Total Maximum Daily Loads for Total Maximum Daily Loads for PCBs in the Trinity RiverPCBs in the Trinity River

Segments 0829, 0806, 0841, & 0805Segments 0829, 0806, 0841, & 0805

May 11, 2009May 11, 2009

Kirk Dean, Ph.D., Parsons presenting

Texas Commission on Environmental Quality

Dania Grundmann, TCEQ Project Manager

IntroductionIntroductionSection 303(d) of the federal Clean Water Act Section 303(d) of the federal Clean Water Act (CWA) requires States to identify water bodies that (CWA) requires States to identify water bodies that do not meet applicable water quality standardsdo not meet applicable water quality standards

Pursuant to the CWA and development of the 303(d) Pursuant to the CWA and development of the 303(d) list, the Texas Commission on Environmental Quality list, the Texas Commission on Environmental Quality (TCEQ) is responsible for development of Total (TCEQ) is responsible for development of Total Maximum Daily Loads (TMDLs)Maximum Daily Loads (TMDLs)

IntroductionIntroduction

The goal of a TMDL is to determine the amount (or The goal of a TMDL is to determine the amount (or load) of a pollutant that a body of water can receive load) of a pollutant that a body of water can receive and still support its designated usesand still support its designated uses

That allowable load is then allocated among all That allowable load is then allocated among all sources of pollution within the watershedsources of pollution within the watershed

Measures to reduce the pollutant loads are developedMeasures to reduce the pollutant loads are developed

Impaired Segments/Assessment UnitsImpaired Segments/Assessment Units

Texas Department of State Health Services (TDSHS) Texas Department of State Health Services (TDSHS) issued Aquatic Life Order 14 (ALissued Aquatic Life Order 14 (AL--14) and Fish 14) and Fish Consumption Advisory 25 (ADVConsumption Advisory 25 (ADV--25) in 2002 due to 25) in 2002 due to ““PCBs in fish tissuePCBs in fish tissue”” for 150 miles of the Trinity for 150 miles of the Trinity RiverRiver

As a result the TCEQ placed four segments (nine As a result the TCEQ placed four segments (nine Assessment Units (Assessment Units (AUsAUs)) of the Trinity River on the )) of the Trinity River on the CWA 303 (d) list due to impairment of the CWA 303 (d) list due to impairment of the ““fish fish consumptionconsumption”” designated usedesignated use

Polychlorinated Biphenyls (PCBs)Polychlorinated Biphenyls (PCBs)

A group of 209 compounds, known as PCB congenersA group of 209 compounds, known as PCB congenersFrom 1 to 10 chlorines on 2 connected benzene ringsFrom 1 to 10 chlorines on 2 connected benzene ringsProperties and toxicity vary, but all poorly soluble in waterProperties and toxicity vary, but all poorly soluble in waterTend to be associated with sediments in aquatic systemsTend to be associated with sediments in aquatic systemsHighly resistant to degradationHighly resistant to degradationResidence times in aquatic systems on the order of decadesResidence times in aquatic systems on the order of decades

Polychlorinated Biphenyls (PCBs)Polychlorinated Biphenyls (PCBs)

Sold in the USA under trade name AroclorSold in the USA under trade name AroclorUsed mainly asUsed mainly as

Dielectric fluids in transformersDielectric fluids in transformersHeat transfer fluidsHeat transfer fluidsHeatHeat--resistant hydraulic fluidsresistant hydraulic fluids

Myriad other usesMyriad other usesProduction, distribution and new use banned in Production, distribution and new use banned in 1976 by Toxic Substances Control Act (TSCA)1976 by Toxic Substances Control Act (TSCA)

PCB Conceptual ModelPCB Conceptual Model

Point source effluent

Wet

/dry

de

posit

ion

Wet

/dry

de

posit

ion

Discharges from tributaries

Runoff

Equilibrium partitioning

Discharges

Bottom sedimentsfrom groundwater

Volat

ilizat

ion

BurialResuspension

Dissolved phase

BSAFBSAFBAF Suspended solids

IN

OUT

Phot

odeg

rada

tion

Biodegradation

Point source effluent

Wet

/dry

de

posit

ion

Wet

/dry

de

posit

ion

Discharges from tributaries

Runoff

Equilibrium partitioning

Discharges

Bottom sedimentsfrom groundwater

Volat

ilizat

ion

BurialResuspension

Dissolved phase

BSAFBSAFBAF Suspended solids

IN

OUT

Phot

odeg

rada

tion

Biodegradation

Point source effluent

Wet

/dry

de

posit

ion

Wet

/dry

de

posit

ion

Discharges from tributaries

Runoff

Equilibrium partitioning

Discharges

Bottom sedimentsfrom groundwater

Volat

ilizat

ion

BurialResuspension

Dissolved phase

BSAFBSAFBAF Suspended solids

IN

OUT

Phot

odeg

rada

tion

Biodegradation

BED SEDIMENTS

INFLOWS (UPSTREAM,

TRIBUTARIES,POINT AND NONPOINT SOURCES)

Mass Balance Model Will Mass Balance Model Will Capture the Key ProcessesCapture the Key Processes

OUTFLOWS TO DOWNSTREAM REACHES

SUSPENDED SEDIMENTS

Particle Settling

Sediment Re-suspension

DISSOLVED PCB

ATMOSPHERIC LOSSES + DEGRADATION

BIOTABioaccumulation Factor

Distribution Coefficient

Flux from sediment pore water

PCB fate in water is largely controlled PCB fate in water is largely controlled by their partitioning to sedimentsby their partitioning to sediments

PCBs and water mix like oil and waterPCBs and water mix like oil and waterGiven the chance, PCBs dissolved in water will tend to Given the chance, PCBs dissolved in water will tend to ““sorbsorb””to suspended or bed sediment particlesto suspended or bed sediment particlesOrganic particles can absorb a large amount of PCBs relative Organic particles can absorb a large amount of PCBs relative to most mineral particles. to most mineral particles. This is also why fish This is also why fish ““bioaccumulatebioaccumulate”” PCBs to high levelsPCBs to high levelsAmong minerals, clays can take up more PCB than silt or sand Among minerals, clays can take up more PCB than silt or sand due to greater surface area. due to greater surface area. PCB uptake by sediments is controlled largely by their organic PCB uptake by sediments is controlled largely by their organic content.content.Given enough time, an equilibrium distribution of PCB Given enough time, an equilibrium distribution of PCB concentrations between dissolved and sediment phases occursconcentrations between dissolved and sediment phases occurs

1

10

100

1000

0.1 1 10 100Dissolved Sum of PCB Congeners (ng/l)

Sedi

men

t-Ass

ocia

ted

Sum

of P

CB

Con

gene

rs (n

g/g)

Ambient Samples

Stormwater Samples

WWTP Samples

Sediment-Water DistributionCoefficient

Suspended Sediment : Dissolved Phase Suspended Sediment : Dissolved Phase Partitioning of PCBs in Trinity River WaterPartitioning of PCBs in Trinity River Water

3.2

3.7

4.2

4.7

5.2

5.7

-3.50 -3.00 -2.50 -2.00 -1.50 -1.00Log Sediment Organic Carbon Content

Log

Sedi

men

t: W

ater

Dis

tribu

tion

Coe

ffici

ent (

L/kg

)

Clear Fork

Seg 0806

Seg 0841

Seg 0805 Upper

Seg 0805 Lower

Log Distribution Coefficient =Log Organic Carbon Content + 6.4

Bed SedimentBed Sediment--Dissolved Phase PartitioningDissolved Phase Partitioning

Data CollectionData Collection March March –– August 2008August 2008

InIn--stream PCB concentration measurementsstream PCB concentration measurements18 measurements at 13 main stem sites18 measurements at 13 main stem sites

Sediment PCB concentration measurements Sediment PCB concentration measurements 77 measurements at 32 main stem and 43 tributary sites77 measurements at 32 main stem and 43 tributary sites

PCB loads from wastewater dischargesPCB loads from wastewater discharges8 measurements at 4 facilities8 measurements at 4 facilities

PCB loads from storm waterPCB loads from storm water9 measurements at 5 sites9 measurements at 5 sites

Individual PCB congeners measured by EPA Method 1668AIndividual PCB congeners measured by EPA Method 1668A-- results presented reflect sum of results presented reflect sum of ““detecteddetected”” congenerscongeners

0.0

1.0

2.0

3.0

4.0

5.0

-10 0 10 20 30 40 50 60 70 80 90 100 110 120Project Distance (miles)

Sum

of P

CB

con

gene

rs (n

g/L)

Total PCB in waterLow-Flow Total PCB in WaterDissolved PCB in waterLow-Flow Dissolved PCB in Watersegment boundaries

FM 85SH 34

Dowdy Ferry Rd

S. Loop 12

FM 157 (Collins St.)Beach St

W. Loop 12

Segment0806

Segment0841

Segment 0805Seg0829

water quality criterion for total PCB

PCB Levels in Trinity River WaterPCB Levels in Trinity River Water

0%

20%

40%

60%

80%

100%

0% 20% 40% 60% 80% 100%

Stream Flow Percentile During Sampling (Compared to 1988-2008 Flows)

Frac

tion

of S

tream

PC

B L

oad

Ass

ocia

ted

with

S

uspe

nded

Par

ticle

s

Low Flows High Flows

Spring 2008 Survey Points

Summer 2008 Low-FlowSurvey Points

Flow Dependence of Suspended PCB LevelsFlow Dependence of Suspended PCB Levels

0

1

10

100

-15 -5 5 15 25 35 45 55 65 75 85 95 105 115 125

Project Distance Downstream of Confluence of West and Clear Forks (miles)

Sum

of P

CB

Con

gene

rs (u

g/kg

)

SH 34

S. Loop 12

SH 360

Dowdy Ferry

above Tenmile Ck

W. Beltline

Greenbelt Rd

Beach St.

below Lake Worth

W. Loop 12

FM 85

Handley Rd

Seg 0806/0829 Seg 0841 Seg 0805

PCB Levels in Trinity RiverPCB Levels in Trinity River Bed SedimentsBed Sediments

100

1,000

10,000

-15 -5 5 15 25 35 45 55 65 75 85 95 105 115 125

Project Distance Downstream of Confluence of West and Clear Forks (miles)

Sum

of P

CB

Con

gene

rs (u

g/kg

OC

)

SH 34

S. Loop 12

SH 360

Dowdy Ferry

above Tenmile Ck

W. Beltline

Greenbelt Rd

W. Loop 12

Beach St.

below Lake Worth

FM 85

East 1st St

Organic Carbon Normalized PCB Organic Carbon Normalized PCB Levels in Trinity River Bed SedimentsLevels in Trinity River Bed Sediments

0.1

1

10

100

1000

10000

-15 -5 5 15 25 35 45 55 65 75 85 95 105 115 125Project Distance Downstream of Confluence of West and Clear Forks (miles)

Sum

of P

CB

Con

gene

rs (u

g/kg

)

2008 data

1974-75 data

1980's data

SH 34

SH 360

Dowdy Ferry

Greenbelt Rd

Beach St.

below Lake Worth

FM 85

Handley Rd

Historical Bed Sediment PCB LevelsHistorical Bed Sediment PCB Levels

0

2

4

6

8

10

12

14

16

18

20

Big Fos

sil Cree

k

Big Foss

il Cree

k

Purcey

St drai

n

Purcey

St drai

n

Able Pum

p stat

ion

Able Pum

p stat

ion

Hampto

n pum

p stati

on

Hampto

n pump s

tation

Parson

s Slou

ghFW Villa

ge C

reek

FW Village

Cree

kTRA C

entral

TRA Cen

tral

Dallas

Cen

tral

Dallas C

entra

l

Dallas S

outhsid

e

Dallas

Southsid

eTo

tal P

CB

(ng/

L) Stormwater WWTP Effluent

Average River Conc. 1.85 ng/L

51 ng/l

PCB Sources: PCB Sources: StormwaterStormwater and WWTP Effluentand WWTP Effluent

0

10

20

30

40

50

60

70

80

90

100

PurceyStreetDrain

MarineCreek @Marine

Creek Park

MarineCreek

LebowCreek

SycamoreCreek at E.Seminary

Dr

SycamoreCreek atUS 287

SycamoreCreek at

Lancaster

Unnamedtributary @Haltom Rd

Big FossilCreek

Little FossilCreek

VillageCreek

Sum

of P

CB

Con

gene

rs in

Sed

imen

t (ug

/kg)

Segment Average

PCB Levels in Bed Sediments of PCB Levels in Bed Sediments of Tributaries to Segment 0806/0829Tributaries to Segment 0806/0829

0

10

20

30

40

50

60

70

80

90

100

Walker B

ranch

Sulphur B

ranch

Unnamed

tribu

tary a

t Mosie

r Vall

ey R

d

Unnamed

tribu

tary a

t S. M

ain St. i

n Eules

sJo

hnso

n Cree

kDalw

orth C

reek

Bear Cree

kBear

Creek

Mounta

in Cree

k

Mounta

in Cree

k @ W

est J

efferso

n Blvd

Delaware

Creek

Elm Fork

@ C

aliforni

a Cros

sing

Elm Fork

above

Carro

lton D

amElm

ForkSum

of P

CB

Con

gene

rs in

Sed

imen

t (ug

/kg)

Segment Average

PCB Levels in Bed Sediments of PCB Levels in Bed Sediments of Tributaries to Segment 0841Tributaries to Segment 0841

0

10

20

30

40

50

60

70

80

90

100

Delta S

ump

Hampto

n Sum

pBak

er Sum

pPav

aho S

ump

Coombs

Cree

kCha

rlie Sum

pAble

Sump

Cedar

Creek

White R

ock C

reek @

US 17

5

White R

ock C

reek

Roche

ster S

ump

Honey

Spring

s Bran

chElam

Cree

kFive

Mile

Cree

kPrai

rie C

reekTen

Mile

Cree

kPars

ons S

lough

Parson

s Slou

ghEas

t Fork

Red O

ak C

reek

Sum

of P

CB

Con

gene

rs in

Sed

imen

t (ug

/kg)

Segment Average

PCB Levels in Bed Sediments of PCB Levels in Bed Sediments of Tributaries to Segment 0805Tributaries to Segment 0805

ObservationsObservations

Total PCB levels in water exceeded water quality Total PCB levels in water exceeded water quality criteria in 13 of 18 samples from the Trinity criteria in 13 of 18 samples from the Trinity RiverRiver

Total PCB levels in storm water from older, Total PCB levels in storm water from older, densely developed urban areas are much higher densely developed urban areas are much higher than those inthan those in--stream, but low in rural and stream, but low in rural and suburban areassuburban areas

Total PCB levels in wastewater effluent were Total PCB levels in wastewater effluent were generally lower than ambient levels in the rivergenerally lower than ambient levels in the river

ObservationsObservations

PCB levels in sediment appear to have declined PCB levels in sediment appear to have declined since the 1970s and 1980s in Segment 0805 and since the 1970s and 1980s in Segment 0805 and 0841, but perhaps not in Segment 08060841, but perhaps not in Segment 0806

The range in PCB levels in tributary sediments The range in PCB levels in tributary sediments indicates continuing local sources in some areasindicates continuing local sources in some areas

TMDL Process and Project ScheduleTMDL Process and Project Schedule

Next Steps: Modeling and TMDL Next Steps: Modeling and TMDL DevelopmentDevelopment

Model under development to:Model under development to:assist in determining the TMDL and quantify pollutant loadsassist in determining the TMDL and quantify pollutant loadsevaluate future loading scenarios and load reductionsevaluate future loading scenarios and load reductions

InstreamInstream model is a multiplemodel is a multiple--box mass balance modelbox mass balance modelInstreamInstream segmentation and hydraulics based on TCEQ segmentation and hydraulics based on TCEQ QualQual--TX modelsTX modelsWatershed runoff and suspended sediment loading from Watershed runoff and suspended sediment loading from tributaries using GWLF modeltributaries using GWLF modelModeling expected to be complete late this monthModeling expected to be complete late this monthModeling report expected this summerModeling report expected this summer

Questions?Questions?

For further questions:For further questions:

Dania Dania GrundmannGrundmanndgrundma@tceq.state.tx.usdgrundma@tceq.state.tx.us512512--239239--34493449