o f awareness and commitment t o t h e implementation o f remedial measures.

This eva lua t ion process must be cont inued through t h e pe r i od o f more

widespread implementat ion i n order t o r e g u l a r l y assess t h e l e v e l o f

achievement and t h e changing a t t i t u d e s o f those implementing t h e programs t o

a1 low f o r necessary mod i f i ca t ions i n program de l i very .

Level 1 Remedial Measures

Level 1 remedial measures3 a re low cos t o r no cos t measures which should

be implemented where appropr ia te across t h e basin. They are based on

u t i l i z i n g sound management p rac t i ces o r good land stewardship i n r u r a l areas

and programs f o r p o l l u t a n t reduc t i on a t source i n urban areas. U n t i l a more

thorough ana lys is o f t h e s p e c i f i c problem areas and a l t e r n a t i v e remedial

measures i s undertaken, t h e implementation o f these measures should remain on

a vo lun ta ry basis. Both PLUARG and t h e LEWMS have ind icated, however, t h a t

these measures are t h e most c o s t - e f f e c t i v e next s tep i n a phosphorus

management s t rategy. PLUARG est imates a 900 t /yr reduc t i on i n urban and r u r a l

d i f f use sources w i l l r e s u l t from implementat ion o f these p rac t i ces . LEWMS

es t imated t h a t a r e d u c t i o n of 1,800 t o 5,000 t /y r would r e s u l t i n t h e Lake

E r i e b a s i n if reduced t i l l a g e were adopted on those s o i l s where appropr ia te ,

and assuming f u l l implementat ion, t h a t n e t fa rm income would remain t h e same

o r increase. A reasonable expec ta t i on w i t h i n t h e next 10 yea rs i s t h a t a

2,000 t /yr r e d u c t i o n i n nonpoint source phosphorus l oad i s achievable.

7.4.3 C r i t i c a l Area I d e n t i f i c a t i o n

Not a l l l and areas c o n t r i b u t e e q u a l l y t o t h e nonpoint source phosphorus

load t o su r f ace waters. As w e l l , t h e lakes va ry w i d e l y i n t h e i r r e s p e c t i v e

t r o p h i c cond i t i ons . Given t h i s s i t u a t i o n i t i s v i t a l t h a t these areas where

degraded water q u a l i t y and h igher t i n i t l oad ings o f p o l l u t a n t s occur be

i d e n t i f i e d . . .

A number o f s t ud ies (PLUARG, LEWMS"" have i d e n t i f i e d areas where

problems are most acute. Be fo re implementat ion takes p l a c e i t , i s impor tan t

t h a t f u r t h e r d e f i n i t i o n of these areas t a k e p l ace t o ensure t h e e f f e c t i v e

d e l i v e r y of remedia l measures. Areas w i t h h i g h l y e r o d i b l e s o i l s , i n t e n s i v e

f a rm ing p rac t i ces , s teep s lopes and f r equen t storm events e x h i b i t h i g h r a t e s

o f s o i l l o ss and, t he re fo re , a r e de f i ned as c r i t i c a l areas f o r t h e c o n t r o l of

phosphorus i n p u t s t o t h e Great Lakes.

PLUARG, i n i t s bas inwide approdch t o h o l i s t i c problems, d e f i n e d t h e f i r s t

genera l l e v e l o f c r i t i c a l area i d e n t i f i c a t i o n . The Lake E r i e Wastewater

Management Study focussed on a s i n g l e lake. It then i d e n t i f i e d a watershed i n

Ohio, Honey Creek, t o p rov ide a more d e t a i l e d second- leve l e v a l u a t i o n of

c r i t i c a l areas w i t h i n a major basin. Th is l e v e l o f p l ann ing i s s t i l l t o o

l a r g e t o p r i o r i t i z e c r i t i c a l sub-basins f o r implementat ion o f bes t management

p rac t i ces . A t h i r d l e v e l o f d e t a i l e d sub-basin p l ann ing i s needed t o i d e n t i f y

c r i t i c a l areas o f a managable s i z e i n o rde r t o demonstrate s p e c i f i c p r a c t i c e s

app rop r i a te t o reduce t h e t o t a l phosphorus i n p u t s f rom a g r i c u l t u r a l land.

Some areawide water q u a l i t y management p lans have i d e n t i f i e d c r i t i c a l areas a t

t h i s l e v e l o f d e t a i l . 'These areas a r e p r ime candidates f o r demonstration

p r o j e c t s such as those r e c e n t l y funded under , t he Rura.1 Clean. Water Program and

Model Imp1 ementation Program. ~ u r t h e r gu id lnce on the e f fec t iveness of urban housekeeping measures i n reducing~phosphorus, meta ls and t o x i c s should be

forthcoming from t h e U.S. Nat ional Urban ~ u n o f f Program.

Since i t w i l l be d i f f i c u l t t o accura te ly assess t h e e f f e c t s o f Level 1

programs on t r i b u t a r y loads due t o v a r i a t i o n s i n t h e hydro log ic cycle, t r end

moni to r ing us ing b i o l o g i c a l i n d i c a t o r s and chemical measurement w i l l be

necessary t o i n d i c a t e t h e o v e r a l l d i r e c t i o n o f load reduct ions. Fur ther

evidence of progress can be gathered by measuring t h e adopt ion r a t e of these

prac t ices . Surveys should be made i n t h e f i r s t year t o es tab l i sh base1 i n e

data and i n t h e t h i r d and f i f t h years t o measure t h e r a t e of adoption.

Demonstrat i o n watersheds

Wi th in t h e c r i t i c a l problem areas i t i s espec ia l l y important t h a t a number

of demonstratibn watersheds, rep resen ta t i ve of those land use and land form

c h a r a c t e r i s t i c s which c o n t r i b u t e t o t h e problem, be establ ished. As w i t h t h e

p rev ious l y noted T r e a t a b i l i t y Studies Program, t h i s would g i v e dec is ion makers

t h e necessary f l e x i b i l i t y t o evaluate a v a r i e t y o f approaches w i t h ample t ime

f o r review. The demonstration watershed program w i l l p rov ide an i n s i g h t i n t o

t h e problems assocated w i t h implementation and an eva lua t ion o f t h e r e l a t i v e

cos ts and e f fec t iveness o f a v a r i e t y o f remedial measures i n reducing t h e l oss

of bo th t o t a l and a v a i l a b l e forms o f phosphorus. These.studies w i l l a lso be

useful i n demonstrating t o farmers and urban dwel le rs i n o ther areas t h e

b e n e f i t s t o be der ived from implementation of remedial measures.

Wi th in each demonstration watershed t h e r e w i l l be requirements t o e n l i s t

t h e f u l l cooperat ion o f farmers and l o c a l government agencies and t o

underwr i te t h e f u l l cos ts o f implementation o f remedial measures. This

support w i l l be requ i red f o r a per iod o f a t l e a s t t h ree years t o ensure t h a t

s u f f i c i e n t mon i to r ing i s c a r r i e d ou t t o adequately assess t h e e f fec t iveness of

remedial measures. Each watershed study w i l l a l so r e q u i r e t h e development of

a watershed management Study plan. These plans w i l l i d e n t i f y t h e phosphorus

sources w i t h i n t h e watershed and t h e measures which w i l l be used t o t r e a t

these sources f o r t h e l e a s t cost . It i s probable t h a t no t a l l sources w i t h i n

a watershed w i l l be t rea ted . It i s .also probable t h a t w i t h i n severa l . .

demonstrat ion basins t h e same k inds o f s-ources w i l l no t be t r e a t e d . . . 8

un i fo rmal l y . For example, i n one watershed management o f 1 ivestock. manure may

be more e f f e c t i v e than a sediment c o n t r o l program i n reducing t h e l oss of

phosphorus.

7.5 INFORMATION NEEDS

Throughout t h i s r e p o r t many i n fo rma t i on needs have been i d e n t i f i e d which

need t o be f i l l e d so t h a t f u t u r e phosphorus management s t r a t e g i e s can be

de f ined more p rec i se l y . There i s a need t o improve t h e est imates . o f

phosphorus loads, develop new phosphorus c o n t r o l technologies fo r bo th p o i n t

and nonpoint sources, and demonstrate t h e cos t e f f ec t i veness o f new as w e l l as

e x i s t i n g technologies.

I n add i t ion , t h e r e a re two in fo rmat iona l needs which r e q u i r e spec ia l

a t t e n t i o n i n o rder t o reduce major u n c e r t a i n t i e s i n t h e d i r e c t i o n and ex ten t

of implementat ion f o r f u t u r e phosphorus c o n t r o l programs. ~ t i e s e are t h e

quest ions o f t h e b i o a v a i l a b i l i t y o f var ious forms o f phosphorus (Sec t ion

3.2.3) and t h e a b i l i t y o f models t o p r e d i c t i n - l a k e e f f e c t s i n response t o

reduc t i on i n phosphorus i npu ts (see Chapter 4 ) .

RECOMMENDATION NO. 9

It is recommended that a permanent organization be established within the institutions under the Great Lakes Water Quality

Agreement to serve the phosphorus management needs of the Great

Lakes. This organization would be charged with the task of

reducing uncertainties, regarding:

o Target loads

o Bioavailability

o Social benefits and costs of control measures

o The appropriateness of institutional approaches

o The structure of analytical models as well as the

development of appropriate data bases to facilitate

attainment of the above objectives. 106

, The a b i l i t y of t h i s t a s k f o r c e t o f u l f i l l i t s r e s p o n s i b i 1 i t i . e ~ has been

hampered by i t s i n a b i l i t y t o conduct i t s own research. Thus, i t was forced t o adopt secondary sources o f - i n f o rma t i on and had 1 i t t l e o p p o r t u n i t y t o r e s o l v e

c o n f l i c t s between t hese sources.

I n p a r t i c u l a r , t h e t ask f o r c e had t o r e l y on models w i t h s t r u c t u r e s t h a t

were inadequate t o r e s o l v e c r u c i a l issues rega rd ing t h e r e l a t i o n between

phosphorus load ings and t h e water q u a l i t y i n s p e c i f i c reg ions o f t h e lakes.

C l e a r l y new model s t r u c t u r e s w i l l have t o be developed if, f o r example, t h e

focus s h i f t s t o nearshore areas o f t h e lakes r a t h e r than t h e l a k e as a whole.

. . S i m i l a r l y , r e s o l u t i o n o f t h e cho i ce between l i m i t i n g phosphorus i n

de te rgen ts and reduc ing t h e ptlusphorus loads a t t h e mun ic ipa l t rea tment p l a n t

cou ld n o t be reso l ved s i n c e independent i n f o r m a t i o n on t h e s o c i a l cos t s of

de te rgen t l i m i t a t i o n s cou ld no t be developed.

A we l l - funded research and ana l ys i s e f f o r t , w i t h i n t h e framework o f t h e

proposed o r g a n i z a t i o n and one which would be d i r e c t l y respons ive t o t h e needs

o f policy-makers, i s r e q u i r e d t o p r o v i d e t h e i n f o r m a t i o n needed f o r t h e

management s t r a t e g y t o move f rom one s tage t o t h e next.

An a p p r o p r i a t e s tep i n t h i s d i r e c t i o n would be t h e f o rma t i on of a

committee t o eva lua te more f u l l y t h e d i f f e r e n c e s between t h e l oad ing models

and l a k e responses. One o f t h e impor tan t and most i m e d i a t e tasks of t h i s

committee would be t o per fo rm computat ions on a1 1 models f o r t h e purpose o f

syn thes i z i ng t h e va r i ous approaches and reconc i 1 i n g d i f f e r e n c e s as t h e y

a r i se . Such an ana l ys i s would p r o v i d e a more q u a n t i t a t i v e bas i s f o r r e s o l v i n g

t h e u n c e r t a i n t i e s o f t h e p resen t s t a t e o f t h e ana lys is .

A second, b u t e q u a l l y s i g n i f i c a n t task, would be t h e f o rma t i on of a

comprehensive and un i f o rm s c i e n t i f i c and eng ineer ing r e p o r t on t h e models and

more impor tan t l y , on t h e most r ecen t developments o f these models. S ince t h e

estab l ishment o f t h e t a r g e t loads, f u r t h e r advances have been made i n t h e

understanding o f t h e phenomena and i n t h e re f inement o f t h e models. The

i m p l i c a t i o n s o f these developments should be eva lua ted w i t h respec t t o t h e

t a r g e t loads.

F i n a l l y , t h e committee would e s t a b l i s h t h e procedures f o r continuous

rev iew and analyses o f cu r ren t research t o be incorpora ted i n t h e

comprehensive r e p o r t a t r e g u l a r i n t e r v a l s . These repor ts , analyses and

procedures would be s p e c i f i c a l l y o r i e n t e d t o serve t h e needs of t h e IJC and

i t s Advisory Boards. Such a r e p o s i t o r y o f i n fo rma t i on would be i nva luab le t o

t h e dec i s i on makers. . . ,

It i s a n t i c i p a t e d t h a t t h e next major dec i s i on p o i n t i n t h e phosphorus

management program f o r t h e Great Lakes w i l l occur i n about 5 years. At t h a t

time, assuming t h e recommended imp1 ementation, evaluat ion, and i n fo rma t i on

ga ther ing are c a r r i e d out, i t w i l l be p o s s i b l e t o determine, w i t h more

c e r t a i n t y , t h e magnitude o f f u r t h e r reduc t ions o f phosphorus i npu ts which may

be requi red. I n add i t ion , dec is ions can be made w i t h a g rea ter degree o f

conf idence as t o what sources should be c o n t r o l l e d w i t h an assurance t h a t t h e

cos ts associated w i t h t h e implementat ion o f a d d i t i o n a l c o n t r o l s a re

commensurate w i t h expected bene f i t s .

At t h e present time, t h e degree o f u n c e r t a i n t y which i s s t i l l a t tached t o

major elements o f t h e phosphorus ques t ion suggest t h a t e x i s t i n g programs

should be more f u l l y implemented and evaluated be fo re committments a re made t o

major programs t o f u r t h e r reduce i n p u t loads o f phosphorus on a whole l a k e

basis. However, t h e bas ic premise t h a t phosphorus loadings t o t h e Great Lakes

must be reduced i n order t o c o n t r o l eu t roph i ca t i on i s s t i l l v a l i d and t h e

u n c e r t a i n t y associated w i t h t h e magnitude o f f u r t h e r reduc t ions requ i red and

bes t means o f achiev ing them, should no t be construed as a lack o f support f o r

t h e bas ic program.

Although t h e need f o r f u r t h e r phosphorus c o n t r o l s i s evident, c l e a r

d i r e c t i o n s on t h e extent, t im ing , and t y p e o f addit i -onal c o n t r o l s needed a re

' no t apparent. The e f fec t i veness o f nonpoint source cont ro ls , phosphorus

b i o a v a i l a b i l i t y , and t h e cos t o f these remedial measures can on l y be

q u a n t i f i e d i n a very incomplete f ash ion w i t h t h e i n fo rma t i on a v a i l a b l e t o t h e

task f o r c e and t h e i r a p p l i c a b i l i t y ' i s l i k e l y very s i t e s p e c i f i c . 1 t i s f o r

t hese reasons t h a t t h e t ask f o r c e i s no t prepared t o recommend across-

the-board a d d i t i o n a l remedia l measures a t t h i s t ime. Instead,. i t recommends

t o governments! . tha t a d d i t i b n a l phosphorus i-embval shou'ld b e implemented, as a

ma t te r of p r i o r i t y , 'f&.'tho.se l a k e P o r t i o n s and nearshore areas which c l e a r l y , ,

e x h i b i t severe e u t r o p h i c a t i o n problems such as Saginaw Bay i n Lake Huron, t h e

western b a s i n of Lake E r i e , and t h e B a y , o f Q u i n t e i n Lake Ontar io .

The ex ten t t o which f u r t h e r r educ t i ons a re made i n t h e p o i n t and nonpoint

sources o f phosphorus respons ib l e f o r these e u t r o p h i c a t i o n problems should be

governed by t e c h n i c a l f e a s i b i 1 i t y , cos t -e f f ec t i veness , and s o c i a l accept-

a b i l i t y . These f a c t o r s a r e l i k e l y t o be ve ry s i t e s p e c i f i c and w i l l r e q u i r e

demonstrat ion s tud ies . Such s tud ies should be c a r r i e d o u t as soon as

poss ib le , completed and imp1ement;ed soon there i i f t e r .

Desp i te t h e i n d i c a t i o n s t h a t a d d i t i o n a l reduc t ions ' w i 11 be r e q u i r e d t o

meet present t a r g e t loads i t i s ' recommended t h a t t h e impact' o f t h e reduc t i ons

e f f e c t e d by ach iev ing t h e 1.0 'mg/L t o t a l phosptiorus o b j e c t i v e on t h e water

q u a l i t y o f t h e two lower lakes be moni tored and evaluated p a r t i c u l a r l y i n t h e

1 i t t o r a l areas w i t h emphasis on ch lo rophy i 1. Recommendations f o r t h e

implem&ntat ion o f d d d i t i o n a l major, 'lake-wid;, phosphorus c o n t r o l programs

should be con t i ngen t upon i d e n t i f i c a t i o n t h a t these observed i n - l a k e responses

a re cons is t .ent i n magnitude and d i r e c t i o n w i t h des i r ed goals.

The t ask f o r c e ' s recommendations f o r t h e immediate phase o f a phosphorus . . ,

management s t r a t e g y are:

t h a t a program i n c l u d i n g in format ion/educat ion, , . , technology

development, demonstrat ion watersheds, and model

eva luat ions, be undertaken as soon as p o s s i b l e i n o rder t o

p rov ide t h e knowledge base needed t o develop and implement

p o l i c y i n p a r a l l e l w i t h a staged approach t o phosphorus

management;

t ha t , as q u i c k l y as possible, a l l munic ipal wastewater

t reatment p l a n t s d ischarg ing i n excess o f 3,800 cu m/d ( 1 MGD)

i n the ' Great Lakes bas in be designed and operated so t h a t t h e

t o t a l phosphorus concentrat ions i n t h e i r e f f l u e n t s w i l l not

exceed a maximum of 1.0 rng/L;

t h a t governments immediately evaluate t h e ab i 1 i t y o f munic ipal

wastewater treatment f a c i l i t i e s i n t h e lower Great Lakes basin,

c u r r e n t l y requ i red t o meet an e f f l u e n t l i m i t o f 2.0 mg/L t o t a l

phosphorus, t o be operated t o achieve e f f l u e n t concentrat ions

below 1.0 mg/L and those which can be so operated should begin

as soon as possib le;

t h a t f o r p lanning purposes, a l l f u t u r e munic ipal p o i n t source

discharges t o t h e lower Great Lakes bas in should consider

requirements f o r t o t a l phosphorus removals t o concen-

t r a t i o n s on t h e order o f 0.1 t o 0.5 mg/L;

t h a t f u t u r e discharge ob jec t i ves f o r munic ipal f a c i 1 i t i e s

should be developed employing mass loading a l l o c a t i o n s i n o rder

t o encourage t h e cons idera t ion o f a v a r i e t y o f managerial and

o ther s t r u c t u r a l approaches t o reduce phosphorus inputs. These

approaches may inc lude:

- i n d u s t r i a l pre-treatment requirements f o r phosphorus

- detergent phosphorus c o n t r o l s

- e f f l u e n t f e e s

- user fees dependent on phosphorus i npu ts

- o ther treatment op t ions such as land a p p l i c a t i o n

- cornbinations o f t he above.

The p lann ing should i nc lude d e t a i l e d cons idera t ion of costs,

ef fect iveness, and poss ib le implementation d i f f i c u l t i e s ;

r t h a t e x i s t i n g laws and r e g u l a t i o n s t o c o n t r o l t h e phosphorus , . :

con ten t of de t 'e r ien ts i n t h e Great ~ a k e s ' b a s i n be r e t a i n e d and

t h a t c o n t r o l s be extended immediately t o i n c l u d e Pennsylvania . I . .

and, i n p a r t i c u l a r , Ohio;

r t h a t an independent s tudy be conducted on t h e d i r e c t and

i n d i r e c t costs , bene f i t s and d i s b e n e f i t s assoc ia ted w i t h

de te rgen t phosphorus c o n t r o l s ;

. . .

r t h a t t h e governments i n i t i a t e a technology bevelopment and . . . .

demonstrat ion program t o develop and evaluate, . . by f i e l d

s tud ies , a1 t e r n a t i v e and i n n o v a t i v e mun ic ipa l wastewater

t rea tment techno log ies which can r e l i a b l y and c o s t - e f f e c t i v e l y

achieve va r i ous e f f l u e n t t o t a l phosphorus r e s i d u a l s down t o 0.1

mg/L which can be used f o r bo th new f a c i l i t i e s and t o upgrade , .

e x i s t i n g f a c i l i t i e s ; . .

r t h a t where cos t -e f f ec t i ve , 1 and appl i c a t i o n o f " wastewaters be

u t i 1 ized;

r t h a t s t ud ies be i n i t i a t e d t o q u a n t i f y t h e reduc t i ons i n t o x i c

and hazardous substances t h a t occur concur ren t w i t h phosphorus

removal ;

a t h a t t h e nonpoint source component o f comprehensive management

p lans developed f o r each c o u n t r y i n c l u d e t h e implementat ion of:.

- a basin-wide p u b l i c i n f o r m a t i o n and educat ion program; and

- where appropr ia te , those low c o s t measures which can

r e s u l t i n a r e d u c t i o n i n nonpoint loadings based on a

common sense approach t o problem so l v i ng ;

and t h e development o f :

- a model 1 i n g capabi 1 i t y f o r p r e d i c t i n g phosphorus

reduc t ions f o r c r i t i c a l areas w i t h i n t h e basin; and

- demonstrat ion watershed s tud ies w i t h i n these c r i t i c a l

problem areas t o eva lua te t h e cos t -e f fec t i veness o f a

v a r i e t y o f remedi a1 measures, i d e n t i f y any problems

associated w i t h t h e i r implementation, and p rov ide examples

o f implementat ion as i ncen t i ves f o r o the r farm operators;

t h a t a permanent o rgan i za t i on be es tab l i shed t o serve t h e

phosphorus management needs o f t h e Great Lakes. This

o rgan i za t i on would be charged w i t h t h e task o f reduc ing

u n c e r t a i n t i e s regard ing:

- , t a r g e t loads - b ioava i l a b i 1 i t y o f var ious forms o f phosphorus - s o c i a l b e n e f i t s and cos ts o f c o n t r o l measures

- t h e appropriateness o f i n s t i tu t ional . :approaches - t h e s t r u c t u r e o f a n a l y t i c a l models as w e l l as t h e

development o f appropr ia te da ta bases t o f a c i 1 i t a t e

at ta inment o f t h e above ob jec t i ves .

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Q u a l i t y Board prepared f o r t h e I n t e r n a t i o n a l J o i n t Commission.

Windsor, Ontar io, June 1979.

74. Loehr, R. C. Phosphorus Removal Usi nq Land Treatment Systems.

Phosphorus Management S t ra teg ies Task Force. I n t e r n a t i o n a l

J o i n t Commission, Windsor, Ontar io, Aug~tqt 1979. '.

75. Great Lakes Water Q u a l i t y Board. J I n d u s t r i a l Po in t Source Dischargers i n t h e Great Lakes Basin.

Report o f t h e Great Lakes Water Qual i t y Board, I n t e r n a t i o n a l

J o i n t Commission, Windsor, Ontar io, J u l y 1979.

76. Report t o t h e Great Lakes Research Advisory Board o f t h e I n t e r -

n a t i o n a l J o i n t Commission on t h e Heal th I m p l i c a t i o n s o f NTA.

I n t e r n a t i o n a l J o i n t Commission, Windsor, Ontar io, May 1977.

77. Report t o t h e Great Lakes Research Advisory Board o f t h e I n t e r -

n a t i o n a l J o i n t Commission o n . t h e Eco log ica l E f f e c t s o f

Non-Phosphate Detergent Bu i lders : F i n a l Report on NTA from t h e

Task Force on Eco log ica l E f f e c t s on Non-Phosphate Detergent '

Bui lders. Windsor, Ontar io, December 1978.

78. Thames R ive r Irnpl ementat i o n Committee. Progress Report on Imp1 emen-

t a t i o n Aspects o f t h e Thames R ive r Basin Water Management

Study. On ta r i o M i n i s t r y o f t h e Environment, London, Ontar io,

May 1978.

79. Lake, J. and J. Morrison. Environmental Impact o f Land Use on Water

Qual i ty . U. S. Environmental P r o t e c t i o n Agency, Chicago, October 1977.

80. Andrews, S.C. -- e t a l . Impact o f Nonpoint P o l l u t i o n Con t ro l on Western

Lake Superior, Red Clay P r o j e c t F i n a l Report : Summary. Prepared f o r

U.S. Environmental P r o t e c t i o n Agency, O f f i c e of t h e Great Lakes

Coord inator , Chicago, n.d.

81. Honey Creek J o i n t Board o f Supervi'sors. Honey Creek Watershed

P ro jec t , T i 11 age Demonstrat ion Resu l ts 1979. Prepared

f o r Lake E r i e wastewater Management Study. U.S. Army corps o f

Engineers, Bu f f a l o , N.Y., March 1980.

82. Chesters, G. -- e t a l . P i l o t Watershed S tud ies Summary Report.

I n t e r n a t i o n a l Reference Group on Great Lakes P o l l u t i o n f rom Land Use

A c t i v i t i e s , Windsor, O l ~ t a r i o , June l'', 0.

83. A g r i c u l t u r e Canada, O n t a r i o M i n i s t r y o f A g r i c u l t u r e and Food and

On ta r i o M- i n i s t r y o f t h e Environment. A g r i c u l t ~ ~ r a l Watershed Studies,

Great Lakes Drainage Basin, Canada; F i n a l Summary Report. Submit ted

t o I n t e r n a t i o n a l Reference Group on Great Lakes P o l l u t i o n from Land

Use A c t i v i t i e s , Task Group C ( ~ a n a d i a n Sec t ion) A c t i v i t y 1. Windsor,

Ontar io . May 1978.

84. M i l l e r , M.H. and A.C. Spires. C o n t r i b u t i o n o f Phosphorus t o t h e

Great Lakes f rom ~ ~ r i c u l t u r a ' l Land i n t h e Canadian Great Lakes

Basin. Submit ted t o PLUARG Task Group C (Canadian Sec t ion) A c t i v i t y

1. 1978.

85. Knap, K. M. and W. F. M i ldner . Streambank Eros ion i n t h e Great Lakes

Basin. Submitted t o PLUARG Task Group C. June 1978.

86. Gregor, 0. J. V a r i a b i l i t y o f T r i b u t a r y and Upstream Lake Loads t o '

Lakes' Onta r io and ~ r i e . Canada. Centre f o r I n l a n d Waters,. B u r l ington,

Ontar io, 1979. (unpubl ished r e p o r t )

87. Logan, T. J. Maumee R i v e r Bas in P i l o t Watershed Study, Summary P i l o t

Watershed Report. Submit ted t o PLUARG Task Group C (U. S. Sec t ion) .

Windsor, Ontar io, A p r i l 1978.

;?.

88. Van V l i e t , L.J.P., G.J.-~a-1-1 and W.T. D.ickinson. S o i l E ros ion f rom

A g r i c u l t u r a l Land i n t h e Canadian Great ~ a k e s Basin. Submitted t o

PLUARG Task Group C (Canadian Sec t ion) A c t i v i t y 1, Prso jects 16 and

17. Windsor, Ontar io , March 1978.

89. Romkens, M.J.M., D.W. Nelson, and J.V. Mannering. "Niitrogen and

~hosphb rus Composit ion o f su r f ace Runoff as A f f ec ted by T i 1 lage

Met hod. " - J. Environmental Qua1 i t y , Vol . 2, No. 2, 1.973, p. 293.

90. Marsha l l Mack l i n Monaghan Ltd. - Evalua t i on o f -- Remedial Measures t o

Cont ro l Nonpoint Sources o f Water P o l l u t i o n i n t h e - Great Lakes

Basin. Submit ted t o PLUARG Task Group A. Windsor, Ontar io , 1977, p.

38.

91. Burns, N.M. and C. Ross. P r o j e c t H.ypo - -- An I n t e n s i v e Study o f the

Lake E r i e Cent ra l Bas in Hypol imnion -- and Re la ted Sur face Water

Phenomena. C C I W Paper #6, EPA Technolog ica l Report T5-05-71-208-24,

Canada Centre f o r I n l a n d Waters, Bu r l i ny ton , On ta r i o and U. S.

Environmental P r o t e c t i o n Agency, Fa i r v i ew Park, Ohio, 1972.

92. I n t e r n a t i o n a l Reference Group on P o l l u t i o n f rom Land Use A c t i v i t i e s .

Reports o f t h e U n i t e d S ta tes P u b l i c Consu l t a t i on ---..-- Panels t o t h e

P o l l u t i o n f r om Land Use A c t i v i t i e s Reference Group. Windsor,

Ontar io , 1978.

92a . In te rna t iona l Reference Group on P o l l u t i o n f rom Land Use A c t i v i t i e s .

Reports o f t h e Canadian P u b l i c Consu l t a t i on Panels t o t h e P o l l u t i o n

f rom Land Use A c t i v i t i e s Reference Group. Windsor, Ontar io , 1978.

93. Powers, E.C. and E.A. Ja reck i . Survey o f U.S. Great Lakes Basin

Farmers Regarding Water P o l l u t i o n f rom A g r i c u l t u r . a l A c t i v i t i e s .

Survey by S t a t i s t i c a l Repor t ing Services. Submit ted t o PLUARG Task

. Group A (U. S. Sec t ion) . I n t e r n a t i o n a l J o i n t Commission. Windsor,

Ontar io , November 1977.

94. Bangay, G . E . Agr icul ture and Wat.er Pol lu t ion - An Assessment of t h e ----.----.- -- . - -- -- Pract ices and At t i tudes of Ontario Farmers. Submitted t o t h e

In terna t ional Reference Group on Pollut ion from Land Use A c t i v i t i e s

of t h e In te rna t iona l Jo in t Commission. Wi ndsor, Ontario, February

1979.

95. U. S. Comptrol l e r General. Water Qual i t y Management I s Not

Comprehensive and May Not he Effec t ive f o r Many Years. U.S.

Government Accounting Off i c e CED-78-167. December 1979.

96. In t e rna t iona l Jo in t Commission. Water Qua1 i t y o t ' ---- t h e Upper. --.-- Great

Lakes. Report t o the Governments of Canada and the United Stat.es.

Ottawa, Ontario and Washington, D . C , F1a.y 1.979.

97. Great Lakes Basin Commission. Grmt Lakes - -- - Environ~nental - .- - - P l a n n 3 - -

Study - A Process f o r Assessing -. Effects -- of Po1ic.y ----------- Options on t h e

Lakes. Great Lakes Basin Commission, Ann Arbor, Michigan, June 1.978.

APPENDIX 1

TERMS OF REFERENCE FOR

PHOSPHORUS MANAGEMENT STRATEGIES TASK FORCE

I. I n t r o d u c t i o n

Several ac t i ons have been taken by some j u r i s d i c t i o n s i n t h e Great Lakes

Basin t o reduce phosphorus inputs, as f o r example, phosphate bans i n household

detegents and e f f luen t l i m i t a t i o n s f o r phosphorus f rom sewage t reatment

p lan ts . Experts recognize t h a t m u l t i p l e c o n t r o l s on phosphorus are needed t o

achieve t h e des i rab le water qua1 i t y cond i t i ons and t h a t present c o n t r o l s may

no t be optimum. P a r t i c u l a r l y , t h e f i n d i n g s o f PLUARG need t o be woven i n t o

t h e over a l l c o n t r o l s t ra tegy , and as yet , a c l e a r assessment o f t h e

t r a d e - o f f s between a l t e r n a t i v e c o n t r o l s t r a t e g i e s has no t been l a i d o u t so

t h a t decision-makers can be assured t h a t a l l e f f e c t i v e avenues a re being used

and opt imized. For such reasons, a task f o r c e needs t o examine t h e ques t ion

o u t l i n e d above f o r t h e use o f t h e j u r i s d i c t i o n s w i t h i n t h e Great Lakes basin.

Terms o f Reference

Review and evaluate t h e adequacy o f e x i s t i n g data, f a c t o r s a f f e c t i n g

phosphorus loads, analyses and technologies p e r t i n e n t t o t h e

development of a l t e r n a t i v e phosphorus management s t ra teg ies : Items

o f concern t o inc lude: t h e assumptions and r a t i o n a l e unde r l y i ng t h e

phosphorus loads recommended i n t h e 1978 Water Q u a l i t y Agreement

between Canada and t h e Un i ted States on Great Lakes Water Q u a l i t y ,

dated November 22, 1978; t h e a v a i l a b i l i t y and p r a c t i c a b i l i t y o f

technology and t h e cos ts f o r c o n t r o l o f p o i n t and nonpoint sources;

t h e reduc t i on o f phosphorus co'ntent i n detergents and associated

costs'; cons ide ra t i on o f t h e b i o l o g i ' c a l avai l a b i 1 i t y o f phosphorus i n

t h e assessment o f a1 t e r n a t i v e phosphorus management s t ra teg ies ; and

t h e appl i c a b i 1 i ty o f systems approaches f o r determin ing c o n t r o l

s t ra teg ies .

2. Evaluate and t e s t a1 t e r n a t i v e phosphorus management s t r a t e g i e s

s p e c i f i c a l l y as t h e y impact on: a) ecology; b ) waste t reatment ; c )

s ludge d isposa l ; d) energy cons idera t ions ; and e) economics.

3. To incorpora te , as t i m e al lows, t h e f i n d i n g s o f t h e assoc ia ted task

f o r ces and committees on h e a l t h e f f e c t s , environmental impacts,

s o c i e t a l aspects, and n u t r i e n t ob jec t i ves .

4. I d e n t i f y s p e c i f i c sub jec t areas where a d d i t i o n a l i n f o r m a t i o n i s

needed.

111. Members h i p

The Task Force should c o n s i s t o f r ep resen ta t i ves o f indus t ry , government

and u n i v e r s i t i e s w i t h u n i - o r m u l t i - e x p e r t i s e t o address t h e t h r e e preceding

items.

The rep resen ta t i ves would, f o r example, have e x p e r t i s e on: e c o l o g i c a l

e f f e c t s due t o va r i ous phosphorus loadings; nonpoint source c o n t r o l

technology, s u b s t i t u t e s ; phosphorus r e g u l a t o r y processes; e tc .

I V . L i a i s o n

'The Task Force should con tac t and work c l o s e l y w i t h o t h e r c u r r e n t I JC Task

Forces and Reference Groups which a re examining o t h e r f a c e t s o f t h e phosphorus

i ssue i n r e l a t i o n t o t h e Great Lakes. These would inc lude, f o r example, t h e

Task Force on Hea l t h E f f e c t s o f Non-NTA Detergent B u i l d e r s N u t r i e n t Ob jec t i ves

Work Group, t h e Pol l u t i o n f rom. Land Us,e A c t i v i t i e s Reference Group and Task

Group I 1 1 o f t h e F i v e Year Review o f t h e Water Q u a l i t y Agreement. The

f i n d i n g s , o f t hese groups ' ,should be u t i 1 ized, wherever appropr ia te , i n t h e

development o f t h e Task Force 's F i n a l Report.

V. T iming

The Task Force should p rov ide an i n t e r i m r e p o r t i n t h e summer o f 1979, and

i t s f i n a l r e p o r t b y January 1980.

128

APPENDIX 2

GREAT LAKES SCIENCE ADVISORY BOARD PHOSPHORUS MANAGEMENT STRATEGIES TASK FORCE

D r . Gerard A. Rohl i c h (Co-Chairman) Professor Department o f C i v i l Engineering 8.6 East Cockerel H a l l The U n i v e r s i t y o f Texas Aust in, Texas 78712

M r . Garth Bangay D i rec to r , Lands D i r e c t o r a t e On ta r i o Region, Environment Canada 867 Lakeshore Road Bur l ington, On ta r i o L7R 4A6

D r . A. M. Beeton, D i r e c t o r , Great Lakes and Marine Water Center

I ' 2200 Bonisteel Road Ann Arbor, Michigan 48109

D r . G. Anders Carlson N.Y. S ta te Dept. o f Heal th Div. o f Env. Health, Toxic Substances Empire Sta te Plaza, Tower Bldg. Rm 372 Albany, New York 12237

D r . Raymond C. Loehr Professor and D i r e c t o r Environment a1 Studies Program 207 Riley-Robb Cornel 1 U n i v e r s i t y I thaca. New York 14853

Mr . John Mancini 320 Brookmere Court Ridgewood, New Jersey 07450

D r . N. W. Schmidtke D i r e c t o r Wastewater Technology Centre Department o f the Environment Canada Centre f o r I n land Waters P. 0. Box 5050 Bur l ington, Ontar io L7R 4A6

Dr . Henry Peskin Resources f o r t h e Future 1755 Massachusetts Avenue, N.W. Washington, D.C. 20036

D r . Dona1 d J. 0 ' Connor ( Co-Chai rman) Professor, Env. Engineering Manhattan Col lege Bronx, New York 10471

D r . Stephen Yaksich Corps o f Engineers Department o f t he Army 1.776 Niagara S t ree t Buf fa lo , New York 14207

M r . Steve Salbach Water Resources Branch Ontar io M i n i s t r y o f the Environment 135 S t . C l a i r Avenue West Toronto, Ontar io M4V 1P5

M r . Gordon Van F l e e t . P o l l u t i o n Contro l Branch Ontar io M i n i s t r y o f the Environment 135 S t . C l a i r Avenue West Toronto, Ontar io M4V 1P5

M r . Gary Wil l iams, Chief Water Q u a l i t y Management Branch U.S. EPA, Region V 230 S. Dearborn S t r e e t Chicago, I l l i n o i s 60604

SAB L ia i son Member M r . John J. Convery, D i r e c t o r Wastewater ~ e s e a r c h - D i v i s i o n Munic ipal Environmental Research Lab. U.S. Environmental P ro tec t i on Agency 26 West S t . C l a i r S t ree t C inc inna t i , Ohio 45268

Sec re ta r i a t R e s p o n s i b i l i t i e s D r . W.R. Dr-ynan Seni o r ~ n ~ i n e e r Great Lakes Regional O f f i c e I n t e r n a t i o n a l J o i n t Commission 100 Ouel l e t t e Avenue, 8 t h F loo r Windsor, On ta r i o N9A 6T3