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Request f or a T i m e C r i t i c a l Removal A c t i o n a t the U p p e rA r k a n s a s - F l u v i a l T a i l i n g s ( C a l i f o r n i a G u l c h N P L ) [ O U 1 1 ]S i t e , L e a d v i l l e , Lake C o u n t y , C o l o r a d o .Mike Zimmerman, OSCEmergency R e s p o n s e T e a mS t e v e H a w t h o r n , S u p e r v i s eEmergency R e s p o n s e U n i tD o u g l a s M . S k i e , D i r e c t o rP r e p a r e d n e s s , A s s e s s m e n t & Emergency R e s p o n s e ProgramM a x H . D o d s o n , A s s i s t a n t Regional A d m i n i s t r a t o rO f f i c e o f E c o s y s t e m P r o t e c t i o n a n d Remed ia t i onS i t e I D # :C a t e g o r y o f Removal:

2 9 ( O U 1 1 )T i m e C r i t i c a l , N P L

I . P U R P O S EThe p u r p o s e o f t h i s A c t i o n Memorandum i s to request anddocument approva l o f the Removal A c t i o n de s cr ibed herein fort h e U p p e r Arkansa s - F l u v i a l T a i l i n g s ( C a l i f o r n i a G u l c h N P L )[ O U 1 1 ] s i t e ( S i t e ) , L e a d v i l l e , Lake C o u n t y , C o l o r a d o .T h i s Removal A c t i o n a d d r e s s e s th e r e s p o n s e t o the threatp o s e d by t a i l i n g s w i th e l eva t ed metal c o n c e n t r a t i o n s o fl e a d , c o p p e r , cadmium, and zinc on riverbanks and ina d j a c e n t s u r f a c e channel s thr ea t ened by erosion f r o m thew a t e r f l o w in the Arkansas River. C o n d i t i o n s e x i s t i n g at theS i t e pr e s en t an imminent and s u b s t a n t i a l endangerment tohuman h e a l t h and the environment and meet the c r i t e r i a fori n i t i a t i n g a T i m e C r i t i c a l Removal A c t i o n under 40 C F R ,§ 3 0 0 . 4 1 5 ( b ) ( 2 ) o f t h e N a t i o n a l C o n t i n g e n c y P l a n ( N C P ) .

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I I . S I T E C O N D I T I O N S A N D B A C K G R O U N DA . S i t e D e s c r i p t i o n

1. Removal s i t e eva lua t i onT h e C E R C L I S I D number o f t h e U p p e r Arkansa s -F l u v i a l T a i l i n g s S i t e i s C O D 9 8 0 7 1 7 9 3 8 . S i t ec o n d i t i o n s are such that t h i s Removal A c t i o n isc l a s s i f i e d a s T i m e C r i t i c a l . T h e area o f t h i sRemoval A c t i o n f o c u s e s upon 3 areas in a series oft a i l i n g s a l o n g the Arkansa s River south o f thec o n f l u e n c e w i t h C a l i f o r n i a G u l c h . T h e s e l o c a t i o n sare a d j a c e n t to the pre s ent course of the Arkansa sRiver, and f l u v i a l t a i l i n g s are e r o d i n g into thewater on a d a i l y basi s . The erosion of t a i l i n g shas been observed by l a n d o w n e r s , E P A , and manyother p a r t i e s . T h e U . S . Environmental P r o t e c t i o nA g e n c y ( E P A ) ta sked t h e S u p e r f u n d T e c h n i c a lA s s e s s m e n t and Respons e T e a m (START) to p r o v i d e ana l t e r n a t i v e s a n a l y s i s f o r r e spons e t o t h e f l u v i a lt a i l i n g s a d j a c e n t to 11 m i l e s of the Arkansa sRiver ( S e e A t t a c h m e n t A - A l t e r n a t i v e s A n a l y s i s -U p p e r Arkansa s River F l u v i a l T a i l i n g s , LakeC o u n t y . C o l o r a d o [ C o n t r a c t # 6 8 - W 5 - 0 0 3 1 ] - M a y1 9 9 9 ) ; i n T a b l e 1 p a g e s 2 9 - 3 7 t h e f l u v i a l d e p o s i t shave been c h a r a c t e r i z e d , and in T a b l e 3, p a g e s 38-49 o f t h e A l t e r n a t i v e s A n a l y s i s . The a l t e r n a t i v e sa n a l y s i s was used to s e l e c t a p p r o p r i a t e areas anda p p r o p r i a t e t e c h n o l o g i e s which w i l l reduce th eimpac t o f f l u v i a l t a i l i n g s d e p o s i t s o n t h e U p p e rArkansa s River a n d i t s f l o o d p l a i n . A l t e r n a t i v e scon s id er ed i n c l u d e d no a c t i o n , i n s t i t u t i o n a lc o n t r o l s , i n - p l a c e s t a b i l i z a t i o n , removal, andriver channel a l t e r a t i o n . Each a l t e r n a t i v e wasrated a c c ord ing t o e f f e c t i v e n e s s , i m p l e m e n t a b i l i t y ,c o s t , and a c c e p t a b i l i t y . The S i t e s , which weres e l e c t e d , are l o c a t e d in three areas of theArkansa s River and are d e p i c t e d on p a g e s 3 9 - 4 9 oft h e A l t e r n a t i v e s A n a l y s i s - A t t a c h m e n t A .

2. P h y s i c a l l o c a t i o nThe p o r t i o n o f the Arkansa s River to which t h i sRemoval A c t i o n a p p l i e s i s l o c a t e d in Lake C o u n t y ,C o l o r a d o , and begins at the c o n f l u e n c e ofC a l i f o r n i a G u l c h and the Arkansa s River. The areais shown on the a t t a c h e d F i g u r e 1, S i t e L o c a t i o nM a p . A l o n g the segment which was c o n s i d e r e d , theriver i s f ed by Lake F o r k C r e e k , Iowa G u l c h ,T h o m p s o n G u l c h , Empir e G u l c h , D r y Union G u l c h , B i gUnion C r e e k , S p r i n g C r e e k , S a w m i l l G u l c h , B o x

C r e e k , a n d T w o b i t G u l c h . T h e L e a d v i l l e miningarea is drained by C a l i f o r n i a G u l c h . S e v e r a lunnamed w e t l a n d s are l o c a t e d a l ong the river, andthe river is a d j a c e n t to p r i v a t e p r o p e r t y and theS a n I s a b e l N a t i o n a l F o r e s t . T h i s Removal A c t i o nw i l l be c onduc t ed at three l o c a t i o n s on theArkansas River. The l o c a t i o n s are shown inF i g u r e s 9, 10, and 11 of the a t t a c h e d A l t e r n a t i v e sA n a l y s i s a s A A - A B - A C - A D - A E - A G - C A - C C - C D - C E - C F - C G -C J - C K - C P - C R - C S - M F - M G - M I - M J - M K - M L - M N - N A - N B - N C - N D -N G - N H - N I - N J - N L - N R - N T a n d N U , a n d d e p i c t e d w i ths i t e l o c a t i o n s on p a g e s 40-47. Areas AA thru AGw i l l be t r ea t ed as one d i s t i n c t l o c a t i o n as w i l lareas CA, CC thru CS and areas MF - NU. All areasi d e n t i f i e d w i l l b e s u b j e c t t o in- s i t u trea tmentinvo lv ing th e a p p l i c a t i o n o f soil amendment s .

3 . S i t e c h a r a c t e r i s t i c sMine t a i l i n g s f r o m t h e L e a d v i l l e h i s t o r i c a l mininga c t i v i t y , t r a n s p o r t e d by weather events andf l u v i a l p r o c e s s e s , were carried downs tr eam viaC a l i f o r n i a G u l c h to the Arkansa s River andd e p o s i t e d in many l o c a t i o n s a d j a c e n t to the river.R e s i d e n t s s t a t e that t a i l i n g s e d i m e n t s were a l s ot r a n s p o r t e d a l o n g i r r i g a t i o n channe l s andr e d e p o s i t e d in f i e l d s in the river v a l l e y . TheArkansa s River i s used for r e c r ea t i on , i r r i g a t i o no f a g r i c u l t u r a l , and range l a n d s . I r r i g a t i o n o frange land and a g r i c u l t u r a l land w i th h igh metalcontent water may have c o n t r i b u t e d to e l e v a t e dl e v e l s o f m e t a l s in animals and p l a n t s . T a i l i n g s ,h igh in metal c o n c e n t r a t i o n s , a l o n g riverbankshave reduced or e l i m i n a t e d r iver s id e v e g e t a t i o n ,incr ea s ing erosion p o t e n t i a l . H i g h metalc onc en tra t i on s in stream water can caused e g r a d a t i o n o f f i s h h a b i t a t s , recreat ional areas,and a g r i c u l t u r a l l a n d . Area s o f h igh metalc on tamina t i on are becoming more a c c e s s i b l e asd e v e l o p m e n t encroaches on the U p p e r A r k a n s a sRiver. E x t r e m e l y h igh metal l e v e l s f o r s e l e c t e dremoval areas are i n d i c a t e d in T a b l e 3, page 39 ofthe A l t e r n a t i v e A n a l y s i s , and in A t t a c h m e n t E,Summary o f P h y t o t o x i c C o n c e n t r a t i o n s . T h e metall e v e l s are many t imes the a l l o w a b l e t h r e s h o l d f orv e g e t a t i v e g r o w t h , thereby l e a d i n g t o s c a r i f i e dareas a d j a c e n t to the river that are e a s i l y erodedwith cont inuous river f l o w s . T h e a l l o w a b l ec o n c e n t r a t i o n f o r s u c c e s s f u l p l a n t growth f o rcadium, c o p p e r , l e a d , and zinc are; 3 to 8 m g / k g ,60 to 125 m g / k g , 100 to 400 m g / k g , and 70 to 400i n g / k g , r e s p e c t i v e l y . Mangane s e has no value

a s s i g n e d . T h e average t a i l i n g s c onc en t ra t i on o fthe s e e l e m e n t s in the p r o p o s e d r emed ia t i on areasare; 680 m g / k g , 840 k g / m g , 1 0 , 9 0 0 k g / m g , and3 2 , 9 0 0 k g / m g , r e s p e c t i v e l y wi th manganese measureda t 7 , 3 0 0 k g / m g ( S e e A t t a c h m e n t D ) . T h e s e t a i l i n g sare e s s e n t i a l l y s t e r i l e and w i l l never s u s t a inp l a n t l i f e i n th e i r current c o n d i t i o n . T h econveyance of hazardous m a t e r i a l s into theArkansas River continues unabated. Each weatheror h igh f l o w event l e a d s t o f u r t h e r d e g r a d a t i o n o fth e U p p e r Arkansa s River.F u r t h e r evidence o f the s p o i l e d r ipar ian areas areevidenced by d e p r e s s e d soil pH l e v e l s which arer e p r e s e n t e d i n A t t a c h m e n t E . T h e nine t e en ( 1 9 )s t r e a m s i d e t a i l i n g s areas s l a t e d f o r r e m e d i a t i o nhave been a n a l y z e d . F o u r (4) were f o u n d in the pH1 to 2 range, f i v e (5) in the pH 2 to 3 range, andf i v e ( 5 ) i n t h e p H 3 t o 4 range; very d i f f i c u l t ,i f no t i m p o s s i b l e growing c o n d i t i o n s f o r any t y p eo f v e g e t a t i o n . S t a n d i n g rainwater ( t a i l i n g sa r e a s ) wi th a pH of 1.0 has been observed a d j a c e n tto the river in many of the p r o p o s e d r e m e d i a t i o nareas, f u r t h e r a d d i n g to the environmental in su l to f th e t a i l i n g s . Heavy m e t a l s are e a s i l ys o l u b i l i z e d in the s e a c i d i c c o n d i t i o n s , and thusl each into groundwater and s u r f a c e waters of theArkansa s River.

4. Release or threatened re lease into the environmentof a hazardous subs tance, or p o l l u t a n t orcontaminantT h e m e t a l s o f g r e a t e s t concern f o r exposurea t t r i b u t a b l e t o t h e S i t e a r e l e a d , c o p p e r ,cadmium, and zinc. Cadmium is c l a s s i f i e d as knownhuman carcinogens for c er ta in routes o f e xpo sure ,and al l f o u r of the m e t a l s are a s s o c i a t e d w i thnoncarc inogenic e f f e c t s o n s p e c i f i c organ sy s t ems .Human H e a l t h C r i t e r i aCadmiumCadmium is a hazardous sub s tance as d e f i n e d byS e c t i o n 1 0 1 ( 1 4 ) o f C E R C L A . I t i s a heavy m e t a l ,and has been shown to be a carcinogen in bo thanimal s t u d i e s and o c c u p a t i o n a l l y e xpo s ed group sof humans via the i n h a l a t i o n route of expo sure .No evidence has l inked cadmium to cancer via thei n g e s t i o n p a t h w a y . The CAG ha s c l a s s i f i e d cadmiumas a G r o u p Bl - - Probab l e Human C a r c i n o g e n for

i n h a l a t i o n only based on l i m i t e d evidence ofc a r c i n o g e n i c i t y in humans f r o m o c c u p a t i o n a ls t u d i e s . Cadmium may al so be a human mutagen ort e r a t o g e n , and thus may a f f e c t the k i d n e y s , bones ,l iv er , r e p r o d u c t i v e sy s t em, r e s p i r a t o r y tract orimmune sys t em. Cadmium i n h i b i t s t h e b o d y ' sa b i l i t y to absorb e s s en t ia l e l e m e n t s , such asc o p p e r and c a l c i u m , and may l ead to d e f i c i e n c i e sof those e l e m e n t s . Expo sure to t ox i c amounts o fcadmium by e i th er i n h a l a t i o n or i n g e s t i o n w i l lcause cadmium to accumulate in the renal s y s t e mand e v e n t u a l l y cause k idney f a i l u r e .LeadLead is a hazardous sub s tance as d e f i n e d byS e c t i o n 1 0 1 ( 1 4 } o f C E R C L A . Lead i s a l s oc l a s s i f i e d as a B2 carc inogen by E P A . T h i sc l a s s i f i c a t i o n i s the r e su l t o f adequat e animals t u d i e s d e t e r m i n i n g that these compounds arep r o b a b l e human carc inogens . Lead can enter thebody via i n g e s t i o n and i n h a l a t i o n . C h i l d r e na p p e a r to be the segment of the p o p u l a t i o n atg r e a t e s t risk f r o m t ox i c e f f e c t s o f l e a d .I n i t i a l l y , l ead t r a v e l s in th e b l o o d t o t h e s o f tt i s sue s ( h e a r t , l iver, k idney, brain, e t c . ) , thenit g r a d u a l l y r e d i s t r i b u t e s to the bones and t e e t hwhere it t e n d s to remain. The most seriouse f f e c t s a s s o c i a t e d wi th m a r k e d l y e l e v a t e d b l oodlead l e v e l s i n c l u d e neuro tox i c e f f e c t s such a si rr ever s i b l e brain damage. C h i l d r e n haveexh ib i t ed nerve damage, permanent mentalr e t a r d a t i o n , c o l i c , anemia, brain damage , andd e a t h .C o p p e rC o p p e r is a hazardous sub s tance as d e f i n e d byS e c t i o n 1 0 1 ( 1 4 ) o f C E R C L A . Because many c o p p e rcompounds and c o m p l e x e s are r e a d i l y s o l u b l e ,c o p p e r is among the more m o b i l e heavy m e t a l s insoil and s u r f a c e environments. The m a j o r p r o c e s sthat l i m i t s the environmental m o b i l i t y of c o p p e ri s a d s o r p t i o n to organic m a t t e r , c l a y s , and o therm a t e r i a l s . A t m o s p h e r i c t r a n s p o r t o f c o p p e rcompounds can a l s o occur. S u f f i c i e n t d a t a i s nota v a i l a b l e for c o p p e r to derive a l evel which wouldp r o t e c t agains t t h e p o t e n t i a l t o x i c i t y o f t h i scompound re la t ive to human hea l th . H i g h l e v e l s ofc o p p e r can be tox i c to humans. Expo sure tom e t a l l i c c o p p e r dust can cause a s h o r t - t e r mi l l n e s s s i m i l a r to metal f u m e f e v e r that i s

c h a r a c t e r i z e d by c h i l l s , f e v e r , aching m u s c l e s ,drynes s of mouth and t h r o a t , and headache.Exposure to c o p p e r f u m e s can p r o d u c e u p p e rr e s p i r a t o r y tract i r r i t a t i o n , a m e t a l l i c or sweett a s t e , nausea, metal f u m e f e v e r , and somet imesd i s c o l o r a t i o n of skin and hair. I n d i v i d u a l se xpo s ed to dust and m i s t s of c o p p e r s a l t s mayexh ib i t c o n g e s t i o n of nasal mucous membranes,somet imes of the pharynx, and o c c a s i o n a l l yu l c e r a t i o n wi th p e r f o r a t i o n o f nasal s ep tum. I fs u f f i c i e n t c onc en tra t i on s o f c o p p e r s a l t s reachthe g a s t r o i n t e s t i n a l t r a c t , they act as i r r i t a n t sand can produc e s a l i v a t i o n , nausea, v o m i t i n g ,g a s t r i t i s and diarrhea. The i n g e s t i o n o f ionicc o p p e r can cause c onvu l s i on s , and d e a t h . Chronicexposure may re su l t in anemia. C o p p e r s a l t s actas skin i r r i t a n t s p r o d u c i n g an i t c h i n g eczema.C o n j u n c t i v i t i s or even u l c e r a t i o n and t u r b i d i t yof the cornea may re su l t f r o m d i r e c t contac t ofionic c o p p e r w i th th e eye. U s i n g a v a i l a b l eo r g a n o l e p t i c d a t a f o r c o n t r o l l i n g u n d e s i r a b l et a s t e and odor q u a l i t y of ambient water , thee s t i m a t e d level i s 1 m g / L . It shou ld ber e c ogniz ed that o r g a n o l e p t i c d a t a , a s a basi s fore s t a b l i s h i n g as a water q u a l i t y c r i t e r ia havel i m i t a t i o n s , and have no d e m o n s t r a t e d r e l a t i o n s h i pt o p o t e n t i a l adverse human h e a l t h e f f e c t s .Z i n cZ i n c is a hazardous sub s tance as d e f i n e d byS e c t i o n 1 0 1 ( 1 4 ) o f C E R C L A . Z i n c can occur in bo ths u s p e n d e d and d i s s o l v e d f o r m s . It i s m o b i l e inbo th aquat ic sy s t ems and in s o i l . A t m o s p h e r i ct r a n s p o r t o f zinc i s a l s o p o s s i b l e . H o w e v e r ,ex c ep t near sources such as s m e l t e r s , zincc onc en tra t i on s in air are r e l a t i v e l y low andf a i r l y c o n s t a n t . S i n c e i t i s an e s s e n t i a ln u t r i e n t , zinc is s t r o n g l y b i oac cumula t ed even inthe absence of abnormal ly h i g h ambientc o n c e n t r a t i o n s . It does not a p p e a r to beb i o m a g n i f i e d . Z i n c i s one of the most impor tan tm e t a l s in b i o l o g i c a l sy s t ems .Z i n c may be i n d i r e c t l y i m p o r t a n t w i t h regard tocancer since its pr e s enc e seems to be neces saryfor th e growth o f tumors. I n g e s t i o n o f excessiveamounts of zinc may cause f e v e r , v o m i t i n g , s t omachcramps , and diarrhea. F u m e s o f f r e s h l y - f o r m e dzinc oxide can p e n e t r a t e d e e p in to the a l v e o l i andcause metal f u m e f e v e r . Z i n c oxide du s t doe s notp r o d u c e t h i s d i s o r d e r . C o n t a c t w i th zinc c h l o r i d e

B.

can cause skin and eye i r r i t a t i o n . I n h a l a t i o n ofm i s t s or f u m e s may i r r i t a t e the r e s p i r a t o r y andg a s t r o i n t e s t i n a l t r a c t s . Z i n c in excess o f 0 . 2 5 %in the d i e t of rats causes growth r e t a r d a t i o n ,hypochromic anemia, and d e f e c t i v e m i n e r a l i z a t i o nof bone. No zinc t o x i c i t y is observed at d i e t a r yl e v e l s l e s s than 0.25%. S t u d i e s w i th animals andhumans i n d i c a t e that m e t a b o l i c changes may occurdue to the i n t e r a c t i o n of zinc and other m e t a l s inthe d i e t . Exposure to cadmium may cause changesin the d i s t r i b u t i o n of z inc , w i th increases in thel iver and k i d n e y s , organs where cadmium a l s oa c c u m u l a t e s . Exce s s ive intake of zinc may causec o p p e r d e f i c i e n c i e s and re su l t in anemia.I n t e r a c t i o n of zinc wi th iron or l ead may a l s ol ead to changes that are not p r o d u c e d when them e t a l s are i n g e s t e d i n d i v i d u a l l y .Other A c t i o n s to Date1. Previous ac t ions

Other Removal A c t i o n s w i th in O p e r a b l e Uni t 11 andand a l o n g the Arkansas River in the C a l i f o r n i aG u l c h ar e d i s c u s s e d in th e C a l i f o r n i a G u l c h A c t i o nMemoranda d a t e d March 7 , 1 9 8 6 ; October 28 , 1 9 9 3 ;November 1. 1 9 9 4 ; S e p t e m b e r 15, 1 9 9 7 ; and A u g u s t4, 1998 . A l s o , th e waiver f or s t a t u t a r y maximum o f$ 2 , 0 0 0 , 0 0 0 f o r Removal A c t i o n s w a s approved p e rA c t i o n Memoranda, da t ed J u n e 2 4 , 1997 . T h ef o l l o w i n g summary l i s t s F u n d Lead Removalsi n i t i a t e d , o r p e r f o r m e d , t o d a t e f o r C a l i f o r n i aG u l c h N P L S i t e :

Previous S u p e r f u n d Removal A c t i o n s - F u n d LeadC a l i f o r n i a G u l c h N P L S i t e

O p e r a b l e U n i t -P r o p o s e d A c t i o nou 2 DMGTI-

N T C R2 ) L M G -

T C R3 ) M T T -

T C R4 ) MGTI -

T C R

A c t i o n Memo -C o s t C e i l i n g$ 3 7 4 , 0 0 0$ 4 8 0 , 0 0 0

$ 9 0 , 0 0 0$ 1 0 5 , 6 7 0

A c t i o n Memo -A p p r o v a l DateS e p t e m b e r 1 0 , 1 9 9 3A u g u s t 9 , 1995A u g u s t 9 , 1996A p r i l 15 , 1998

C o n t i n u e d - N e x t Page

Operab l e U n i t -P r o p o s e d A c t i o no u 6 D H T I -

T C R2 ) 5 T h S t -S t a r rD i t c h -

T C R3 ) Hamms -PenroseT C R4 ) M W P - P 1N T C R

5 ) M W P - P 2N T C R

6 ) R E S # 1 - T PN T C R

7 ) R E S # 1 - T PAmendm ' tN T C R8 ) R E S # 1 - P 3

N T C ROU 7 1) A p a c h eEnergy &Minera l -T C ROU11 D M a e s t a sW e l l s -ER2 ) R i v e r T g sER3 ) R i v e r T g sER4 ) R i v e r T g sT C R5 ) R i v e r T g s

T C R -Amendm ' tC u m u l a t i v e T o t a l

A c t i o n Memo -C o s t C e i l i n g$ 5 0 , 0 0 0$ 5 0 , 0 0 0

$ 2 , 7 2 6 , 0 0 0

$ 7 , 2 9 0 , 0 0 0 *Amendment

$ 8 5 , 0 0 0$ 2 4 0 , 0 0 0

Amendment

$ 6 0 , 0 0 0

$ 2 0 , 2 4 2

$ 5 0 , 0 0 0$ 5 0 , 0 0 0

$ 1 , 1 2 5 , 0 0 0Amendment**

$ 1 2 , 7 1 0 , 9 1 2

A c t i o n Memo -S i g n e d DateNovember 9, 1995May 1, 1996

J u l y 2 6 , 1996

J u n e 24, 1997J u l y 1 5 , 1998October 26 , 1998J u n e 2 , 1999

J u n e 2 , 1999

A u g u s t 6 , 1996

March 7, 1986

October 28, 1993November 1, 1994S e p t e m b e r 1 5 , 1 9 9 7A u g u s t 4, 1998

* Waiver o f S t a t u a t o r y $ 2 , 0 0 0 , 0 0 0 Limi t f o r Removals .* * T w e l v e ( 1 2 ) M o n t h E x e m p t i o n A p p r o v a l f o rS e p t e m b e r 15, 1997 Removal A c t i o n .P r o p o s e d A c t i o n Leg-endER : Emergency RemovalTCR : T i m e C r i t i c a l RemovalN T C R : N o n - T i m e C r i t i c a l Removal

2. Current ac t ionsOther than m o n i t o r i n g of the S i t e , there are noother a c t i on s b e ing taken or p r o p o s e d o ther thanthose d i s c u s s e d in t h i s A c t i o n Memorandum.Cont inued r e s p o n s e a c t i on s are required top r e v e n t , l i m i t , or m i t i g a t e cont inued to l o a d i n gof heavy m e t a l s in to the Arkansa s River and thesurrounding v a l l e y . A l o n g w i t h p o t e n t i a l t h r e a t st o w i l d l i f e a n d p l a n t s , t h i s erosion w i l l d e g r a d eriver q u a l i t y and increase the p o t e n t i a l f orp u b l i c e xpo sure t o heavy m e t a l s t hrough i n g e s t i o no f c on taminat ed p l a n t s / c r o p s i r r i g a t e d wi thcon taminat ed water. W i t h conversion of land useas a r e su l t of the Lake C o u n t y Open S p a c eI n i t i a t i v e ( L C O S I ) , l a r g e t r a c t s o f land w i l l b eopen to p u b l i c access under the control andmanagement o f t h e C o l o r a d o S t a t e D e p a r t m e n t o fParks . The Arkansa s River Ranch and the H a y d e nRanch, c o m p r i s i n g 5 , 2 0 0 acres o f f o r m e r l yp r i v a t e l y owned land a d j a c e n t to the river, arebe ing opened to p u b l i c access for r e cr ea t i on andf i s h i n g dur ing th e summer o f 1999 . P r o p o s e dremoval areas M F - M G - M I - M J - M K - M L - M N - N A - N B - N C - N D - N G -NH-NI-NJ-NL-NR-NT and NU are l o c a t e d on theArkansas River Ranch. P o t e n t i a l for humanexposure to e l eva t ed m e t a l s w i l l occur w i thou tt h i s p r o j e c t .

S t a t e a n d Local A u t h o r i t i e s ' Role s1. S t a t e and loca l ac t ions to da t e

R e s i d e n t s in the Arkansa s River f l o o d p l a i n haveobserved dead v e g e t a t i o n a d j a c e n t to the riverover the la s t seventy years. Land owners b e l i ev ethat i r r i g a t i o n wat er , carrying metal l o a d s f r o mthe Arkansas River and C a l i f o r n i a G u l c h havecaused d imin i sh ed u s a b i l i t y o f f a r m andr a n g e l a n d s . T h e e f f e c t s o f t h e Arkansas Riverwater q u a l i t y on f i s h and w i l d l i f e have been andcontinue to be s t u d i e d by the U. S. F i s h andW i l d l i f e S e r v i c e ( U S F W S ) . I n recent years t h eLake County S o i l C o n s e r v a t i o n D i s t r i c t ( L C S C D ) h a sbrought the s e concerns to E P A .U n d e r t h e l e a d e r s h i p o f t h e Lake C o u n t y S o i lCons erva t i on D i s t r i c t ( L C S C D ) , a p u b l i c f o r u m h a sbeen created f o r t h e p u r p o s e o f a d d r e s s i n g th e

current c o n d i t i o n of the U p p e r Arkansa s River. Agroup o f s t a k e h o l d e r s invo lv ing l o ca l l a n d o w n e r s ,L C S C D , s t a t e a n d f e d e r a l natural resourcet r u s t e e s , p r i v a t e i n d u s t r y , and EPA was f o r m e d andis known as the U p p e r Arkansa s River R e s t o r a t i o nP r o j e c t S t a k e h o l d e r s CORE T e a m . Regu lar m o n t h l ym e e t i n g s are c onduc t ed wi th s t a k e h o l d e rr e p r e s e n t a t i v e s invi t ed to a t t e n d and p a r t i c i p a t e .E P A , a l t h o u g h s u p p o r t i v e o f t h e r e s t o r a t i o n e f f o r ti n s p i r i t , c o n f i n e d i t s e f f o r t s t o a d d r e s s i n g t h ehazardous m a t e r i a l s w i t h i n t h e f l u v i a l t a i l i n g s .2 . P o t e n t i a l f o r continued S t a t e / l o c a l re sponse

As d i s c u s s e d above r e p r e s e n t a t i v e s o f S t a t e andC o u n t y agenc i e s are concerned about the c o n d i t i o n se x i s t i n g at the S i t e ; however, they do not havethe f u n d s to conduct the needed removal a c t i on s .S u p p o r t for the Removals has been e x p r e s s e d by theLake C o u n t y S o i l Cons erva t i on D i s t r i c t , LakeC o u n t y Board o f County C o m m i s s i o n e r s , p r i v a t el a n d o w n e r s , and the U p p e r Arkansa s RiverR e s t o r a t i o n P r o j e c t S t a k e h o l d e r s Core T e a m .I I I . T H R E A T S T O P U B L I C H E A L T H O R W E L F A R E O R T H E E N V I R O N M E N T , A N D

S T A T U T O R Y A N D R E G U L A T O R Y A U T H O R I T I E SA . T h r e a t s t o P u b l i c H e a l t h o r W e l f a r e

The c o n d i t i o n s at the S i t e p r e s en t an imminent ands u b s t a n t i a l endangerment to human h e a l t h and theenvironment and meet the c r i t e r i a for i n i t i a t i n g aRemoval A c t i o n under 4 0 C F R § 3 0 0 . 4 1 5 ( b ) ( 2 ) o f t h e N C P .T h e f o l l o w i n g f a c t o r s f r o m § 3 0 0 . 4 1 5 ( b ) ( 2 ) o f t h e N C Pf o r m t h e bas i s f o r E P A ' s d e t e r m i n a t i o n o f t h e threatp r e s e n t e d , and the a p p r o p r i a t e a c t i on to be taken:1. " A c t u a l or p o t e n t i a l expo sure to nearby animal sor the f o o d chain f r o m hazardous sub s tance s orp o l l u t a n t s or contaminant s" - water f r o m the Riveri s used f or i r r i g a t i o n and c a t t l e / o t h e r animal s f e e don p l a n t s which are i r r i g a t e d ;2. " H i g h l e v e l s of hazardous sub s tance s orp o l l u t a n t s or c on taminant s in s o i l s l a r g e l y at ornear the s u r f a c e , that may migra t e" - t a i l i n g s atthe riverbank had a p o t e n t i a l for migra t i on toareas which h e r e t o f o r e did not have con taminat eds o i l .3. " W e a t h e r c o n d i t i o n s that may cause hazardoussubs tance s or p o l l u t a n t s or contaminant s to

10

migra t e or be r e l ea s ed" - s torm events a n d / o r theS p r i n g r u n o f f may cause the Arkansa s River to riseand a c c e l e r a t e the p o t e n t i a l t h r e a t s which arel i s t e d above.B. T h r e a t s to the Environment

S p e c i f i c t h r e a t s t o w i l d l i f e a n d p l a n t s which c a na l r e a d y be seen have been reviewed under " S i t eC h a r a c t e r i s t i c s " and a d d i t i o n a l damage to w i l d l i f e inthe a d j a c e n t h a b i t a t s and the f i s h in the c o n f l u e n c ewaters could r e su l t f r o m the continued exposure toc o n t a m i n a t i o n e i th er through d i r e c t contac t w i th thee f f l u e n t s , s t a n d i n g water , s e d i m e n t s , o r i n d i r e c t l y -through c o n s u m p t i o n o f organisms ( a l g a e , aquat ici n s e c t s , or a n i m a l s ) f e e d i n g in the area.C o p p e rMean acute t o x i c i t y values for a l a r g e number o ff r e s h w a t e r animal s range f r o m 7 . 2 u g / L f o r d a p h n i ap u l i c a r i a t o 10,200 u g / L f o r t h e b l u e g i l l . T o x i c i t yt e n d s to decrease as hardne s s , a l k a l i n i t y , and t o t a lorganic carbon increase. Chronic values are a v a i l a b l efor 15 f r e s h w a t e r s p e c i e s and range f r o m 3 .873 u g / L to6 0 . 3 6 u g / L f o r northern p i k e . F i s h a n d inver t ebrates p e c i e s seem to be about e q u a l l y s e n s i t i v e to thechronic t o x i c i t y o f c o p p e r .An e x a m p l e of t o x i c i t y to l i v e s t o c k is evident byexpo sure to sh e ep . S h e e p are very s u s c e p t i b l e toc o p p e r t o x i c o s i s , and p o i s o n i n g may be acute orchronic. A c u t e p o i s o n i n g is caused by d irec t a c t i on ofc o p p e r s a l t s on th e g a s t r o i n t e s t i n a l t r a c t , r e s u l t i n gin g a s t r o e n t e r i t i s , shock, and d e a t h . The t ox i c doseis about 200 m g / k g and is u s u a l l y ob ta ined througha c c i d e n t a l overdose o f an a n t i h e l m i n t h i c . I n g e s t i o n o fexcess c o p p e r over a p e r i o d of t ime r e s u l t s in thea d s o r p t i o n and a c cumula t i on of c o p p e r by the l iver.T h i s t y p e o f chronic cumulative p o i s o n i n g may s u d d e n l yd e v e l o p in to an acute h e m o l y t i c cr i s i s . C o p p e r intakeof 1.5 g / d a y for 30 days i s known to be f a t a l for manybreeds of s h e e p . Exce s s ive c o p p e r may be s tored in thel iver as a r e su l t of excess c o p p e r i n g e s t i o n , as aconsequence of impair ed l iver f u n c t i o n , or inconnec t ion w i th a d e f i c i e n c y or excess of o ther tracee l e m e n t s .LeadLead is ubiquitous in the environment and a l t h o u g hb i o a c c u m u l a t i o n is known to occur, and lead is f o u n d in

11

th e t i s s u e o f many w i l d a n i m a l s , i n c l u d i n g b i r d s ,mammals , f i s h e s , and i n v e r t e b r a t e s , the most p u b l i c i z e de f f e c t s o f l ead have been on the impact of i n g e s t i o n ofl ead by w a t e r f o w l . A c u t e and chronic lead t o x i c i t yhave been d e m o n s t r a t e d as a d e f i n i t e threat to birdp o p u l a t i o n s . Chroni c values for d a p h n i a magna and therainbow trout are 12.26 and 83 .03 u g / l i t e r ,r e s p e c t i v e l y , at a f r e s h w a t e r hardne s s of about 50m g / l i t e r . F r e s h w a t e r a l g a e show an i n h i b i t i o n o fgrowth at l ead c o n c e n t r a t i o n s above 500 u g / l i t e r .T h e r e i s evidence that l e a d , at c onc en t ra t i on so c c a s i o n a l l y f o u n d near r o a d s i d e s and s m e l t e r s , cane l i m i n a t e p o p u l a t i o n s o f ba c t e r ia and f u n g i on l e a fs u r f a c e s and in s o i l . Many of the microorgani sms p l a ykey role s in the d e c o m p o s e r f o o d chain. C a s e s of leadp o i s o n i n g have been r e p o r t e d for a varie ty o f d o m e s t i ca n i m a l s , i n c l u d i n g c a t t l e , hor s e s , d o g s , and ca t s .Severa l t y p e s of man-made sources are c i t e d as thesource of l ead in the s e r e p o r t s . Because of t h e i rc u r i o s i t y , and the ir i n d i s c r i m i n a t e e a t i n g h a b i t s ,c a t t l e e xper i ence th e g r e a t e s t inc idence o f leadt o x i c i t y among d o m e s t i c animal s .CadmiumL a b o r a t o r y e x p e r i m e n t s s u g g e s t that cadmium may haveadverse e f f e c t s on r e p r o d u c t i o n in f i s h at l e v e l spre s en t i n l i g h t l y t o m o d e r a t e l y p o l l u t e d water s . N oadverse e f f e c t s on d o m e s t i c or w i l d animals werer e p o r t e d in the s t u d i e s reviewed.Z i n cZ i n c p r o d u c e s acute t o x i c i t y in f r e s h w a t e r organismsover a range of c onc en tra t i on s f r o m 90 to 5 8 , 1 0 0u g / l i t e r , and appear s to be l e s s t ox i c in harder water.A c u t e t o x i c i t y i s s im i lar f o r f r e s h w a t e r f i s h a n dinver t e bra t e s . A f i n a l a cu t e- chroni c rat io f o rf r e s h w a t e r s p e c i e s o f 3 .0 has been r e p o r t e d . Z i n cp o i s o n i n g has occurred in c a t t l e . Some researchershave s p e c u l a t e d that exposure to exces s ive amounts ofzinc may c o n s t i t u t e a hazard to horses. L a b o r a t o r ys t u d i e s and f i n d i n g s in f o a l s l i v i n g near l e a d - z i n cs m e l t e r s s ugge s t that excess ive exposure to zinc mayp r o d u c e bone change s , j o i n t a f f l i c t i o n s , and lamenes s .T o f u r t h e r d e m o n s t r a t e t h e environmental in su l t f r o mt h e f l u v i a l t a i l i n g s , t h e p h y t o t o x i c c h a r a c t e r i s t i c s o fcadmium, c o p p e r , l e a d , and zinc are p r e s e n t e d inA t t a c h m e n t D. The metal c oncentra t ions pre s en t are manyt imes the maximum recommended l e v e l s , thus p r e s e n t i n g ah o s t i l e environment f o r p l a n t growth . A l l o f t h e areas

12

s e l e c t e d for Removal A c t i o n s or r e v e g e t a t i o n have metall e v e l s e x c e ed ing the maximum recommended values byorders o f m a g n i t u d e . F o r e x a m p l e , average zinct a i l i n g s l e v e l s have been measured at 3 2 , 9 0 0 m g / k g wi tha peak c o n c e n t r a t i o n o f 115 ,000 m g / k g f o r t h e p r o p o s e dareas. The maxmium recommended level for zinc tosu s ta in a h e a l t h y p l a n t environment is 70 - 400 m g / k g .The t a i l i n g s are overwhe lmingly s t e r i l e .

I V . E N D A N G E R M E N T D E T E R M I N A T I O NA c t u a l or t hr ea t ened r e l ea s e s of hazardous s u b s t a n c e s ,p o l l u t a n t s a n d c on taminant s f r o m t h i s S i t e , i f n o t a d d r e s s e dby i m p l e m e n t i n g the r e spon s e a c t i o n d e s c r i b e d in t h i s A c t i o nMemorandum, pr e s en t a p o t e n t i a l imminent and s u b s t a n t i a lendangerment to p u b l i c h e a l t h , or w e l f a r e , or theenvironment.

V . P R O P O S E D A C T I O N S A N D E S T I M A T E D C O S T SA . P r o p o s e d A c t i o n s

1. P r o p o s e d ac t ion d e s c r i p t i o nT h i s Removal A c t i o n i s d e s i g n e d to a d d r e s s thethreat p o s e d by an e s t i m a t e d 7 , 8 0 0 cubic yards oft a i l i n g s w i th h igh c o n c e n t r a t i o n s o f l e a d ,cadmium, c o p p e r , and zinc which have beent r a n s p o r t e d a n d / o r are e rod ing into the A r k a n s a sRiver. The a c t i on s f or each o f th e areas s u b j e c tto t h i s Removal are l i s t e d in the A l t e r n a t i v e sA n a l y s i s ( A t t a c h m e n t A ) , a n d involve t h ea p p l i c a t i o n o f soil amendments wi th l ime p l u sr e v e g e t a t i o n wi th native s p e c i e s , or i n - s i t ur e m e d i a t i o n , for areas AA thru AG, CA and CC thruC S , a n d M F thru N U .

2. C o n t r i b u t i o n to remedial p e r f o r m a n c eThe Removal A c t i o n w i l l no t i n t e r f e r e w i th anyf u t u r e Remedial A c t i o n o n t h e S i t e .

3. D e s c r i p t i o n of a l t e r n a t i v e t e c h n o l o g i e sT h e U . S . Environmental P r o t e c t i o n A g e n c y ( E P A )tasked the S u p e r f u n d T e c h n i c a l A s s e s s m e n t andR e s p o n s e T e a m ( S T A R T ) t o prov id e a n a l t e r n a t i v e sa n a l y s i s f o r r e spon s e t o t h e f l u v i a l t a i l i n g sa d j a c e n t to 11 m i l e s o f the Arkansa s River ( S e eA t t a c h m e n t A - A l t e r n a t i v e s A n a l y s i s - U p p e r

13

Arkansa s River F l u v i a l T a i l i n g s , Lake County ,C o l o r a d o ) . T h i s a l t e r n a t i v e s a n a l y s i s wa s used t os e l e c t a p p r o p r i a t e areas and a p p r o p r i a t et e c h n o l o g i e s which w i l l reduce the impact off l u v i a l t a i l i n g s d e p o s i t s o n t h e U p p e r Arkansa sRiver a n d i t s f l o o d p l a i n . A l t e r n a t i v e scons idered i n c l u d e d no a c t i o n , i n s t i t u t i o n a lc o n t r o l s , i n - p l a c e s t a b i l i z a t i o n , removal, andriver channel a l t e r a t i o n . Each a l t e r n a t i v e wasrated according to e f f e c t i v e n e s s ,i m p l e m e n t a b i l i t y , c o s t , a n d a c c e p t a b i l i t y . T h er e s u l t s o f t h i s a n a l y s i s i n d i c a t e d that i n - p l a c es t a b i l i z a t i o n u t i l i z i n g soil amendments w i th l imeis recommended due to t h e i r lower cost ande f f e c t i v e n e s s at s i m i l a r s i t e s .Comments f r o m t h e C o l o r a d o D e p a r t m e n t o f P u b l i cH e a l t h and the Environment, th e C i t y o f Aurora ,a n d t h e U . S . F i s h a n d W i l d l i f e S e r v i c e have beenreceived. A Respon s iv ene s s Summary, as perA t t a c h m e n t E has been p r e p a r e d to a d d r e s s theconcerns e xpr e s s ed in comments received to theA l t e r n a t i v e A n a l y s i s .

4. E E / C AT h i s Removal A c t i o n i s a T i m e C r i t i c a l R e s p o n s eA c t i o n and an E E / C A is not required. AnA l t e r n a t i v e A n a l y s i s o f viable o p t i o n s wasp e r f o r m e d t o a l l o w f o r input f r o m t h e l o ca ll a n d o w n e r s , t h e Lake County S o i l C o n s e r v a t i o nD i s t r i c t , l o ca l government s , t h e S t a t e o fC o l o r a d o , p r i v a t e i n d u s t r y , o ther F e d e r a lA g e n c i e s , a n d . t h e general p u b l i c .

5. A p p l i c a b l e or relevant and a p p r o p r i a t erequirements ( A R A R s )Because t h i s A c t i o n is be ing c onduc t ed as a T i m eC r i t i c a l Removal A c t i o n , a l l F e d e r a l a n d S t a t eARARs have not been i d e n t i f i e d at t h i s t ime. AnyARARs that have been i d e n t i f i e d w i l l be met to theextent p r a c t i c a b l e , given the e x ig enc i e s o f thes i t u a t i o n . A t e n t a t i v e l i s t o f ARARs i s a t t a c h e df o r i n f o r m a t i v e p u r p o s e s .

B. E s t i m a t e d C o s t sCos t E s t i m a t e : A t a b l e c o n t a i n i n g cost e s t i m a t e s f o rthe Removal p r o j e c t c e i l i n g for OU 11 is shown b e l ow:

14

Extramural C o s t s ;

ERRSM a t e r i a l A c q u i s i t i o n( B i o s o l i d s / C o m p o s t )S T A R T C o s tC o n t i n g e n c yT O T A L , E X T R A M U R A L C O S T S

C o s t s ;I n t r a m u r a l Direc t C o s t sI n t r a m u r a l I n d i r e c t C o s t sT O T A L , I N T R A M U R A L C O S T S

E s t . C o s t sT o Date$ 4 5 0 , 0 0 0$ 2 5 , 0 0 0$ 8 0 , 0 0 0

$ 5 5 5 , 0 0 0

$ 3 0 , 0 0 0$ 6 0 . 0 0 0$ 9 0 , 0 0 0

E s t . C o s t s P r o p o s e dT h i s A c t i o n C o s t ( E s t )$ 3 5 0 , 0 0 0 8 0 0 , 0 0 0$ 1 7 5 , 0 0 0 $ 2 0 0 , 0 0 0$ 7 0 , 0 0 0$ 8 9 , 2 5 0

$ 4 5 , 0 0 0$ 4 0 , 0 0 0

$ 1 5 0 , 0 0 0$ 8 9 . 2 5 0

$ 6 8 4 , 2 5 0 $ 1 , 2 3 9 , 2 5 0

$ 7 5 , 0 0 0$ 100.000

T O T A L - R E M O V A L P R O J E C T C E I L I N G $ 6 4 5 , 0 0 0$ 8 5 , 0 0 0 $ 1 7 5 , 0 0 0$ 7 6 9 , 2 5 0 $ 1 , 4 1 4 , 2 5 0

V I . E X P E C T E D C H A N G E I N T H E S I T U A T I O N S H O U L D A C T I O N B E D E L A Y E D O RN O T T A K E NIf no a c t i on i s c onduc t ed a t th e S i t e , increased l o a d i n g o fheavy m e t a l s into the Arkansa s River and the surroundingv a l l e y w i l l continue t o occur. A l o n g w i th p o t e n t i a l t h r e a t st o w i l d l i f e and p l a n t s , t h i s erosion w i l l d e g r a d e riverq u a l i t y and increased the p o t e n t i a l f or p u b l i c expo sure t oheavy m e t a l s through i n g e s t i o n o f contaminated p l a n t s / c r o p si r r i g a t e d w i th contaminat ed river water. T h i s a c t i on coversonly 19 areas of 149 contaminated l o c a t i o n s i d e n t i f i e d int h e f l u v i a l p l a i n . V a l u a b l e i n f o r m a t i o n w i l l b e g enera t edf r o m t h i s Removal A c t i o n that w i l l u s e f u l in f u t u r er e m e d i a t i o n work on the U p p e r Arkansa s River.

V I I . O U T S T A N D I N G P O L I C Y I S S U E SN o n e .

V I I I . E N F O R C E M E N TA t t a c h m e n t B is a c o n f i d e n t i a l summary of the e n f o r c e m e n ts t a t u s .

15

I X . R E C O M M E N D A T I O NT h i s d e c i s i o n document r e p r e s e n t s t h e s e l e c t e d RemovalA c t i o n f o r t h e U p p e r Arkansa s G u l c h - F l u v i a l T a i l i n g s( C a l i f o r n i a G u l c h N P L ) S i t e , i n t h e L e a d v i l l e , Lake C o u n t y ,C o l o r a d o , d e v e l o p e d in accordance w i t h C E R C L A as amended ,and no t in c on s i s t en t w i th the NCP. T h i s d e c i s i o n i s basedon the a d m i n i s t r a t i v e record for the S i t e .C o n d i t i o n s a t t h e S i t e meet t h e N C P § 3 0 0 . 4 1 5 ( b ) ( 2 ) cr i t er iafor a Removal A c t i o n , and I recommend your a p p r o v a l . Thet o t a l p r o j e c t c e i l i n g f or th i s a c t i on i s e s t i m a t e d t o b e$ 1 , 4 1 4 , 2 5 0 and of t h i s , an e s t i m a t e d $ 6 1 4 , 2 5 0 comes f r o m theRegional removal a l l o w a n c e .

A p p r o v e : DateM a x H . DodsonA s s i s t a n t Regional A d m i n i s t r a t o rO f f i c e o f Eco sy s t ems P r o t e c t i o nand R e m e d i a t i o n

D i s a p p r o v e : D a t e :M a x H . DodsonA s s i s t a n t Regional A d m i n i s t r a t o rO f f i c e o f E c o s y s t e m s P r o t e c t i o nand Remediat ion

A t t a c h m e n t s :A t t a c h m e n t AA t t a c h m e n t BAttachmen t CA t t a c h m e n t DA t t a c h m e n t EA t t a c h m e n t F

A l t e r n a t i v e s A n a l y s i s ( C o n t r a c t # 6 8 - W 5 - 0 0 3 1 ]E n f o r c e m e n t S e c t i o nARARsP h y t o t o x i c C h a r a c t e r i s t i c s SummaryRespon s iv ene s s SummaryP r o p o s e d 1999 S o i l A m e n d m e n t / R e v e g e t a t i o nS i t e s , S o i l p H A n a l y s i s

16

S T A R T S u p e r f u n d T e c h n i c a l Ass e s smen t a n d R e s p o n s e T e u n i- Region V I I I

i S S t o . U n i t e d S t a t e sE n v i r o n m e n t a l P r o t e c t i o n A g e n c yC o n t r a c t No. 68-W5-0031

A L T E R N A T I V E S A N A L Y S I SU P P E R A R K A N S A S R I V E R F L U V I A L T A I L I N G SLake C o u n t } , C o l o r a d o

TDD No. 9702-0025

May 4, 1999

O P E R A T I X G S E R V I C E S , I N C .

U R S O p e r a t i n g S e r v i c e s , I n c .S T A R T , E P A Region V I I IContract N o . 6 8 - W 5 - 0 0 3 1

U p p e r Arkansas River F l u v i a l T a i l i n g s - A l t e r n a t i v e s A n a l y s i sS i g n a t u r e Page

Revis ion: 2Date: 0 5 / 1 9 9 9

Pase i of iv

A L T E R N A T I V E S A N A L Y S I SUPPER A R K A N S A S R I V E R F L U V I A L T A I L I N G S

Lake C o u n t y , C o l o r a d oEPA C o n t r a c t No. 68-W5-0031

TDD No. 9702-0025Prepared By:

Jan C h r i s t n e r , P.E.C h e m i c a l Engineer

URS O p e r a t i n g Servi c e s , Inc .1099 18th S t r e e t , S u i t e 710

Denver, CO 80202-1908

A p p r o v e d : Date:M i k e Z i m m e r m a p f ^ n - S c e n e C o o r d i n a t o r , E P A , Region V I I I

A p p r o v e d :T . F . S t a i b l e , S T A R T T e a m Leader , U O S

Date:

A p p r o v e d :/ f a n C h r i s t n e r , P.E., Chemica l Engineer, U O S

Date:

T h i s document has been prepared for the U . S . Environmental Protec t ion Agency under ContractNo. 68-W5-0031. The material contained herein is not to be d i s c l o s e d to, d i s c u s s e d w i t h , or made a v a i l a b l eto any person or per sons for any reason without prior expre s s a p p r o v a l of a r e s p o n s i b l e o f f i c e r of the U.S.Environmenta l P r o t e c t i o n Agency. In the intere s t o f conserving natural resources, t h i s document i s p r i n t e don recycled p a p e r and d o u b l e - s i d e d as a p p r o p r i a t e .

75-70225.00F : \ S T A R T \ U P P E R . A R K A 7 0 2 2 5 \ A l t e r n a t i v e s A n a l y s i s \ F i n a l l 9 9 9 \ S i g - p a g e . w p d : b a s

U R S O p e r a t i n g S e r v i c e s , I n c . U p p e r Arkansas River F l u v i a l T a i l i n g s - A l t e r n a t i v e s A n a l y s i sS T A R T , E P A Region V I I I Revis ion: 2Contract No. 68-W5-0031 Date: 0 5 / 1 9 9 9

P a g e i i o f i v

D I S T R I B U T I O N L I S T

U.S. E N V I R O N M E N T A L P R O T E C T I O N A G E N C YMike Zimmerman On-Scene C o o r d i n a t o r , E P A Region V I I I

U R S O P E R A T I N G S E R V I C E S , I N C .J a n C h r i s t n e r , P.E. C h e m i c a l Engineer, S T A R T , E P A Region V I I IF i l e ( 2 c o p i e s ) S T A R T , E P A Region V I I I

75-8O7O1.OOK : \ S ' l ' A i r r \ U P P E R . A R K \ 7 O 2 2 3 V V L . T E I O J A T I V E S A N A L Y S I S \ F I N A I , 1 9 9 9 \ D I S T - L , S T . W P D : B A S

U R S Operat ing S e r v i c e s , Inc. U p p e r Arkansas River F l u v i a l T a i l i n g s - A l t e r n a t i v e s A n a l y s i sS T A R T , E P A Region V I I I Revi s ion: 2Contract N o . 68-W5-0031 Date: O S / 1 9 9 9

Page iii of iv

U P P E R A R K A N S A S R I V E R F L U V I A L T A I L I N G SA l t e r n a t i v e s A n a l y s i s

T A B L E O F C O N T E N T SPage No.

S I G N A T U R E P A G E iD I S T R I B U T I O N L I S T i iT A B L E O F C O N T E N T S i i i

1.0 INTRODUCTION 12.0 B A C K G R O U N D 1

2.1 S i t e L o c a t i o n and D e s c r i p t i o n2.2 S i t e H i s t o r y and Previous Work2.3 S i t e C h a r a c t e r i s t i c s

2.3.1 G e o l o g y2.3.2 H y d r o l o g y2.3.3 C l i m a t e2.3.4 V e g e t a t i o n and A q u a t i c L i f e

3.0 O B J E C T I V E 74 . 0 D E S C R I P T I O N O F F L U V I A L T A I L I N G S D E P O S I T S 75.0 DESCRIPTION OF ALTERNATIVES 8

5.1 No A c t i o n5.2 I n s t i t u t i o n a l C o n t r o l s

5.2.1 W a t e r Management Prac t i c e s5.2.2 A g r i c u l t u r a l Best Management P r a c t i c e s

5 .3 I n - p l a c e S t a b i l i z a t i o n5.3.1 V e g e t a t i o n

5.3.1.1 V e g e t a t i o n w i th M e t a l s T o l e r a n t S p e c i e s5.3.1.2 Revege ta t i on wi th N a t i v e S p e c i e s

5.3.2 R e t a i n i n g W a l l s5.3.2.1 R e t a i n i n g W a l l s5.3.2.2 W i l l o w W a t t l i n g5.3.2.3 Anchored T r e e s

5.3.3 C o v e r / C a p5.3.4 Soi l Amendment

5.4 Removal5.4.1 Of f -Si t e D i s p o s a l5.4.2 O n - S i t e D i s p o s a l

5.5 A l t e r a t i o n of the River Channe l

75-70225.00F : \ S T A R T \ U P P E R . A R K \ 7 0 2 2 5 \ A l t e r n a t i v e s A n a l y s i s \ F i n a l l 9 9 9 \ R e v i s i o n 2 . w p d : b a s

URS Operat ing S e r v i c e s , Inc.S T A R T , E P A Region V I I IContract No. 68-W5-0031

U p p e r Arkansas River F l u v i a l T a i l i n g s - A l t e r n a t i v e s A n a l y s i sRevis ion: 2

Date: 0 5 / 1 9 9 9Page i v o f i v

T A B L E O F C O N T E N T S ( c o n t i n u e d )

6.0 S E L E C T I O N OF ALTERNATIVES7.0 1999 DEMONSTRATION P R O J E C T S8.0 LIST OF R E F E R E N C E S

Page No.222426

T A B L E ST a b l e 1T a b l e 2T a b l e 3F I G U R E SF i g u r e 1F i g u r e 2F i g u r e 3F i g u r e 4F i g u r e 5F i g u r e 6F i g u r e 7F i g u r e 8F i g u r e 9F i g u r e 10F i g u r e 1 1

F l u v i a l T a i l i n g s D e p o s i t Charac t e r i za t i onEvalua t i on o f A l t e r n a t i v e sP r o p o s e d 1999 Response A c t i o n S i t e s

S i t e Loca t i on DiagramT a i l i n g s D e p o s i t L o c a t i o n sT a i l i n g s D e p o s i t L o c a t i o n sT a i l i n g s D e p o s i t Loca t i on sT a i l i n g s D e p o s i t Locat ionsT a i l i n g s D e p o s i t Loca t i on sT a i l i n g s D e p o s i t L o c a t i o n sT a i l i n g s D e p o s i t Loca t i on s1999 P r o j e c t L o c a t i o n s1999 P r o j e c t L o c a t i o n s1999 P r o j e c t Loca t i on s


URS O p e r a t i n g Serv i c e s , Inc.S T A R T , E R A Region V I I IContrac t No. 68-W5-0031

1.0 INTRODUCTION

U p p e r Arkansas River F l u v i a l T a i l i n g s - A l t e r n a t i v e s A n a l y s i sRevi s ion: 2

Date: 0 5 / 1 9 9 9Page 1 of 50

T h e U . S . Environmental P r o t e c t i o n A g e n c y ( E P A ) tasked t h e S u p e r f u n d T e c h n i c a l Asse s sment a n d ResponseTeam ( S T A R T ) , U R S O p e r a t i n g S e r v i c e s , I n c . ( U O S ) , t o analyze t h e a l t e r n a t i v e s f o r r e spons e t o f l u v i a lt a i l i n g s a d j a c e n t t o e l even mile s o f the Arkansa s River. T h i s a l t e r n a t i v e s a n a l y s i s w i l l b e used to s e l e c ta p p r o p r i a t e t e c h n o l o g i e s t o reduce the impac t o f f l u v i a l t a i l i n g s d e p o s i t s on the U p p e r Arkansa s River andi t s f l o o d p l a i n .

A l t e r n a t i v e s c on s ider ed i n c l u d e no a c t i on , i n s t i t u t i o n a l c o n t r o l s , i n - p l a c e s t a b i l i z a t i o n , removal, and riverchannel a l t e r a t i o n . Each a l t e r n a t i v e i s rated according to e f f e c t i v e n e s s , i m p l e m e n t a b i l i t y , c o s t , anda c c e p t a b i l i t y . T h e a p p l i c a b i l i t y o f t h e o p t i o n s t o i n d i v i d u a l f l u v i a l t a i l i n g s d e p o s i t s i s then p r e s e n t e d .Because t h e f l u v i a l d e p o s i t s have w i d e l y varying p h y s i c a l and chemical c h a r a c t e r i s t i c s , d i f f e r e n t a l t e r n a t i v e sa r e c on s id e r ed a p p r o p r i a t e f o r d i f f e r e n t d e p o s i t s .

2.0 BACKGROUND

M i n e t a i l i n g s f r o m h i s t o r i c a l mining a c t i v i t y were carried downs t r eam v ia C a l i f o r n i a G u l c h t o th e Arkansa sRiver and d e p o s i t e d in many l o c a t i o n s a d j a c e n t to the river. M a n y o f the f l u v i a l t a i l i n g s d e p o s i t s haves t r e s s ed or no v e g e t a t i o n and are g r a d u a l l y e rod ing and l e a c h i n g into the Arkansa s River. P e r i o d i c stormevent s wash s l u g s o f me ta l-r i ch s a l t s f r o m th e s u r f a c e o f t a i l i n g s d e p o s i t s i n t o t h e river. L e a c h i n g o f m e t a l sf r o m the t a i l i n g s d e p o s i t s in to the groundwat er may a l so add to the mass l o a d i n g o f m e t a l s i n t o the river.

2 . 1 S I T E L O C A T I O N A N D D E S C R I P T I O N

The site i s located a long the Arkansas River from the c o n f l u e n c e with C a l i f o r n i a G u l c h to j u s t southof C o u n t y Road 55 in Lake C o u n t y , C o l o r a d o . The area is shown on F i g u r e 1, Site L o c a t i o nDiagram. A l o n g the segment under s t u d y , the river i s f ed by C a l i f o r n i a G u l c h , Lake F o r k Creek,H a l f Moon Creek, Iowa G u l c h , T h o m p s o n G u l c h , Empir e G u l c h , D r y U n i o n G u l c h , B i g U n i o nCreek, and S p r i n g Creek. S e v e r a l unnamed w e t l a n d s are l o c a t e d a l o n g the river (ASARCO, Inc.1992). The river i s a d j a c e n t to p r i v a t e p r o p e r t y and i s w i t h i n two mi l e s o f the San I s a b e l N a t i o n a l

F o r e s t on bo th the east and west. The river is l o ca t ed between the M o s q u i t o Range to the east and

75-70225.00F : \ S T A R T \ U P P E R . A R K \ 7 0 2 2 5 \ A l t e m a t i v e s A n a l y s i s \ F i n a l l 9 9 9 \ R e v i s i o n 2 . w p d : b a s

URS Operating Service s , Inc. U p p e r Arkansas River F l u v i a l T a i l i n g s - A l t e r n a t i v e s A n a l y s i sS T A R T , E P A Region V I I I R e v i s i o n : 2Contract No. 68-W5-0031 Date: 0 5 / 1 9 9 9

Page 2 of 50

the S a w a t c h Range to the west. The e l e v a t i o n is between 9,150 and 9,500 f e e t above Mean SeaLevel ( U . S . Geologi ca l Survey ( U S G S ) 1975).

The site inc lude s parts of S e c t i o n 32 of T. 9 S., R. 80 W.; S e c t i o n s 5, 8, 9, 15, 16, 22, 27, and 34 ofT. 10 S., R. 80 W.; and S e c t i o n s 2 and 3 of T. 11 S., R. 80 W. (USGS 1975).

2 . 2 S I T E H I S T O R Y A N D P R E V I O U S WORK

The U p p e r Arkansas River is l o c a t e d in a mineral rich area of the Rocky Mounta in s . C o p p e r , g o l d ,s i l v e r , l e a d , and zinc have been mined i n t e r m i t t e n t l y since the 1850s. C u r r e n t l y o n l y one mine iso p e r a t i n g in the area. The h i s t ory of the L e a d v i l l e mining d i s t r i c t i s documented more f u l l y inS u r f a c e W a t e r Remedial I n v e s t i g a t i o n Report ( W o o d w a r d - C l y d e C o n s u l t a n t s 1 9 9 3 ) .

H e a v y m e t a l s - c o n t a m i n a t e d t a i l i n g s were d e p o s i t e d in the L e a d v i l l e area f r o m m i n i n g and m i l l i n ga c t i v i t i e s a l o n g C a l i f o r n i a G u l c h . S u b s e q u e n t r u n o f f / f l o o d events t r a n s p o r t e d t h e t a i l i n g sdownstream via C a l i f o r n i a G u l c h and the Arkansa s River where they were d e p o s i t e d in i s l a n d s andon riverbanks. R e s i d e n t s s ta t e that t a i l i n g s were a l s o t r a n s p o r t e d a l o n g i r r iga t i on channe l s andd e p o s i t e d in f i e l d s in the river va l l ey . The river has changed p a t h s over the years, so f l u v i a l t a i l i n gd e p o s i t s are also l o ca t ed in dry river channe l s and oxbows.

The Arkansas River is used for recreation, i r r iga t i on of agr i cu l tura l and range l a n d s , and munic ipa ld r i n k i n g water. I r r i g a t i o n of range land and a g r i c u l t u r a l land w i th h i g h metal content water maycontribute to elevated l e v e l s of me ta l s in animals and p l a n t s ( R o l i n e and Boehmke 1981; Levy 1989).H i g h m e t a l s c onc en tra t i on a l o n g riverbanks can reduce or e l i m i n a t e r i v e r s i d e v e g e t a t i o n , increa s ingerosion p o t e n t i a l . Periodic storm events can wash s lug s of metal-rich s a l t s f r om the sur face oft a i l i n g s d e p o s i t s into the river. High meta l s c onc en tra t i on in stream water can cause d e g r a d a t i o n off i s h hab i ta t , recreational areas, and agricultural land.

Charac t er i za t i on of environmental c o n t a m i n a t i o n in the C a l i f o r n i a G u l c h S u p e r f u n d s i te has beenongo ing since 1982. E x t e n s i v e sur fac e water s a m p l i n g has been p e r f o r m e d a l o n g C a l i f o r n i a G u l c hand i t s tr ibutarie s ( C o l d e r A s s o c i a t e s 1996; S h e p h e r d M i l l e r / T e r r a M a t r i x / M o n t g o m e r y W a t s o n -1998). I m p a c t s on t erre s tr ia l s p e c i e s were de s c r i b ed in the T e r r e s t r i a l E c o l o g i c a l Risk Ass e s smen t

75-70225.00F : \ S T A R T \ U P P E R . A R K \ 7 0 2 2 5 \ A I t e r n a t i v e s A n a l y s i s X F i n a l 1999\Revi s i on2 .wpd:ba s

U R S O p e r a t i n g S e r v i c e s , Inc. U p p e r Arkansa s River F l u v i a l T a i l i n g s - A l t e r n a t i v e s A n a l y s i sS T A R T , E P A Region V I I I R e v i s i o n : 2Contrac t N o . 68-W5-0031 Date: 0 5 / 1 9 9 9

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( W e s t o n 1996). I m p a c t s on aquatic spec ie s were described in the Aquat i c EcosystemC h a r a c t e r i z a t i o n Report ( W o o d w a r d - C l y d e C o n s u l t a n t s 1996). S y s t e m a t i c so i l s a m p l i n g o f t h eC a l i f o r n i a G u l c h s i t e i s documented in the F i n a l S o i l s I n v e s t i g a t i o n Data Report ( C a m p Dresser &M c K e e 1994).

S t u d i e s t o i d e n t i f y a n d character ize f l u v i a l t a i l i n g s d e p o s i t s w i t h v i s i b l e impac t t o v e g e t a t i o n( d e a d / m i n i m a l v e g e t a t i o n ) were p e r f o r m e d by UOS ( U O S 1997b; UOS 1998a). The 1997 reportde s cr ib e s the s t u d y of t a i l i n g s c onduc t ed on 10 mi l e s of the Arkansa s River f r o m the c o n f l u e n c e w i t hC a l i f o r n i a G u l c h to C o u n t y Road 55, e x c ep t for the H a y d e n Ranch where access was not gran t ed .The 1998 report d e s c r i b e s the s t u d y of t a i l i n g s on the H a y d e n Ranch a f t e r access was g r a n t e d .S a m p l i n g and a n a l y s i s showed that the d e p o s i t s c on ta in material wi th h i g h metal c on t en t . M e t a lconcentrations far above p h y t o t o x i c concentrations were f o u n d . Maximum concentrations of 1,300m i l l i g r a m s per k i l o g r a m ( m g / k g ) cadmium, 1,500 m g / k g c o p p e r , 25,000 m g / k g l e a d , 12,000 m g / k gmanganese, and 141,000 m g / k g zinc were measured. Cut banks i n d i c a t e tha t the t a i l i n g s d e p o s i t sare a c o n t i n u i n g source of me ta l-r i ch s ediment l o a d i n g to the river.

A s t u d y to i n v e s t i g a t e the t r a n s p o r t of me ta l s t h r o u g h g r o u n d w a t e r as a p o t e n t i a l source ofc o n t a m i n a t i o n o f t h e river w a s p e r f o r m e d b y t h e U . S . G e o l o g i c a l S u r v e y ( U S G S ) ( U S G S 1 9 9 6 ) ; t h er e s u l t s of t h i s s t u d y have not been p u b l i s h e d as of March 1999.

A g e o m o r p h o l o g i c assessment of the river was p e r f o r m e d by I n t e r - F l u v e , I n c . d u r i n g 1997 and 1 9 9 S( I n t e r - F l u v e 1998). The assessment shows i n s t a b i l i t y in the river sy s t em due to a h igh s e d i m e n tl o a d , h i g h l y aggradational and degrada t i ona l river segments , a perched river s egment, and watermanagement. H y d r a u l i c and h y d r o l o g i c a s s e s sment s of the river were p e r f o r m e d to a s s i s t in theg e o m o r p h o l o g i c assessment and to p r o v i d e i n f o r m a t i o n on the s t a b i l i t y o f t a i l i n g s d e p o s i t s a l o n g theriver ( U O S 1998b). A 500-year f l o o d p l a i n map and a 2- f oo t contour map were pr epar ed as part oft h i s as ses sment.

A smal l d e m o n s t r a t i o n r e v e g e t a t i o n p r o j e c t to show the e f f e c t i v e n e s s and cost o f v e g e t a t i o ncombined wi th so i l amendment was begun in S e p t e m b e r 1997 by C o l o r a d o S t a t e U n i v e r s i t y andA S A R C O . The goal was to encourage natural success ion to r e e s t a b l i s h s u s t a i n a b l e native v e g e t a t i v ecommuni t i e s . Lime and organic mat t er in v a r y i n g rates and c o m b i n a t i o n s were a p p l i e d to the soi land w i l l o w s were p l a n t e d . The r e s u l t s o f t h i s s t u d y are not yet a v a i l a b l e .

75-70225.00F : \ S T A R T \ U P P E R . A R K \ 7 0 2 2 5 \ A I t e r n a t i v e s A n a I y s i s \ F i n a l l 9 9 9 \ R e v i s i o n 2 . w p d : b a s

U R S Operat ing Serv i c e s , Inc. U p p e r Arkansas River F l u v i a l T a i l i n g s - A l t e r n a t i v e s A n a l y s i sS T A R T , E P A Region V 1 1 I Rev i s i on: 2Contract N o . 68-W5-0031 Date: O S / 1 9 9 9

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A b i o s o l i d s d emons tra t i on p r o j e c t was p e r f o r m e d on f o u r t a i l i n g s d e p o s i t s i t e s (CL/CN/CO,M B / M E , M P / M Q , and R A / R B ) covering a p p r o x i m a t e l y 10 acres dur ing the summer of 1998 (UOS1998c). The p r o j e c t was p e r f ormed by EPA wi th c o op era t i on by the U . S . Depar tment ofA g r i c u l t u r e . Previous experience on metal c on taminat ed s i t e s i n d i c a t e s that the a p p l i c a t i o n o f h i g hiron b i o s o l i d s in c o m b i n a t i o n w i th a h i g h ca l c ium carbonate material is able to restore and su s ta ina v ege ta t iv e cover ( O y l e r 1990; S o p p e r 1988; Brown 1996). The l ime a p p l i e d wi th the b i o s o l i d sf orms water s o l u b l e organo-metal c o m p l e x e s that correct both surface and sub sur face a c i d i t y andreduce the b i o a v a i l a b i l i t y of metals. The amorphous iron and manganese oxides prov ide ana d s o r p t i v e surface to l imi t the p h y t o a v a i l a b i l i t y o f me ta l s . The p h o s p h o r u s in b i o s o l i d s can reducethe lead and zinc up take by p l a n t s as well as the s o l u b i l i t y of l ead , p o s s i b l y f r om the p r e c i p i t a t i o nof lead and zinc p h o s p h a t e minerals. B i o s o l i d s can al so increase the water h o l d i n g c a p a c i t y of theso i l . ( U . S . Department o f Agricu l ture (USDA) 1998a). B i o s o l i d s (100 dry tons per acre) anda g r i c u l t u r a l l ime (average of 140 tons per acre) were a p p l i e d to the sur face and mixed to a d e p t h ofa p p r o x i m a t e l y one f o o t . A nurse crop of annual ryegrass was p l a n t e d a p p r o x i m a t e l y one month a f t e rt r ea tmen t and p e r e n n i a l s p e c i e s were s eeded p r i o r to the onset of winter . M o n i t o r i n g of thed e m o n s t r a t i o n p r o j e c t s i s o n g o i n g as d e s cr ib ed in the U p p e r Arkansa s River R e v e g e t a t i o n P r o j e c tM o n i t o r i n g P l a n .

2 . 3 S I T E C H A R A C T E R I S T I C S

2.3.1 G e o l o g y

The U p p e r Arkansas River V a l l e y i s composed of Holo c ene stream terrace, stream channel ,and f l o o d p l a i n d e p o s i t s . The mat er ia l s were t r a n s p o r t e d and r e d e p o s i t e d by g l a c i a l andf l u v i a l proce s s e s and are p o o r l y sor t ed , l oo s e , and porous ( W o o d w a r d - C l y d e C o n s u l t a n t s1993).

The land a d j a c e n t t o the Arkansas River i s n e a r l y l eve l or g e n t l y s l o p i n g . The s o i l s ared e e p , p o o r l y d r a i n e d , a n d s u b j e c t t o f l o o d s . T h e soil t y p e s a r e W e t A l l u v i a l , M a r s h ,N e w f o r k grave l ly sandy loam, and Roseanne loam (Soil Conservation Service (SCS) 1975).Areas up s t r eam of the s i t e are h e a v i l y minera l i z ed . The most prominent minera l s in the ored e p o s i t s up s t r eam i n c l u d e iron, manganese, zinc, l e a d , c o p p e r , and s m a l l amounts o f g o l dand s i lver. W a s t e rock mat er ia l s i n c l u d e quartz, s e r i c i t e , c h l o r i t e , d o l o m i t e , l i m e s t o n e ,

75-70225.00F : \ S T A R T \ U P P E R . A R K Y 7 0 2 2 5 \ A l t e m a t i v e s A n a l y s i s \ F i n a l l 9 9 9 \ R e v i s i o n 2 . w p d : b a s

U R S Operat ing S e r v i c e s , Inc. U p p e r Arkansas River F l u v i a l T a i l i n g s - A l t e r n a t i v e s A n a l y s i sS T A R T , E P A Region V I I I Revi s i on: 2Contract No. 68-W5-0031 Date: 0 5 / 1 9 9 9

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p y r i t e , h emat i t e , j a r o s i t e , and low-grade or e ( U . S . Environmenta l P r o t e c t i o n A g e n c y ( E P A )1987).

2.3.2 H y d r o l o g y

The Arkansa s River i s f ormed j u s t west of L e a d v i l l e at the c o n f l u e n c e of T e n n e s s e e Creekand the East F o r k of the Arkansas River. In the s t u d y area, the Arkansa s River is fed byC a l i f o r n i a G u l c h , Lake F o r k Creek, H a l f Moon Creek, I o w a G u l c h , T h o m p s o n G u l c h ,Empire G u l c h , Dry U n i o n G u l c h , Big Union Creek, and S p r i n g Creek. S e a s o n a l f l o o d i n goccurs in May and J u n e as a resul t of rapid snowmel t . U p p e r A r k a n s a s River s t r e a m f l o wranges f rom 40 to 500 cubic f e e t per second ( W o o d w a r d - C l y d e C o n s u l t a n t s 1 9 9 3 ) .S t r e a m f l o w s are augmented by transmounta in water d i v e r s i o n s .

S t r e a m f l o w sou th o f the c o n f l u e n c e o f the A r k a n s a s River and Lake F o r k Creek i s h i g h l yd e p e n d e n t on d i s charge s f r om the S u g a r l o a f Dam at T u r q u o i s e Lake. T h e r e are tworec ep tor s of water re l ea s ed f r o m S u g a r l o a f Dam: Mt. Elber t C o n d u i t and Lake F o r k Creek.W a t e r released to the Mt. Elber t C o n d u i t f l o w s t hrough the Mt. E lb e r t Power P l a n t and i sreleased to T w i n Lakes. W h e n water is re l eased to Lake F o r k Creek, e f f o r t i s made torelease the minimum amount of water, but s i g n i f i c a n t v a r i a t i o n s in s t r e a m f l o w do occur.Release volumes t o Lake F o r k Creek increase s i g n i f i c a n t l y dur ing p e r i o d s when re l ea s e sf r o m S u g a r l o a f Dam exceed the c a p a c i t y o f the Mt. Elb er t C o n d u i t (Bureau o f R e c l a m a t i o n(BOR) 1996).

A g e o m o r p h o l o g i c asse s sment of the river was p e r f o r m e d and p r o v i d e s an a n a l y s i s of thes t a b i l i t y o f seven reaches o f t h e Arkansa s River ( I n t e r - F l u v e 1 9 9 8 ) . T h e s t u d y i d e n t i f i e st a i l i n g s d e p o s i t s that are at risk as h igh pr i or i ty erosion s i te s .

2.3.3 C l i m a t e

Normal t e m p e r a t u r e extremes range f r o m 8 6 ° F t o - 3 0 ° F . T h e average f r o s t - f r e e season i s79 days. The wind is p r e d o m i n a n t l y f r o m the n o r t h w e s t ana ranges f r o m calm to 30 mile sper hour. Average annual p r e c i p i t a t i o n i s 18 inches wi th July and A u g u s t r e c o r d i n g the

75-70225.00F : \ S T A R T \ U P P E R . A R K \ 7 0 2 2 5 \ A l t e r n a t i v e s A n a l y s i s \ H n a l l 9 9 9 \ R e v i s i o n 2 . w p d : b a s

U R S O p e r a t i n g S e r v i c e s , I n c . U p p e r Arkansa s River F l u v i a ! T a i l i n g s - A l t e r n a t i v e s A n a l y s i sS T A R T , E P A Region V I I I Revi s i on: 2Contract No. 68-W5-0031 Date: 0 5 / 1 9 9 9

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most p r e c i p i t a t i o n , and J a n u a r y and December r e c ord ing the l ea s t p r e c i p i t a t i o n .Summert ime p r e c i p i t a t i o n i s u s u a l l y a s s o c ia t ed w i t h convect ive showers. A n n u a l averages n o w f a l l d e p t h s for mountains in the area are between 200 and 300 inches. During w i n t e rmonths, the d e p t h of snow on the ground in L e a d v i l l e is commonly six inche s (EPA 1 9 8 7 ) .

2.3.4 V e g e t a t i o n and A q u a t i c L i f e

The U p p e r Arkansas River V a l l e y conta ins sedge-grass meadows and marshy areas a l o n gstream banks. W e t l a n d s a l o n g the river are characterized mainly by tal l w i l l o w shrub, w i t hvarious emergent herbs, grasses, and s edge s o c c u p y i n g open areas and w e t l a n d margins( W o o d w a r d - C l y d e C o n s u l t a n t s 1 9 9 3 ) . W e t l a n d t y p e s i n c l u d e P a l u s t r i n e scrub-shrub,s e a s o n a l l y f l o o d e d ( w i l l o w shrub), p a l u s t r i n e emergent , s e a s o n a l l y f l o o d e d (wet meadow),a n d p a l u s t r i n e u n c o n s o l i d a t e d shore, s e a s o n a l l y f l o o d e d ( u n v e g e t a t e d ) ( A S A R C O , I n c .1992). S o m e land a d j a c e n t to the river i s used as r a n g e l a n d . The U.S. Depar tment o fA g r i c u l t u r e , N a t u r a l Resources C o n s e r v a t i o n S e r v i c e , p e r f o r m e d a v e g e t a t i o n assessmentof the 11-mile reach and mapped the vege ta t ive communities w i t h i n the f l o o d p l a i n ( U S D A1998b). T h r e e p l a n t community t y p e s were d e s i g n a t e d in the area: riparian meadow,ripar ian sub i rr iga t ed , and s ub i r r iga t ed .

The U p p e r Arkansa s River c on ta in s brown trout and brook trout. B o t t o m - d w e l l i n g macroinver t ebrat e s i n c l u d e a variety o f m a y f l i e s , s t o n e f l i e s , D i p t e r a , and c a d d i s f l i e s . O n l y a veryfew l i m i t e d s p e c i e s of aquatic inver t ebra t e s are f o u n d w i t h i n 1.5 mile s downs t r eam of thec o n f l u e n c e wi th C a l i f o r n i a G u l c h due t o h i g h m e t a l s content in the water ( W o o d w a r d - C l y d eC o n s u l t a n t s 1993).

The b en th i c f a u n a i s rich and diver se u p s t r e a m of C a l i f o r n i a G u l c h but was s l i g h t l y tom o d e r a t e l y a f f e c t e d by t h e C a l i f o r n i a G u l c h d i s c h a r g e pr i or t o water t r ea tmen t in C a l i f o r n i aG u l c h ( W o o d w a r d - C l y d e C o n s u l t a n t s 1993).

Severa l s t u d i e s p e r f o r m e d on the A r k a n s a s River have shown nega t iv e impac t on rivers p e c i e s d i v e r s i t y a n d p o p u l a t i o n s downstream o f t h e c o n f l u e n c e w i t h C a l i f o r n i a G u l c h .

75-70225.00F : \ S T A R T \ U P P E R . A R K Y 7 0 2 2 5 \ A l t e m a t i v e s A n a l y s i s \ F i n a l 1 9 9 9 \ R e v i s i o n 2 . w p d : b a s

U R S O p e r a t i n g S e r v i c e s , I n c . U p p e r Arkansa s River F l u v i a l T a i l i n g s - A l t e r n a t i v e s A n a l y s i sS T A R T , E P A Region V I I I R e v i s i o n : 2Contract N o . 68-W5-0031 Date: 0 5 / 1 9 9 9

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Diver s i ty of s p e c i e s increases downs tr eam as water w i t h lower me ta l s c on t en t enters theriver f r om other t r i bu tar i e s ( W o o d w a r d - C l y d e C o n s u l t a n t s 1993).

The U p p e r Arkansa s River v a l l e y i s i m p o r t a n t winter range for deer and elk. C o y o t e s arecommon in the v a l l e y and bobcat , red f o x , and mountain l i o n are seen o c c a s i o n a l l y .W a t e r f o w l such as m a l l a r d s , t e a l , and coot s use the w e t l a n d areas a l o n g the river for n e s t i n g .A variety of large and sma l l b ird s p o p u l a t e the area ( W o o d w a r d - C l y d e C o n s u l t a n t s 1993).U p p e r Arkansas River v a l l e y terrestrial specie s i n c l u d e b e l t ed k i n g f i s h e r , s p o t t e d s a n d p i p e r ,red-winged b l a c k b i r d , l o n g - t a i l e d vole, ba ld e a g l e , and mule deer ( W e s t o n 1996). Of t h e s e ,the bald eagl e i s a f e d e r a l - and s t a t e - l i s t e d t h r e a t e n e d spe c i e s . T e r r e s t r i a l s p e c i e s and b ird sobserved by START during the S e p t e m b e r / O c t o b e r 1996 s a m p l i n g event i n c l u d e e lk,mountain b l u e b i r d , red f o x , b lue wing t e a l , green wing t e a l , marsh hawk, m a l l a r d duck, andbeaver. Many c a t t l e and some horses were observed on and near the f l u v i a l t a i l i n g d e p o s i t s .L i v e s t o c k were not pre s ent on the H a y d e n Ranch d u r i n g the October 1997 s a m p l i n g event,but c a t t l e tracks i n d i c a t e d that c a t t l e are pre s en t on the ranch d u r i n g part of the year. Thepre s enc e o f w i l d l i f e on th e d e p o s i t s i n d i c a t e s p o t e n t i a l e xpo sur e o f t e r r e s t r i a l s p e c i e s t o th et a i l i n g s .

3 .0 O B J E C T I V E

The o b j e c t i v e o f r e sponse ac t ion on th e f l u v i a l t a i l i n g s d e p o s i t s a l o n g th e U p p e r A r k a n s a s River i s t o reduceor e l i m i n a t e the impac t of mine waste on water q u a l i t y , env i ronmenta l r e c e p t o r s , and stream m o r p h o l o g y .

4 . 0 D E S C R I P T I O N O F F L U V I A L T A I L I N G S D E P O S I T S

T a i l i n g s d e p o s i t s a l o n g t h e 1 1 - m i l e reach were i d e n t i f i e d a n d charac t er ized i n S a m p l i n g A c t i v i t i e s R e p o r t s(UOS 1997b; UOS 1998a). Over 70,000 cubic yards of t a i l i n g s mat er ia l were i d e n t i f i e d at 149 l o c a t i o n swhere v e g e t a t i o n wa s n o t a b l y s t r e s s e d . The l o c a t i o n o f each i d e n t i f i e d t a i l i n g s d e p o s i t i s shown on F i g u r e s2 through 8. A e r i a ! p h o t o g r a p h s s h o w i n g in d e t a i l the e x t en t of the d e p o s i t s , and ground p h o t o g r a p h ss h o w i n g s i t e c o n d i t i o n s may be f o u n d in A p p e n d i x B of each S a m p l i n g A c t i v i t i e s Repor t .

75-70225.00F : \ S T A R T \ U P P E R . A R K \ 7 0 2 2 5 \ A l t e r n a t i v e s A n a l y s i s \ F i n a l 1 9 9 9 \ R e v i s i o n 2 . w p d : b a s

U R S O p e r a t i n g Serv i c e s , I n c . U p p e r Arkansas River F l u v i a l T a i l i n g s - A l t e r n a t i v e s A n a l y s i sS T A R T , E P A Region V I M ~ R e v i s i o n : 2Contrac t N o . 68-W5-0031 Date: O S / 1 9 9 9

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E s t i m a t e s of maximum metal concentrat ions , volume, area, d e p t h , and v e g e t a t i o n c h a r a c t e r i s t i c s weredetermined for each t a i l i n g s d e p o s i t and de s cr ibed in the S a m p l i n g A c t i v i t i e s Repor t s . The area i m p a c t e dby t a i l i n g s may be more extensive than the estimate. A j u d g m e n t a l s a m p l i n g approach was used for soils a m p l i n g . The s a m p l i n g o b j e c t i v e was to de t ermine the l o c a t i o n o f "hot spo t s "; t h e r e f o r e , the c o n c e n t r a t i o n sl i s t e d should be i n t e r p r e t e d to be the maximum for the d e p o s i t . M e t a l - r i c h s a l t s f o u n d on the s u r f a c e of manyof the d e p o s i t s were the source of the h ighe s t c onc en tra t i on s o f the s o l u b l e metal s , p a r t i c u l a r l y zinc. S o m ed e p o s i t s were s a m p l e d during or a f t e r inc l ement weather and metal s a l t s were not observed on the s u r f a c e ;there fore , the absence of sa l t s at a par t i cu lar t a i l i n g s d epo s i t does not necessarily indica t e that the s a l t s donot form. M o i s t u r e f r o m the inc l ement weather may have caused lower maximum c o n c e n t r a t i o n s of s o l u b l emetal s f or some d e p o s i t s . G e n e r a l l y , s a m p l e s o f s ur fa c e s a l t s showed the h i g h e s t c o n c e n t r a t i o n s o f zinc,manganese, and c o p p e r ; t h e r e f o r e , d e p o s i t s that were s a m p l e d a f t e r a storm event when no sur fa c e s a l t s werepresent showed lower concentra t i on s of these me ta l s . Because of t h i s , great v a r i a b i l i t y in c o n c e n t r a t i o n maybe seen between d e p o s i t s when there may be l i t t l e variation in average metal concentration. The maximumc o n c e n t r a t i o n s of the s e s o l u b l e m e t a l s can be a good i n d i c a t o r of s i t e t o x i c i t y because t h e y are very mob i l eand l i k e l y to be washed into the river or groundwat er or taken up by v e g e t a t i o n , l i v e s t o c k , or w i l d l i f e .

The v a r i a b i l i t y of the d e p o s i t s requires that the areas be charac t er ized a c c ord ing to f a c t o r s that can i n f l u e n c ethe s e l e c t i on of response a l t ernat ive s . T a i l i n g s d e p o s i t s were characterized according to a c c e s s i b i l i t y ,erosion p o t e n t i a l , average and maximum t a i l i n g s d e p t h , t a i l i n g s volume and area, and m e t a l s c oncentra t ions .S i t e s i d e n t i f i e d as h i g h p r i o r i t y erosion s i t e s , l o c a t i o n s that are v u l n e r a b l e to erosion in the short-term ornear-long-term, in the I n t e r - F l u v e g e o m o r p h o l o g i c assessment are no t ed . T a b l e 1 summarizes the s ec h a r a c t e r i s t i c s . F a c t o r s such as exposure of environmental r e c e p t o r s to the t a i l i n g s are c on s ider ed to bes imi lar in all d e p o s i t s and t h e r e f o r e are not tabularized.

5 . 0 D E S C R I P T I O N O F A L T E R N A T I V E S

A l t e r n a t i v e s d i s c u s s e d in th i s ana ly s i s i n c l u d e no act ion, i n s t i t u t i o n a l c o n t r o l s , s t a b i l i z a t i o n , removal, andriver channel a l t e r a t i o n . The f o l l o w i n g p a r a g r a p h s contain brie f d e s c r i p t i o n s o f the a l t e r n a t i v e s and ad e s c r i p t i o n o f how the e f f e c t i v e n e s s , i m p l e m e n t a b i l i t y , c o s t , and a c c e p t a b i l i t y to l a n d o w n e r s and otheri n t e r e s t e d p a r t i e s a f f e c t the p o t e n t i a l use o f the a l t e r n a t i v e . The a l t e r n a t i v e s are then compared based on thef o u r cr i t er ia . F r o m t h i s a n a l y s i s , the most p r o m i s i n g a l t e r n a t i v e s are s e l e c t e d for use as d e s cr ib ed in S e c t i o n6. T a b l e 2 p r o v i d e s a summary of the a p p l i c a t i o n of the f o u r cr i t er ia to each a l t e r n a t i v e .

75-70225.00F : \ S T A R T M J P P E R . A R K \ 7 0 2 2 5 \ A l t e m a t i v e s A n a l y s i s \ F i n a l l 9 9 9 \ R e v i s i o n 2 . w p d : b a s

U R S O p e r a t i n g Serv i c e s , I n c . U p p e r Arkansas River F l u v i a l T a i l i n g s - A l t e r n a t i v e s A n a l y s i sS T A R T , E P A Region V I I I Revi s ion: 2Contrac t N o . 68-W5-0031 Date: O S / 1 9 9 9

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5.1 NO ACTION

Leave all material in p lace . Release s to the s tream in the f orm of erosion and l e a c h i n g of m e t a l scontaminated t a i l i n g s and s ed imen t s w i l l continue.

E f f e c t i v e n e s s : Not e f f e c t i v e f o r r educ t i on o f t h e impac t o f t a i l i n g s on th e environment .

I m p l e m e n t a b i l i t y : N o act ion required.

Cos t : N o cost.

A c c e p t a b i l i t y : L a n d o w n e r request s f or a s s i s t a n c e i n d i c a t e s that some act ion i s d e s i r e d .I m p a c t to the river and environment w i l l cont inue.

5 . 2 I N S T I T U T I O N A L C O N T R O L S

5.2.1 W a t e r Management Prac t i c e s

Current water management p r a c t i c e s a l l o w large , somet imes r a p i d , increases in water f l o winto the A r k a n s a s River via Lake F o r k Creek. R e d u c t i o n in the f r e q u e n c y a n d / o r methodof s t r e a m f l o w variations are management p r a c t i c e s that can reduce stress on erosional banks.

E f f e c t i v e n e s s : Change s in water management p r a c t i c e s can reduce erosion of thet a i l i n g s d e p o s i t s , thereby reducing impact on the river and reducingthe a f f e c t e d area. C h a n g e of water management p r a c t i c e s mayprevent some but not all erosion that is occurring in the area.W a t e r management changes would not prevent damage f romnatural proce s s e s . Preven t i on of erosion would reduce r e l o c a t i o nof t a i l i n g s downs tream e i t h e r in the 1 1 - m i l e reach or f a r t h e rdownstream. T h e t a i l i n g s would s t i l l b e pre s ent i n t h e f l o o d p l a i n

75-70225.00F : \ S T A R T \ U P P E R . A R K Y 7 0 2 2 5 \ A l t e m a t i v e s A n a l y s i s \ F i n a ! 1 9 9 9 \ R e v i s i o n 2 . w p d : b a s

U R S O p e r a t i n g S e r v i c e s , Inc.S T A R T , E P A Region V I HContrac t No. 68-W5-0031

U p p e r Arkansas River F l u v i a l T a i l i n g s - A l t e r n a t i v e s A n a l y s i sR e v i s i o n : 2

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and a v a i l a b l e to erode i n t o the river, l each in to groundwater ,reduce v e g e t a t i v e cover, and minimize h e a l t h y h a b i t a t .

I m p l e m e n t a b i l i t y : W a t e r r igh t s and the l i m i t e d size of the Mount Elber t C o n d u i t maynot a l l o w s i g n i f i c a n t changes in current water managementp r a c t i c e s . W a t e r management p r a c t i c e s can be easy to changep h y s i c a l l y , bu t p o l i t i c a l and l e g a l c o n s i d e r a t i o n s may pr even ti m p l e m e n t a t i o n o f t h i s a l t e r n a t i v e .

C o s t : A minimal to moderate cost to research a p p r o p r i a t e watermanagement p r a c t i c e s may be needed. Large c o s t s would bea s s o c ia t ed wi th p u r c h a s i n g or i n f r i n g i n g on water r igh t s .

A c c e p t a b i l i t y : Based on comments at community mee t ing s , amendment of currentwater management p r a c t i c e s wou ld be d e s i r a b l e to l a n d o w n e r sbecause o f the r e d u c t i o n o f a l l eros ion, no t j u s t t a i l i n g s erosion.C h a n g e s in water management p r a c t i c e s may not be a c c e p t a b l e toe n t i t i e s w i t h water r i g h t s or water management r e s p o n s i b i l i t i e s inth e a f f e c t e d reach.

5.2.2 A g r i c u l t u r a l Best Management Prac t i c e s

C a t t l e add s tre s s to v e g e t a t i o n a l r e a d y s tres sed by h i g h m e t a l s c o n c e n t r a t i o n s by t r a m p l i n gand overgrazing. C a t t l e al so t r a m p l e riverbanks, causing erosion and r e d u c i n g v e g e t a t i o non the riverbank. Best Management Pract ice s may require f e n c i n g a corridor a l o n g the riveror p r o v i d i n g other means to r e s t r i c t c a t t l e access.

E f f e c t i v e n e s s : I n s t i t u t i o n o f Best M a n a g e m e n t Prac t i c e s can a l l o w v e g e t a t i o n togrow u n a s s i s t e d in t a i l i n g s d e p o s i t s w i t h lower metalc onc en tra t i on s and can reduce erosion of t a i l i n g s i n t o the river.T a i l i n g s d e p o s i t s that a r e unab l e t o s u p p o r t v e g e t a t i o n p r i m a r i l ybecause o f c a t t l e t r a f f i c wou ld b e th e most e f f e c t i v e l y treated w i t h

75-70225.00F : \ S T A R T \ U P P E R . A R K Y 7 0 2 2 5 \ A l t e m a t i v e s A n a l y s i s \ F i n a I 1 9 9 9 \ R e v i s i o n 2 . w p d : b a s

U R S O p e r a t i n g S e r v i c e s , I n c .S T A R T , E R A Region V I I IContrac t No. 68-W5-0031


Date: 0 5 / 1 9 9 9Page 11 of 50

t h i s m e t h o d ; however, in general those areas have lower metalc onc en tra t i on s so are not on the p r i o r i t y l i s t . The method would bem i n i m a l l y e f f e c t i v e on d e p o s i t s w i th very h i g h m e t a l sc o n c e n t r a t i o n s because the c a t t l e are not the primary de t errent tov e g e t a t i v e growth. W i l d a n i m a l s may have an impac t s i m i l a r tothat of c a t t l e , but would be more d i f f i c u l t to re s tr ic t . A c c e s sr e s t r i c t i o n s to w i l d l i f e may not be d e s i r a b l e in t h i s l o c a t i o n due tonearby breeding grounds. Requires long-term cooperat ion andi m p l e m e n t a t i o n by p r o p e r t y owners to remain e f f e c t i v e .

I m p l e m e n t a b i l i t y : F e n c i n g i s r e l a t i v e l y s i m p l e t o i m p l e m e n t . F e n c i n g t o preventaccess by deer, e lk , and other w i ld a n i m a l s would be more d i f f i c u l tt o i m p l e m e n t .

C o s t : Landowner s would lo se value der ived f r o m g r a z i n g acreage. Aminimal cost is required to p r o v i d e and cons truc t f e n c i n g . F e n c i n gmay be an inconvenience to l a n d o w n e r s and recreat ional users.

A c c e p t a b i l i t y : L a n d o w n e r s may be r e l u c t a n t to lo s e g r a z i n g acreage, but that canbe o f f s e t by the l o n g - t e r m r e d u c t i o n in l o s s of l and due to erosion.

5.3 I N - P L A C E S T A B I L I Z A T I O N

T a i l i n g s material may be made l e s s erosive and b i o a v a i l a b l e by s t a b i l i z i n g the material in its currentl o c a t i o n . T h r e e general a p p r o a c h e s to i n - p l a c e s t a b i l i z a t i o n are d i s c u s s e d : p h y s i c a l , c h e m i c a l , andb i o l o g i c a l . P h y s i c a l me thod s i n c l u d e r e t a i n i n g w a l l s a n d c a p p i n g . C h e m i c a l m e t h o d s i n c l u d e soilamendment w i th l ime, t o p s o i l , a n d / o r various t y p e s o f f e r t i l i z e r . B i o l o g i c a l m e t h o d s i n c l u d e variousm e t h o d s o f r e v e g e t a t i o n . C o m b i n a t i o n s o f ch emi ca l , p h y s i c a l , and b i o l o g i c a l m e t h o d s may be themost p r a c t i c a l and e f f e c t i v e means o f r e d u c i n g the hazard po s ed by the f l u v i a l t a i l i n g s . S p e c i f i cm e t h o d s o f i n - p l a c e s t a b i l i z a t i o n are d i s c u s s e d in th e f o l l o w i n g s e c t i on s .


U R S Operat ing Serv i c e s , I n c . U p p e r Arkansas River F l u v i a l T a i l i n g s - A l t e r n a t i v e s A n a l y s i sS T A R T , E P A Region V I I I . Revi s i on: 2Contract No. 68-W5-0031 Date: OS/1999

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The primary b e n e f i t of s t a b i l i z a t i o n is that c on tamina t ed material need not be t r a n s p o r t e d andd i s p o s e d o f e l s ewhere, s o f i l l ma t e r ia l , d i s p o s a l f a c i l i t i e s , and l o n g term m o n i t o r i n g o f d i s p o s a l s i t e sare not required.

However , s t a b i l i z a t i o n only reduces th e l i k e l i h o o d f or f l u v i a l t a i l i n g s t o impac t th e environment anddoes no t e l i m i n a t e th e p o t e n t i a l . A l s o , some s t a b i l i z a t i o n me thod s would a l l o w c on t inued expo sureof t e rr e s t r ia l s p e c i e s to t a i l i n g s or would a l l o w t a i l i n g s to erode and l each i n t o the river d u r i n gextreme river f l o w s . Acce s s roads would be required for most in p l a c e s t a b i l i z a t i o n m e t h o d s .

5.3.1 V e g e t a t i o n

V e g e t a t e the t a i l i n g s d e p o s i t u s ing native or m e t a l s - r e s i s t a n t grass cover or w i l l o w s .V e g e t a t i o n may be most e f f e c t i v e f or d e p o s i t s w i thou t e x t r e m e l y h i g h c o p p e r and zinccontent due to the p h y t o t o x i c i t y of tho s e m e t a l s , p a r t i c u l a r l y where both are p r e s e n t . Dueto the low metal c onc en tra t i on s that cause p h y t o t o x i c i t y and the h igh metal content f o u n din most of the t a i l i n g s d e p o s i t s , soil amendment may be required pr i or to r e v e g e t a t i n g anyarea d e s i g n a t e d as a h igh p r i o r i t y for r e spon s e act ion. F e n c i n g may be required to re s tr ic tl i v e s t o c k access.

E f f e c t i v e n e s s : V e g e t a t i o n can be very e f f e c t i v e in r e d u c i n g erosion. V e g e t a t i o nw i t h o u t so i l amendment w i l l no t pr even t e x p o s u r e o f t e rr e s t r ia ls p e c i e s to high m e t a l s content s o i l s and f orage .

I m p l e m e n t a b i l i t y : The i m p l e m e n t a b i l i t y o f v eg e ta t i v e r e s t o r a t i o n d e p e n d s on manyvariable s i n c l u d i n g c onc en tra t i on and a v a i l a b i l i t y o f m e t a l s ,cons i s t ency of t a i l i n g s , and h e i g h t above water t a b l e , and w i l lrange f r o m i m p o s s i b l e t o m o d e r a t e l y d i f f i c u l t u n l e s s so i lamendment i s a l s o ' p r o v i d e d . D e p o s i t s w i th h i g h a n d moderatemeta l s content w i l l not s u p p o r t v e g e t a t i o n wi thou t soil amendment.D e p o s i t s c o n t a i n i n g p r i m a r i l y sand and cobb l e s on the sur fac e maybe d i f f i c u l t to revegetate. H e a v y e q u i p m e n t , and t h e r e f o r e accessroads, w i l l be required to amend the soi l and p l a n t v eg e ta t i on . The


U R S O p e r a t i n g S e r v i c e s , I n c .S T A R T , E P A Region V I I IContract No. 68-W5-0031

U p p e r Arkansas River F l u v i a l T a i l i n g s - A l t e r n a t i v e s A n a l y s i sRevi s ion: 2

Date: 0 5 / 1 9 9 9Page 13 of 50

p l a n t i n g and growing seasons are short at h igh a l t i t u d e and mayl i m i t s p e c i e s s e l e c t i o n . L o n g term maintenance , such as i r r i g a t i o n ,f e r t i l i z a t i o n , r e s e e d i n g , and f e n c i n g , of v eg e ta t ed areas may berequired.

C o s t : Cost i s m o d e r a t e l y h igh . C o s t s i n c l u d e s p e c i e s research, s e l e c t i o n ,and purchas e , cost o f soil amendment s ( f e r t i l i z e r , t o p s o i l , l i m e ) ,t r a n s p o r t a t i o n o f so i l amendment s , heavy equipment cos t , labor( v e g e t a t i o n can be a l o n g term labor- in t en s ive p r o c e s s ) , and so i lp r e p a r a t i o n .

A c c e p t a b i l i t y : V e g e t a t i o n i s an a t t r a c t i v e o p t i o n f or r e m e d i a t i o n u n l e s s l a r g eareas of range land a n d / o r w e t l a n d s must be d e s t royed for access orthe area is h i g h l y s u s c e p t i b l e to erosion.

5.3.1.1 V e g e t a t i o n with M e t a l s T o l e r a n t S p e c i e s

V e g e t a t e w i t h metal t o l e rant s p e c i e s c a p a b l e o f growth at h i g h a l t i t u d e w i th a shortgrowing season. M e t a l t o l e r a n t s p e c i e s and a s u p p l y source of seed need to bede t e rmined . M e t a l t o l e ranc e i s o f t e n an a d a p t a t i o n of a l e s s metal t o l e r a n t s p e c i e sand seeds of the s p e c i e s may not succeed in me ta l -r i ch s o i l .

The b e n e f i t t o metal t o l e r a n t s p e c i e s i s t h e i r a b i l i t y to grow in the t a i l i n g s w i thou tlarge amounts o f soi l amendment. The drawback to u s ing m e t a l s t o l e r a n t s p e c i e sis that they may overrun or prevent the growth of n a t i v e s p e c i e s and th er eby d i s t u r bthe natural succes s ion process. T h e y a l s o may p r o v i d e a t r a n s p o r t mechani sm form e t a l s f r o m the soil t o w i l d l i f e . M i c r o b e s required f or s u s t a i n i n g v e g e t a t i o n andd e v e l o p i n g a soil horizon may not be v iab l e w i t h o u t soi l amendment .

5.3.1.2 Revege ta t ion with N a t i v e S p e c i e s


U R S Operat ing S e r v i c e s , I n c . U p p e r Arkansas River F l u v i a l T a i l i n g s - A l t e r n a t i v e s A n a l y s i sS T A R T , E P A Region V I I I Revi s ion: 2Contract No. 68-W5-0031 Date: 0 5 / 1 9 9 9

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Plant native s p e c i e s on the t a i l i n g s d e p o s i t s and prov ide water and n u t r i e n t s asnecessary.

The b e n e f i t to native s p e c i e s i s that t h ey p r o v i d e the natural v e g e t a t i o n for the area and areproven to grow in the s i t e c l i m a t e and a l t i t u d e . The drawback to native spe c i e s is that deadv e g e t a t i o n was observed on many of the t a i l i n g s d e p o s i t s and al l o f the i d e n t i f i e d d e p o s i t shave e i ther v i s i b l y s tres sed or no v ege ta t iv e grow th , i n d i c a t i n g an i n a b i l i t y of n a t i v ev eg e ta t i on to grow in untreated t a i l i n g s m a t e r i a l , so so i l amendment or t a i l i n g s removalwould be required prior to r evege ta t i on .

5.3.2 R e t a i n i n g W a l l s

Cons t ru c t r e t a i n i n g w a l l s or o ther d ev i c e s to p r o v i d e s truc tural i n t e g r i t y to e r o d i n gstreambanks. Quasi-permanent r e t a i n i n g w a l l s can a l s o be used to p r o t e c t in- s i tu t r e a t m e n t su n t i l na t ive v e g e t a t i o n i s e s t a b l i s h e d on f o r m e r l y u n v e g e t a t e d t a i l i n g s . P o t e n t i a lc on s t ruc t i on mater ia l s i n c l u d e gabions, t r e e s / w i l l o w s , or b ou ld e r s . A cobb l e gabion wal li s in p l a c e a d j a c e n t to a t a i l i n g s d e p o s i t near the c o n f l u e n c e of Lake F o r k Creek.S t a b i l i z a t i o n w a l l s made of e igh t e en- inch and larger rip rap covered by na t iv e river m a t e r i a l swere p l a c e d a d j a c e n t t o D e p o s i t s CL, M P / M Q , and MB dur ing the b i o s o l i d s d e m o n s t r a t i o np r o j e c t s p e r f o r m e d in 1998. Permanent r e t a i n i n g w a l l s s h o u l d be d e s i g n e d w i t h i n theframework of a c o m p r e h e n s i v e river r e s t o ra t i on p l a n . Quasi-permanent r e t a i n i n g w a l l s maybe cons truc t ed to prevent the release of c o n t a m i n a n t s into the river d u r i n g in- s i tur emed ia t i on e f f o r t s .

E f f e c t i v e n e s s : R e t a i n i n g w a l l s can b e e f f e c t i v e in r edu c ing eros ion o f t a i l i n g s i n t othe river. Many t y p e s o f r e t a i n i n g w a l l s have a l i m i t e d l i f e s p a n butthat may be all tha t is necessary to restore a f u n c t i o n a l streambankif r e v e g e t a t i o n i s i n c l u d e d . R e t a i n i n g w a l l s do no t prevent t a i l i n g sf r o m i m p a c t i n g v e g e t a t i o n or e x p o s i n g t e r r e s t r i a l s p e c i e s t h r o u g hh i g h metal content soil and f o r a g e . R u n o f f may s t i l l i n c l u d e me ta l-rich s a l t s .

75-70225.00F : \ S T A R T \ U P P E R . A R K \ 7 0 2 2 5 \ A l t e m a t i v e s A n a l y s i s V F m a l 1 9 9 9 \ R e v i s i o n 2 . w p d : b a s

URS Operating S e r v i c e s , Inc.S T A R T , E P A Region V I I IContract No. 68-W5-0031

I m p l e m e n t a b i l i t y :

U p p e r Arkansas River F l u v i a l T a i l i n g s - A l t e r n a t i v e s A n a l y s i sRevision: 2

Date: 0 5 / 1 9 9 9Page 15 of 50

B u i l d i n g r e t a i n i n g w a l l s i s labor i n t e n s i v e and requires heavyequipment. Heavy use access roads are required to bui ld r e ta iningw a l l s w i t h p r i m a r i l y o f f - s i t e mat er ia l s . A short c o n s t r u c t i o n seasonwould be a v a i l a b l e for some d e p o s i t s due to a h i g h water t a b l e(moi s t s o i l p r e v e n t i n g heavy veh i c l e access). B u i l d i n g a r e t a i n i n gwall may require t e m p o r a r i l y d i v e r t i n g river f l o w , even dur ingp e r i o d s o f l ow f l o w , t o prevent s p i l l i n g t a i l i n g s i n t o th e river andto a l l o w heavy equ ipment access.

C o s t : Cos t of c on s t ru c t i on equipment and labor may be very h igh. Costof ma t e r ia l s varies w i t h the c on s t ruc t i on m a t e r i a l s , but may behigh. D e p e n d i n g on l o c a t i o n and e x t e n t , river d i v e r s i o n may beexpens ive .

A c c e p t a b i l i t y : L a n d o w n e r s have i n d i c a t e d tha t t h i s i s not the p r e f e r r e d method ofr e spons e , but may be c on s id er ed in certain l o c a t i o n s under certainc o n d i t i o n s . R e t a i n i n g w a l l s i n c l u d i n g v e g e t a t i o n would gain moreacceptance than rock or metal w a l l s . U n a t t r a c t i v e r e t a i n i n g w a l l swould be u n a c c e p t a b l e .

5.3.2.1 Re ta in ing W a l l s

R e t a i n i n g w a l l s can be c on s t ruc t ed of rock or c obb l e c on ta ined in f e n c i n g andanchored to the bank. One gabion wal l can be used, or a s t a i r s t e p p e d series of w a l l scan be c on s t ruc t ed wi th vege ta t i on between the w a l l s . The v e g e t a t i o n would coverthe s t r u c t u r i n g c o m p o n e n t s , a l l o w i n g for a more a t t r a c t i v e w a l l . G a b i o n or r i p r a pw a l l s can be used in c o n j u n c t i o n with w i l l o w w a t t l i n g and other f o rms of v e g e t a t i o nto p r o v i d e a more a t t r a c t i v e w a l l whose s tructure may be buried wi th t ime, l e a v i n gon ly the v ege ta t i on v i s i b l e .

75-70225.00F : \ S T A R T \ U P P E R . A R K \ 7 0 2 2 5 \ A l t e m a t i v e s A n a l y s i s V F i n a l 1999\Revi s i on2 .wpd:ba s

U R S Opera t ing S e r v i c e s , I n c . U p p e r Arkansas River F l u v i a l T a i l i n g s - A l t e r n a t i v e s A n a l y s i sS T A R T , E P A R e g i o n V I I I R e v i s i o n : 2Contrac t No. 68-W5-0031 Date: 0 5 / 1 9 9 9

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5.3.2.2 W i l l o w W a t t l i n g

W i l l o w b u n d l e s s t a b i l i z e d by g e o f a b r i c or f e n c i n g can be used to construct ar e t a i n i n g w a l l . As th e w i l l o w s begin growth , o ther v e g e t a t i o n w i l l b e e s t a b l i s h e daround them and increase s t a b i l i z a t i o n of the streambank. T h i s method w i l l notwork on s treambanks wi th h igh metal c o n c e n t r a t i o n s u n l e s s so i l amendment isincorpora t ed into the cons truc t ion.

5.3.2.3 Anchored Tree s

Tree s can be anchored a l o n g the shore to prov ide bank s t a b i l i t y through s i l t a t i o n .Tree anchors may not be e f f e c t i v e due to a lack of trees a v a i l a b l e in the area foranchor ing. A l s o , tree anchor ing may not be e f f e c t i v e because of the v e l o c i t y ands e d i m e n t l o a d i n g at t h i s p o i n t on the A r k a n s a s River.

5.3.3 C o v e r / C a p

T a i l i n g s d e p o s i t s could b e covered wi th c l a y , c l ean s o i l , l i m e s t o n e , a n d / o r c o b b l e and l e f tin p l a c e . The e l e v a t i o n o f the d e p o s i t i s increased by the d e p t h o f the cap , p o t e n t i a l l ycaus ing changes in the stream channel or requir ing s t a b i l i z a t i o n to keep the t a i l i n g s and capf r o m e r o d i n g in to the river. C a p p i n g may require l o n g term m o n i t o r i n g and maintenance.Because most of the t a i l i n g s are l o ca t ed in the f l o o d p l a i n , c a p p i n g would o n l y bea p p r o p r i a t e in l i m i t e d s i t u a t i o n s where migration of c o n t a m i n a n t s wou ld not occur.

E f f e c t i v e n e s s : C a p p i n g t a i l i n g s d e p o s i t s would prevent t h e e xpo sure o f t e rr e s t r ia ls p e c i e s t o t h e h i g h me ta l s content t a i l i n g s . T h e u s e f u l n e s s o f t h ecap to prevent m o b i l i z a t i o n o f m e t a l s t h r o u g h sur fa c e wateri n f i l t r a t i o n d e p e n d s on the p e r m e a b i l i t y o f the cap material towater. M o b i l i z a t i o n of me ta l s in to ground water may or may not bea p r o b l e m d e p e n d i n g on the c o n s t r u c t i o n of the cap and thee l e v a t i o n of the d e p o s i t in r e l a t i o n to the water t a b l e and the river.The c a p p i n g material can be s e l e c t e d to p r o v i d e a good growth

75-70225.00F : \ S T A R T \ U P P E R . A R K Y 7 0 2 2 5 \ A l t e m a t i v e s A n a l y s i s X F i n a l 1999\Revi s i on2.wpd:ba s

URS Operat ing S e r v i c e s , Inc .S T A R T , E P A Region V I I IContract No. 68-W5-0031


Date: 0 5 / 1 9 9 9Page 17 of 50

medium for nat ive v ege ta t i on . If the cap does not prevent themigrat ion of m e t a l s and a d d i t i o n a l treatment is deemed necessary,the c a p p i n g material w i l l add to the or ig inal volume of thecontaminated material .

I m p l e m e n t a b i l i t y : Cap material can be e a s i l y eroded if not s t a b i l i z e d p r o p e r l y .Lime s t one and cobb l e are a v a i l a b l e l o c a l l y ; so i l and c l a y may needto be ob ta ined f r o m a greater di s tance . The l o n g term i n t e g r i t y ofthe cap d e p e n d s on the mat er ia l s and mechanic s of c o n s t r u c t i o n .The cap would need to be d e e p enough to prevent t a i l i n g s andu p w a r d l y migra t ing m o b i l e me ta l s f r o m i m p a c t i n g v e g e t a t i o n .

C o s t : M o d e r a t e t o h igh . C o s t s i n c l u d e c a p p i n g mat er ia l , roadc o n s t r u c t i o n , labor, heavy e q u i p m e n t , r e v e g e t a t i o n m a t e r i a l s , andm u l t i - y e a r moni t or ing .

A c c e p t a b i l i t y : C a p p i n g would be a m o d e r a t e l y a c c e p t a b l e method of t r ea tment asl o n g as c on t inued erosion was p r e v e n t e d and v e g e t a t i o n wass u p p o r t e d .

5.3.4 S o i l A m e n d m e n t

Amend t h e t a i l i n g s d e p o s i t s i n p l a c e wi th l i m i n g ag en t s , t o p s o i l , organic m a t e r i a l , a n d / o rf e r t i l i z e r to reduce the a c id-genera t ing p o t e n t i a l of the medium and p r o v i d e a moreh o s p i t a b l e growth environment f o r native v eg e ta t i on . A f t e r amendmen t , t h e d e p o s i t s wouldbe v ege ta t ed or le f t to natural succes s ion. T h i s a l t e r n a t i v e i s most e f f e c t i v e in c o n j u n c t i o nwith v e g e t a t i o n wi th native or me ta l s r e s i s t a n t s p e c i e s . R e t a i n i n g w a l l s or r e g r a d i n g maybe required to s t a b i l i z e s t e e p cut banks.

E f f e c t i v e n e s s : Amendment can be e f f e c t i v e in c h a n g i n g metal s p e c i a t i o n th er ebyreduc ing the b i o a v a i l a b i l i t y and l e a c h i n g p o t e n t i a l o f m e t a l s in thet a i l i n g s . Long term success d e p e n d s on h a v i n g the a p p r o p r i a t e

75-70225.00F : \ S T A R T \ U P P E R . A R K \ 7 0 2 2 5 \ A i t e r n a t i v e s A n a l y s i s \ F i n a l l 9 9 9 \ R e v i s i o n 2 . w p d : b a s

U R S O p e r a t i n g S e r v i c e s , Inc.S T A R T , E R A Region V I I IContrac t No. 68-W5-0031


Date: 0 5 / 1 9 9 9Page 18 of 50

ratio o f f a s t d i s s o l v i n g and s low d i s s o l v i n g f o r m s o f l i m e , bu ts t u d i e s have been done to p r e d i c t a p p r o p r i a t e ra t i o s d e p e n d i n g onthe acid-base p o t e n t i a l o f t h e t a i l i n g s . The permanence o fr e d u c t i o n i n l e a c h i n g p o t e n t i a l i s uncertain. T h e t a i l i n g s m a y s t i l lbe s u b j e c t to t r a n s p o r t d u r i n g h igh f l o w events.

I m p l e m e n t a b i l i t y : S p e c i f i c a t i o n s and sources of l i m i n g agen t s must be o b t a i n e d .M a t e r i a l s must be t r a n s p o r t e d to the s i t e . H e a v y machinery isrequired t o t i l l amendment s into t h e t a i l i n g s . T i l l i n g p e r f o r m e d o nt a i l i n g d e p o s i t s wi th large amounts o f c o b b l e s may pre s entcompl i ca t i ons , d e p e n d i n g on th e d e p t h o f t i l l i n g s e l e c t ed . Ti l l ingon s i t e s w i t h h igh a p p l i c a t i o n rates o f b i o s o l i d s can be d i f f i c u l t .Long-t erm f e r t i l i z a t i o n and o t h e r amendment a d j u s t m e n t s may berequired.

C o s t : C o s t s i n c l u d e r a w m a t e r i a l s ( l i m i n g ag en t s , t o p s o i l , f e r t i l i z e r ) ,t r a n s p o r t a t i o n o f raw mat e r ia l s , labor, heavy machinery, t i l l i n gb l a d e s , and road cons truc t i on. Cos t may be reduced by the use ofr e s i d u a l s such as fly ash and b i o s o l i d s . The cost can vary f r o mmoderat e to h i g h d e p e n d i n g on m a t e r i a l s and i n c o r p o r a t i o nm e t h o d s used.

A c c e p t a b i l i t y : S o i l amendment would be a c c e p t a b l e to l a n d o w n e r s i f a p p r o p r i a t er ev eg e ta t i on a n d / o r bank s t a b i l i z a t i o n m e t h o d s are i n c o r p o r a t e d .S o i l amendment can, in the l ong- t e rm, a l l o w l a n d o w n e r sb e n e f i c i a l u s e o f p r e v i o u s l y unu sab l e p r o p e r t y . A m e n d m e n t w i t hb i o s o l i d s may not be a c c e p t a b l e to all l andowner s .

5.4 R E M O V A L

Excavate the t a i l i n g s and d i s p o s e of them at on-si te or o f f - s i t e r e p o s i t o r i e s . E x c a v a t i o n is c o m p l e t e du s i n g heavy equ ipment . T a i l i n g s are removed to r e p o s i t o r i e s by trucks. Fill material may be p l a c e d


URS O p e r a t i n g S e r v i c e s , Inc .S T A R T , E P A Region V I I IContrac t No. 68-W5-0031

U p p e r Arkansa s River F l u v i a l T a i l i n g s - A l t e r n a t i v e s A n a l y s i sRevi s i on: 2

Date: 0 5 / 1 9 9 9Page 19 of 50

where t a i l i n g s have been removed if it is necessary to prevent r ea l ignment of the Arkansa s River.Acce s s roads w i l l be required.

E f f e c t i v e n e s s : E f f e c t i v e in r e d u c i n g the impac t o f mine t a i l i n g s t o Arkansa s River q u a l i t y ,m o r p h o l o g y , and env ironmenta l r e c ep tor s . The t a i l i n g s cou ld s t i l l b e a

•threat to the environment to the e x t en t to which the r e p o s i t o r y is a t h r e a t ;however, the river and r i p a r i a n r e c ep t or s wou ld no l o n g e r be t h r e a t e n e d .Removal is a permanent s o l u t i o n .

I m p l e m e n t a b i l i t y : Removal by truck requires heavy d u t y roads for c o n t i n u a l truck t r a f f i c .A c c e s s to d e p o s i t s w i t h c o m p l e x access routes or w i t h routes t h r o u g hw e t l a n d s may be d i f f i c u l t and d e s t r u c t i v e . C o n s t r u c t i o n season may bel i m i t e d in l o w - l y i n g d e p o s i t s because of water- saturated s o i l . Removal i sonly p o s s i b l e i f a r e p o s i t o r y can be i d e n t i f i e d . On-site r e p o s i t o r i e s arep o s s i b l e on some l a n d o w n e r s ' p r o p e r t y ; however, o ther l a n d o w n e r s maynot own land a p p r o p r i a t e for a r epo s i t o ry . One p o t e n t i a l o f f - s i t e r e p o s i t o r y ,the H e c l a I m p o u n d m e n t s , may be a v a i l a b l e , but may be l e g a l l y u n w i l l i n gor unable t o accep t waste f r o m o u t s i d e o f th e C a l i f o r n i a G u l c h S u p e r f u n dS i t e . Borrow material needs t o b e i d e n t i f i e d , p o s s i b l y f r o m on-s i t er e p o s i t o r y l o c a t i o n s . The river may require t emporary d i v e r s i o n to avoidr e l e a s i n g t a i l i n g s to the river when d e p o s i t s d i r e c t l y a d j a c e n t to the river areremoved.

Cos t: The cost of removal i s h igh . E q u i p m e n t , labor, road c o n s t r u c t i o n ,t r a n s p o r t a t i o n , borrow mat er ia l , r e v e g e t a t i o n of i m p o r t e d borrow materialand d e d i c a t e d roads, and d i s p o s a l at o f f - s i t e r e p o s i t o r y or landp u r c h a s e / l o n g - t e r m moni t o r ing at on-s i t e r e p o s i t o r i e s are al l p o t e n t i a l co s t sof excavat ion and removal. L o n g term maintenance a l o n g the river maynot be required for t h i s a l t e r n a t i v e , t hu s r e d u c i n g the l o n g term cost. W h e nth i s a l t e r n a t i v e i s p e r f o r m e d in c o n j u n c t i o n w i t h channel m o d i f i c a t i o n , f o re x a m p l e when a t a i l i n g s d e p o s i t must be moved to a l l o w channel s t a b i l i t y ,


U R S O p e r a t i n g Serv i c e s , I n c . U p p e r Arkansa s River F l u v i a l T a i l i n g s - A l t e r n a t i v e s A n a l y s i sS T A R T , E P A Region V I I I Revi s ion: 2Contrac t No. 68-W5-0031 Date: 0 5 / 1 9 9 9

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the re la t ive cost of d i s p o s a l as compared to other treatment me thod s maybe reduced.

A c c e p t a b i l i t y : Landowners would no l o n g e r be i m p a c t e d by t a i l i n g s , but the in t e r imp r o b l e m s with road c o n s t r u c t i o n through range land a n d / o r w e t l a n d s ,d e d i c a t i o n o f land for on-site r e p o s i t o r i e s , and long-term l i a b i l i t y f or on-si t er e p o s i t o r i e s may be a p r o b l e m wi th landowner s . W i t h p r o p e r d e s i g n ofb a c k f i l l and bank s t a b i l i z a t i o n , water r igh t s h o l d e r s s h o u l d not be a f f e c t e dunle s s t a i l i n g s were re l eased to the river dur ing excavat ion.

5.4.1 O f f - S i t e D i s p o s a l

T a i l i n g s can be removed f r o m t h e i r current l o c a t i o n to a r e p o s i t o r y away f r o m the ArkansasRiver. The t a i l i n g s can be s taged on a s e c t i on of the l a n d o w n e r s p r o p e r t y for a short p er i odbetween removal f r o m the f l u v i a l d e p o s i t s i t e and t r a n s p o r t a t i o n to the r e p o s i t o r y to e x p e d i t et r a n s p o r t a t i o n a c t i v i t i e s .

A d i s p o s a l s i t e ( s ) needs t o b e i d e n t i f i e d . The H e c l a I m p o u n d m e n t i s a p o t e n t i a l o f f - s i t ed i s p o s a l l o c a t i o n , but H e c l a may not be a v a i l a b l e to receive material f r o m o u t s i d e theC a l i f o r n i a G u l c h S u p e r f u n d S i t e . T h e cost o f d i s p o s a l a t t h i s f a c i l i t y i s unknown a t t h i st ime.

5.4.2 O n - S i t e D i s p o s a l

On-site sur fac e i m p o u n d m e n t s may be used, d e p e n d i n g on landowner, l o c a l , and s ta t ea p p r o v a l . On-site i m p o u n d m e n t s require l a n d o w n e r s t o i d e n t i f y p o t e n t i a l i m p o u n d m e n tl o c a t i o n s and agree to long-term moni t o r ing around the i m p o u n d m e n t . On-siteimpoundment s would be most e f f e c t i v e for landowners w i th land o u t s i d e the 500-yearf l o o d p l a i n . Landowner s may no t b e w i l l i n g t o accept another l a n d o w n e r ' s t a i l i n g s d e p o s i t ,so excavat ion could be c o m p l i c a t e d by p r o p e r t y boundarie s . On-site d i s p o s a l reducest r a n s p o r t a t i o n costs but requires construction costs and l ong term monitor ing for eachimpoundment . Landowner l i a b i l i t y s h o u l d not be an issue for on-si te i m p o u n d m e n t s i f the


U R S O p e r a t i n g Serv i c e s , Inc. U p p e r Arkansas River F l u v i a l T a i l i n g s - A l t e r n a t i v e s A n a l y s i sS T A R T , E P A Region V I I I Revi s i on: 2Contract No. 68-W5-0031 Date: 0 5 / 1 9 9 9

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p a r t i e s r e s p o n s i b l e f o r t h e t a i l i n g s d e p o s i t s retain l i a b i l i t y a n d p e r f o r m l ong- t ermmonitoring.

An on-site r e p o s i t o r y may require that certain requirements o f the S t a t e o f C o l o r a d o S o l i dW a s t e D i s p o s a l R e g u l a t i o n s be met i n c l u d i n g s i t e s t a n d a r d s , g roundwa t e r moni t or ing ,de s ign and o p e r a t i n g requirements, c losure requirements, and long-term maintenance. TheH a y d e n Ranch has been i d e n t i f i e d as a p o t e n t i a l r e p o s i t o r y l o c a t i o n .

5 . 5 A L T E R A T I O N O F T H E R I V E R C H A N N E L

A l t e r th e river channel t o decrease f l o w pa s t f l u v i a l t a i l i n g d e p o s i t s and t h e r e f o r e reduce eros ion o ft a i l i n g s into the river. J e t t i e s / d e f l e c t o r s , moving the river channel , or check dams are p o t e n t i a l riverchannel a l t e r a t i o n s . Other o p t i o n s are p r e s e n t e d in the G e o m o r p h o l o g i c A s s e s s m e n t ( I n t e r - F l u v e1998). S i g n i f i c a n t a l t e ra t i on of the river channel shou ld be done w i t h i n the f ramework of acomprehens ive channel de s ign so that a l t e r a t i o n of one river segment does not have an adverse e f f e c ton another river segment.

E f f e c t i v e n e s s : M o v i n g th e river channel may reduce th e p o t e n t i a l f or t a i l i n g s t o erode i n t othe Arkansa s River but would not reduce the impac t of m e t a l s on t erre s t r ia ls p e c i e s and v e g e t a t i o n . F l o o d i n g event s and storm events cou ld s t i l l a l l o wt a i l i n g s erosion. A new river channel may reduce t a i l i n g s l o a d i n g to theArkansas River, but because river sy s t ems are d y n a m i c , the r e d u c t i o n ison ly as permanent as active channel maintenance. For d e p o s i t si n a c c e s s i b l e by land but acc e s s i b l e t h r o u g h the river, river a l t e r a t i o n maybe the best method of l i m i t i n g the e f f e c t of t a i l i n g s on the river.

I m p l e m e n t a b i l i t y : H y d r o l o g i s t s are able to d e s i g n river c h a n n e l s and d i r e c t water f l o w s wi thvarying degre e s o f success. U l t i m a t e l y river channe l s evo lve , so c o n t i n u i n gmaintenance of the channel a l t e r a t i o n s may be required to keep the riveraway f r o m t a i l i n g s . H e a v y e q u i p m e n t may be required. An overa l l d e s i gnfor the entire 1 1 - m i l e reach i s d e s i r a b l e pr i or to s i g n i f i c a n t channelm o d i f i c a t i o n .

75-70225.00F : \ S T A R T \ U P P E R . A R K \ 7 0 2 2 5 \ A l t e r n a t i v e s A n a ] y s i s \ F i n a ! 1 9 9 9 \ R e v i s i o n 2 . w p d : b a s

U R S Operat ing Serv i c e s , I n c . U p p e r Arkansas River F l u v i a l T a i l i n g s - A l t e r n a t i v e s A n a l y s i sS T A R T , E P A Region V I I I R e v i s i o n : 2Contract N o . 68-W5-0031 Date: O S / 1 9 9 9

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Cos t: Channe l m o d i f i c a t i o n m e t h o d s vary in cost f r o m moderate to very h i g ha c c o r d i n g to d e s i g n , c o n s t r u c t i o n me thod s , and mater ia l s . The river mayrequire diversion prior to and dur ing c h a n n e l i z a t i o n . The cost of the des ignof river m o d i f i c a t i o n s may be h i g h , even for short segment of river. H e a v ye q u i p m e n t , labor, and t r a n s p o r t a t i o n of c o n s t r u c t i o n m a t e r i a l s may berequired.

A c c e p t a b i l i t y : T h i s o p t i o n w i l l b e a c c e p t a b l e t o l a n d o w n e r s t o t h e e x t e n t tha t t h e i r l andarea is not reduced by the r ede s ign. The channel d e s ign would need toc o n s i d e r each l a n d o w n e r ' s p r i o r i t y f o r t h e river ( r e c r e a t i o n a l , a g r i c u l t u r a l ,maximizat ion of dry l a n d , max imiza t i on of w e t l a n d s ) to encourageac c ep tanc e of the d e s i g n .

C h a n g i n g the river channel wou ld not addre s s many of the t e rr e s t r ia l i m p a c t s o f the t a i l i n g s d e p o s i t s ,but would minimize d irec t i m p a c t s to the river. H i g h water events , storm event s , and g r o u n d w a t e ri n f i l t r a t i o n m a y s t i l l a l l o w t h e t a i l i n g s t o impac t t h e river. T h e d e p o s i t s would s t i l l a f f e c t v e g e t a t i o n ,soil organi sms, and w i l d l i f e .

6 . 0 S E L E C T I O N O F A L T E R N A T I V E S

In S e c t i o n 5, several r e sponse a c t i on s were de s cr ibed for p o t e n t i a l use on the U p p e r Arkansas River f l u v i a lt a i l i n g s . In th i s s e c t i on, these o p t i o n s w i l l b e assessed for th e i r a p p l i c a b i l i t y t o th e U p p e r Arkansas Riverf l u v i a l t a i l i n g s i n general a n d t o s p e c i f i c d e p o s i t s i d e n t i f i e d i n t h e S a m p l i n g A c t i v i t i e s R e p o r t s .

The "No Action" al ternative remains an op t i on for d e p o s i t s with d i f f i c u l t access, low impac t s f rom me ta l s ,a n d / o r o ther c h a r a c t e r i s t i c s that make r e m e d i a t i o n a low p r i o r i t y at t h i s t ime.

The " I n s t i t u t i o n a l C o n t r o l s - Water Management Practices" o p t i o n wi l l be pursued for the overal l h ea l t h ofthe riverine sy s t em but w i l l not be the primary response action for any of the f l u v i a l t a i l i n g s d e p o s i t s . TheBureau of Rec lamat ion has i n d i c a t e d in t ere s t in s t u d y i n g the i n f l u e n c e of water management p r a c t i c e s onthe Arkansas River in the 11-mile reach.


U R S Operat ing S e r v i c e s , Inc. U p p e r Arkansas River F l u v i a l T a i l i n g s - A l t e r n a t i v e s A n a l y s i sS T A R T , E P A Region V I I I Revi s i on: 2Contract No. 68-W5-0031 Date: 0 5 / 1 9 9 9

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The " I n s t i t u t i o n a l C o n t r o l s - A g r i c u l t u r a l Best Management Pract ice s" o p t i o n w i l l b e recommended for thoseareas in which c a t t l e are the primary cause of i m p a c t s to v e g e t a t i o n a n d / o r s treambank erosion.

The " S t a b i l i z a t i o n - V e g e t a t i o n " a l t e r n a t i v e w i l l b e c on s ider ed f or d e p o s i t s with l ow enough me ta l sconcentrat ions to s u p p o r t e i t h e r native or metal r e s i s t an t s p e c i e s . In d e p o s i t s w i t h h i g h meta l sconcentra t ions , v e g e t a t i o n w i l l be used in c o n j u n c t i o n wi th one or more of the f o l l o w i n g : soi l amendment ,r e ta in ing w a l l s , c o v e r / c a p p i n g , Best Management Prac t i c e s , and p o s s i b l y removal.

The " S t a b i l i z a t i o n - R e t a i n i n g W a l l s " a l t e r n a t i v e w i l l b e cons idered in c o n j u n c t i o n w i th other a l t e r n a t i v e sthat would addre s s t h e t erre s tr ia l i m p a c t s o f t h e t a i l i n g s . S t a b i l i z a t i o n a l t e r n a t i v e s that f i t w i th th eg e o m o r p h o l o g i c a s s e s sment w i l l be used.

The " S t a b i l i z a t i o n - C o v e r / C a p " a l t e r n a t i v e w i l l not be used because there are more a c c e p t a b l e , e c o n o m i c a l l yf e a s i b l e , a n d e f f e c t i v e m e t h o d s t o s t a b i l i z e t h e t a i l i n g s .

The " S t a b i l i z a t i o n - Amend in Place" a l t e r n a t i v e w i l l be used in c o n j u n c t i o n w i t h r e v e g e t a t i o n and p o s s i b l yr e t a i n i n g w a l l s . Lime and b i o s o l i d s w i l l be the primary choice for s t a b i l i z a t i o n at t h i s t ime due to t h e i r lowercost and t h e i r e f f e c t i v e n e s s a t s imi lar s i t e s ( O y l e r 1990; S o p p e r 1988). B i o s o l i d s r e g u l a t i o n s w i l l b ef o l l o w e d and b i o s o l i d s w i l l not be used w i t h i n 33 f e e t of the river. D e p o s i t s w i th s t e e p cut banks w i l l beregraded and s t a b i l i z e d aga in s t erosion.

The "Removal - O f f - S i t e D i s p o s a l " a n d / o r "Removal - O n - S i t e D i s p o s a l " a l t e r n a t i v e s w i l l b e pursued fortho s e d e p o s i t s with h i g h me ta l s c o n c e n t r a t i o n s , l i t t l e o r no v e g e t a t i o n , d e e p t a i l i n g s , a c c e s s i b i l i t y t o heavye q u i p m e n t , and h igh channel i n s t a b i l i t y . The "On-Site D i s p o s a l " o p t i o n w i l l o n l y b e a p p l i c a b l e i f a s u i t a b l el o c a t i o n for an on-site r e p o s i t o r y can be i d e n t i f i e d .

The " A l t e r a t i o n of the River Channel" a l t e r n a t i v e may be used in the f orm of minor a l t e r a t i o n s for s m a l ls ca le changes in areas of extreme channel i n s t a b i l i t y . For e x a m p l e , a smal l s id e channel of the river c ou ldbe r ed irec t ed i n t o the main por t i on of the river to pro t e c t an a c t i v e l y e r o d i n g s tr eambank composed p r i m a r i l yof t a i l i n g s . M a j o r a l t e r a t i o n s of moderate or large s e c t i ons w i l l not be cons idered at t h i s t ime due to the h i g hc o s t , u n c e r t a i n t y of i m p a c t s to a d j a c e n t s e g m e n t s , and l o n g term maint enance needs. A comprehens ive

75-70225.00F : \ S T A R T \ U P P E R . A R K \ 7 0 2 2 5 \ A I t e m a t i v e s A n a l y s i s \ F i n a l l 9 9 9 \ R e v i s i o n 2 . w p d : b a s

U R S O p e r a t i n g Serv i c e s , Inc. U p p e r Arkansas River F l u v i a l T a i l i n g s - A l t e r n a t i v e s A n a l y s i sS T A R T , E P A Region V I I I R e v i s i o n : 2Contract No. 68-W5-0031 Date: 0 5 / 1 9 9 9

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channel d e s i gn should be in p l a c e prior to s i g n i f i c a n t a l t e r a t i o n s in the river channel . M a i n t e n a n c e ofe x i s t i n g bank s t a b i l i z a t i o n s tructures i s s ugge s t ed .

A p p l i c a b i l i t y o f these a l t e r n a t i v e s t o th e d e p o s i t s wa s c on s ider ed t o sugge s t r e sponse ac t ions f or s p e c i f i cd e p o s i t s . The s e l e c t i o n proce s s i s i n t e n d e d to suggest a l t e r n a t i v e s that best f i t each s i t e given the currentlevel of k n o w l e d g e as p r e s e n t e d in the previous sect ions. New i n f o r m a t i o n gained d u r i n g i m p l e m e n t a t i o nand m o n i t o r i n g o f r emed ia t i on p r o j e c t s may p r o v i d e a d d i t i o n a l i n s i g h t in to the most a p p r o p r i a t e t e c h n o l o g yfor each f l u v i a l t a i l i n g s d e p o s i t and shou ld be incorporated into the d e c i s i o n making proces s . It i s e x p e c t e dthat c l o s e l y l o c a t e d t a i l i n g s d e p o s i t s w i l l be treated at one time w i th one me thod , p o s s i b l y a l t e r i n g s u g g e s t e da l t e r n a t i v e s f or some d e p o s i t s . L a n d o w n e r ac c ep tance o f s p e c i f i c a l t e rna t iv e s t o t h e i r land shou ld be soughtprior to a p p l i c a t i o n o f the s e l e c t e d a l t e r n a t i v e s .

7.0 1999 D E M O N S T R A T I O N P R O J E C T S

S e v e r a l l o c a t i o n s were s e l e c t e d f o r a d d i t i o n a l d e m o n s t r a t i o n p r o j e c t s . T a b l e 3 l i s t s l o c a t i o n s s u g g e s t e d f o rt r ea tment dur ing the 1999 f i e l d season. The area treated may be increased or decreased d e p e n d i n g on f i e l dc o n d i t i o n s . T h e s e l o c a t i o n s were s e l e c t e d in part because of t h e i r l o c a t i o n r e l a t i v e to 1998 d e m o n s t r a t i o np r o j e c t s w i th the a n t i c i p a t i o n that the impac t o f t r e a t i n g a larger reach of the river w i l l p r o v i d e a b e t t e ri n d i c a t i o n o f th e p o t e n t i a l long-term success o f th e soil a m e n d m e n t / r e v e g e t a t i o n a l t e r n a t i v e . The l o c a t i o n swere a l s o s e l e c t e d for t h e i r var ia t ion in c h a r a c t e r i s t i c s , such as l o c a t i o n r e l a t i v e to groundwat er , d e p t h o ft a i l i n g s , maximum metal c on t en t , and e l e v a t i o n r e l a t i v e t o the river. The s e l e c t e d trea tment for a l l t h e s ed e p o s i t s is s o i l amendment w i th l ime or a s i m i l a r p r o d u c t and organic mat ter , and subsequent r evege ta t i onwith native sp e c i e s . The t y p e o f so i l amendment and the method of i n c o r p o r a t i o n in to the t a i l i n g s w i l l bevaried. Organic soil a d d i t i v e s are e x p e c t e d to i n c l u d e b i o s o l i d s at varying rates, b i o s o l i d s p e l l e t s , and animalmanure. I n c o r p o r a t i o n of so i l amendment s and seed w i l l be p e r f o r m e d u s i n g varying t e chnique s to de t erminethe most economical and e f f e c t i v e me thod s . One of the s e l e c t e d areas (N E a s t ) was the l o c a t i o n of agroundwater s tudy (USGS 1999). Because USGS groundwat er m o n i t o r i n g wa s c onduc t ed p r i o r t o t r e a t m e n t ,p e r f o r m i n g a d e m o n s t r a t i o n p r o j e c t in that area s h o u l d p r o v i d e a c ompar i s on of the e x t e n t of the t r a n s p o r tof m e t a l s in the g r o u n d w a t e r b e f or e and a f t e r t r ea tment . Groundwat e r m o n i t o r i n g , combined w i th the s t u d i e sin progre s s by USGS and ERT (de s c r i b ed in S e c t i o n 2.2), can be used to assess the e f f e c t i v e n e s s of in-s i tutreatment o f t a i l i n g s in the f l o o d p l a i n .


U R S O p e r a t i n g S e r v i c e s , I n c . U p p e r Arkansa s River F l u v i a l T a i l i n g s - A l t e r n a t i v e s A n a l y s i sS T A R T , E P A Region V I I I Revi s ion: 2Contract No. 68-W5-0031 Date: 0 5 / 1 9 9 9

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Bank s t a b i l i z a t i o n w i l l b e i n c l u d e d for d e p o s i t s w i th banks cons idered i m m e d i a t e l y v u l n e r a b l e to erosion,such as those d e p o s i t s with cut banks a l o n g the Arkansa s River or its d i s t r i b u t a r i e s . Bank s t a b i l i z a t i o n workw i l l incorporate the i n f o r m a t i o n prov id ed in the G e o m o r p h o l o g i c A s s e s s m e n t ( I n t e r - F l u v e 1998). It i se x p e c t e d that the river w i l l evolve, but the w a l l s are not i n t e n d e d to be p ermanent , but to p r o v i d e thei n f r a s t r u c t u r e necessary to s u p p o r t r e v e g e t a t i o n e f f o r t s . The s t a b i l i z a t i o n work w i l l be quasi-permanent soi f another river s t a b i l i z a t i o n method or l o c a t i o n i s s e l e c t e d for the long-term overal l channel d e s i g n , theses t a b i l i z a t i o n a t t e m p t s may be amended or removed.

M o n i t o r i n g of 1998 and 1999 EPA demons t ra t i on p r o j e c t s w i l l be c onduc t ed accord ing to the U p p e rArkansa s River R e v e g e t a t i o n P r o j e c t M o n i t o r i n g Plan ( U O S 1999). M o n i t o r i n g e f f o r t s i n c l u d e unsaturatedzone moni t or ing , groundwater m o d e l i n g and moni t o r ing , soi l f u n c t i o n a l i t y moni t or ing , metal r e su sp en s i onm o n i t o r i n g , t e s t p l o t m o n i t o r i n g , and b i o s o l i d s s a m p l i n g . A d d i t i o n a l m o n i t o r i n g w i l l b e p e r f o r m e d a sdeemed necessary by EPA to moni tor the success of the soil a m e n d m e n t / r e v e g e t a t i o n d e m o n s t r a t i o n p r o j e c t s .

75-70225.00F : \ S T A R T \ U P P E R . A R K Y 7 0 2 2 5 \ A l t e r n a t i v e s A n a l y s i s \ F i n a l 1999\Revi s i on2 .wpd:ba s

URS Opera t ing S e r v i c e s , Inc .S T A R T , E P A Region V I I IContract No. 68-W5-0031

8.0 LIST OF R E F E R E N C E S


Date: 0 5 / 1 9 9 9Page 26 of 50

A S A R C O , I n c . 1992. W e t l a n d s M a p f o r C a l i f o r n i a G u l c h R I / F S S t u d y Area, L e a d v i l l e , C o l o r a d o . Preparedby W o o d w a r d - C l y d e C o n s u l t a n t s , Denver, C o l o r a d o .

Brown, R. e t al . 1996. E c o l o g i c a l R e s t o r a t i o n of A c i d i c M i n e S p o i l s a t H i g h E l e v a t i o n s : Long- t ermS i g n i f i c a n c e o f Rev eg e t a t i o n a n d Natural S u c c e s s i o n . I n W . R . Keammerer ( e d . ) P r o c e e d i n g s : H i g h A l t i t u d eRevege ta t i on W o r k s h o p N u m b e r 12 . February 21-23, 1996. C o l o r a d o W a t e r Resources I n s t i t u t e , C o l o r a d oS t a t e U n i v e r s i t y , F o r t C o l l i n s , C o l o r a d o .

Bureau o f Rec lamat ion (BOR). 1996. Memorandum f r o m J o h n Guiad regarding S u g a r l o a f D a m / T u r q u o i s eL a k e / M t . Elber t C o n q u e s t , A p r i l t hrough J u l y Operat ion. December 1 7 , 1996.

Camp Dresser & M c K e e . 1994. F i n a l S o i l s I n v e s t i g a t i o n Data Repor t , C a l i f o r n i a G u l c h C E R C L A S i t e ,L e a d v i l l e , C o l o r a d o . J u l y 1 5 , 1994.

C o l d e r A s s o c i a t e s . 1996. S u r f a c e W a t e r Remedial I n v e s t i g a t i o n Repor t , C a l i f o r n i a G u l c h S i t e , L e a d v i l l e ,C o l o r a d o . Prepared f o r A S A R C O , I n c . M a y 1996.

I n t e r - F l u v e , I n c . 1998. F l u v i a l G e o m o r p h o l o g i c A s s e s s m e n t o f U p p e r A r k a n s a s River. N o v e m b e r 2 3 , 1998.

Levy, D. B., et al. 1989. H e a v y Metal Contaminat ion in S o i l s and Plant S p e c i e s of the Arkansas V a l l e y nearL e a d v i l l e , C o l o r a d o . T e c h n i c a l Report T R 8 9 - 7 , F o r t C o l l i n s , C o l o r a d o .

Oyler, J. 1990. R e m e d i a t i o n o f m e t a l s - c o n t a m i n a t e d s i t e near a s m e l t e r u s i n g s l u d g e / f l y a sh amendments .I n P r o c e e d i n g s o f t h e 44th Purdue I n d u s t r i a l W a s t e C o n f e r e n c e . L e w i s P u b l i s h e r s , C h e l s e a , M I .

R o l i n e , R. A .and J. R. Boehmke. 1981 . H e a v y M e t a l s P o l l u t i o n o f the U p p e r Arkansa s River, C o l o r a d o ,and Its E f f e c t s on th e D i s t r i b u t i o n o f th e A q u a t i c M a c r o f a u n a . REC-ERC-81-15 . , Denver, C o l o r a d o .

75-70225.00F : \ S T A R T \ U P P E R . A R K Y 7 0 2 2 5 \ A l t e m a t i v e s A n a l y s i s \ F m a l l 9 9 9 \ R e v i s i o n 2 . w p d : b a s

U R S Opera t ing Servi c e s , I n c . U p p e r Arkansa s River F l u v i a l T a i l i n g s - A l t e r n a t i v e s A n a l y s i sS T A R T , E P A Region V I I I Revi s i on: 2Contract N o . 68-W5-0031 Date: O S / 1 9 9 9

Page 27 of 50

S h e p h e r d M i l l e r / T e r r a M a t r i x / M o n t g o m e r y W a t s o n . 1998. Final W o r k Plan f o r a W a t e r and A q u a t i cB i o l o g i c a l M o n i t o r i n g Program f o r U p p e r Arkansa s R i v e r / C a l i f o r n i a G u l c h . F o r Resurrection M i n i n gCompany. J a n u a r y 30, 1998:

S o i l Con s e rva t i on S e r v i c e ( S C S ) . 1975. S o i l Survey o f C h a f f e e - L a k e Area, C o l o r a d o ; Denver, C o l o r a d o .

S o p p e r , W. 1988. R e f o r e s t a t i o n of a zinc sme l t e r s u p e r f u n d s i t e . P r o c e e d i n g s of a c o n f e r e n c e spon sor edby the American S o c i e t y for S u r f a c e M i n i n g and Reclamat ion, the Bureau of M i n e s and the o f f i c e o f S u r f a c eM i n i n g Rec lamat i on and E n f o r c e m e n t , P i t t s b u r g h , PA. A p r i l 19-21, 1988.

U . S . Department o f A g r i c u l t u r e , A g r i c u l t u r a l Research S e r v i c e ( U S D A ) . 1998a. E x p e r i m e n t a l Design f o rDemons t ra t i on S i t e s in L e a d v i l l e , C o l o r a d o , by Sal ly Brown. May 1998.

U.S. Department o f A g r i c u l t u r e , Natura l Resources Cons e rva t i on S e r v i c e (USDA). 1998b. U p p e r ArkansasRiver V e g e t a t i o n A s s e s s m e n t . A l a m o s a , C o l o r a d o .

U.S. Environmental P r o t e c t i o n A g e n c y (EPA). 1987. Phase I Remedia l I n v e s t i g a t i o n Repor t , C a l i f o r n i aG u l c h , L e a d v i l l e , C o l o r a d o ,

U . S . G e o l o g i c a l S u r v e y ( U S G S ) . 1975. 1:50,000 T o p o g r a p h i c M a p , Lake C o u n t y , C o l o r a d o .

U . S . G e o l o g i c a l S u r v e y ( U S G S ) . 1996. Personal communication wi th K a t h e r i n e W a l t o n D a y .

U R S O p e r a t i n g S e r v i c e s , I n c . ( U O S ) . 1997a. A l t e r n a t i v e s A n a l y s i s , U p p e r A r k a n s a s River F l u v i a l T a i l i n g s .J u n e 27, 1997.

U R S O p e r a t i n g S e r v i c e s , I n c . ( U O S ) . 1997b. S a m p l i n g A c t i v i t i e s R e p o r t , U p p e r A r k a n s a s River F l u v i a lT a i l i n g s . F e b r u a r y 10, 1997.

U R S O p e r a t i n g S e r v i c e s , I n c . ( U O S ) . 1998a. S a m p l i n g A c t i v i t i e s Repor t , F a l l 1997 S a m p l i n g , U p p e rArkansa s River F l u v i a l T a i l i n g s . J a n u a r y 1 6 , 1998.


U R S O p e r a t i n g Serv i c e s , Inc. U p p e r Arkansas River F l u v i a l T a i l i n g s - A l t e r n a t i v e s A n a l y s i sSTART, EPA Region VIII Revision: 2Contrac t No. 68-W5-0031 Date: 0 5 / 1 9 9 9

Page 28 of 50

URS Opera t ing Service s , I n c . (UOS). 1998b. H y d r o l o g i c and H y d r a u l i c A s s e s s m e n t , U p p e r Arkansas River.November 19, 1998.

U R S O p e r a t i n g Serv i c e s , I n c . ( U O S ) . 1998c. U p p e r A r k a n s a s F l u v i a l T a i l i n g s B i o s o l i d s Revege ta t i onP r o j e c t Work Plan. July 8, 1998.

W e s t o n . 1996. D r a f t E c o l o g i c a l Risk Ass e s smen t f o r t h e T e r r e s t r i a l Eco sy s t em, C a l i f o r n i a G u l c h , L e a d v i l l e ,C o l o r a d o

W o o d w a r d - C l y d e C o n s u l t a n t s . 1993. S u r f a c e W a t e r Remedial I n v e s t i g a t i o n Repor t , C a l i f o r n i a G u l c h S i t e ,L e a d v i l l e , C o l o r a d o . D r a f t report. J u n e 1993.

W o o d w a r d - C l y d e C o n s u l t a n t s . 1996. A q u a t i c Eco sy s t em C h a r a c t e r i z a t i o n Repor t . C a l i f o r n i a G u l c h s i t e ,L e a d v i l l e , Colorado . J a n u a r y 1996.

75-70225.00F : \ S T A R T \ U P P E R . A R K Y 7 0 2 2 5 \ A l t e m a t i v e s A n a I y s i s \ F i n a l ] 9 9 9 \ R e v i s i o n 2 . w p d : b a s

U R S O p o n i l i n g S e r v i c e s , I n c .S T A R T . l l l ' A Region V I I IC o n t r a c t N o . 6 8 - W 5 - 0 0 3 1

U p p e r A r k a n s a s River F l u v i a l T a i l i n g s - A l t e r n a t i v e s A n a l y s i sR e v i s i o n : 2

Dale: 0 5 / 1 9 9 9Page 29 of 50

T A B L E 1F l u v i a l T a i l i n g s D e p o s i t C h a r a c t e r i z a t i o n

Deposit

AAABAC

A D , A EAGA H

A I , A JBBCAccCDCECFCGCJ

CKCL*

T a i l i n g sV o l u m e

(cubic f e e t )3,50019,00019,00034,00013,0002,5005,3005,300

52,0003,60019,00024,0003,4003,600

20,00012,00027,000

Area(acres)

0.040.200.270.700.170.070.120.250.670.060.32.0550.160.170.410.280.44

M a x i m u mDepth

( f e e t )3.54.03.02.53.01.32.00.92.51.52.01.00.50.54.03.04.0

AverageT a i l i n g s Dep th

( f e e t )3.53.03.01.61.80.80.90.51.81.5l . i1.00.50.51.01 . 11.4

Access

M o d e r a t eM o d e r a t e

EasyM o d e r a t eM o d e r a t e

D i f f i c u l tM o d e r a t e l y D i f f i c u l t

V e r y D i f f i c u l tM o d e r a t e

D i f f i c u l tM o d e r a t e

D i f f i c u l tD i f f i c u l tD i f f i c u l t

M o d e r a t e l y EasyM o d e r a t e l y EasyM o d e r a t e l y Easy

Maximum M e t a lC o n c e n t r a t i o n s '

H i g hH i g hH i g hH i g hH i g h

M o d e r a t eM o d e r a t e l y H i g h

H i g hM o d e r a t e l y H i g h

H i g hH i g hH i g hH i g hLowH i g hLowH i g h

Erosion P o t e n t i a l 2

H i g hH i g hH i g h

M o d e r a t eH i g hH i g hH i g hH i g hH i g hLowH i g hH i g h

M o d e r a t eLowH i g hH i g hH i g h

75-70225.00F : \ S T A R ' n U I > P E R . A R K \ 7 0 2 2 5 \ A l t e r n a t i v e s A n a l y s i s \ F i n a l I 9 9 9 \ R e v i s i o n 2 . w p < l : h a s

U R S O p e r a t i n g S e r v i c e s , I n c .S T A R T , E P A Region V I I IC o n t r a c t N o . 68-W5-0031

U p p e r A r k a n s a s River F l u v i a l T a i l i n g s - A l t e r n a t i v e s A n a l y s i sRevision: 2

Date: 0 5 / 1 9 9 9Page 30 of 50

T A B L E 1F l u v i a l T a i l i n g s D e p o s i t C h a r a c t e r i z a t i o n( c o n t i n u e d )

Depos i t

C N *CO*

CPCRCS

F A *FB*

FCF EF F

F HF J

F L , F MF NG A


(cubic f e e t )38,00090,0006,800

44,00035,00049,00022,000

12,000700

4,2005

8,6009,9002,5006,900

Area(acre s)

0.511.680.11.240.781 . 1 51.01

0.280.010.150.010.280.420.080.34

M a x i m u mD e p t h

( f e e t )3.03.02.03.03.02.51.5

1.02.51.51.51.51.00.80.8

AverageT a i l i n g s D e p t h

( f e e t )0.51.51.40.91.01.00.8

0.51.30.60.20.70.60.70.5

Acce s s

F a s yF a s y

M o d e r a t e l y D i f f i c u l tM o d e r a t e

M o d e r a t e l y EasyM o d e r a t e l y Easy

M o d e r a t e


M o d e r a t e l y EasyD i f f i c u l t

M o d e r a t e l y D i f f i c u l tM o d e r a t eM o d e r a t e

M o d e r a t e l y D i f f i c u l t

M a x i m u m M e t a lC o n c e n t r a t i o n s '

H i g hH i g h

M o d e r a t eH i g hH i g hH i g hH i g h

U n k n o w nH i g h

M o d e r a t e l y H i g hU n k n o w n

H i g hH i g hLow

M o d e r a t e l y H i g h


LowH i g hH i g hH i g h


M o d e r a t e t o h i g hd e p e n d i n g on c o b b l e

w a l l in D e p o s i t CSH i g hH i g h

M o d e r a t eLowH i g hH i g hH i g hH i g h

75-70225.00F : \ S T A R T \ U P P E R . A R K \ 7 0 2 2 5 \ A l l e m a l i v e s A n a l y s i s \ R n a l l 9 9 9 \ R e v i s i o n 2 . w p d : b a s

U R S O p i - r u l i n g S e r v i c e s , I n c .S T A R T , i;i>A Region V I I IC o n t r a c t N o . 6 8 - W 5 - 0 0 3 1

U p p e r A r k a n s a s River F l u v i a l T a i l i n g s - A l t e r n a t i v e s A n a l y s i sRevision: 2

Date : 0 5 / I 9 9 9Page 31 of 50

T A B L E 1F l u v i a l T a i l i n g s Depos i t Charac t er iza t ion( c o n t i n u e d )

D e p o s i t

GEGCG H

G IG K

G L , H AGM

G N , H BH D

H E , H I , H KI A1C

K KK LLALBLC


(cubic f e e t )3,700780560

6,600330

5,000200500710

33,3002,90017,00013,00038,000

1,8001 1 ,00016,000

Area(acres)

0.090.020.020.250.010.270.0 10.050.031.120.100.460.920.570.170.210.46

M a x i m u mD e p t h( f e e t )

1.52.00.90.90.91.51.40.30.71.52.01.50.32.0

0.802.402.50

A v e r a g eT a i l i n g s D e p t h

( f e e t )1.01.00.60.60.80.50.50.30.50.60.70.90.31.5

0.251.300.80

Access

M o d e r a t eM o d e r a t e l y D i f f i c u l t


D i f f i c u l tD i f f i c u l t

M o d e r a t e l y D i f f i c u l tD i f f i c u l t

M o d e r a t e l y D i f f i c u l tD i f f i c u l tD i f f i c u l tD i f f i c u l t

V e r y D i f f i c u l tV e r y D i f f i c u l t

D i f f i c u l tD i f f i c u l tD i f f i c u l t


M o d e r a t eU n k n o w n

LowLow

U n k n o w nH i g hH i g hLow

M o d e r a t eH i g h

M o d e r a t e l y H i g hLow


M o d e r a t e l y H i g hM o d e r a t e l y H i g h

H i g h


H i g hM o d e r a t eM o d e r a t eM o d e r a t e

H i g hLowH i g hH i g hH i g h

Modera t e to h i g hH i g hH i g hH i g hH i g hLow

M o d e r a t eLow

75-70225.00F : V S T A K T \ U l > l ) E R . A R K \ 7 0 2 2 5 \ A l ( e r n a t i v e s A n a l y s i s \ F m a l l 9 9 9 \ R e v i s i o n 2 . w p d : b a s

U R S O p e r a t i n g S e r v i c e s , I n c .S T A R T , E P A Region V I I IContrac t No. 68-W5-0031


Date: 0 5 / 1 9 9 9Page 32 of 50

T A B L E 1F l u v i a l T a i l i n g s Depo s i t C h a r a c t e r i z a t i o n

( c o n t i n u e d )

Depo s i t

LDLGLH

LILKLL

LMLNLOLPLQLRLSLTLULV

M A


(cubic f e e t )10,600

1006,7001 1 ,0007,3006,50015,6007,30019,60011,0009,0001,500

25,2002,200360

13,000960

Area(acres)

0.490.030.390.210.340.210.300.210.380.310.130.030.580.060.010.210.02

MaximumD e p t h( f e e t )0.800.801.002.601.100.902.002.003.501.202.202.003.001.900.802.50

1.5

AverageT a i l i n g s Dep th

( f e e t )0.500.400.401.200.500.701.200.801.200.801.601.301.000.800.701.401.3

Access

D i f f i c u l tD i f f i c u l tD i f f i c u l tD i f f i c u l tD i f f i c u l tD i f f i c u l tD i f f i c u l tD i f f i c u l tD i f f i c u l tD i f f i c u l tD i f f i c u l tD i f f i c u l tD i f f i c u l tD i f f i c u l t

M o d e r a t eD i f f i c u l t

M o d e r a t e l y D i f f i c u l t

Maximum M e t a lC o n c e n t r a t i o n s 'M o d e r a t e l y H i g hM o d e r a t e l y H i g hM o d e r a t e l y H i g h

H i g hH i g hH i g hH i g hH i g hH i g hH i g hH i g hH i g hH i g h

M o d e r a t eLowH i g h

M o d e r a t e


LowM o d e r a t eM o d e r a t e

M o d e r a t e l y H i g hM o d e r a t e

LowH i g h

M o d e r a t eM o d e r a t eM o d e r a t e

M o d e r a t e l y H i g hM o d e r a t e l y L o wM o d e r a t e l y L o wM o d e r a t e l y L o w

LowM o d e r a t e l y H i g h

H i g h75-70225.00F : \ S T A i m U P P E R . A R K \ 7 0 2 2 5 \ A l t e r n a t i v c s A n a l y s i s X F i n a l 1 9 9 y \ R e v i s i o n 2 . w p d : b a s

U R S O p e r a t i n g S e r v i c e s , I n c .S T A R T , l i l ' A Region V I I IC o n t r a c t N o . 68-W5-0031


Date: 0 5 / 1 9 9 9Page 33 of 50

T A B L E 1F l u v i a l T a i l i n g s Depos i t Charac t er i za t i on


D e p o s i t

M B *ME*

MFMGM H

M IM J

M KML

M M . M N

MP*MQ*

N AN B , N J

N C


(cubic f e e t )26,00033,0003,1002,1001,900

20,0002,5003,6001,300630

7,90068,1006,50012,30017,700

Area(acres)

0.531.060.060.080.060.250.230.160.040.09

0.110.780.070.400.29


1.52.02.00.81.03.00.31.31.51.5

2.502.803.002.0

2.10


( f e e t )1 . 10.71.30.60.81.80.80.50.70.2

1.702.002.200.61.40

Access


D i f f i c u l tM o d e r a t e

M o d e r a t e l y D i f f i c u l tM o d e r a t eM o d e r a t eM o d e r a t e



M o d e r a t e l y D i f f i c u l tM o d e r a t e l y D i f f i c u l tM o d e r a t e l y D i f f i c u l t

Maximum MetalC o n c e n t r a t i o n s '



LowM o d e r a t e l y H i g h

H i g hLow

MM - M o d e r a t eM N - M o d e r a t e l y

H i g hM o d e r a t e

H i g hM o d e r a t e l y H i g h



H i g hLowH i g hLowLowLowLowLowH i g h

M o d e r a t e

H i g hH i g h

M o d e r a t e l y H i g hH i g h

M o d e r a t e

75-70225.00F : \ S T A R T \ U P P E R . A R K \ 7 0 2 2 5 \ A l l e m a t i v e s A n a I y s i s \ F m a M 9 9 9 \ R e v i s i o n 2 . w p ( l : b a s

U R S O p e r a t i n g S e r v i c e s , I n c .S T A R T , E P A Region V I I IC o n t r a c t N o . 6 8 - W 5 - 0 0 3 1


Date: 0 5 / 1 9 9 9Page 34 of 50

T A B L E 1F l u v i a l T a i l i n g s D e p o s i t C h a r a c t e r i z a t i o n


Depos i t

N DN GN H

N IN J

N LN NNON PN RN TN UOAOBOCODOE


(cubic f e e t )38,40047,00035,00054,000

1,30010,0006,4008,0004,400

40,9005,90012,60049,00042,0005,2004,50030,800

Area(acre s)

0.490.730.851.220.060.160.390.140.250.590.340.320.940.940.390.130.71

MaximumD e p t h

( f e e t )3.003.03.53.00.74.00.53.00.9

3.000.901.802.003.0

0.901.503.20

A v e r a g eT a i l i n g s D e p t h

( f e e t )1.801.50.91.00.51.40.41.30.41.600.400.901.201.0

0.300.801.00

Access

M o d e r a t e l y D i f f i c u l tM o d e r a t eM o d e r a t eM o d e r a t eM o d e r a t eM o d e r a t e

M o d e r a t e l y D i f f i c u l tM o d e r a t e l y D i f f i c u l tM o d e r a t e l y D i f f i c u l tM o d e r a t e l y D i f f i c u l tM o d e r a t e l y D i f f i c u l tM o d e r a t e l y D i f f i c u l tM o d e r a t e l y D i f f i c u l tM o d e r a t e l y D i f f i c u l tM o d e r a t e l y D i f f i c u l tM o d e r a t e l y D i f f i c u l t

M o d e r a t e


LowM o d e r a t e

M o d e r a t e l y H i g hH i g hLowLow

M o d e r a t e l y H i g hM o d e r a t eM o d e r a t e

H i g hM o d e r a t eM o d e r a t e



H i g h


M o d e r a t e l y H i g hH i g hH i g hH i g hH i g h

M o d e r a t eH i g hH i g hH i g h

M o d e r a t e l y LowH i g hH i g h


M o d e r a t e l y H i g hM o d e r a t e l y L o w

M o d e r a t e75-70225.00F : \ S T A R T \ U P P E R . A R K \ 7 0 2 2 5 \ A l t e r n a t i v e s A n a l y s i s \ F i n a l l 9 9 9 \ R e v i s i o n 2 . w p d : b a s

U R S O p e r a t i n g S e r v i c e s , I n c .S T A R T , 1 : P A R e g i o n V I I IC o n t r a c t N o . 6 8 - W 5 - 0 0 3 I

U p p e r A r k a n s a s River F l u v i a l T a i l i n g s - A l t e r n a t i v e s A n a l y s i sRevi s i on: 2

Date: 0 5 / 1 9 9 9Page 35 of 50

T A B L E 1F l u v i a l T a i l i n g s Depo s i t C h a r a c t e r i z a t i o n( c o n t i n u e d )

D e p o s i t

OFOGOH

OIOJ

OKPAPCPDPEPFPG

P J . P XPMPNPP

QA


(cubic f e e t )6,00018,5003,400

—2,4001,700

16,0003,50014,0006,700

14061,90033,0001,8002,30015,0003,700

Area(acre s)

0.230.270.07—

0.060.100.340.110.200.130.031.420.830.060.060.370.16


2.02.001.10—

1.500.803.02.03.0

2.500.802.502.00.53.02.01.5


( f e e t )0.61.601.10—

0.900.40

1.20.71.7

1.200.101.000.90.71.31.00.5

Acce s s




M o d e r a t e l y D i f f i c u l tM o d e r a t e l y D i f f i c u l tM o d e r a t e l y D i f f i c u l tM o d e r a t e l y D i f f i c u l tM o d e r a t e l y D i f f i c u l t

M o d e r a t eM o d e r a t e l y D i f f i c u l tM o d e r a t e l y D i f f i c u l t

D i f f i c u l tM o d e r a t e l y D i f f i c u l tM o d e r a t e l y D i f f i c u l t


LowLow

M o d e r a t e l y H i g hH i g hH i g h



H i g hLow

M o d e r a t e l y H i g hH i g hLowH i g h

M o d e r a t e l y H i g hM o d e r a t e


H i g hM o d e r a t e l y L o w

H i g hLowLow

M o d e r a t e l y L o wH i g hLowH i g h


M o d e r a t eLowLowLow


75-70225.00F : \ S T A R T \ U P P E R . A R K \ 7 0 2 2 5 \ A l t e r n a l i v e s A n a l y s i s \ F i n a l l 9 9 9 \ R e v i s i o n 2 . w p d : b a s


U p p e r A r k a n s a s River F l u v i a l T a i l i n g s - A l t e r n a t i v e s A n a l y s i sRevi s i on: 2

Date: 0 5 / 1 9 9 9Page 36 of 50

T A B L E 1F l u v i a l T a i l i n g s D e p o s i t C h a r a c t e r i z a t i o n( c o n t i n u e d )

Depo s i t

QDQFQGQH

QIQJ

QKQMQNQOQPQQQRQTQVQWQX


(cubic f e e t )5,40082,00021,0009,5007,1001,9005,8008,100

43,0009,700850170

5,9005,2002,60011,8004,800

Area(acres)

0.172.530.510.440.280.050.130.11.090.0510.050.010.140 . 1 10.030.120.08

MaximumD e p t h( f e e t )

2.02.01.51.92.01.32.03.02.00.91.51.02.01.5

2.503.002.30


( f e e t )0.50.61.00.50.61.01 . 11.81.00.50.40.91.01.2

2.002.301.40

Access

M o d e r a t e l y D i f f i c u l tM o d e r a t e l y D i f f i c u l tM o d e r a t e l y D i f f i c u l tM o d e r a t e l y D i f f i c u l tM o d e r a t e l y D i f f i c u l tM o d e r a t e l y D i f f i c u l tM o d e r a t e l y D i f f i c u l tM o d e r a t e l y D i f f i c u l tM o d e r a t e l y D i f f i c u l t

M o d e r a t eM o d e r a t eModera t eM o d e r a t eM o d e r a t eD i f f i c u l tD i f f i c u l tD i f f i c u l t

M a x i m u m M e t a lC o n c e n t r a t i o n s 'M o d e r a t e l y H i g h


M o d e r a t e l y H i g hM o d e r a t eM o d e r a t eM o d e r a t e

LowH i g h







LowH i g hH i g hLowLowH i g h


ModerateLowH i g hLowLowH i g h

75-70225.00F : \ S T A R T \ U P P E R . A R K \ 7 0 2 2 5 \ A I t e r n a t i v c s A n a l y s i s V F i n a l 1 9 9 9 \ R e v i s i o n 2 . w p d : b a s


U p p e r A r k a n s a s River F l u v i a l T a i l i n g s - A l t e r n a t i v e s A n a l y s i sRevis ion: 2

Date: 0 5 / 1 9 9 9Page 37 of 50

T A B L E 1F l u v i a l T a i l i n g s Depo s i t C h a r a c t e r i z a t i o n( c o n t i n u e d )

Depos i t

QYQZ

RA*RB*

RCRF


(cubic f e e t )1,800500

31 ,10015,6001,8001,100

Area(acres)

0.080.041.020.600.080.01

MaximumD e p t h( f e e t )0.800.401.201.300.803.00


( f e e t )0.500.300.700.600.503.00

Acces s

D i f f i c u l tD i f f i c u l t

EasyEasyEasy

D i f f i c u l t

Maximum Meta lC o n c e n t r a t i o n s '


Modera t eM o d e r a t e

H i g h


M o d e r a t e l y LowM o d e r a t e l y L o w



2-

D e m o n s t r a t i o n p r o j e c t l o c a t i o n .C a d m i u m C o n c e n t r a t i o n -C o p p e r C o n c e n t r a t i o n -Lead C o n c e n t r a t i o n -M a n g a n e s e C o n c e n t r a t i o n -Z i n c C o n c e n t r a t i o n -Erosion P o t e n t i a l -

H i g h (>4()0 m g / k g )H i g h (>540 m g / k g ) . M o d e r a t e l y H i g h (400 - 5 4 0 m g / k g )H i g h (>6,700 m g / k g ) , M o d e r a t e l y H i g h (3,500 - 6,700 m g / k g ) , M o d e r a t e (2,000 m g / k g )H i g h (>4,000 m g / k g ) , M o d e r a t e l y H i g h (2,000 - 4,000 m g / k g )H i g h (>20,000 m g / k g ) , M o d e r a t e l y H i g h (5,000 - 20,000 m g / k g ) , M o d e r a t e (1,000 - 5,000 m g / k g )High ( c u r r e n t l y e r o d i n g bank s) . M o d e r a t e (se t back f r o m river but near d i s t r i b u t a r i e s or o therwi s e v u l n e r a b l e ) , low (se t back f r o m river, no s i g n o f short- ormodera t e term v u l n e r a b i l i t y t o e r o s i o n )

75-70225.00F : \ S T A R T \ U P P E R . A R K \ 7 0 2 2 5 \ A l t e r n a l i v e s A n a I y s i s \ F i n a l l 9 9 9 \ R e v i s i o n 2 . w p d : b a s

U R S O p e r a t i n g S e r v i c e s , I n c .S T A R T , E P A Region V I I IContrac t N o . 68-W5-0031

U p p e r A r k a n s a s River F l u v i a l T a i l i n g s - A l t e r n a t i v e s A n a l y s i sRevi s ion: 2

Date: 0571999Page 3 8 of 50

T A B L E 2E v a l u a t i o n o f A l t e r n a t i v e s

A l t e r n a t i v e

N o a c t i onW a t e r Management P r a c t i c e s

A g r i c u l t u r a l BestManagement P r a c t i c e sV e g e t a t i o nR e t a i n i n g W a l l s

C o v e r / C a pS o i l A m e n d m e n tRemoval -O f f - S i t e D i s p o s a lRemoval -O n - S i t e D i s p o s a lRiver C h a n n e l A d j u s t m e n t

E f f e c t i v e n e s s 1

ReduceErosion

01

0

++++

+0

++

++

+

ReduceExposure

00

0

00

++

++

++

0

Long-Term

00

0

+0

0.+++

+

0

S h o r t -Term

00

0

++

++

++

+

+

I m p l e m e n t a b i l i t y

EasyM o d e r a t e l yD i f f i c u l tM o d e r a t e l y Easy



D i f f i c u l t

V a r i a b l e

Cost

N o n eU n k n o w n

M o d e r a t e

M o d e r a t eM o d e r a t e l yH i g hM o d e r a t eM o d e r a t eH i g h

H i g h

V a r i a b l e

A c c e p t a b i l i t y

LowLandowner s - H i g hW a t e r R i g h t s H o l d e r s - LowM o d e r a t e


M o d e r a t e l y L o wH i g hH i g h

M o d e r a t e

H i g h+ • Highly e f f e c t i v e 0 - Lit t l e or no e f f e c t i v e n e s s

75-70225.00F : \ S T A R T \ U P P E R . A R K Y 7 0 2 2 5 \ A l t e r n a t i v c s A n a l y s i s \ F i n a I I 9 9 9 \ R c v i s i o n 2 . w p d : b a s

U R S O p e r a t i n g S e r v i c e s , I n e .S T A R T , E P A Region V I I IC o n t r a c t N o . 6 8 - W 5 - 0 0 3 1

U p p e r A r k a n s a s R i v e r F l u v i a l T a i l i n g s - A l t e r n a t i v e s A n a l y s i sR e v i s i o n : 2

Date: 0 5 / 1 9 9 9Page 39 of 50

T A B L E 3Proposed 1999 Response A c t i o n S i t e s

L o c a t i o nN a m e

A A / A B / A C *A D / A E

AGCA*

C C / C F / C GC D * / C J * / C K *

CE*C P / C R / C S

M HastN E a s t

Sum

Area(acre s)

0.503.100.200.700.802.000.602.301.605.0016 80

M a x i m u m D e p t h( f t )4.02.53.01.81.51.31.01.41.30.7

V o l u m e 1

( Y d 3 )1600

1300+5001926133704889252138407

7849

M e t a l C o n c e n t r a t i o n s ( m g / k g )C a d m i u m

5601,100

—

_

_

930—

420„_

C o p p e r1.500790

1,300

1,1001,300540

1,100610380

Lead8,80015,0007,80014,0008,500

. 16,0007,1005,500

1 1 ,00014,000

M a n g a n e s e1 1 ,00020,0006,5004,2002,200

2 1 ,0002,8009,0006,7005,000

Z i n c57,000115,00040,0008,500

36,0009 1 ,0008,600

34,00033,00019,000

M a x i m u m A c i dBase P o t e n t i a l

______

-86_--_

- 1 3 1—

BankS t a b i l i z a t i o n ?

Y e sY e s

P o s s i b l eY e sN o

Y e sY e sN oN oY e s

V o l u m e c a l c u l a t i o n s i n c l u d e d th e m i n i m u m amount o f mat er ia l d e t e rmined t o b e t a i l i n g s . A removal a c t i on w o u l d require removal o f a d d i t i o n a l c o n t a m i n a t e d mat er ia l over and under th e t a i l i n g s .

75-70225.00F : \ S T A R T \ U P P E R . A R K \ 7 0 2 2 5 \ A l t e r n a t i v e s A n a l y s i . s \ F i n a l l 9 9 9 \ R e v i s i o n 2 . w p d : b a s

g : / d r o w i n g s / U p p e r A r k o n s o s / S i t e l o c . d w g J M M T 1 E M 1 1 / 3 0 / 9 8

URS Operating Services, Inc.S T A R T , E P A Region V I I I _ 3 0C o n t r a c t No. 68-W5-0031

rvrkansas K i v e r F l u v i a l l a i l i n g s - A i l e r n a l i v e s A n a l y s i sRevi s ion: 2

Dale: 0 5 / 1 9 9 9Page 40 of 5

M t ' M a s s i v e ' C a k .

~' T a i l i n g s ' - . * * . .. W -/\- • - • • • • • ^ r - \i < - : - - * : "

4.;.... :..-7 j -' y-^Twin f r / A rT X ' : " ' - r Lakes

C O L O R A D O•^ M o p L o c o t i o n

75-70225.00F : \ S T A R T \ U P P E R . A R K \ 7 0 2 2 5 \ A l l e r n a t i v e s A n a l y s i s \ F m a I I 9 9 9 \ R e v i s i o n 2 . w p d : b a s

&+.

S&S T A R T R E G I O N 8J o b f l 75-70225.00

U p p e r A r k a n s a s River F l u v i a l T a i l i n g sS I T E L O C A T I O N M A P

F i g u r e 1J A N U A R Y 1999 URSOPERAIWG SVCS.

F : \ S T . A R T \ T i t l e B l k . 1 2 \ 2 3 \ S 8 J M M T t E M i3 O p e r a t i n g S i

a &*;«>^ vf.-:

75-70225.00™ T A R T M J P P E R . A R K \ 7 0 2 2 5 U I « e m a , i v e S A n a ] y s i s \ F i n a l l 9 9 9 \ R e v i s i o n 2 . w p d : b a S

Alternatives AnalysisUOS Job No. 75-70225.00

Arkansas River Fluvial Tailingsr««j . . .-77_ /-r i , yTailings Deposit LocationsFigure 2

F : \ S T A R T \ T H I e a i k . 12\23\9S J M M T i E M IU R S O p e r a t i n g S e r v i c e s . I n cS T A R T . E P A R e g i o n V I ! IC o n t r a c i N o . 6 8 - W 5 - 0 0 3 1

""" %^?->spS^"; ii:t i i S S i t l l P

•^< v^^^^^'^s^-^i

75-70225.00F : \ S T A R T \ U P P E R . A R K \ 7 0 2 2 5 \ A l . e m a t i v e s A n a I y s i s \ H n a l I 9 9 9 \ R e v i s i o n 2 . w p d : b a s


Arkansas River Fluvial TailingsLeadville, ColoradoTailings Deposit Locations

_______Figure 3Hay 1999

S E R M C E S

: \ S T A R T \ T i t l e B i k . 12\23\98 J M M T I E M lU K b O p e r a t i n g S e r v i c e s ,S T A R T , E P A R e g i o n V I I IC o n t r a c t N o . 6 8 - W 5 - 0 0 3 1

g S H M i ^ f f R J «r-i, ,-1 ^:,fl'/^K^iSS^^KoiSf^;^ t j-reSS w a a j s / ^ f - i " ' " - - I f ^

# f e ^ j ^ , ^ J s ^ ' ~ * f e w s ^ > - » : * K 4 f t . v i a i f c a ! % ; . - ) ' -

4wemarives AnalysisUOS Job No, 75-70225.00

/ J i v e r Fluvial TailingsLeadville, ColoradoTailings Deposit LocationsFigure 4

7:5-70225.00F : \ S T A K T . U P P E R . A R K \ 7 0 2 2 5 U l t c r n a t i v e s A n a l v s i s \ F i n a ! 1 9 9 9 \ R e v i s i o n 2 . w p d : b a s

F : \ S T A R T \ T i l l e B i k . 12\23\98 J M M T t E M l

- - - . . . ,

~.- 1

7?-70225.00F : \ S T A R T . U P P E R . A R K \ 7 0 2 2 5 V A l t e m a i i v e s A n a l y s i s \ F i n a l l 9 9 9 \ R e v i s i o n 2 . w p d : b a s


Arkansas River Fluvial TailingsLeadville, ColoradoTailings Deposit Locations________Figure 5May 1999

O P E R A T I N G S E R V I C E S

F : \ S T A R T \ T i t l e 3 ! k . 12\23\98 J M W T t E M Iu R S O p e r a t i n g S e r v i c e s ,S T A R T , E R A R e g i o n V l l iC o n t r a c t N o . 6 S - W 5 - 0 0 3 I

. • • a ^ a f t J S i f i t i j * »J^f -jrfte"*BE*&<^3Welb>*f s?1¥%;fcsi?W._<t t o s S S I S S w W * * !

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• W ^ ^ ' - ' ^ l ^^ . v ^ ^ ' ' - ^ ; - € S3^^^§-Sf ^ *~*$ii',. •: *?^j?£*"-** ^ f e f l

f W a f e i S ^ S , * ' / * •.F ; U H f ^ - ^ y i \ ^ ' - i i - ' V -,;.V \ «v1:|fej, % - | ,yS%AiSPi;%SSS S r - J - t " ^k-fSZcfj^sklSss

75-70225.00F : \ S T A R T \ U P P E R . A R K \ 7 0 2 2 5 V A l t e r n a l i v e s A n a l y s i s V F i n a i l 9 9 9 \ R e v i s i o n 2 . w p d : b a s


Arkansas River Fluvial TailingsLeadville, ColoradoTailings Deposit Locations________Figure 6___________

O P E R A T I N G S E f W C E S

F : \ S T A R T \ H t l e B l k . 12\23\96L ' R S O p e r a t i n g S e r v i c e s . I nS T A R T . E P A R e g i o n V I I IC o n t r a c t N o . 6 8 - V V 5 - 0 0 3 1

im^rn^

•^J^Sfc^l-^-.- - ,,7->4 J^^^-%,-- ^ V-".- ' /I '•?- • t . t j f fjf

^ T ' - i ' a 5 . " ' 1 - " - - ' . ; " > - • " ' ^ ^ 1 - ' - • i: W ' " t;ig^y^.Sr a-»-. ,' • • • v.-ir*: -jff^.---.. -t

i s a s a £ ^ 5 ^ , - . ? & > ' * ' - . v s n & f - * -

75-70225.00F : \ S T A R T i U P P E R . A R K \ 7 0 2 2 5 \ A I t e m a t i v e s A n a l y s i s \ F i n a n 9 9 9 \ R e v i s i o n 2 . w p d : b a s


Arkansas River Fluvial TailingsLeadville, ColoradoTailings Deposit Locations________Figure 7May 1999

O P E R A T I N G S E R V O S

F : \ S T A R T \ T i t l e B ; k . 12\23\98U R S O p e r a t i n g S e r v i c e s , i n cS T A R T . E P A R e g i o n VC o n t r a c t N o . 6 8 - W 5 - 0 0 3 !

' : • • ! ; - ' . • : * : i . S r i - i s ' . > . " £ - it5?*-*

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75-70225.00F : \ S T A R T \ U P P E R . A R K \ 7 0 2 2 5 U l t e r n a t i v e s A n a i y s i s \ F i n a l l 9 9 9 \ R e v i s i o n 2 . w p d : b a s

Alternatives ATialysisUOS Job No. 75-70225.00

Arkansas River Fluvial TailingsLeadvitte, ColoradoTailings Deposit Locations____ Figure 8May 1939

OPEMrwG S E R V I C E S

•r Ark i i v c rK e v i s i o n : 'L'

D a l e : 0 5 / 1 9 4 9P;ic;L-4S of 50

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f^ - = i= r ;>> ;- -- ~. =<,, . T?-± '--- •*' •--=r" '_-'Twi--t-_-H--3*-^5*.^ f t t » - » - ^<- - r^-rt^g^^-sajyiMv^AL.-^- •• - *•}&,.*•*^ ^ ^ p W i s j S M s i — — — — D e p o s i t s A A , A B , A C , A D , A E , A GP r o p o s e d 1999 S o i i A m e n d m e n t - R e v e g e t a t i o r t P r o j e c t s Kt^Cf:;^^ .j^liiipiSc";

G r o u n d w a t e r M o n i t o r i n g ( A C )


Arkansas River Fluvial TailingsLeadville, Colorado1999 Project Locations__ Figure 9

May 1999

U R S O p e r a t i n g S e r v i c e s , I n cS T A R T , E P A Region V l f ]C o n t a c t \o. 6 8 - W 5 - 0 0 3 )

U p p e r A r k a n s a s R i v e r F l u v i a l T a i l i n g s - A l l e r n ; .uives A n a l y s i sRevi s i on: 2

D a l e : 0 5 / 1 9 9 9Paae 49 of 50

D e p o s i t s C A , C C , C D / C J / C K , C E , C FPropo s ed 1 9 9 9 S o i l A m e n d m e n t / R e v e g e t a t i o n P r o j e c t s

U n s a t u r a t e d Z o n e M o n i t o r i n g ( C D )G r o u n d w a t e r M o n i t o r i n g ( C D )

D e p o s i t s C L / C N / C O1998 S o i l A m e n d m e n t / R e v e g e t a t i o n P r o j e c t s

U n s a t u r a t e d Z o n e M o n i t o r i n gG r o u n d w a t e r M o n i t o r i n g

T e s t P l o t s

agy^^ssp' tV• j p i j i S S * it?.;* X-* ,•'' • * * " S > i .

D e p o s i t s C P / C R / C SP r o p o s e d 1 9 9 9 S o i l A m e n d m e n t / R e v e g e t a t i o n P r o j e c t s | | ?

G r o u n d w a t e r M o n i t o r i n g

U S D A T e s t P l o t s ( F A )G r o u n d w a t s r M o n i t o r i n a

75-70225.00F : \ S T A R T i U P P E R . A R K \ 7 0 2 2 5 \ A l t e r n a i i v e s A n a I y s i s \ F i n a l l 9 9 9 \ R e v i s i o n 2 . v \ p d : b a s


Arkansas River Fluvial TailingsLeadville, Colorado1999 Project Locations_ Figure 10

liay 1999

U R S O p e r a t i n g S e r v i c e s , I n c .S T A R T , E P A R e g i o n V f l lC o m r a c l N o . 6 8 - W 5 - 0 0 3 1

U p p e r A r k a n s a s R i v e r I - I i m s i s - U t e r n a t i v e s

D e p o s i t s M B / M E1 9 9 8 S o i l A m e n d m e n t / R e v e g e t a t i o n P r o j e c t s

G r o u n d w a t e r M o n i t o r i n g

. • T . - . - . i - . ; -j, . _-.- -4-1" i;.'^";--^^^^l^-^;i^^^y^f%ig-.;iL.^~S3iL--=' S a f e K ^ AD e p o s i t s M F / M G / M H / M I / M J / M K / M L / M N

P r o p o s e d 1 9 9 9 S o i l A m e n d m e n t / R e v e g e t a t i o n P r o j e c t s

D e p o s i t s N B , N G / N H / N I / N L , N JP r o p o s e d 1 9 9 9 S o i l A m e n d m e n t / R e v e g e t a t i o n P r o j e c t s

G r o u n d w a t e r M o n i t o r i n gU S G S G r o u n d w a t e r S t u d y— — — • - 4 " . ' T ! ! i S ' E K B t 5 S 3 " A . L s . * ! S ! . , T F T . ' ^ * i ' - r l . T 1 ^ . ? S 1 9 S — — " , ; ' \ ^ .Ty^s

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Download - ACTION MEMORANDUM, REQUEST FOR A TIME … · alternatives analysis for response to the fluvial ... Sawmill Gulch, Box. Creek, and Twobit Gulch. The Leadville mining ... death. Copper

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