golder associates inc. · 2020. 11. 25. · golder associates inc. consulting engineers final...

G o l d e r Associate s Inc .C O N S U L T I N G E N G I N E E R S

F I N A LT E C H N I C A L MEMORANDUM

ON C O M P A R A T I V E ANALYSISvO«vf

C V jVOCo

Prepared by:Golder Associates Inc.

D i s t r i b u t i o n :3 copie s - W a s t e Management of N o r t h Amer i ca , I n c . , Oak Brook, IL2 cop i e s - W a s t e Management o f N o r t h A m e r i c a , I n c . , I r v i n g , TX2 copie s - G o l d e r A s s o c i a t e s I n c . , Lakewood , CO2 cop i e s - U. S. EPA Region 6, D a l l a s , TX2 cop i e s - Oklahoma S t a t e Department of H e a l t h , Oklahoma C i t y , OK1 copy - PRC E n v i r o n m e n t a l , D a l l a s , TX1 copy - A F R C E - C R / R O V , D a l l a s , TX1 copy - E n g i n e e r i n g S c i e n c e , Denver, COAugus t 1991 903-2223

G O L D E R A S S O C I A T E S I N C . • 2 0 0 U N I O N B O U L E V A R D . S U I T E 100, L A K E W O O D ( D E N V E R ) , C O L O R A D O , U . S . A . 80228 • T E L . (303) 980-0540 • F A X (303) 985-2080

O F F I C E S I N C A N A D A • U N I T E D S T A T E S • U N I T E D K I N G D O M • S W E D E N • G E R M A N Y • I T A L Y • A U S T R A L I A

• V f ZY\ G o l d e r AssociatesZ^ C O N S U L T I N G E N G I N E E R S

R E C E I V E DE P A R E G I O N V I16 PH 2=33

S U P E R F W B R A N C HAugust 13, 1991 Our Ref: 903-2223.700

Ms. Monica Chapa (6H-EO)Mosley Road Project CoordinatorOklahoma/New Mexico Enforcement SectionU . S . Environmental Protection Agency, Region 61445 Ross AvenueDallas , Texas 75202-2733RE: REVISED "FINAL TECHNICAL MEMORANDUM ON C O M P A R A T I V E

A N A L Y S I S "Dear Ms. Chapa:The U . S . Environmental Protection Agency (EPA) provided one comment on the "FinalTechnical Memorandum on Comparative Analys i s" . The comment was received by WasteManagement of Oklahoma, Inc. on July 18, 1991. The EPA comment requested that Section5 and all related tables be deleted.In response to the EPA comment, Section 5 and all related tables have been deleted.We trust this adequately addresses the EPA comment.Sincerely,GOLDER A S S O C I A T E S I N C .

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Ward E. H e r s t , P.O.Senior H y d r o g e o l o g i s t

W. Rowe, P.E.Principal

cc: Chie f of S u p e r f u n dD. Dolan - WMNAM. S n y d e r - WMNAR. Melton - PRCH. Cantwell - OSDH

R. O'Hara - WMNAL. Barinka - WMNAM. Drake Denning - WMNAD. Hrebec - OSDHV. Lopez - Air Force

G O L D E R A S S O C I A T E S I N C , • 2 0 0 U N I O N B O U L E V A R D . S U I T E 100. L A K E W O O D ( D E N V E R ) . C O L O R A D O , U . S . A . 80228 • T E L . (303) 980-0540 • F A X (303) 985-2080

O F F I C E S I N C A N A D A • U N I T E D S T A T E S • U N I T E D K I N G D O M • S W E D E N • G E R M A N Y • I T A L Y • A U S T R A L I A

August 1991 F I N A Li Rev 1903-2223

T A B L E O P C O N T E N T SPage

1.0 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . 11.1 S i t e H i s t o r y . . . . . . . . . . . . . . . . . . 11.2 I n v e s t i g a t i v e A p p r o a c h . . . . . . . . . . . . . 3

2 . 0 S U M M A R Y O F S I T E C H A R A C T E R I S T I C S . . . . . . . . . . . 62.1 S i t e D e s c r i p t i o n . . . . . . . . . . . . . . . . 62.2 Summary of Techn i ca l F i n d i n g s . . . . . . . . . . 7

3 . 0 R E F I N E D A L T E R N A T I V E S . . . . . . . . . . . . . . . . . 93.1 A l t e r n a t i v e 2 . . . . . . . . . . . . . . . . . . 143.2 A l t e r n a t i v e 4A . . . . . . . . . . . . . . . . . 143.3 A l t e r n a t i v e 5A . . . . . . . . . . . . . . . . . 153.4 A l t e r n a t i v e 6A . . . . . . . . . . . . . . . . . 153.5 A l t e r n a t i v e 6B . . . . . . . . . . . . . . . . . 153.6 A l t e r n a t i v e 7A . . . . . . . . . . . . . . . . . 163.7 A l t e r n a t i v e 7B . . . . . . . . . . . . . . . . . 163.8 A l t e r n a t i v e 8A . . . . . . . . . . . . . . . . . 173.9 A l t e r n a t i v e 8B . . . . . . . . . . . . . . . . . 17

4 .0 C O M P A R A T I V E ANALYSIS OF ALTERNATIVES . . . . . . . . . 184.1 Overall P r o t e c t i o n of Human H e a l t h and theEnvironment . . . . . . . . . . . . . . . . . . . 21

4.1.1 C a p p i n g O p t i o n s . . . . . . . . . . . . . 214.1.2 A l t e r n a t i v e s . . . . . . . . . . . . . . . 214.2 C o m p l i a n c e with ARARs . . . . . . . . . . . . . . 25

4.2.1 C a p p i n g Opt i on s . . . . . . . . . . . . . 254.2.2 A l t e r n a t i v e s . . . . . . . . . . . . . . . 254.3 L o n g - T e r m E f f e c t i v e n e s s and Permanence ..... 29

4.3.1 C a p p i n g O p t i o n s . . . . . . . . . . . . . 294.3.2 A l t e r n a t i v e s . . . . . . . . . . . . . . . 294.4 Reduct ion of T o x i c i t y , M o b i l i t y , and Volume T h r o u g hTreatment . . . . . . . . . . . . . . . . . . . . 33

4.4.1 C a p p i n g O p t i o n s . . . . . . . . . . . . . 334.4.2 Alt erna t iv e s . . . . . . . . . . . . . . . 33

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G o l d e r A s s o c i a t e s

August 1991 F I N A Lii Rev 1903-2223T A B L E OF CONTENTS ( C o n t i n u e d )

4.5 S h o r t - T e r m E f f e c t i v e n e s sPacre

. 354.5.1 C a p p i n g Options . . . . . . . . . . . . . . 354.5.2 A l t e r n a t i v e s . . . . . . . . . . . . . . . . 36

4.6 I m p l e m e n t a b i l i t y . . . . . . . . . . . . . . . . . 404.6.1 C a p p i n g Opt i on s . . . . . . . . . . . . . . 404.6.2 Alternat ive s . . . . . . . . . . . . . . . . 41

4.7 Cost 414.7.1 C a p p i n g O p t i o n s . . . . . . . . . . . . . . 414.7.2 A l t e r n a t i v e s . . . . . . . . . . . . . . . . 41

4.8 S t a t e A c c e p t a n c e . . . . . . . . . . . . . . . . . 424.9 Community A c c e p t a n c e . . . . . . . . . . . . . . . 435 . 0 R E F E R E N C E S 44

T a b l e 3-1T a b l e 3-2T a b l e 4-1

F i g u r e 1-1F i g u r e 1-2

L I S T O F T A B L E SA n a l y s i s o f C o l l e c t i o n O p t i o n s Cons id er edEvalua t i on o f R e f i n e d A l t e r n a t i v e s A g a i n s t t h e N i n eC r i t e r i aRole o f the N i n e Eva lua t i on Cr i t e r ia During RemedyS e l e c t i o n

L I S T O F F I G U R E SS i t e Loca t i on M a pW a s t e Pit Boring Loca t i on s

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C o l d e r Asso c ia t e s

Augus t 1991 F I N A L1

Rev 19 0 3 - 2 2 2 3

1.0 INTRODUCTION

1.1 S i t e H i s t o r y

The M o s l e y Road S a n i t a r y L a n d f i l l ( F i g u r e 1-1) is a 72 acref a c i l i t y that operated f or a p p r o x i m a t e l y s ix teen years prior t obeing c lo s ed in N o v e m b e r , 1987. The f a c i l i t y accepted predomi-n a n t l y m u n i c i p a l s o l i d waste dur ing i t s o p e r a t i n g l i f e o f 1971 to1987. Between February 20, 1976 and August 24, 1976, the l a n d f i l lwas authorized by the Oklahoma S t a t e Department o f H e a l t h (OSDH) toaccept indu s t r ia l was te s , m o s t l y l i q u i d , which may have containedhazardous const i tuents . T h i s authorizat ion resulted f rom thetemporary closure of the Royal H a r d a g e l a n d f i l l in Criner,Oklahoma, which had been p r e v i o u s l y a c c e p t i n g the wastes. Duringth i s six month p e r i o d , it is e s t imated that a p p r o x i m a t e l y 1.7m i l l i o n g a l l o n s of i n d u s t r i a l wastes may have been d i s p o s e d of inthree unlined d e p r e s s i o n s , r e f e r r e d to h e r e a f t e r as the waste p i t s ,at the M o s l e y Road S a n i t a r y L a n d f i l l . T h e s e wastes are h e r e a f t e rr e f e r r e d to as indu s t r ia l hazardous wastes since they p o t e n t i a l l ycontained hazardous substances.

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The prec i s e l o c a t i o n s o f i n d u s t r i a l hazardou s waste d i s p o s a l areasare not known; however, based on a 1976 aerial p h o t o g r a p h of thes i te and an interview with a f o r m e r l a n d f i l l e m p l o y e e , it a p p e a r sthat the wastes may have been d e p o s i t e d in three d e p r e s s i o n s ( i . e . ,p i t s #1-3) within t h e l a n d f i l l ( F i g u r e 1 - 2 ) . T h e s e d e p r e s s i o n swere sub s equent ly covered with f i l l d i r t , muni c ipa l s o l id waste,and a low p e r m e a b i l i t y c lay cap.

The s i te was scored by the U . S . Environmental P r o t e c t i o n Agency( E P A ) o n F e b r u a r y 6 , 1987 us ing t h e H a z a r d Ranking S y s t e m ( H R S )

M I T R E mode l . T h e H R S numer i ca l ly evaluated t h e p o t e n t i a l f o r harmto humans and the environment in three categories:



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• M i g r a t i o n of a hazardous substance away f r o m the f a c i l i t yby routes invo lv ing groundwater, s u r f a c e water, or air.The numerical value as s igned to th i s category is ac ompo s i t e of the s eparat e scores for each of the threemigra t i on routes.• F i r e / e x p l o s i o n character i s t i c s of the hazardous sub-stances .• Direct contact with hazardous substances at the f a c i l i t y .

The l a n d f i l l was j u d g e d to pose no p o t e n t i a l harm through eitherthe direct contact or f i r e and e x p l o s i o n modes of exposure.F u r t h e r m o r e , no observed release of contaminants to the groundwaterwas documented. The only migra t i on pa thway j u d g e d to be ofs i g n i f i c a n c e was the groundwater route. On thi s basi s , a score of38.06 was a s s i g n e d , which exceeded the t hr e sho ld value of 28.5required f o r in c lu s i on o n t h e N a t i o n a l P r i o r i t i e s Lis t ( N P L ) .

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On J u n e 24, 1988, the EPA p r o p o s e d the M o s l e y Road S a n i t a r yL a n d f i l l f or inclus ion on the N a t i o n a l Prior i t i e s L i s t . The sitewas p r o p o s e d based on the acc ep tance of the above mentionedi n d u s t r i a l hazardous wastes and c o r r e s p o n d i n g p o t e n t i a l for ax-elease into the groundwater.

On J a n u a r y 12, 1989, the EPA Region VI issued a General N o t i c eL e t t e r for the s i te. On March 24, 1989, EPA Region VI issued aS p e c i a l N o t i c e l e t t e r r e g a r d i n g Remedial I n v e s t i g a t i o n / F e a s i b i l i t yS t u d y ( R I / F S ) a c t i v i t i e s a t t h e site. O n M a y 2 6 , 1989, W a s t eManagement o f Oklahoma, I n c . ( W M O ) submitted a good f a i t h o f f e r t othe EPA to conduct an RI/FS at the site. The EPA Region VI and WMOsub s equent ly d e v e l o p e d an RI/FS statement o f work which became partof the A d m i n i s t r a t i v e Order on Consent ( C o n s e n t O r d e r ) . On J u l y 28,1989 , the EPA signed the Consent Order requiring WMO to in i t i a t eR I / F S a c t i v i t i e s a t t h e l a n d f i l l .

G o l d e r Assoc ia te s

August 1991 F I N A L3

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On October 26 , 1989, WHO submit ted an RI/FS Work P l a n ( C o l d e rA s s o c i a t e s , 1 9 8 9 ) to EPA for it s review and comment. EPA re spondedwith comments on December 10, 1989. WHO m o d i f i e d the Work P l a na c c o r d i n g l y and submitted a f i n a l version to EPA on J a n u a r y 2,1990. EPA approved the Work P l a n on January 26, 1990, at whichtime inve s t i ga t iv e a c t iv i t i e s began.

1.2 I n v e s t i g a t i v e A p p r o a c h

T h e R I / F S Work P l a n pr e s en t s a phas ed a p p r o a c h towards charac-t e r i z i n g the nature and extent of any p o t e n t i a l threat posed byreleases f r o m the indus tr ia l hazardous wastes. Thre e in i t ia lpha s e s , source charac t e r i za t i on , p h y s i c a l charac t er iza t ion, andcontaminant charac t e r i za t i on , were p r o p o s e d as part of the remedialinve s t i ga t i on . Phys i ca l charac t er i za t i on was p r i m a r i l y de s igned toe s t imate p o t e n t i a l m i g r a t i o n pa thways o f contaminant s f r o m thei n d u s t r i a l hazardous waste s . R e s u l t s o f p h y s i c a l charac t er iza t ionare d e t a i l e d in a document e n t i t l e d " F i n a l T e c h n i c a l Memorandum onP h y s i c a l C h a r a c t e r i z a t i o n " ( C o l d e r A s s o c i a t e s , 1 9 9 0 a ) , which wa sapproved by the EPA on J u n e 11, 1990.

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Source charac t e r i za t i on a c t i v i t i e s were d e s igned to addre s s thechemical nature of the i n d u s t r i a l hazardous wastes present in thed i s p o s a l areas and to i d e n t i f y other p o t e n t i a l sources of contami-nation near the s i t e , i n c l u d i n g p u m p i n g o i l w e l l s . Sourcecharac t e r i za t i on r e su l t s were submit t ed to the EPA on October 2,1990, in a document e n t i t l e d " F i n a l T e c h n i c a l Memorandum on SourceCharac t e r i za t i on" ( C o l d e r A s s o c i a t e s , 1 9 9 0 b ) , which was approved bythe EPA on October 4, 1990.

The nature and extent of p o t e n t i a l s u r f a c e water, s ed iment , andgroundwater c on tamina t i on at the s i te were evaluated duringcontaminant charac t e r i za t i on a c t i v i t i e s . Resu l t s f r o m contaminant

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charac t er iza t ion were inc luded in the " F i n a l T e c h n i c a l Memorandumon Contaminant Charac t e r i za t i on" ( C o l d e r A s s o c i a t e s , 1 9 9 0 c ) , whichwas approved by February 12, 1991.

Resul t s of the three phas e s of the remedial inve s t iga t i on aresummarized in the " F i n a l Remedial I n v e s t i g a t i o n Report ( G o l d e rA s s o c i a t e s , 1 9 9 1 d ) submit ted to the EPA for rece ipt on A p r i l 15,1991.

T h e R I / F S Work P l a n i d e n t i f i e s T a s k 6 0 0 - Deve lopment a n d Scre en ingof Remedial A l t e r n a t i v e s as being Phase I of the F e a s i b i l i t y S t u d y .A series of f o u r documents were submit ted under T a s k 600. Volume1, e n t i t l e d " F i n a l T e c h n i c a l Memorandum on Ref in emen t of RemedialObje c t i v e s " ( G o l d e r A s s o c i a t e s , 1 9 9 0 d ) was submit ted to the EPA onS e p t e m b e r 21, 1990 and approved by the EPA on October 4, 1990.V o l u m e 2, e n t i t l e d " F i n a l T e c h n i c a l Memorandum on RemedialT e c h n o l o g i e s Screening" ( G o l d e r A s s o c i a t e s , 1 9 9 0 e ) , w a s submittedto the EPA on November 7, 1990 and approved by the EPA on November23, 1990. V o l u m e 3, e n t i t l e d " F i n a l T e c h n i c a l Memorandum onA l t e r n a t i v e Deve l opmen t a n d Screen ing" ( G o l d e r A s s o c i a t e s , 1 9 9 1 a ) ,was submit ted to the EPA on J a n u a r y 9, 1991. Volume 4, e n t i t l e d" F i n a l A l t e r n a t i v e s Array Document" ( G o l d e r A s s o c i a t e s 1 9 9 1 b ) , w a sa l s o submi t t ed on J a n u a r y 9, 1991. Both V o l u m e s 3 and 4 wereapproved by the EPA on F e b r u a r y 1, 1991.

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T a s k 700 - D e t a i l e d A n a l y s i s o f Remedial A l t e r n a t i v e s - i s Phase IIo f t h e F e a s i b i l i t y S t u d y . T h e " F i n a l T e c h n i c a l Memorandum o n N i n eC r i t e r i a Ass e s smen t" ( G o l d e r A s s o c i a t e s , 1 9 9 I c ) , approved b y t h eEPA on J u l y 11, 1991, was the f i r s t document pr epared under T a s k700. The " F i n a l T e c h n i c a l Memorandum on N i n e C r i t e r i a Asse s sment"evaluated the r e f i n e d a l t e rna t iv e s against the nine criteriai d e n t i f i e d by the EPA in "Guidance for C o n d u c t i n g RemedialI n v e s t i g a t i o n and F e a s i b i l i t y S t u d i e s Under C E R C L A - I n t e r i m F i n a l "



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( E P A , 1 9 8 8 a ) . N i n e a l t e r n a t i v e s were retained f o r d e t a i l e da n a l y s i s in the revised " F i n a l T e c h n i c a l Memorandum on N i n eC r i t e r i a A s s e s s m e n t . "

T h i s document, e n t i t l e d " F i n a l T e c h n i c a l Memorandum on Comparat iveA n a l y s i s " , evaluates the re lat ive p e r f o rmanc e of each of the ninealternatives . The " F i n a l Technica l Memorandum on ComparativeA n a l y s i s " pre s ent s the ana ly s i s in a manner consistent with thatou t l ined in the "Guidance for C o n d u c t i n g Remedial I n v e s t i g a t i o n sa n d F e a s i b i l i t y S t u d i e s Under C E R C L A - I n t e r i m F i n a l " ( E P A , 1 9 8 8 a ) .

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2.0 S U M M A R Y OF SITE CHARACTERISTICS

2 . 1 S i t e D e s c r i p t i o n

The M o s l e y Road S a n i t a r y L a n d f i l l i s p r e d o m i n a n t l y an above-gradef a c i l i t y . The N o r t h Canadian River, a m a j o r perennial stream,f l o w s f r o m southwest to northeast about 1/2 mile west of the site( F i g u r e 1-1). Crutcho Creek, a perennial stream tributary to the

N o r t h Canad ian River, f l o w s f r o m south to north near the easternboundary of the f a c i l i t y . Other s u r f a c e water bodies near thel a n d f i l l inc lude N o r t h P o n d , S o u t h S w a m p , and an inactive sand andgravel operation. In a d d i t i o n , a small ( a p p r o x i m a t e l y 1/2 acre)s ed imenta t i on p o n d , r e f e r r e d to as the re tention p o n d , is locatedin the northeastern corner of the l a n d f i l l and c o l l e c t s s u r f a c er u n o f f f r o m near the pond.

The g e o l o g y o f the area in c lud e s two p r i n c i p a l un i t s ; the N o r t hCanadian River a l luv ium and the G a r b e r - W e l l i n g t o n f o rmat i on . Thea l l u v i u m is composed of u n c o n s o l i d a t e d s ed iment s d e p o s i t e d by theN o r t h C a n a d i a n River. The a l l u v i u m is the uppermo s t of the twounits and ex t ends to an average d e p t h of a p p r o x i m a t e l y 40 f e e tbelow ground s u r f a c e in the s tudy area. The u n d e r l y i n g Garber-W e l l i n g t o n f o r m a t i o n i s a c o n s o l i d a t e d unit composed of sands tone ,s i l t s t o n e , and c lay s t one . Por t i on s o f the G a r b e r - W e l l i n g t o nf o r m a t i o n compri s e an a q u i f e r that is used as a source of dr ink ingwater by the c i t i e s of M i d w e s t C i t y , S p e n c e r , and Oklahoma C i t y .The maximum thicknes s o f the G a r b e r - W e l l i n g t o n f o r m a t i o n i sr epor t ed to be a p p r o x i m a t e l y 900 f e e t ( W i c k e r s h a m , 1 9 7 9 ) .

A compacted c lay cap was i n s t a l l e d over the l a n d f i l l in 1988. Thecap has a minimum th i ckne s s of three f e e t on top and two f e e t onthe s ide s . The hydrau l i c c o n d u c t i v i t y of the cap is in the rangeo f S x l O " 4 f t / d a y ( I x l O ' 7 c m / s e c ) , based o n f i e l d t e s t i n g p e r f o r m e d b y

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Augus t 1991 F I N A L7 Rev 1903-2223

Terracon C o n s u l t a n t s , I n c . ( 1 9 8 9 ) . V e g e t a t i o n h a s been e s t ab l i s h edon the cover to reduce erosion p o t e n t i a l and reduce i n f i l t r a t i o ninto the l a n d f i l l . The cover is maintained by WMO on a routinebasis.

2 . 2 Summary o f T e c h n i c a l F i n d i n g s

The f o l l o w i n g technical f i n d i n g s are based on data and analyse spre sented in the " F i n a l Remedial I n v e s t i g a t i o n Report" ( C o l d e rA s s o c i a t e s , 1 9 9 1 d ) :

The l a n d f i l l was f o u n d to contain saturated zones o fl eachat e near its base t y p i c a l l y ranging f r o m 10 to 15f e e t thick. At least one of these zones ( i . e . inl eachate riser L R - 1 0 3 ) is e v i d e n t l y perched above thea l l u v i a l groundwater t a b l e by a p p r o x i m a t e l y 15 f e e t .Leachate l e v e l s measured in two other leachate risers( i . e . LR-102 and L R - 1 0 6 ) were a p p r o x i m a t e l y the same asa n t i c i p a t e d a l l u v i a l groundwater l ev e l s beneath thel a n d f i l l .Groundwat er l e v e l s in the a l l u v i a l a q u i f e r surroundingt h e l a n d f i l l range f r o m a p p r o x i m a t e l y e l evat ion 1149 f e e ton the south s ide of the l a n d f i l l to 1145 f e e t on thenorth s ide . The base of the l a n d f i l l , which i sa p p r o x i m a t e l y 20 f e e t be low the p r e - e x i s t i n g grounds u r f a c e , is a p p r o x i m a t e l y e l eva t i on 1134 f e e t as measuredin boring B H - 1 0 1 . T h u s , a l l u v i a l groundwater l e v e l s are10 to 15 f e e t above the base of the l a n d f i l l .H y d r a u l i c heads in the a l l u v i a l a q u i f e r are c o n s i s t e n t l yhigher than in the u n d e r l y i n g G a r b e r - W e l l i n g t o n a q u i f e rin the immedia t e area of the l a n d f i l l . H e a d s in thea l l u v i a l a q u i f e r range f r o m a p p r o x i m a t e l y 0 to 1.5 f e e thigher on the northern s ide of the l a n d f i l l to 3.9 to 5.8f e e t higher on the southern s ide o f the l a n d f i l l . T h i sr e s u l t s in a downward vertical gradi en t f r o m the a l l u v i a la q u i f e r to the G a r b e r - W e l l i n g t o n a q u i f e r and the poten-t ia l f o r downward l eakage .Contaminant s were d e t e c t ed in both a l l u v i a l and Garber-W e l l i n g t o n groundwater. A l l u v i a l groundwater in the areanorth of the l a n d f i l l is a f f e c t e d by organic and inor-ganic compounds that or ig inated f r o m the r e f u s e and

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5.

p o s s i b l y th e waste p i t s . The G a r b e r - W e l l i n g t o n groundwa-ter has been s l i g h t l y a f f e c t e d by downward leakage ofcontaminants f r o m the ov er ly ing a l l u v i a l a q u i f e r in thearea i m m e d i a t e l y north o f the l a n d f i l l . Contaminantl ev e l s in the G a r b e r - W e l l i n g t o n a q u i f e r do not currentlypose a measurable risk to human hea l th .W a s t e pi t s o i l s were d r i l l e d and s a m p l e d dur ing theremedial i n v e s t i g a t i o n but a d i s cr e t e and concentratedsource of indu s t r ia l hazardous waste in the l a n d f i l l wasnot i d e n t i f i e d . Fur th ermore , it is not p o s s i b l e tod i s t i n g u i s h between contaminants o r ig ina t ing f r o m thei n d u s t r i a l hazardous waste and contaminants o r i g i n a t i n gf r o m m u n i c i p a l l a n d f i l l r e f u s e .

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3 .0 REFINED ALTERNATIVES

The memoranda d e v e l o p e d as part of T a s k 600 - Development andS c r e e n i n g of Remedial A l t e r n a t i v e s i d e n t i f y three media that mayrequire remedial action at the site. T h e s e media include waste pits o i l s , l ea cha t e , and a l l u v i a l groundwater ( C o l d e r A s s o c i a t e s ,199 ib) . Based on the r e su l t s of the remedial inve s t i ga t i on ( G o l d e rA s s o c i a t e s , 1 9 9 1 d ) , s u r f a c e water, s ed imen t s , s u r f a c e s o i l s , andair are not i d e n t i f i e d as media of concern for the site.

F o u r t e e n a l t e rnat ive s were considered as p o t e n t i a l l y a p p l i c a b l e f orthe site. The " F i n a l T e c h n i c a l Memorandum on N i n e Cri t er iaAssessment" di scussed the rat ionale for e l iminat ing f i v e of thea l t e rna t iv e s f r o m f u r t h e r c on s id era t i on , i n c l u d i n g the "no-action"a l t e r n a t i v e .

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The f o l l o w i n g a s s u m p t i o n s were used to r e f i n e the p o t e n t i a lremedial a l t e r n a t i v e s :

It is assumed that p o t e n t i a l remedial actions at the siteshould e l iminat e or s i g n i f i c a n t l y reduce the p o s s i b i l i t yf or m i g r a t i o n o f contaminant s t o the G a r b e r - W e l l i n g t o na q u i f e r . As de s cr ibed in S e c t i o n 2 .0 , the p o t e n t i a l f orvertical f l o w f r o m th e a l l u v i a l a q u i f e r t o th e Garber-W e l l i n g t o n a q u i f e r curr en t ly ex i s t s beneath t h e l a n d f i l l .T h i s p o t e n t i a l f l o w p a t h can be e l i m i n a t e d by decreas ingheads in the a l l u v i a l a q u i f e r on the order of 3 to 6 f e e tsuch that vertical f l o w g r a d i e n t s between the a l l u v i a land G a r b e r - W e l l i n g t o n a q u i f e r would be upwards f r o m theG a r b e r - W e l l i n g t o n t o the a l l u v i a l a q u i f e r .The groundwater l e v e l s in the a l l u v i a l a q u i f e r area p p r o x i m a t e l y 10 to 15 f e e t above the base of thel a n d f i l l . T h u s , at l eas t 10 to 15 f e e t of head reduct ionin the a l l u v i a l a q u i f e r would be needed to lower thegroundwater t a b l e b e low the base o f the l a n d f i l l .It i s assumed that some f o r m of l e a c h a t e / g r o u n d w a t e rremoval f r o m wi thin or a d j a c e n t to the l a n d f i l l w i l l be



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•

required to reverse f l o w grad i en t s between the a l l u v i a land G a r b e r - W e l l i n g t o n a q u i f e r s .4. P o t e n t i a l impac t s on groundwater q u a l i t y f r o m indus tr ia lhazardous wastes cannot be c l e a r l y d e l i n e a t e d f r o m theimpac t s of muni c ipa l r e f u s e . T h e r e f o r e , it is assumedthat p o t e n t i a l remedial a l t e rna t iv e s at the s i te w i l laddre s s both i n d u s t r i a l hazardous waste and munic ipalr e f u s e . However , s p e c i f i c components o f the remediala l t e r n a t i v e s considered may vary d e p e n d i n g on whetherthey p e r t a i n to the i n d u s t r i a l hazardous waste ormunic ipa l r e f u s e ( e . g . , d i f f e r e n t cover systems may beused for the indu s t r ia l hazardous waste and munic ipalr e f u s e p o r t i o n o f t h e l a n d f i l l ) .

F i v e c a p p i n g o p t i o n s were considered during the in i t ia l deve lopmentand screening of a l t e r n a t i v e s i n c l u d i n g :

(1) Repair of the e x i s t i n g cap and a d d i t i o n of a vegetativesoil layer;( 2 ) Repair o f t h e e x i s t i n g c a p , a d d i t i o n o f 2 f e e t o fa d d i t i o n a l c lay cover over the waste pit areas, anda d d i t i o n of a vege ta t ive soil layer;( 3 ) Repair o f t h e e x i s t i n g c a p , a d d i t i o n o f RCRA t y p ec ompo s i t e ( c l a y and s y n t h e t i c ) cover over the waste pitareas, and a d d i t i o n of a vege tat ive soil layer;( 4 ) Repair o f t h e e x i s t i n g c a p , a d d i t i o n o f 2 f e e t o fa d d i t i o n a l c lay cover over the entire l a n d f i l l , anda d d i t i o n of a v ege ta t ive soil l ayer; and,( 5 ) A d d i t i o n o f a RCRA t y p e c o m p o s i t e ( c l a y a n d s y n t h e t i c )cover over the entire l a n d f i l l .

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C a p p i n g o p t i o n s 1, 2, and 4 are r e t a in ed , with the f o l l o w i n g minorr e f i n e m e n t s :

• Minor r e f i n e m e n t s to c a p p i n g o p t i o n #1 inc ludes t r i p p i n g the u p p e r 1 f o o t o f e x i s t i n g c layc a p , f o l l o w e d by r ep lac ement and recompact ion.The minimum l iner th i ckne s s o f s ide s l o p e s wasincreased f r o m 2 .0 t o 2 .5 f e e t . A d d i t i o n a l l y ,erosion control p r o t e c t i o n covering 50% of thes ide s l o p e s was a d d e d .


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• Minor r e f i n e m e n t s to c a p p i n g o p t i o n #2 arei d en t i ca l to o p t i o n #1 with the e x c ep t i on thatthe 2 f e e t of a d d i t i o n a l c lay liner isextended 20 f e e t beyond the area of wastep i t s .• Minor r e f i n e m e n t s to c a p p i n g o p t i o n #4 areid en t i ca l to o p t i o n #1.

The third and f i f t h op t i on s l i s t ed above are not retained forseveral reasons:

• The a d d i t i o n of a synthe t i c cover would only m i n i m a l l yreduce the amount of i n f i l t r a t i o n through the cover.• M u n i c i p a l s o l i d r e f u s e and at least one indus tr ia lhazardous waste pit are in contact with groundwater.T h e r e f o r e , a cover system by i t s e l f w i l l not preventp o t e n t i a l groundwater contaminat ion through e l imina t i ono f i n f i l t r a t i o n .• The pr imary f u n c t i o n of a cover at this s i te should be tominimize (but not e l i m i n a t e ) i n f i l t r a t i o n and preventerosion of the muni c ipa l r e f u s e .• C a p p i n g o p t i o n s 3 and 5 are s i g n i f i c a n t l y more c o s t l y(see T a b l e 4-3 of the " F i n a l T e c h n i c a l Memorandum on N i n eC r i t e r i a A s s e s s m e n t " ) but do not o f f e r s i g n i f i c a n tt e chnical advantage s over other o p t i o n s .

T r e a t m e n t o p t i o n s are d i s cu s s ed in d e t a i l in the " F i n a l T e c h n i c a lMemorandum on Remedial T e c h n o l o g i e s Scr e en ing" ( C o l d e r A s s o c i a t e s ,1 9 9 0 e ) and are summarized in the " F i n a l T e c h n i c a l Memorandum onN i n e C r i t e r i a Ass e s smen t" ( C o l d e r A s s o c i a t e s , 1 9 9 1 c ) . A s di s cus s edin the " F i n a l T e c h n i c a l Memorandum on N i n e C r i t e r i a Asse s sment" onetreatment scheme i s d e v e l o p e d for the d e t a i l e d ana ly s i s . Itinc lude s pre tr ea tment f o r m e t a l s , b i o l o g i c a l t r ea tment , a i rs t r i p p i n g , and carbon a d s o r p t i o n . All o f the retained a l t e rna t iv e swhich involve treatment inc lude th i s treatment scheme.

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Two treatment o p t i o n s are i n c l u d e d under the treatment scheme. Thef i r s t treatment o p t i o n is d e s igned to reduce contaminant



Rev 1903-2223

concentrat ions to a level which w i l l a l l o w for direct d i s charge tos u r f a c e water under an NPDES permi t . The second treatment o p t i o nis de s igned to reduce contaminant concentrat ions to a level whichwi l l a l l o w for d i s charge t o a POTW. The second o p t i o n requiresl e s s t r ea tment , since it assumes that a d d i t i o n a l treatment w i l l beac c ompl i s h ed at the POTW.

The two treatment o p t i o n s d i f f e r only in the reduction ofcontaminant concentrat ions prior to d i s charge .

In the f o l l o w i n g s e c t ions , wherever treatment is r e f erenced itinc lude s treatment o p t i o n 1 and treatment o p t i o n 2 .

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F o u r d i s charge o p t i o n s were considered in the p r e l i m i n a r yd e v e l o p m e n t and screening of a l t e r n a t i v e s i n c l u d i n g :

• On-site spray i r r i g a t i o n ;• O f f - s i t e d i s c h a r g e to s u r f a c e water under a N a t i o n a lP o l l u t a n t Dis charge E l i m i n a t i o n S y s t e m ( N P D E S ) p e r m i t ;• Underground i n j e c t i o n under an Underground I n j e c t i o nContro l ( U I C ) p e r m i t ; and,• Discharge to a P u b l i c l y Owned T r e a t m e n t Works (POTW).

The on-site spray i r r i g a t i o n o p t i o n i s e l im ina t ed f r o m f u r t h e rconsideration because of l imi t ed on-site areas su i table foro p e r a t i o n o f th i s system. F u r t h e r m o r e , the a d d i t i o n o f water f r o mspray i rr iga t i on to the a l l u v i a l a q u i f e r would have a negativeimpact on other component s of the p o t e n t i a l remedial a l t e rna t iv e sbeing considered at the s i te ( i . e . , it would tend to increasea l l u v i a l water l e v e l s ) . The underground i n j e c t i o n o p t i o n i s a l s od r o p p e d f r o m f u r t h e r c o n s i d e r a t i o n a t th i s time. No p e r m i t t e di n j e c t i o n w e l l s are known to exist in the immedia t e v i c in i ty of thesite. P e r m i t t i n g and cons truc t i on of new i n j e c t i o n w e l l s at thesite is l i k e l y to be d i f f i c u l t f r o m a legal and regulatory basis


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and is l i k e l y to be s i g n i f i c a n t l y more c o s t l y than other o p t i o n s .S h o u l d other o p t i o n s prove u n f e a s i b l e , the o p t i o n o f on-siteunderground r e i n j e c t i o n of water w i l l be re-evaluated.

W i t h t h e e x c e p t i o n o f A l t e r n a t i v e 2 ( l i m i t e d a c t i o n s / i n s t i t u t i o n a lc o n t r o l s ) , all retained a l t e rna t iv e s in c lude some degree of source( i . e . , waste p i t and l a n d f i l l ) containment through construct ion o fa s lurry wall or c o m p l e t i o n of recovery w e l l s a n d / o r drains. As lurry wal l is t y p i c a l l y cons tructed by excavat ing a trench aroundthe per imeter of the s i te and f i l l i n g it with a low p e r m e a b i l i t ymaterial in order to p r o v i d e hor i zon ta l containment. At the M o s l e yRoad site thi s would p r o b a b l y require the construct ion of a trencha p p r o x i m a t e l y 30 to 40 f e e t d e e p to the top of the Garber-W e l l i n g t o n f o r m a t i o n .

Recovery w e l l s a n d / o r drains are assumed to be p l a c e d in variousl o ca t i on s to extract l ea cha t e and groundwater for subsequenttreatment (if n e c e s sary) and d i s charge . T a b l e 3-1 pr e s en t s asummary of the c o l l e c t i o n o p t i o n s considered for the site.Recovery w e l l s are assumed to be p l a c e d ei ther (1) around theper imeter o f t h e l a n d f i l l ; ( 2 ) wi th in t h e l a n d f i l l f o o t p r i n t ; ( 3 )north of the l a n d f i l l in an area h y d r a u l i c a l l y downgradient of thel a n d f i l l ; or, a combinat ion of the above as described in thef o l l o w i n g sec t ions. Drains , which may consist o f hor izontal p i p i n gp l a c e d into excavated trenches , may be p l a c e d north of the l a n d f i l lor around the p er ime t er of the l a n d f i l l .

Other than A l t e r n a t i v e 2, al l a l t e rna t iv e s in c lude ex trac t ion ofgroundwater, l e a c h a t e , or both. Some a l t e rna t iv e s a l s o inc lude on-s i te treatment of ex trac t ed groundwater or l e a c h a t e , whereas othera l t e rna t iv e s assume that the groundwater or l eachate w i l l bed i s charged to a P u b l i c l y Owned T r e a t m e n t W o r k s (POTW) or w i l l bed i s charged to s u r f a c e water under an N a t i o n a l P o l l u t a n t Discharge

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E l i m i n a t i o n S y s t e m ( N P D E S ) permi t . Each o f t h e remaining ninea l t e rna t iv e s is evaluated against the nine criteria in T a b l e 3-2and b r i e f l y de scr ibed in the f o l l o w i n g sections.

3.1 A l t e r n a t i v e 2

A l t e r n a t i v e 2 inc lude s l i m i t e d act ions and in s t i t u t i ona l actions.T h e s e actions may in c lud e access r e s t r i c t i on s , in s t i t u t i ona lcontro l s on groundwater use, and moni t or ing . The N a t i o n a l Oil andH a z a r d o u s S u b s t a n c e s P o l l u t i o n C o n t i n g e n c y P l a n ( N C P ) ( 4 0 C F R 3 0 0 )requires the d e v e l o p m e n t of one or more a l t e rna t iv e s that involvel i t t l e or no treatment but prov id e p r o t e c t i o n of human h ea l th andthe environment p r i m a r i l y by pr even t ing or c o n t r o l l i n g exposure tohazardous substances. A l t e r n a t i v e 2 s a t i s f i e s this requirement.

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3.2 A l t e r n a t i v e 4A

A l t e r n a t i v e 4A is a source c on ta inment; groundwater ex trac t ion andd i s charge a l t e r n a t i v e that in c lud e s c a p p i n g , access r e s t r i c t i on s ,and moni tor ing. T h i s a l t e rna t iv e i n c l u d e s groundwater ex trac t ionou t s id e the l a n d f i l l f o o t p r i n t via recovery w e l l s or a drain.Extrac t ed groundwater would a l s o contain l eacha t e drawn into theex t rac t i on system. T h u s , th i s a l t e r n a t i v e ha s th e p o t e n t i a l f orreducing l eachat e l e v e l s in the l a n d f i l l and a l l u v i a l water l ev e l sunder th e l a n d f i l l . T h i s a l t e r n a t i v e a l s o ha s th e p o t e n t i a l t oachieve the goal of reversing vert ical g r a d i e n t s between thea l luv ia l and G a r b e r - W e l l i n g t o n a q u i f e r s to prevent downward f l o w .

T h i s a l t e rna t iv e does not i n c l u d e treatment of extracted water.T h e r e f o r e , it would need to be d emons t ra t ed that extracted watercould be d i r e c t l y d i s charged to a POTW or s u r f a c e water via anNPDES di s charge permit without treatment for this a l t e rna t iv e to bef e a s i b l e .



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A l t e r n a t i v e 5A is a source containment; groundwater extract ion viarecovery w e l l s or a drain, tr ea tment , and di s charge a l t ernat ivethat inc lude s c a p p i n g , access r e s t r i c t i on s , and monitoring. It isi d en t i ca l to A l t e r n a t i v e 4A with the a d d i t i o n of water treatment.The inclus ion of water treatment adds more f l e x i b i l i t y in di s chargeo p t i o n s f r o m those a v a i l a b l e under A l t e r n a t i v e 4A. Extractedgroundwater c on ta in ing l eachate would be treated prior to di s chargeto a POTW or s u r f a c e water.

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3 .4 A l t e r n a t i v e 6A

A l t e r n a t i v e 6A is a source con ta inment; l eachate ex trac t ion viarecovery w e l l s , t r ea tment , and d i s charge a l t ernat ive that inc ludesc a p p i n g , access r e s t r i c t i o n s , and moni tor ing. The l eachateex trac t ion system would a l s o draw a l l u v i a l groundwater f r o m ou t s idet h e l a n d f i l l f o o t p r i n t . A l t e r n a t i v e 6A would prov ide f o r areversal in the vertical g r a d i e n t s between the a l l u v i a l and Garber-W e l l i n g t o n a q u i f e r s , and, thus , would meet th e a s s u m p t i o n s f orr e f in emen t l i s t e d p r e v i o u s l y in thi s section. Trea tment ofl eachate pr ior to d i s charge to a POTW or s u r f a c e water prov ide s theadded f l e x i b i l i t y in d i s charge o p t i o n s as pre s en t ed in A l t e r n a t i v e5 A.

3.5 A l t e r n a t i v e 6B

A l t e r n a t i v e 6B is a source con ta inment; l eachate ex trac t ion viarecovery w e l l s , t r ea tment , and d i s c h a r g e a l t e r n a t i v e that inc lude saccess r e s t r i c t i o n s , m o n i t o r i n g , s lurry w a l l , and c a p p i n g .A l t e r n a t i v e 6B is i d e n t i c a l to A l t e r n a t i v e 6A with the a d d i t i o n ofa s lurry w a l l .



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The use of a s lurry wall under this a l t e rna t iv e would i s o l a t e thel a n d f i l l f r o m the surrounding a l l u v i a l a q u i f e r and prevent f u r t h e rla t e ra l migrat ion o f contaminants . T h i s a l t e rna t iv e prov ide s f o rreversal of vertical grad i en t s between the a l l u v i a l and Garber-W e l l i n g t o n a q u i f e r s . The s lurry wall would prevent a l l u v i a lgroundwater f r o m f l o w i n g l a t e r a l l y under t h e l a n d f i l l , thusreducing required p u m p i n g volumes in the l eachate ex tract ionsystem. Remediation of groundwater outs ide of the l a n d f i l l as asecondary e f f e c t o f p u m p i n g f r o m wi thin and beneath the l a n d f i l lwould not be a c c o m p l i s h e d by A l t e r n a t i v e 6B.


A l t e r n a t i v e 7A is a source conta inment; groundwater extraction viarecovery w e l l s or a drain and subsequent d i s charge; l eachateex trac t i on via recovery w e l l s , treatment and d i s charge a l t e rna t iv ethat in c lud e s c a p p i n g , access r e s t r i c t i on s , and monitoring. T h i sa l t e rna t iv e is i d e n t i c a l to A l t e r n a t i v e 6A with the a d d i t i o n ofgroundwater e x t rac t i on and d i s charge .

Groundwater ex tract ion would be a c c o m p l i s h e d by w e l l s or drainsl o ca t ed ou t s id e th e l a n d f i l l f o o t p r i n t . It i s assumed thatextracted groundwater would be d i s charged to s u r f a c e water under aN a t i o n a l P o l l u t a n t Dis charge E l i m i n a t i o n S y s t e m ( N P D E S ) p e r m i t , o rdi s charged t o a POTW. T h i s a l t e r n a t i v e prov id e s direct remediat iono f contaminated a l l u v i a l groundwater o u t s i d e t h e l a n d f i l lf o o t p r i n t .


A l t e r n a t i v e 7B is a source containment; groundwater extraction viarecovery w e l l s or a drain and subsequent d i s charge; l eachateex tract ion via recovery w e l l s , t r ea tment , and d i s charge a l t ernat ive

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that inc lude s c a p p i n g , s lurry w a l l , access r e s t r i c t i on s , andmoni tor ing. A l t e r n a t i v e 7B is i d en t i ca l to A l t e r n a t i v e 7A with thea d d i t i o n of a s lurry w a l l .

Ex trac t i on f r o m wi th in the s lurry wall would be conducted toreverse vertical g r a d i e n t s between the a l l u v i a l and Garber-W e l l i n g t o n a q u i f e r s . C o l l e c t i o n o f groundwater out s ide o f th es lurry wall through drains or w e l l s would provide remediation ofcontaminated groundwater. It is assumed that extracted groundwatercould be discharged ( e . g . , to a POTW or sur face water via an NPDESp e r m i t ) without treatment .


A l t e r n a t i v e 8A is a source containment; groundwater and leachateex trac t ion via recovery w e l l s ( l e a c h a t e and groundwat er) or a drain( g r o u n d w a t e r ) , t r ea tment , and d i s charge a l t e rna t iv e that inc lude s

c a p p i n g , access r e s t r i c t i o n s , and moni tor ing. It is i d en t i ca l toA l t e r n a t i v e 7A with the a d d i t i o n of groundwater treatment.


A l t e r n a t i v e 8B is a source containment; groundwater and leachateex trac t ion via recovery w e l l s ( l e a c h a t e and groundwat er) or a drain( g r o u n d w a t e r ) , t r ea tmen t , and d i s c h a r g e a l t e rna t iv e that inc lude sc a p p i n g , s lurry w a l l , access r e s t r i c t i o n , and moni tor ing. It i si d en t i ca l to A l t e r n a t i v e 8A with the a d d i t i o n of a s lurry wall toi s o l a t e t h e l a n d f i l l f r o m t h e surrounding a l l u v i a l a q u i f e r .

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4.0 C O M P A R A T I V E ANALYSIS OF ALTERNATIVES

The " F i n a l T e c h n i c a l Memorandum on N i n e Cr i t e r ia Asses sment"( C o l d e r A s s o c i a t e s , 1 9 9 I c ) compares the various a l t ernat ive s t o thenine evaluat ion criteria d e f i n e d by the EPA in the "Guidance forC o n d u c t i n g Remedial I n v e s t i g a t i o n s and F e a s i b i l i t y S t u d i e s UnderC E R C L A - I n t e r i m F i n a l " ( E P A , 1 9 8 8 a ) . T h e nine evaluation criteriaare:

• Overall P r o t e c t i o n of Human H e a l t h and the Environment;• C o m p l i a n c e with A R A R s ;• Long-term E f f e c t i v e n e s s and Permanence;• Reduction of T o x i c i t y , M o b i l i t y , and Volume ThroughT r e a t m e n t ;• S h o r t - T e r m 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 s ;• S t a t e A c c e p t a n c e ; and,• Community A c c e p t a n c e .

T a b l e 4-1 summarizes the nine eva lua t i on criteria and their roleduring the s e l e c t i on of a remedy. As shown on T a b l e 4-1, threet y p e s of ro le s are i d e n t i f i e d by the EPA ( 1 9 8 8 a ) . T h e s e rolesinc lude:

( 1 ) T h r e s h o l d f a c t o r s ;( 2 ) Primary b a l a n c i n g f a c t o r s ; and ,( 3 ) M o d i f y i n g c on s id era t i on s .

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T h r e s h o l d f a c t o r s include (1) overall pro t e c t i on o f human heal thand the environment and (2) c o m p l i a n c e with A R A R s . T h r e s h o l df a c t o r s must be met by each a l t e rna t iv e re tained. All of theretained a l t ernat ive s discussed in the " F i n a l Techni ca l Memorandumon N i n e C r i t e r i a A s s e s s m e n t " , with the p o s s i b l e e x c ep t i on ofA l t e r n a t i v e s 2, 6A, and 6B, are l i k e l y to meet the thre sho ldf a c t o r s .

A l t e r n a t i v e 2 ( l i m i t e d a c t i o n ) may not provide pro t e c t i on toenvironmental receptors located in areas where groundwaterd i s charge s to s u r f a c e water or is in contact with p l a n t roots.F u r t h e r m o r e , A l t e r n a t i v e 2 may not meet A R A R s . As di scus sed inthe " F i n a l Remedial I n v e s t i g a t i o n Report", no s i g n i f i c a n t threat tothe environment f r o m the s i te current ly e x i s t s , based on re su l t s ofthe risk asses sment. T h e r e f o r e , A l t e r n a t i v e 2 i s retained forcomparative ana ly s i s .

A l t e r n a t i v e 6A (source conta inment; l eachate e x t rac t i on , t r ea tment ,and d i s c h a r g e ) , may not meet ARARs for groundwater qua l i ty in thearea north of the l a n d f i l l . A l t e r n a t i v e 6B (source containment;l eachate e x t rac t i on , t r ea tment , and d i s c h a r g e ; s lurry w a l l ) wouldnot be e f f e c t i v e in r e m e d i a t i n g e x i s t i n g a l l u v i a l groundwatercontaminat ion on the north s ide of the l a n d f i l l and t h e r e f o r e maynot meet ARARs for groundwater q u a l i t y . As di s cus s ed in the " F i n a lT e c h n i c a l Memorandum on N i n e C r i t e r i a A s s e s s m e n t " , naturala t t enuat ion mechanisms may be s u f f i c i e n t to remediate thegroundwater north o f the l a n d f i l l . T h e r e f o r e , A l t e r n a t i v e 6A and6B are retained for comparat ive a n a l y s i s .

Primary b a l a n c i n g f a c t o r s i n c l u d e the cri teria upon which thea l t e rna t iv e a n a l y s i s i s based. T h e s e cri teria inc lude:

• Long-term e f f e c t i v e n e s s and permanence;

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Reduct ion of t o x i c i t y , m o b i l i t y , and volume throughtreatment ;Short- t erm 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 ; and,C o s t s .

M o d i f y i n g f a c t o r s ( i . e . , s ta t e acceptance and community a c c e p t a n c e )are evaluated a f t e r comment on the f e a s i b i l i t y s tudy report and areaddres s ed once the f i n a l dec i s ion is being made and the Record ofDecis ion (ROD) is being p r e p a r e d . The a b i l i t y of the retaineda l t e rna t iv e s to meet these f a c t o r s is described in the f o l l o w i n gsections.

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The " F i n a l T e c h n i c a l Memorandum on N i n e Cr i t e r ia Asses sment"( C o l d e r A s s o c i a t e s , 1 9 9 1 c ) pr e s en t s an assessment of each alterna-tive against the nine cri teria. The comparative ana ly s i s ofal ternat ive s presented in the f o l l o w i n g sections assesses ther e la t iv e p e r f o r m a n c e of each a l t e r n a t i v e with respect to eachevaluat ion cr i t er ion. The p u r p o s e of the comparat ive ana ly s i s i sto i d e n t i f y the advantage s and d i s a d v a n t a g e s of each a l t e rna t iv er e la t iv e to one another. As recommended by the EPA in the"Guidance F o r C o n d u c t i n g Remedial I n v e s t i g a t i o n s a n d F e a s i b i l i t yS t u d i e s Under C E R C L A - I n t e r i m F i n a l " ( E P A , 1 9 8 8 a ) , t h ec i l t e rna t iv e s are d i s cu s s ed in the r e la t iv e order in which theyp e r f o r m , with the a l t e r n a t i v e ( s ) that i s considered to p e r f o r m bestunder each criterion d i s cu s s ed f i r s t . Under cost ( S e c t i o n 4 . 7 ) ,the a l t e rna t iv e with the lowest net present worth cost is presentedf i r s t .



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4.1 Overall Protec t ion of Human H e a l t h and the Environment

4.1.1 C a p p i n g O p t i o n s

Due to the presence of waste in contact with water, which is theprimary mechanism for contaminant migrat ion at the M o s l e y RoadS a n i t a r y L a n d f i l l , none o f t h e three c a p p i n g o p t i o n s o f f e r as i g n i f i c a n t advantage over the other c a p p i n g op t i on s in terms ofp r o t e c t i n g human h e a l t h and the environment. Each c a p p i n g o p t i o nw i l l reduce the p o t e n t i a l for p r e c i p i t a t i o n to i n f i l t r a t e into thel a n d f i l l and thereby assist in p r o t e c t i n g human hea l th and theenvironment. However , the amount of i n f i l t r a t i o n and concomitantincreased p o t e n t i a l f or contaminant m o b i l i z a t i o n i s i n s i g n i f i c a n tcompared to the p o t e n t i a l for contaminant m o b i l i z a t i o n provided bygroundwater migra t ing through waste.

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4.1.2 A l t e r n a t i v e s

Overall p r o t e c t i o n of human h e a l t h and the environment is assumedt o b e achievable through either (1) i n s t i t u t i o n a l control s or (2)source containment, ex trac t ion, and treatment (if necessary) ofgroundwater a n d / o r l eacha t e in c o n j u n c t i o n with i n s t i t u t i o n a lcon tro l s . The manner in which each of the a l t e rna t iv e s p r o t e c t shuman heal th and the environment varies. Certain al ternat ive s( i . e . , 4A, 5A) pro t e c t human h e a l t h and the environment bye x t rac t ing groundwater and a p p l y i n g i n s t i t u t i o n a l contro l s . Otheral t ernat ive s ( i . e . , 6A, 6B) protec t human heal th and theenvironment by e x t r a c t i n g l eachate in combination withi n s t i t u t i o n a l c on tro l s . Some a l t e rna t iv e s ( i . e . , 7 A , 7 B , 8 A , 8 B )protec t human h e a l t h and the environment by ex trac t ing bothgroundwater and l eacha t e in combination with in s t i t u t i ona lcontro l s . A l t e r n a t i v e 2 p r o t e c t s human h e a l t h throughi n s t i t u t i o n a l control s .



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In comparing the a b i l i t y of each of the retained a l t ernat ive s toprotec t human h e a l t h and the environment, p r e f e r e n c e is given tothose a l t e rnat ive s that prov ide for a phys i ca l barrier ( i . e . , as lurry w a l l ) t o migra t i on o f contaminants f r o m th e l a n d f i l l intothe surrounding a l l u v i a l a q u i f e r . A slurry wall is assumed toprovide a higher degree of p r o t e c t i o n than does a series of p u m p i n gw e l l s . Pumping w e l l s are more prone to p e r i o d i c f a i l u r e than as lurry wall and t h e r e f o r e have a c o r r e s p o n d i n g l y higher p o s s i b i l i t yof contaminants e s c a p i n g the containment system.

A l t e r n a t i v e s 6B, 7B, and 8B incorporate construct ion of a slurrywall and thereby p r o v i d e for p h y s i c a l containment of contaminantswithin and d i r e c t l y beneath the l a n d f i l l . A l t e r n a t i v e s 7B and 8Bal so inc lude direct r emed ia t i on of the contaminated a l l u v i a lgroundwater north of the l a n d f i l l . T h e r e f o r e , A l t e r n a t i v e s 7B and8B prov id e the h ighes t degree of p r o t e c t i o n to human h e a l t h and theenvironment. The only d i f f e r e n c e between these two a l t e rna t iv e s i sthat A l t e r n a t i v e 7B assumes that the concentrat ions of contaminantswi th in the a l l u v i a l groundwater north of the l a n d f i l l are lowenough to a l l o w for direct d i s charge to a POTW or s u r f a c e waterwithout t r ea tment , whi l e A l t e r n a t i v e 8B assumes that the a l l u v i a lgroundwater contaminant concentrat ions are high enough to warranttreatment pr ior to d i s charge to a POTW or s u r f a c e water.

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A l t e r n a t i v e 6B does not i n c l u d e active r emedia t i on of thecontaminated a l l u v i a l groundwater north o f th e l a n d f i l l .T h e r e f o r e , A l t e r n a t i v e 6B is e s t imat ed to prov id e a lower degree ofp r o t e c t i o n to human h e a l t h and the environment than wouldA l t e r n a t i v e s 7B or 8B. N a t u r a l a t t enua t i on mechanisms may bes u f f i c i e n t to remediate the a l l u v i a l groundwater north of thel a n d f i l l . I n s t i t u t i o n a l c on tro l s to be enacted as part ofA l t e r n a t i v e 6B may i n c l u d e access r e s t r i c t i on s to the area north ofthe l a n d f i l l to create a c o n t r o l l e d area. T h i s would prevent human



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exposure to a l l u v i a l groundwater w h i l e a t t enua t i on mechanisms actto reduce the contaminant concentrat ions to a c c e p t a b l e l eve l s .

A l t e r n a t i v e s 6A, 7A, and 8A incorporate l eachate ex tract ion f r o mwithin the l a n d f i l l f o o t p r i n t a s the primary mechanism forp r o t e c t i n g human h e a l t h and the environment. A l t e r n a t i v e s 6A, 7A,and 8A do not incorporate construct ion of a slurry w a l l ; t h e r e f o r e ,they are considered to be s l i g h t l y l e s s e f f e c t i v e in p r o t e c t i n ghuman h e a l t h and the environment than would A l t e r n a t i v e s 6B, 7B,and 8B. Leachate ex trac t ion f r o m wi th in the l a n d f i l l f o o t p r i n t hasa high p r o b a b i l i t y of achieving the des ired reduction in a l l u v i a lwater l ev e l s beneath the l a n d f i l l and the corre sponding reversal ofvertical h y d r a u l i c g r a d i e n t s between the a l l u v i a l and Garber-W e l l i n g t o n a q u i f e r s (see S e c t i o n 3 ) .

A l t e r n a t i v e s 7A and 8A a l s o i n c l u d e direct remediat ion of thecontaminated a l l u v i a l groundwater north o f t h e l a n d f i l l , whi l eA l t e r n a t i v e 6A does not. T h e r e f o r e , A l t e r n a t i v e s 7A and 8A providea s l i g h t l y higher degree of p r o t e c t i o n to human h e a l t h and theenvironment than does A l t e r n a t i v e 6A. The only d i f f e r e n c e betweenA l t e r n a t i v e s 7A and 8A is that A l t e r n a t i v e 7A assumes that theconcentrat ions o f contaminant s wi th in the a l l u v i a l groundwaternorth of the l a n d f i l l are low enough to a l l o w for direct d i s chargeto a POTW or s u r f a c e water without t r e a t m e n t , whi l e A l t e r n a t i v e 8Aassumes that the a l l u v i a l groundwater contaminant concentrationsare high enough to warrant treatment pr ior to d i s charge to a POTWor s u r f a c e water. A l t e r n a t i v e 6A, which does not inc lude activeremedia t ion of the contaminated a l l u v i a l groundwater north of thel a n d f i l l , i s e s t imat ed to p r o v i d e a lower degree of p r o t e c t i o n tohuman h e a l t h and the environment than would A l t e r n a t i v e s 7A or 8A.N a t u r a l a t t enua t i on mechanisms may be s u f f i c i e n t to remediate thea l l u v i a l groundwater north o f t h e l a n d f i l l under A l t e r n a t i v e 6A.A d d i t i o n a l l y , l eacha t e wi thdrawal under th i s a l t e rnat ive may

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remediate all or a p o r t i o n of the a l l u v i a l groundwater north of thel a n d f i l l .

2\ l t e rnat ive s 4A and 5A would pro tec t human h ea l th and theenvironment by direct ex trac t ion of a l l u v i a l groundwater around theperimeter of the l a n d f i l l and by i n t e r c e p t i n g contaminatedgroundwater and l eachat e f r o m under and within the l a n d f i l l .A l t e r n a t i v e s 4A and 5A have a lower p r o b a b i l i t y of achieving thedes ired reduct ion in h y d r a u l i c head beneath the l a n d f i l l than wouldA l t e r n a t i v e s 6A, 7A, or 8A. A l t e r n a t i v e s 4A and 5A al so mayadver s e ly a f f e c t the water l ev e l s in surrounding s u r f a c e waterbodie s such as Crutcho Creek. The only d i f f e r e n c e betweenA l t e r n a t i v e s 4A and 5A is that A l t e r n a t i v e 4A assumes that theconcentrations of contaminants wi th in the a l l u v i a l groundwaternorth of the l a n d f i l l are low enough to a l l o w for direct d i s chargeto a POTW or s u r f a c e water without t r ea tmen t , wh i l e A l t e r n a t i v e 5Aassumes that the a l l u v i a l groundwater contaminant concentrationsare high enough to warrant treatment prior to discharge to a POTWor s u r f a c e water.

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A l t e r n a t i v e s 2 r e l i e s on access r e s t r i c t i on s and long-termmoni t or ing to prevent human and environmental exposure to compoundsof concern. A l t e r n a t i v e 2 a l s o would require a p r o h i b i t i o n on thed e v e l o p m e n t and use o f a l l u v i a l groundwater north of the l a n d f i l l .A long-term p o t e n t i a l threat to G a r b e r - W e l l i n g t o n groundwater wouldexist under A l t e r n a t i v e 2 because th i s a l t e r n a t i v e does not a l t e rthe e x i s t ing vertical hydrau l i c gradient s between the al luvium andthe G a r b e r - W e l l i n g t o n a q u i f e r s . A l t e r n a t i v e 2 may not pro tec tagainst exposure of environmental r e c ep tor s in areas wheregroundwater d i s charge s to s u r f a c e water or is in contact with p l a n troot s , or if the extent of groundwater contamination andconcentrat ion of contaminant s increases with time.

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4.2 C o m p l i a n c e with ARARs


Chemical-Specific ARARs

C h e m i c a l - s p e c i f i c ARARs do not a p p l y d i r e c t l y to c a p p i n g op t ions .Each c a p p i n g o p t i o n is d e s igned to i n d i r e c t l y assist in meetingc h e m i c a l - s p e c i f i c ARARs for other media such as groundwater. Dueto the presence of waste in contact with groundwater , which is theprimary mechanism for contaminant migra t i on at the M o s l e y RoadS a n i t a r y L a n d f i l l , none o f th e three c a p p i n g op t i on s o f f e r as i g n i f i c a n t advantage in terms of c ompl iance with c h e m i c a l - s p e c i f i cARARs.

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Action-Specific ARARs

T a b l e 5-2 o f th e " F i n a l A l t e r n a t i v e s Array Document" ( C o l d e rA s s o c i a t e s , 1 9 9 1 b ) l i s t s t h e p o t e n t i a l a c t i o n - s p e c i f i c ARARs f o rthe s i te. All three of the retained c a p p i n g o p t i o n s are expec tedto meet a c t i o n - s p e c i f i c A R A R s .

Location-Specific ARARs

T a b l e 5-3 o f th e " F i n a l A l t e r n a t i v e s Array Document" ( G o l d e rA s s o c i a t e s , 1 9 9 I b ) l i s t s t h e p o t e n t i a l l o c a t i o n - s p e c i f i c ARARs f o rthe site. All three of the retained c a p p i n g o p t i o n s are expec t edto meet l o c a t i o n - s p e c i f i c A R A R s .


T h r e e t y p e s o f p o t e n t i a l ARARs have been i d e n t i f i e d for theal ternatives . T h e s e inc lude c h e m i c a l - s p e c i f i c , a c t i o n - s p e c i f i c ,



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and l o c a t i o n - s p e c i f i c A R A R s . The " F i n a l T e c h n i c a l Memorandum onN i n e C r i t e r i a Asse s sment" ( C o l d e r A s s o c i a t e s , 1991c) pre s ent s asummary o f the p o t e n t i a l ARARs for the site. The f o l l o w i n gsect ions compare each of the a l t e rna t iv e s r e la t ive to each of theARAR t y p e s .

Chemical-specific ARARs

C h e m i c a l - s p e c i f i c ARARs f o r t h e a l t e rna t iv e s p o t e n t i a l l y a p p l y t othe q u a l i t y of groundwater in the a l l u v i a l a q u i f e r immed ia t e lynorth of the l a n d f i l l , and to d i s charge of l eachat e , groundwater,or a combination of l eachate and groundwater. C h e m i c a l - s p e c i f i cARARs are d i s cus s ed in d e t a i l in the " F i n a l T e c h n i c a l Memorandum onN i n e Cr i t e r ia Asse s sment" . The a l t e rna t iv e s that incorporateactive c o l l e c t i o n and treatment of l eachate and a l l u v i a lgroundwater pr ior to d i s charge are assumed to be the most l i k e l y tomeet c h e m i c a l - s p e c i f i c A R A R s . A l t e r n a t i v e s 8A and 8B would meetthese cri teria. A l t e r n a t i v e s that incorporate c o l l e c t i o n andtreatment of l eachate but do not in c lude treatment of c o l l e c t e dgroundwater pr ior to d i s charge would be s l i g h t l y l e s s l i k e l y tomeet c h e m i c a l - s p e c i f i c A R A R s . A l t e r n a t i v e s 7A and 7B f a l l intoth i s category.

A l t e r n a t i v e 6A in c lud e s ex trac t ion and treatment of l eachat e priorto d i s c h a r g e , but does not i n c l u d e direct r emedia t i on of a l l u v i a lgroundwater north o f the l a n d f i l l . It i s e s t imated thatA l t e r n a t i v e 6A w i l l c o l l e c t at l eas t a p o r t i o n of the contaminateda l l u v i a l groundwater north o f t h e l a n d f i l l dur ing p u m p i n g .H o w e v e r , A l t e r n a t i v e 6A may not r emediat e all of the contaminateda l l u v i a l groundwater north of the l a n d f i l l and may not meetc h e m i c a l - s p e c i f i c ARARs f o r a l l u v i a l groundwater qua l i ty .A l t e r n a t i v e 6A would be s l i g h t l y l e s s e f f e c t i v e in meet ingc h e m i c a l - s p e c i f i c ARARs than A l t e r n a t i v e s 7A and 7B.

inr-CMvOoo



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A l t e r n a t i v e 6B inc lude s ex trac t ion and treatment of l eachate priorto d i s c h a r g e , but does not in c lude remediat ion of a l l u v i a lgroundwater north of the l a n d f i l l . A l t e r n a t i v e 6B would rely onnatural a t t enuat i on mechanisms to remediate the a l l u v i a lgroundwater north of the l a n d f i l l . The construct ion of a slurrywal l under A l t e r n a t i v e 6B would assist the natural at tenuationmechanisms by p h y s i c a l l y i s o l a t i n g the source of contaminat ion tothe a l l u v i a l groundwater. I n s t i t u t i o n a l control s to be enacted aspart of A l t e r n a t i v e 6B may i n c l u d e access r e s tr i c t ions to the areanorth of the l a n d f i l l to create a c o n t r o l l e d area. T h i s wouldprevent human exposure to a l l u v i a l groundwater whi l e a t t enuat ionmechanisms act to reduce the contaminant concentrations toa c c e p t a b l e l eve l s . A l t e r n a t i v e 6B would be s l i g h t l y less e f f e c t i v ein meet ing c h e m i c a l - s p e c i f i c ARARs than A l t e r n a t i v e 6A.

vOr~-(M\DCC

A l t e r n a t i v e 5A i n c l u d e s e x t rac t i on and treatment of a l l u v i a lgroundwater north of the l a n d f i l l pr i or to d i s c h a r g e , but does notin c lud e direct r emed ia t i on o f l ea cha t e . Direct r emedia t ion o fl eachat e beneath the l a n d f i l l f o o t p r i n t is considered to be moreb e n e f i c i a l for the s i t e than i s direc t r emed ia t i on of a l l u v i a lgroundwater north o f t h e l a n d f i l l . T h e r e f o r e , A l t e r n a t i v e 5A W o u l dbe s l i g h t l y l e s s e f f e c t i v e in mee t ing c h e m i c a l - s p e c i f i c ARARs thanA l t e r n a t i v e 6B.

A l t e r n a t i v e 4A i n c l u d e s e x t ra c t i on of a l l u v i a l groundwater north ofthe l a n d f i l l , but does not i n c l u d e treatment of the groundwaterprior to d i s charge . A l t e r n a t i v e 4A a l s o does not in c lude directr emed ia t i on o f l e a cha t e beneath t h e l a n d f i l l f o o t p r i n t .A l t e r n a t i v e 4A may not meet c h e m i c a l - s p e c i f i c ARARs for d i s charge .

A l t e r n a t i v e 2 may not meet c h e m i c a l - s p e c i f i c ARARs because thisa l t e rna t iv e does not i n c l u d e remedial act ions that d i r e c t l y addre s s



Rev 1903-2223

compounds of concern in groundwater or d i s charge s to s u r f a c e waterf r o m a l l u v i a l groundwater.

Action-specific ARARs

A c t i o n - s p e c i f i c ARARs p o t e n t i a l l y a p p l y t o c a p p i n g ; closure withwaste i n - p l a c e ; di s charge of untreated groundwater and leachate toa POTW; d i s charge of treated groundwater and l eachate to s u r f a c ewater; and air s t r i p p i n g . The " F i n a l T e c h n i c a l Memorandum on N i n eCr i t e r ia Asse s sment" d i s cu s s e s the a c t i o n - s p e c i f i c ARARs in d e t a i l .W i t h the e x c e p t i o n o f A l t e r n a t i v e 2 , a l l o f the retaineda l t e r n a t i v e s are e xpe c t ed to meet the a c t i o n - s p e c i f i c ARARs forc a p p i n g and closure with waste in-p la c e . A l t e r n a t i v e s 5A, 6A, 6B,8A, and 8B are expec t ed to meet the a c t i o n - s p e c i f i c ARARs ford i s charge of groundwater a n d / o r l eacha t e to a POTW or s u r f a c e waterbody under an NPDES permi t . A l t e r n a t i v e s 4A, 7A, and 7B may notmeet a c t i o n - s p e c i f i c ARARs f or d i s charge o f groundwater a n d / o rl ea cha t e to a POTW or s u r f a c e water b o d y , since these a l t e rna t iv e sdo not i n c l u d e treatment of groundwater a n d / o r l eachate prior tod i s charge . A l t e r n a t i v e 2 may not meet the a c t i o n - s p e c i f i c ARARsr e g a r d i n g closure requirements under the Resource Conservat ion andRecovery A c t ( R C R A ) .

CV!vOoG

Location-specific ARARs

L o c a t i o n - s p e c i f i c ARARs f o r t h e s i t e in c lud e R C R A , t h e N a t i o n a lH i s t o r i c a l Preservat ion A c t ( N H P A ) , t h e Endangered S p e c i e s A c t( E S A ) , a n d prov i s i on s o f t h e C l e a n W a t e r A c t ( C W A ) regardingw e t l a n d s . T h e " F i n a l T e c h n i c a l Memorandum o n N i n e Cr i t e r iaAsse s smen t" d i s cu s s e s the l o c a t i o n - s p e c i f i c ARARs in d e t a i l .L o c a t i o n - s p e c i f i c ARARs do not a p p l y to A l t e r n a t i v e 2, sinceA l t e r n a t i v e 2 does not in c lud e hazardous waste t r ea tment , s torage,or d i s p o s a l ; cons truct ion or a l t e r a t i o n of t errain; actions that



Rev 1903-2223

may impact endangered or threatened s p e c i e s ; or actions that mayimpact w e t l a n d s . All o f the retained a l t e rna t iv e s other thanA l t e r n a t i v e 2 may not meet p o s s i b l e l o c a t i o n - s p e c i f i c ARARsr egard ing w e t l a n d s , since all of the a l t e rna t iv e s other thanA l t e r n a t i v e 2 i n c l u d e prov i s i on s f o r dra in ing N o r t h Pond.

4.3 L o n g - T e r m E f f e c t i v e n e s s and Permanence


Routine maintenance w i l l be required for each of the c a p p i n go p t i o n s . The re s idual risk a s soc ia t ed with each c a p p i n g op t i on i sexpe c t ed to be low. C a p p i n g o p t i o n 4, which inc lude s the a d d i t i o nof two f e e t o f c lay over the entire l a n d f i l l , w i l l increase thethicknes s of the cap and thereby would reduce the p o t e n t i a l forcracks to d e v e l o p through the cap. C a p p i n g o p t i o n 2, whichinc lud e s the a d d i t i o n of two f e e t of c lay over the waste pit areaso n l y , would reduce the p o t e n t i a l for cracks to d e v e l o p over thewaste p i t s but would not reduce the p o t e n t i a l for cracks to d e v e l o pover the remainder of the l a n d f i l l . C a p p i n g o p t i o n 1, whichi n c l u d e s repair of the e x i s t i n g cover, would not increase the capth i ckne s s and thereby reduce the p o t e n t i a l for cracks to d e v e l o p inthe cover. W i t h p r o p e r maintenance, however, the c a p p i n g o p t i o n sare expec t ed to assi s t in ensuring that p o t e n t i a l exposure to humanand environmental r e c ep tor s is w i th in a c c e p t a b l e l ev e l s .

00h-CM\OCO


Alternatives 6B, 7B, and 8B

A l t e r n a t i v e s 6B, 7B, and 8B, which incorporat e cons truct ion of as lurry w a l l , would p r o v i d e the most e f f e c t i v e long-term control oncontaminant migra t i on through in t roduc t i on of a p h y s i c a l barrier to


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f l o w ( i . e . , the s lurry w a l l ) . The s lurry wall would not bea n t i c i p a t e d to require ongoing maintenance or r ep la c ement , a l thoughp e r i o d i c r ep lacement of recovery well p u m p s may be necessary. Itwould continue to be e f f e c t i v e in prevent ing o f f - s i t e migrat ionvia a l l u v i a l groundwater even if the l eachate ex tract ion systemceased op era t i on and is t h e r e f o r e expec t ed to maintain p o t e n t i a lexposure to human and environmental receptors at acc ep tab l e levels .Under A l t e r n a t i v e s 6B, 7B and 8B, long-term p r o t e c t i o n of theG a r b e r - W e l l i n g t o n a q u i f e r p o t e n t i a l l y could be maintained by apas s ive drain system lo ca t ed ou t s id e the s lurry w a l l . The residualrisks as soc iated with these a l t e r n a t i v e s are expec t ed to be low.Some re s idual risk may remain for ing e s t i on of a l l u v i a l groundwaterou t s id e of the s lurry wal l under A l t e r n a t i v e 6B. However, over thelong-term, natural a t t enua t i on mechanisms are a n t i c i p a t e d to reduceth i s re s idual risk to a c c e p t a b l e l ev e l s .

The magn i tud e o f r e s idual risks as soc iated with A l t e r n a t i v e s 6B,7B, and 8B are equivalent . A l t e r n a t i v e 8B assumes that treatmentof a l l u v i a l groundwater north of the l a n d f i l l w i l l be necessary toreduce the m a g n i t u d e o f r e s idua l risks to a c c e p t a b l e l eve l s . Thed e f i n i t i o n of a c c e p t a b l e l e v e l s is to be n ego t ia t ed with the EPAdur ing p r e p a r a t i o n of the Record of Deci s ion ( R O D ) . A l t e r n a t i v e 7Bassumes that the concentrat ion of contaminant s in groundwater arelow enough that treatment w i l l not be necessary to reduce themagni tude of r e s idual risks to a c c e p t a b l e l ev e l s . A l t e r n a t i v e 6Bassumes that natural a t t enua t i on mechanisms w i l l reduce themagni tude of re s idual risks to a c c e p t a b l e l e v e l s . Each of thesea l t e rna t iv e s assume that l ea cha t e w i l l be treated prior tod i s charge . The re s idual risks a s soc ia ted with these a l t e rnat ive sare expe c t ed to be low.

The treatment system p r o p o s e d for use at the s i te u t i l i z e s provent e c h n o l o g i e s . Management c on tro l s w i l l be in s t i t u t ed to ensure

CMvOoo


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that d i s p o s a l of treatment r e s i d u a l s w i l l be conducted inaccordance with a p p l i c a b l e r e g u l a t i o n s , thus p r o v i d i n g continuedp r o t e c t i o n f r o m release of treatment r e s i dua l s into theenvironment .

Alternatives 6 A, 7 A, and 8 A

A l t e r n a t i v e s 6A, 7A, and 8 A prov id e e s s e n t i a l l y equivalent long-term e f f e c t i v e n e s s and permanence. Each of these a l t ernat ive sin c lud e s l eachat e and u n d e r l y i n g a l l u v i a l groundwater extract ionf r o m beneath the l a n d f i l l f o o t p r i n t . A l t e r n a t i v e s 7A and 8A alsoin c lude direct r emedia t i on of a l l u v i a l groundwater north of thel a n d f i l l . A l t e r n a t i v e 6A re l i e s on natural a t t enuat ion mechanismsto reduce the concentrat ions of contaminant s ou t s id e the radius ofi n f l u e n c e o f the recovery w e l l s to a c c e p t a b l e l ev e l s . The long-term e f f e c t i v e n e s s of these a l t e r n a t i v e s would be d e p e n d e n t oncontinued op era t i on and maintenance of the ex trac t ion and d i s chargesystem. P e r i o d i c r ep lac ement of recovery wel l p u m p s may be needed.A l t e r n a t i v e s 6A, 7A, and 8A would require active control of thes i te and op e ra t i on o f t h e ex trac t ion system i n d e f i n i t e l y . Ifp r o p e r l y i m p l e m e n t e d , long-term re s idual risks f o r thesea l t e r n a t i v e s would be w i th in p r o t e c t i v e l e v e l s .

OOCCM\OGO

The treatment system p r o p o s e d for use at the s i te u t i l i z e s provent e c h n o l o g i e s . Management c on t ro l s w i l l be i n s t i t u t e d to ensurethat d i s p o s a l of treatment r e s i d u a l s w i l l be conducted inaccordance with a p p l i c a b l e r e g u l a t i o n s , thus p r o v i d i n g continuedp r o t e c t i o n f r o m release o f treatment r e s i d u a l s into theenvironment .



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Alternatives 4A and 5A

A l t e r n a t i v e s 4A and 5A prov ide e s s e n t i a l l y equivalent long-terme f f e c t i v e n e s s and permanence. T h e s e a l t e rna t iv e s inc lude a l l u v i a lgroundwater ex tract ion f r o m the l a n d f i l l p er imeter , which i sassumed to be le s s d e s i r a b l e than ex tract ion of l eachate f r o mwithin the l a n d f i l l f o o t p r i n t due to the d i f f i c u l t y in achievingthe desired lowering of hydrau l i c heads beneath the l a n d f i l l underthese a l t e rna t iv e s . The long-term e f f e c t i v e n e s s o f A l t e r n a t i v e s 4Aand 5A would be d ep enden t on continued opera t ion and maintenance ofthe ex trac t ion and d i s charge system. Per iod i c replacement ofrecovery we l l p u m p s may be needed. T h e s e a l t ernat ive s wouldrequire active control of the s i te and op era t i on of the ex trac t ionsystem i n d e f i n i t e l y . I f p r o p e r l y i m p l e m e n t e d , t h e long-termre s idual risks would be w i th in p r o t e c t i v e l ev e l s .

00CMvOOo

Alternative 2

A l t e r n a t i v e 2 is considered to be l e s s able to meet the goa l s oflong-term e f f e c t i v e n e s s and permanence than are the othera l t e rna t iv e s . It does not contain or remediat e the source causinggroundwater contaminat ion. Res idual risks to human receptors wouldbe s i g n i f i c a n t unle s s groundwater use was p r o h i b i t e d in a f f e c t e dareas. Residual risks to environmental r e c ep tor s could p o t e n t i a l l yincrease with time if c on taminat i on s p r e a d s in the groundwater,which could result in an increased risk of exposure to human andenvironmental r e c ep tor s .


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4.4 Reduct ion o f T o x i c i t y , M o b i l i t y , and V o l u m e T h r o u g h T r e a t m e n t


Reduction of Contaminant Mobility

Due to the presence of waste in contact with groundwater, which isthe primary mechanism for contaminant migrat ion at the s i t e , noneof the three c a p p i n g op t i on s o f f e r a s i g n i f i c a n t advantage over theother c a p p i n g o p t i o n s in terms of reducing contaminant m o b i l i t y .The c a p p i n g o p t i o n s are not de s igned to reduce contaminantm o b i l i t y .

Reduction of Contaminant Toxicity and Volume

The c a p p i n g op t i on s w i l l not assist in reducing contaminantt o x i c i t y or volume.


deduct ion of Contaminant Mobility

A l t e r n a t i v e s 7B and 8B p r o v i d e the greates t reduct ion incontaminant m o b i l i t y by i n c o r p o r a t i n g a p h y s i c a l barrier ( i . e . , aslurry w a l l ) to reduce the p o t e n t i a l for contaminants to migrateaway f r o m the s i te. A l t e r n a t i v e s 7B and 8B a l s o reduce contaminantm o b i l i t y by in corpora t ing a l l u v i a l groundwater recovery north oft h e l a n d f i l l .

A l t e r n a t i v e 6B incorpora t e s a p h y s i c a l barrier to contaminantm o b i l i t y ( i . e . , a s lurry w a l l ) , bu t does no t in c lude a l l u v i a lgroundwater recovery north o f the l a n d f i l l .

(MCDOJvOoo

G o i d e r Assoc ia t e s


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A l t e r n a t i v e s 7A and 8A are considered to prov id e a s l i g h t l y lowerreduct ion in contaminant m o b i l i t y since they do not inc ludeconstruct ion of a s lurry w a l l .

A l t e r n a t i v e 6A does not inc lude direct a l l u v i a l groundwaterrecovery north of the l a n d f i l l . A l t e r n a t i v e 6A is considered to bel e s s e f f e c t i v e in reducing contaminant m o b i l i t y than areA l t e r n a t i v e s 7 A and 8A.

A l t e r n a t i v e s 4A and 5A p r o v i d e a reduc t ion of contaminant m o b i l i t yout s ide of the l a n d f i l l but may not be able to achieve the desiredreduct ion of h y d r a u l i c head beneath the l a n d f i l l . Under thesea l t e r n a t i v e s , contaminants may have the p o t e n t i a l to migratev e r t i c a l l y downward into the u n d e r l y i n g G a r b e r - W e l l i n g t o n a q u i f e r .

COcvvOoo

A l t e r n a t i v e 2 does not reduce contaminant m o b i l i t y .

Reduction of Contaminant Toxicity and Volume

A l t e r n a t i v e s 7A, 7B, 8A, and 8B p r o v i d e an e s s e n t i a l l y equivalentreduct ion in contaminant volume and t o x i c i t y by ex trac t inggroundwater and l eachat e . A l t e r n a t i v e s 4A, 5A, and 6A would bes l i g h t l y l e s s e f f e c t i v e in reduc ing contaminant volume andt o x i c i t y , since they may or may not remediate all of thecontaminated a l l u v i a l groundwater north o f t h e l a n d f i l l .A l t e r n a t i v e 6B, which does not in c lud e active remediat ion of thea l l u v i a l groundwater north o f the l a n d f i l l , would be les s e f f e c t i v ein reducing contaminant volume and t o x i c i t y than would A l t e r n a t i v e6 A .

A l t e r n a t i v e 2 does not p r o v i d e a reduc t ion in the t o x i c i t y ,m o b i l i t y , or volume of contaminant s through treatment.



Rev 1903-2223

4.5 S h o r t - T e r m E f f e c t i v e n e s s


Protection of the Community During Remedial Actions

Risks to the community during i m p l e m e n t a t i o n of any of the c a p p i n go p t i o n s are expec t ed to be n e g l i g i b l e .

Protection of Workers During Remedial Actions

Risks to workers dur ing i m p l e m e n t a t i o n of any of the c a p p i n go p t i o n s are expec t ed to be n e g l i g i b l e .

Environmental Impacts

Cons truc t i on a c t i v i t i e s for the c a p p i n g o p t i o n s would be conductedp r i m a r i l y o n t h e e x i s t i n g l a n d f i l l . A l l o f t h e c a p p i n g op t i on sinc lude revege ta t ion o f the cap. T h e r e f o r e , environmental impac t sare expec t ed to be i n s i g n i f i c a n t for any of the c a p p i n g op t ions .

Time Until Response Objectives are Achieved

U p g r a d i n g the c lay cap is l i k e l y to be c o m p l e t e d much more quicklythan remedia t ion of the l eachate . U p g r a d i n g the cap w i l l nots i g n i f i c a n t l y a f f e c t t h e time unti l r e sponse o b j e c t i v e s ar eachieved.

00CMvOCo



Rev 1903-2223


Protection of the Community During Remedial Actions

Risks to the community during construct ion and operat ion of any ofthe remedial a l t e rna t iv e s would be n e g l i g i b l e . Risks to thecommunity during i m p l e m e n t a t i o n o f th e a l t ernat ive s inc lude (1)p o t e n t i a l emission o f contaminants during treatment and (2)t ranspor t of ma t e r ia l s via truck or p i p e l i n e to a POTW. Thef o l l o w i n g t a b l e l i s t s the risks a s soc ia ted with each a l t ernat ive:

24A5A6A6B7A7B8A8B

. ' : ' ' . ' . . v • : : ' P d t e i l t i a l i f t q ; • • : : ^ : $ ; | f• ^ :-' :-i -' Generate- ' A i r / ! ; ; ;|ii j; • ;; ; •:.:-^'; '••• \ • . ' i ©miss ion s^^ |f i||

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X

XX

inCO<MvOco

A l t e r n a t i v e s which i n c l u d e treatment ( e . g . A l t e r n a t i v e 5A) a r econsidered to have the p o t e n t i a l to generate emissions.A l t e r n a t i v e s which inc lude d i s charge to a POTW ( e . g . A l t e r n a t i v e4A) are considered to in c lud e t ranspor t of ma t e r ia l s via truck orp i p e l i n e . A l t e r n a t i v e s 7A and 7B are as s igned to each category,since these a l t e r n a t i v e s i n c l u d e treatment of l eachate incombination with d i s charge of a l l u v i a l groundwater to a POTW.



Rev 1903-2223

Based on the p r e c e d i n g t a b l e , A l t e r n a t i v e 2 is considered to o f f e rthe l eas t risk to the community during remedial actions.A l t e r n a t i v e s 4A, 5A, 6A, 6B, 8A, and 8B are considered to o f f e r as l i g h t l y higher risk to the community, since they have thep o t e n t i a l to generate air emiss ions or inc lude transport ofmat er ia l s . A l t e r n a t i v e s 7A and 7B are considered to o f f e r thehighest risk to the community, since these alternatives have thep o t e n t i a l to generate air emissions via treatment of l eachate andinc lude transpor t of m a t e r i a l s via truck or p i p e l i n e to a POTW.

Protection of Workers During Remedial Actions

Risks to workers during remedial act ions taken under A l t e r n a t i v e 2would be n e g l i g i b l e . Risks to workers during remedial actionstaken under A l t e r n a t i v e s 4A and 5A would be comparab l e to risksn o r m a l l y as soc iated with closure of a munic ipal l a n d f i l l andi n s t a l l a t i o n of w e l l s ; t h e r e f o r e , risks to workers under thesea l t e rna t iv e s are not cons idered s i g n i f i c a n t .

Risks to workers dur ing remedial act ions taken under A l t e r n a t i v e s6A, 6B, 7A, 7B, 8A, and SB would be greater than under A l t e r n a t i v e s4A and 5A because w e l l s would be d r i l l e d into municipal r e fu s e .Previous d r i l l i n g exper i ence at the s i t e ind i ca t e s that r e sp i ra t oryp r o t e c t i o n would be needed dur ing d r i l l i n g . Risks to workers'during remedial ac t ions taken under A l t e r n a t i v e s 6A, 6B, 7A, 7B,8A, and 8B would be c omparab l e to each other.

Environmental Impacts

T h i s section d i s cu s s e s the p o t e n t i a l environmental impac t s thatmight occur as a direct resul t of cons truct ion and i m p l e m e n t a t i o nof the various a l t e rna t iv e s . In th i s c on t ex t , environmentalimpac t s do not in c lude i m p a c t s of s i te contamination. See S e c t i o n

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Rev 1903-2223

4 . 1 for a d i s cu s s i on of the overall p r o t e c t i o n of the environmentp o t e n t i a l l y a f f o r d e d by the a l t e rna t iv e s .

No s i g n i f i c a n t environmental impacts would occur as a direct resultof cons truct ion and i m p l e m e n t a t i o n of A l t e r n a t i v e 2. Of theremaining a l t ernat ive s , po t en t ia l environmental impacts would belowest for A l t e r n a t i v e 6B. A l t e r n a t i v e 6B would require p a r t i a l ortotal drainage of N o r t h Pond to a l l ow for construction of a slurryw a l l . However , drawdown e f f e c t s wi th in the area enclosed by thes lurry wall would no t s i g n i f i c a n t l y a f f e c t a l l u v i a l aqu i f e rgroundwater l e v e l s ou t s i d e o f th e s lurry w a l l . T h e r e f o r e , impact sto s u r f a c e water bodie s other than N o r t h Pond would be minimal.

r-oo

oo

P o t e n t i a l environmental impac t s under A l t e r n a t i v e s 7B and 8B wouldbe greater than those under A l t e r n a t i v e 6B because groundwaterc o l l e c t i o n ou t s ide of the s lurry wal l would be conducted. UnderA l t e r n a t i v e 7B, groundwater c o l l e c t i o n ou t s id e o f the s lurry wal lmay be necessary for a p p r o x i m a t e l y one year. T h e r e f o r e , long-termimpac t s to groundwater l e v e l s and s u r f a c e water bodies are notp r o j e c t e d under A l t e r n a t i v e 7B. A l t e r n a t i v e 8B may inc lude somelong-term lowering of the a l l u v i a l water l eve l s outs ide of thes lurry wa l l to maintain upward vert ical grad i en t s f r o m the Garber-W e l l i n g t o n aqu i f e r . However, these changes would be roughly 1 to5 f e e t and should not represent s i g n i f i c a n t impac t s .

P o t e n t i a l environmental i m p a c t s under A l t e r n a t i v e s 4A, 5A, and 6Aare comparab l e to each other. T h e s e a l t e rna t iv e s inc lude drainageof N o r t h P o n d , decreases in a l l u v i a l groundwater l e v e l s , p o t e n t i a ldecreases in s t r e a m f l o w of Crutcho Creek , and p o t e n t i a l lowering ofwater l ev e l s in S o u t h S w a m p and the abandoned sand and gravel p i t .No current groundwater users that would be a f f e c t e d by decreaseda l l u v i a l water l ev e l s have been i d e n t i f i e d near the site. Reducedf l o w s in Crutcho Creek could a f f e c t downstream water users and may



Rev 1903-2223

involve water r igh t s issues (see th e E P A - a p p r o v e d "RI/FS WorkP l a n " , C o l d e r A s s o c i a t e s , 1 9 8 9 ) . Reduced water l eve l s in S o u t hS w a m p would be b e n e f i c i a l to use of the area for d a i l y cover forthe East Oak S a n i t a r y L a n d f i l l .

P o t e n t i a l environmental impac t s under A l t e r n a t i v e s 7A and 8A ares imilar to those an t i c ipa t ed for A l t e r n a t i v e s 4A, 5A, and 6A, witha d d i t i o n a l environmental impac t s r e s u l t i n g f r o m i n s t a l l a t i o n o fboth l eachate and groundwater recovery w e l l s .

Time Until Response Objectives Are Achieved

It i s a n t i c i p a t e d that A l t e r n a t i v e s 4A, 5A, 6A, 7A, and 8A wouldrequire several months to i m p l e m e n t . Once i m p l e m e n t e d , thesea l t e r n a t i v e s would prov id e h y d r a u l i c containment within a relative-ly short per iod ( e . g . , several days to w e e k s ) . Remediat ion ofcontaminated a l l u v i a l groundwater under these a l t e rna t iv e s i se s t imat ed to take up to one year ( C o l d e r A s s o c i a t e s , 1 9 9 1 d ) .C a l c u l a t i o n s i n d i c a t e that A l t e r n a t i v e s 6A, 7A, and 8A may require3 to 15 years to achieve the de s ired reduc t ion in a l l u v i a l waterl ev e l s beneath the l a n d f i l l in order to reverse vertical grad i en t sbetween the a l l u v i a l and G a r b e r - W e l l i n g t o n a q u i f e r s . A l t e r n a t i v e s4A and 5A may require 10 to 150 years to achieve the des iredgradient reversal.

It is a n t i c i p a t e d that A l t e r n a t i v e s 6B, 7B, and 8B would requirea p p r o x i m a t e l y one year to i m p l e m e n t . Once i m p l e m e n t e d , each ofthese a l t e r n a t i v e s would p r o v i d e h y d r a u l i c containment and phy s i ca lcontainment almost i m m e d i a t e l y . Remedia t i on o f contaminateda l l u v i a l groundwater under A l t e r n a t i v e s 7B and 8B may take up toone year. A l t e r n a t i v e 6B does not i n c l u d e remediat ion ofcontaminated groundwater. As d i s cu s s ed in S e c t i o n 3.0, naturalat t enuat i on mechanisms may reduce contaminant concentrations to

00CDCMvOCc



Rev 1903-2223

a c c e p t a b l e l eve l s . A l t e r n a t i v e s 6B, 7B, and 8B may require 3 to 15years to achieve the desired gradient reversal between the a l luv ia la n d G a r b e r - W e l l i n g t o n a q u i f e r s ( C o l d e r A s s o c i a t e s , 1 9 9 I c ) .

The time to achieve re sponse o b j e c t i v e s under A l t e r n a t i v e 2 wouldbe d e p e n d e n t on the time needed to enact a p r o h i b i t i o n ongroundwater use north of the l a n d f i l l . T h i s proces s may requirecons iderab l e time and would have to be u p d a t e d p e r i o d i c a l l y if theextent of contaminated groundwater increases with time.

4.6 I m p 1 e m e n t a b i 1 i t v

CT00CMvDOo


Technical Feasibility

The retained c a p p i n g o p t i o n s are s i m i l a r to one another in thateach o p t i o n inc lude s p la c ement of a d d i t i o n a l c lay on the l a n d f i l l .The primary d i f f e r e n c e between the o p t i o n s in merely the volume ofc lay that would be p l a c e d . T h e r e f o r e , each c a p p i n g o p t i o n ist e c h n i c a l l y f e a s i b l e .

Administrative Feasibility

The retained c a p p i n g o p t i o n s are s imi lar to one another in thateach o p t i o n in c lude s p la c emen t o f a d d i t i o n a l c lay on the l a n d f i l l .The primary d i f f e r e n c e between the o p t i o n s in merely the volume ofc lay that would be p l a c e d . T h e r e f o r e , each c a p p i n g o p t i o n isa d m i n i s t r a t i v e l y f e a s i b l e .



Rev 1903-2223


Technical Feasibility

Each a l t ernat ive u t i l i z e s proven t e c h n o l o g i e s and r e a d i l y ava i lab l emat er ia l s and equipment. Each a l t e rna t iv e is t h e r e f o r e t e c h n i c a l l yf e a s i b l e .

Administrative Feasibility

A l t e r n a t i v e s 6B, 7B, and 8B are considered to be the most f e a s i b l ef r o m a n a d m i n i s t r a t i v e s t a n d p o i n t . A l t e r n a t i v e s 4 A , 5 A , 6 A , 7 A ,and 8A are considered s l i g h t l y l e s s f e a s i b l e f r o m anadmini s t ra t iv e s t a n d p o i n t due to the increased p o t e n t i a l fordi s turbance s to s u r f a c e water bodie s near the site.A d m i n i s t r a t i v e l y , A l t e r n a t i v e 2 would be very d i f f i c u l t toimplement because it p o t e n t i a l l y removes s i g n i f i c a n t groundwaterresources f r o m d e v e l o p m e n t .

OO-OJv£CO

4.7 Cost

4.7.1 C a p p i n g Opt i on s

C a p p i n g o p t i o n 1 i s e s t ima t ed to cost a p p r o x i m a t e l y $1 ,800 ,000 .C a p p i n g o p t i o n 2 is e s t imated to cost a p p r o x i m a t e l y $1 ,900 ,000 .C a p p i n g op t i on 4 is e s t imated to cost about $ 3 , 7 0 0 , 0 0 0 . Plea s er e f e r to the " F i n a l T e c h n i c a l Memorandum on N i n e Cri t er iaAsse s sment" ( C o l d e r A s s o c i a t e s , 1 9 9 1 c ) f o r f u r t h e r d e t a i l .

4.7.2 A l t e r n a t i v e s/

Prel iminary cost ranges in terms of present net worth for each ofthe r e f i n e d a l t e r n a t i v e s are pre s ented in the " F i n a l T e c h n i c a l



Rev 1903-2223

Memorandum on N i n e C r i t e r i a Asse s sment" . For purpo s e s o f thismemorandum, the median cost for each of the a l t ernat ive s is usedf or compari son purpo s e s . M e d i a n present (in 1991 d o l l a r s ) ne tworth costs for the a l t e r n a t i v e s , i n c l u d i n g only c a p p i n g o p t i o n s 1,2 and 4; and, d i s charge to a POTW or s u r f a c e water under NPDES, areas f o l l o w s , in order of increas ing costs:

; i A^it e ' r i i a t i i e l l i i i l:' , ' i , 1 ' 1 , • , ' " • : • . • • ' ' • • ' . • > ' . . ' ' ; . , ; , ; . ; , ; , , , ; v ; . ; ; • ; • ; ; : , • . : X ' X v . ' v . ' v• , ' ' ' ' ! ' : • • • • • , v . • ' • ' • . • • • . , ' . • : • . • ' , ' , ' , ' , • ' : ' ' : • ' : • : > , ' • • • • • • . ' • ' • • • • ' • : • , • . • ! • ! • ; • ! • ! • : • ; • :' . ' • ' , • ' , , , ' , ' ' ' ' • ' " ' : ' ' ' ' ' ' ' : : ' : ' Y L ' X ' y ' ' ' ' - : v ' X ' L ' X ' X : X ' ; ; ' ' ' ; ' : ' ; ' ' . ; ; : ' > ' > . ' ; > : > : ' , : , ; . ] ' ' ! ; ' : ! ' X ; ; ! • '

A l t e r n a t i v e 2A l t e r n a t i v e 4AA l t e r n a t i v e 6AA l t e r n a t i v e 7AA l t e r n a t i v e 6BA l t e r n a t i v e 8AA l t e r n a t i v e 7BA l t e r n a t i v e 8BA l t e r n a t i v e 5 A

fjv- :\ :; .. Range of Co s t s V ::;:;;:|i; $: ( m i i iloiis^'b'f1' ''' dol lar s)l:: :

$0.5$2 .3 - $8.7

$3.6 - $20.4$3.5 - $22 .8$ 5 . 3 - $21.1$3.6 - $ 2 3 . 3$5.4 - $ 2 2 . 1$5.4 - $ 2 2 . 2$3.4 - $31.1

; t { t I i i ; i | m i l b i : ; i : l s i : ' l i ^ i T : ; ; : ; :$0.5$5.5

$12.0$13.2$13.2$13.5$13.8$13.8$17.3

It should be noted that costs are based on a period of per formanceof 20 years as per EPA guidance (EPA, 1 9 8 8 b ) . T h e r e f o r e , the costsdo not account for the p o s s i b i l i t y that remedial actions may needto be continued beyond 20 years.

4.8 S t a t e A c c e p t a n c e

A s p e r E P A guidance ( E P A , 1 9 8 8 a ) , s ta t e acceptance o f c a p p i n go p t i o n s and a l t e r n a t i v e s w i l l be addre s s ed in the Record ofDecis ion ( R O D ) .

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Rev 1903-2223

4.9 Community A c c e p t a n c e

As per EPA guidance ( E P A , 1 9 8 8 a ) , community acceptance of c a p p i n go p t i o n s and a l t e r n a t i v e s w i l l be addre s s ed in the ROD.

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5.0 R E F E R E N C E S

E P A , 1988a. Guidanc e f or C o n d u c t i n g Remedial I n v e s t i g a t i o n andF e a s i b i l i t y S t u d i e s under C E R C L A - I n t e r i m F i n a l . O S W E R19234.0-05.

E P A , 1988b. C E R C L A C o m p l i a n c e with Other Laws Manual . OS-W E R / 9 2 3 4 . 1 - 0 1 .

C o l d e r A s s o c i a t e s I n c . , 1989. M o s l e y Road S a n i t a r y L a n d f i l lRemedial I n v e s t i g a t i o n / F e a s i b i l i t y S t u d y ( R I / F S ) Work P l a n .C o l d e r A s s o c i a t e s I n c . , 1990a. F i n a l T e c h n i c a l Memorandum onPhysi ca l C h a r a c t e r i z a t i o n .C o l d e r A s s o c i a t e s I n c . , 1990b. F i n a l T e c h n i c a l Memorandum onSource C h a r a c t e r i z a t i o n .C o l d e r A s s o c i a t e s I n c . , 1990c. F i n a l T e c h n i c a l Memorandum onContaminant C h a r a c t e r i z a t i o n .C o l d e r A s s o c i a t e s I n c . , 1990d. F i n a l T e c h n i c a l Memorandum o nRef inemen t o f Remedial O b j e c t i v e s .C o l d e r A s s o c i a t e s I n c . , 1990e. F i n a l T e c h n i c a l Memorandum onRemedial T e c h n o l o g i e s S c r e e n i n g .C o l d e r A s s o c i a t e s I n c . , 1991a. F i n a l T e c h n i c a l Memorandum onA l t e r n a t i v e Deve lopment and S c r e e n i n g .C o l d e r A s s o c i a t e s I n c . , 1991b. F i n a l A l t e r n a t i v e s Array Document.C o l d e r A s s o c i a t e s I n c . , 1 9 9 I c . F i n a l T e c h n i c a l Memorandum o n N i n eC r i t e r i a A s s e s s m e n t .C o l d e r A s s o c i a t e s I n c . , 1991d. F i n a l Remedial I n v e s t i g a t i o nReport .NCP, 1980. Environmental P r o t e c t i o n A g e n c y N a t i o n a l Oi l andH a z a r d o u s P o l l u t i o n C o n t i n g e n c y P l a n . 40 CFR 300 under theComprehens ive Environmental Respon s e , C o m p e n s a t i o n , andL i a b i l i t y Act o f 1980.T e r r a c o n C o n s u l t a n t s , I n c . , 1989. M o s l e y Road L a n d f i l l C l a y CoverE v a l u a t i o n , Oklahoma C i t y , Oklahoma. L e t t e r report dated J u n e

13, 1989.

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Rev 1903-2223

W i c k e r s h a m , G i n i a , 1979. "Ground W a t e r Resources o f the SouthernPart of the Garber W e l l i n g t o n Ground W a t e r Basin, in C l e v e l a n dand Southern Oklahoma Count i e s and Part s of Pot tawatomieCounty, Oklahoma", Oklahoma W a t e r Resources Board H y d r o l o g i cI n v e s t i g a t i o n s P u b l i c a t i o n N o . 8 6 .

OJ\Ooo


T A B L ETABLE 3-1A N A L Y S I S O F C O L L E C T I O N O P T I O N S C O N S I D E R E D

1.1

1.2

1.3

2.1

no

no

no

no

4 A . 5 A

4 A . 5 A

4 A . 5 A

6A

10 w e l l s located around theper ime t er o f t h e l a n d f i l l ,s pa c ing approx . 600 f e e t20 w e l l s located around theper ime t er o f t h e l a n d f i l l ,s p a c i n g approx. 300 f e e t

drain on downgrad i en t s ide atan average elevation of 1139'

24 we l l s located in landfill

2.2 no 6A 24 we l l s located in landfill

2.3 yes

2.4 yes

6B 12 w e l l s located in landfill

68 12 w e l l s located in landfill

3 ft. at centero f l a n d f i l l10ft . atcenter ofl a n d f i l l7 ft. in thearea of N.Pond3 f t .t h r o u g h o u tl a n d f i l l

1 0 f t .throughoutl a n d f i l l

3 f t .t h r o u g h o u tl a n d f i l l1 0 f t .t h r o u g h o u tl a n d f i l l

60-120 10-150 yrs 20 years 0.63 to 1.26

200-400 10-150 yrs 20 years 2.10 to 4.20

30 to 130 gpm 3-25 yrs 20 years 0.32 to 1.37

40-120

80-200

3-15 yrs 20 years 0.42 to 1.26

3-15 yrs 20 years 0.84 to 2.10

25-50

75-150

3-15 yrs 20 years

3-15 yrs 20 years

0.26 to 0.53

0.79 to 1.58

Provides f or c o l l e c t i o n o f l eachatea f t e r i t enters a l l u v i a l groundwater.Provides for c o l l e c t i o n o f l eachatea f t e r i t enters a l l u v i a l groundwater.Provides f or c o l l e c t i o n o f l eachateafter i t enters a l l u v i a l groundwater.Does not s i g n i f i c a n t l y lower theleachate level wi thin the landf i l l .Provides for direct c o l l e c t i o n o fleachate. Recovery we l l s locatednear the boundary of the landfill wil i k e l y recover a l l u v i a l groundwatera long with leachate.Provides for direct c o l l e c t i o n ofleachate. Recovery we l l s locatednear the boundary of the landfill wil i k e l y recover a l l u v i a l groundwatera l o n g with leachate.Provides for direct c o l l e c t i on o fleachate. Slurry wall preventsrecovery of a l l u v i a l groundwater.Provides f or direct c o l l e c t i o n o fleachate. Slurry wall preventsrecovery of a l l u v i a l groundwater.

N O T E :1. S t e a d y - s t a t e p u m p i n g rate is d e p e n d e n t on the amount of vertical l eakage f r o m the G a r b e r - W e l l i n g t o n a q u i f e r .See text f or a fu l l e x p l a n a t i o n o f assumptions.2. All a l t e rna t iv e s that do not i n c l u d e a s lurry wall assume that North Pond will be drained.

E x p l a n a t i o n of Cases:1.1 t h r o u g h 1.3: Alluvial Groundwater C o l l e c t i o n2.1 through 2.4: Leachate Col l e c t ion3.1 t h r o u g h 3.10: Alluvial Groundwat er and Leachate C o l l e c t i o n

A u g u s t 1991 Page 1 of 3 1 0 0 6 2 9 5903-2223

3.1 no 7A, 8A 24 w e l l s in landfill, 5 w e l l s ond o w n g r a d i e n t s ide

3.2 no 7A, 8A 24 w e l l s in landfill, 5 w e l l s ond o w n g r a d i e n t side

3.3 no 7A, 8A 24 we l l s in landfill, drain ondowngrad i en t side at anaverage e l evat ion of 1 1 3 9 '3.4 no 7A, 8A 24 w e l l s in landfill, dra in ondowngradient side atan average e l evat ion of 1 1 3 9 '3.5 yes 7B, 88 12 we l l s in landfill, 5 w e l l s ondowngrad i en t side

3.6 yes 7B, 88 12 w e l l s in landfill, 5 w e l l s ondowngradi en t s ide

3 f t .t h r o u g h o u tl a n d f i l l1 0 f t .t hroughou tl a n d f i l l3 f t .t h roughou tl a n d f i l l10 ft.t h r o u g h o u tl a n d f i l l3 f t .t h roughou tl a n d f i l l1 0 f t .t h r o u g h o u tl a n d f i l l

20-60 ( l e a c h a t e ) 3-15 yrs 20 years125 gpm ( g r o u n d w a t e r ) N/A 1 year

80-200 (l ea cha t e) 3-15 yrs 20 years125 gpm ( g r o u n d w a t e r ) N/A 1 year

20-60 (leachate) 3-15 yrs 20 years100 gpm ( g r o u n d w a t e r ) N/A 1 year

80-200 ( l e a c h a t e ) 3-15 yrs 20 years100 gpm ( g r o u n d w a t e r ) N/A 1 year

25-50 ( l e a c h a t e ) 3-15 yrs 20 years100 gpm (groundwat er) N/A 1 year

75-150 (l eacha t e) 3-15 yrs 20 years100 gpm (groundwat er) N/A 1 year

0.21 to 0.63of l eachat e;0.07of groundwater0.84 to 2.10of l eachate;0.07of groundwater0.21 to 0.63of l eachate;

0.05of groundwat er0.84 to 2.10of l eachate;0.05of groundwater0.26 to 0.53of l eachate;0.05of groundwat er0.79 to 1.58of l eachate;0.05of groundwater

Five w e l l s on downgradient sidemay need to p u m p for less than onyear.F i v e w e l l s on downgradi ent sidemay need to p u m p for less than onyear.Drain on downgradi ent side mayneed to operate for less than oneyear.Drain on downgrad i en t side mayneed to operate for less than oneyear.F i v e w e l l s on downgrad i en t s idemay need to p u m p for less than onyear.F i v e wel l s on downgradient sidemay need to p u m p for less than onyear.

N O T E :1. S t e a d y - s t a t e p u m p i n g rate is d ependent on the amount of vertical l eakage f r o m the G a r b e r - W e l l i n g t o n aqui f er .See text f or a fu l l e x p l a n a t i o n o f assumptions.2. All a l t e rna t iv e s tha t do not i n c l u d e a s lurry wall assume that North Pond wi l l be drained.

E x p l a n a t i o n of Cases:1.1 through 1.3: Alluvial Groundwater C o l l e c t i o n2.1 through 2.4: Leachate C o l l e c t i o n3.1 t h r o u g h 3.10: Alluvial Groundwat er and Leachate C o l l e c t i o n

August 1991 Page 2 of 30 0 6 2 9 6

903-2223

3.8 yes 7B.8B 12 w e l l s in landfill, drain ondowngradi en t s ide at anaverage e l e v a t i o n of 1139*

3.9 yes 7B, 8B 12 we l l s in landfill, p er ime t erdrain at an average e l eva t i onof 1143'3.10 yes 7B, 8B 12 we l l s in landfill, per imet erdrain at an average e l eva t i onof 1143'

3 f t .t h r o u g h o u tl a n d f i l l1 0 f t .t hroughou tl a n d f i l l

75-150 ( l e a c h a t e )100 gpm (ground water)

3 ft . I n s i d e 25-50 ( l e a c h a t e )and ou t s id e of 20-55 ( g r o u n d w a t e r )l a n d f i l l10 ft. insidea n d 3 f t .ou t s id e ofl a n d f i l l

75-150 ( l e a c h a t e )20-55 ( g r o u n d w a t e r )

0.26 to 0.53 Drain on d o w n g r a d i e n t s ide mayof l ea cha t e; need to op era t e for less than one0.05 year,of groundwater3-15 yrs 20 years 0.79 to 1.58 Drain on downgradi en t side mayN/A 1 year of l eachate; need to operat e for less than one0.05 year,of groundwater3-15 yrs 3-15 years 0.08 to 0.20 Perimeter dra in des igned to lower20 years of l eachate; water l eve l s out s ide the s lurry wall0.21 to 0.58 to the same level as ins ide the s l u rof groundwater wall .3-15 yrs 3-15 years 0.24 to 0.59 Perimeter drain designed to lower20 years of leachate; water l eve l s o u t s i d e the s lurry wall0.21 to 0.58 to the same level as i n s i d e the s l u rof groundwater wal l .

NOTE:1. Steady-s ta t e p u m p i n g rate is d ependent on the amount of vertical leakage from the Garber-Well ington aquifer.See text for a fu l l e x p l a n a t i o n o f assumptions.2. All a l t e rna t iv e s that do not i n c l u d e a s lurry wall assume that North Pond will be drained.

Exp lana t i on of Cases:1.1 t h r o u g h 1.3: Alluvial Groundwat er C o l l e c t i o n2.1 t h r o u g h 2.4: Leachate C o l l e c t i o n3.1 t hrough 3.10: Alluvial Groundwa t e r and Leachate C o l l e c t i o n

A u g u s t 1991 Page 3 of 30 0 6 2 9 7

903-2223

TABLE 3-2E V A L U A T I O N O F R E F I N E D A L T E R N A T I V E S A G A I N S T T H E N I N E C R I T E R I A

•Sit i sSt l iSMWsiK

; AlternativeDescriptionAlternatives:Limited Action/Inst i tu t i onalAct ionsTechnology Types:AccessRestrictions andMonitoring

M f P W a B O t W t t t f S Ki- Overall Protectionof Human H e a l t hand the :EnvironmentLand use restrictionswould prevent directcontact with waste.Restrictions ongroundwater use wouldprevent inges t ion.Protectiveness of humanh e a l t h would requireenforcement ofrestrictions. Notprotective ofenvironmental receptorsi f groundwatercontamination andconcentration ofcontaminants increaseswith time.

•BPfReaof t&PW*Compliance withA p p l i c a b l e orRelevant andAppropr ia t eRequirements

Unlikely to c o m p l y withchemical- spec i f i cA R A R s f o r groundwaterquality. Act ion- spe c i f i cand l o c a t i o n - s p e c i f i cARARs g e n e r a l l y do nota p p l y to this alternative.

^psraBflBrifetsgai^H: - " . . - - - ":. " -"

C Long-TermEff e c t iv ene s s 1 and:PermanenceLong-terme f f e c t i v e n e s s is poor.Alt erna t iv e does notremediate exi s t ingcontamination orprevent f u t u r e spread ofcontamination.

B s S I S W t S P l i M f f i R i B l!" Reduction ofT o x i d t y , M o b i l i t y: and VolumeThroughTreatmentAlterna t iv e 2 does notprovide a reduction inthe t ox i c i ty , m o b i l i t y , orvolume of contaminantsthrough treatment.

s s scmeBonfNORSasa;'

Short-TermE f f e c t i v e n e s sRisks to workers wou ldbe n e g l i g i b l e . Risks tothe community would ben e g l i g i b l e . Remedialactions wou ld not causes i g n i f i c a n tenvironmental impacts.E f f e c t i v e in prevent ingexposure to humanreceptors. Not e f f e c t i v ein p r e v e n t i n g exposureto environmentalreceptors.

:S8i;.:njOW8qrcNQ*6f<ss»n- - - -

I m p l e m e n t a b i l i t yT e c h n i c a l l y easy toi m p l e m e n t .A d m i n i s t r a t i v e l y d i f f i c u l tto i m p l e m e n t .

i i E W S t e r K S r j B l S Q K i K r ; :

Costs( C a p i t a l and O&M)The 1991 presentnet worth is$500,000.

jssasGrBeaonrwofe»sv*i

State AcceptanceThe s tate has shown nop r e f e r e n c e amongstalternatives . T h eacceptabi l i ty ofal ternat ive s will beassessed f o l l o w i n gcomment on theF e a s i b i l i t y S t u d y Report.

*^?.{SBSrIbl»il*;»«M

CommunityAcceptanceThe community hasshown no pr e f e r enc eamongst alternatives.The acc ep tab i l i ty ofalternatives will beassessed f o l l o w i n gcomment on theF e a s i b i l i t y S t u d y Report.

AUGUST 1981 PAGE 1 OT8 903-2223

" 0 0 6 2 9 8

TABLE 3-2E V A L U A T I O N O F R E F I N E D A U E R N A T I V E S A G A I N S T T H E N I N E C R I T E R I Ap t p f e f i f s S l M l f i i i i

AlternativeDescriptionAlternative 4ASourceContainment:GroundwaterExtraction andDischarge

Technology Types:C a p p i n g ,AccessRestrict ionsand M o n i t o r i n g

^*SPlterio.r«»6ip^Overall Protectionof Human Healthand theEnvironment

Land use restrictionswould prevent directcontact with waste.Hydrau l i c containmentwould provide long-termprotect ion to humanhealth and theenvironment. Remedialaction would remediateexisting groundwatercontamination near thel a n d f i l l .

K K B i 9 9 W J i K $ & i W £Compliance withA p p l i c a b l e orRelevant andAppropr ia t eRequirements

C a p a b l e of meetingchemica l- spe c i f i cA R A R s f o r groundwaterquality. May not meetARARs for discharge ofcontaminated water.A c t i o n - s p e c i f i c A R A R sunder the CWA andRCRA for discharge toPOTW may not be met.Loca t i on- sp e c i f i cARARs shou ld be met.

l ^ t p n p t l B m i K W S i i( .-"- ' " " .

Long-TermEffe c t ivene s s andPermanenceI f p r o p e r l y i m p l e m e n t e dlong-term e f f e c t i v e n e s sis high. A l t e r n a t i v eremediates e x i s t ingcontamination andprevents f u t u r e spreadof contaminants.

ii^ip)teaoij;Sos:4|sssiReduction of': . T o x i c f t y , M o b i l i t yand VolumeThrough:Treatment

T h e volume, m o b i l i t y ,and tox i c i ty ofcontaminants ingroundwater andleachate would bereduced throughco l l e c t i on and dischargeto a POTW. Treatmentof contaminants wouldoccur within theactivated s l u d g e processof the POTW.

"S s s e n t e n o n ' . N o s i » «:*€

Short-TermE f f e c t i v e n e s sT h i s a l t e rna t iv e I se f f e c t i v e in theshort-term. Risks toworkers would begreater than forA l t e r n a t i v e 2. Risks toworkers would becomparable to risksn o r m a l l y associated withclosure of a m u n i c i p a llandfi l l . Risks to thecommunity would ben e g l i g i b l e . Remedia lactions could causeenvironmental impacts.E f f e c t i v e in p r e v e n t i n gexposure to human andenvironmentalreceptors.

«i;B«cmegcnsNOi;6!Ii8: : - :

I m p l e m e n t a b i l i t yT e c h n i c a l l y f e a s i b i l i t y i sgood. A d m i n i s t r a t i v ef e a s i b i l i t y i s fair to good.

s^jmertonvNossls 1!

Costs( C a p i t a l and O&M)The 1991 presentnet worth is$2.3-8.7 m i l l i o n ,i n c l u d i n g c a p p i n gop t i on s 1 , 2, and 4;and, di scharge toa POTW or sur facewater under anN P D E S Permit.

<vt»otteBorc:NOi;:s& -;&"

Stat e AcceptanceThe state has shown nop r e f e r e n c e amongstalternatives. T h ea c c e p t a b i l i t y o falternatives will beassessed f o l l o w i n gcomment on theFeas ib i l i ty S t u d y Report.

i : p ? C f B s H 6 ' r 8 t i t Q i J 9 » % t e

CommunityAcceptanceThe community hasshown no pre f er enc eamongst alternatives.The a c c ep tab i l i ty o fal t ernat ive s will beassessed f o l l o w i n gcomment on theF e a s i b i l i t y S t u d y Report.

er-

AUGUST 1961 PAGE 2 OF 9 903-2223

0 0 6 2 9 9

TABLE 3-2E V A L U A T I O N O F R E F I N E D A L T E R N A T I V E S A G A I N S T T H E N I N E C R I T E R I AB p p M b i K K H i l - . ; :

Alternat iveDescriptionAlternative SASourceContainment:GroundwaterExtraction,Treatmentand DischargeTechno logy Types:C a p p i n g ,AccessRestrictionsand M o n i t o r i n g

»^sj3rjt9ao;rtNDiifia»iOverall Protectionof Human Health

: and the ;•• EnvironmentLand use restrictionswould prevent directcontact with waste.H y d r a u l i c containmentwould provide long-term protec t ion tohuman h e a l t h and theenvironment. Remedialaction would remediateexisting groundwatercontamination near thel a n d f i l l .

i i l iPrt t eBOfl i jp j ig s i s i s !Compliance withA p p l i c a b l e orRelevant andA p p r o p r i a t eRequirements

C a p a b l e o f meet ingchemica l- spe c i f i cA R A R s f o r groundwaterquali ty. Expec t ed tomeet A R A R s f o rdischarge ofcontaminated water tosurface water or POTW.A c t i o n - s p e c i f i c A R A R sare expected to be metL o c a t i o n - s p e c i f i cARARs s h o u l d be met.

t s S r t S f f l e W f c N o ^ v i S i s

Long-TermEf f e c t i v ene s s andPermanenceT h e long-terme f f e c t i v e n e s s of th i sa l t e rna t iv e is comparableto A l t e r n a t i v e 4A.Treatment ofcontaminant s prior todischarge to surfacewater or POTW wouldof f er more long-termflexibi l i ty in meet ingtreatment goal sthanA l t e r n a t i v e 4 A . I f p r o p e r l yI m p l e m e n t e d , long-terme f f e c t i v e n e s s is high.A l t e r n a t i v e r emedia t e sexist ing contaminationand prevents f u t u r espread of contaminants.

f t i a ^ p n T e r J o r s N O e s p g a s iReduction ofi Toxicity. M o b i l i t yand VolumeThroughTreatment

The volume, m o b i l i t y ,and t o x i c i t y ofcontaminants ingroundwater andleachate would bereduced throughc o l l e c t i on and treatment.

sa*i?e(Herlori;NO«&i**ss^

S h o r t - T e r mE f f e c t i v e n e s sThis a l t ernat ive i se f f e c t i v e I n t h eshort-term. Risks toworkers would begreater than f orA l t e r n a t i v e 2. Risks toworkers wou ld becomparab l e to risksnormal ly associated withclosure of a munic ipa llandfi l l . Risks to thecommunity would ben e g l i g i b l e . Remedialactions cou ld causeenvironmental I m p a c t s .E f f e c t i v e in pr even t ingexposure to human andenvironmentalreceptors.

P^uftteiwntisowswsr

I m p l e m e n t a b i l i t yT e c h n i c a l l y f e a s i b i l i t y I sgood. A d m i n i s t r a t i v ef e a s i b i l i t y I s f a i r t o good.

»CfaeRoi*;NOW»;;

Costs( C a p i t a l and O&M)The 1991 presentnet worth costs Is$3.4-31.1 m i l l i o n ,I n c l u d i n g c a p p i n go p t i o n s 1 , 2, and 4;and, di scharge toa POTW or sur facewater under anN P D E S Permit .

s«i^erjteiiOntNo&^;i|s;«s

State AcceptanceThe state has shown nop r e f e r e n c e amongstal t ernat ive s . T h ea c c e p t a b i l i t y o fa l t ernat ive s will beassessed f o l l o w i n gcomment on theF e a s i b i l i t y S t u d y Report.

aiBSunesorewosisisiis

CommunityAcceptanceThe community hasshown no pre f e r enc eamongst alternatives.The acceptabi l i ty ofa l t ernat ive s will beassessed f o l l o w i n gcomment on theF e a s i b i l i t y S t u d y Report.

A U G U S T 1981 PAGE 3 OF 8 903-2223

> 0 0 6 3 0 0

TABLE 3-2E V A L U A T I O N O F R E F I N E D A L T E R N A T I V E S A G A I N S T T H E N I N E C R I T E R I AP ^ I S S - s i - i f r a i g f e f e s g M

AlternativeDescriptionAlternative 6ASourceContainment:LaachateExtraction,Treatmentand DischargeTechno l ogy Types:C a p p i n g ,AccessRestrictionsand M o n i t o r i n g

•^WHWWQiKBas^swOverall Protectionof Human Healthand the •Environment

Land use restrictionsand capp ing wouldprevent direct contactwith waste.H y d r a u l i c containmentof leachate and a l luv ia lgroundwater around theperimeter o f the landf i l lwould provide long-termprotec t ion of humanh e a l t h and theenvironment. Remedialaction would remediategroundwater near thel a n d f i l l .

i^iSrtprionswossEissiPCompliance withA p p l i c a b l e orRelevant andAppropr ia t eRequirements

C h e m i c a l - s p e c i f i cARARs for groundwaterquali ty may not be met.C h e m i c a l - s p e c i f i cARARs for treatment o fleachate prior to surfacewater or POTWdischarge are expectedto be metA c t i o n - s p e c i f i c A R A R sshould be met by thisalternative.Locat ion-spec i f i cARARs should be metby t h i s alternative.

%!p!|:p]temrj!Noi3ili5t!

Long-TermEf f e c t i v ene s s andPermanenceLong-term sourcecontainment of leachateis provided by thi sal ternative. I f p r o p e r l yI m p l e m e n t e d long-terme f f e c t i v e n e s s is high.Residual risks foringe s t l on of groundwaterremain; long-term naturalat tenuat ion mechanismswould reduce this risk toacceptable levels .

f j f g c r i K e r j g n i i ^ ^ i i s sReduction ofToxici ty, M o b i l i t yand Volume:ThroughTreatment

T h e volume, mob i l i ty ,and toxlcity ofcontaminant s ingroundwat er andleachate near thelandfi l l would be reducecthrough c o l l e c t i on andtreatment.

; a = ; S p r i t e r i o n ; N O ( i S « ; l : j

Shor t-TermEf f e c t iv ene s sThis a l t e r n a t i v e ise f f e c t i v e in theshort-term. Risks toworkers wou ld begreater than f o rA l t e r n a t i v e s 4A and 5A.Risks to the communitywould be n e g l i g i b l e .Remedial actions couldcause environmentalimpacts. Effect ive inp r e v e n t i n g expo sure tohuman andenvironmentalreceptors.

i i i« ; CJriler ior i>No>?Ss -as;

I m p l e m e n t a b i l i r yT e c h n i c a l l y f e a s i b i l i t y i sgood. Administrativef e a s i b i l i t y i s f a i r t o good.

•A?efRerion;NO>;7S;^

Costs( C a p i t a l and O&M)The 1991 presentnet worth is$3.6-20.4 m i l l i o n ,i n c l u d i n g c a p p i n go p t i o n s 1 , 2, and 4;and, d i s charge toa POTW or sur facewater under anNPDES Permit.

;;menterionyN6v: 8s;: v --

S t a t e AcceptanceThe state has shown nopreference amongstal t ernat ive s . T h ea c c e p t a b i l i t y o fa l t e rna t iv e s will beassessed f o l l o w i n gcomment on theF e a s i b i l i t y S t u d y Report .

' W t C t t t e a o r r N b i ' S K * ; ' ;

Communi tyAcceptanceThe community hasshown no preferenceamongst al ternatives .The a c c ep tab i l i ty o fal ternatives will beassessed f o l l o w i n gcomment on theF e a s i b i l i t y S t u d y Report.

AUGUST 1981 PAGE 4 OF 9 903-2223

0 0 6 3 0 1

TABLE 3-2E V A L U A T I O N O F R E F I N E D A L T E R N A T I V E S A G A I N S T T H E N I N E C R I T E R I AP s s W W s R S s a ' S t S S i

AlternativeDescript ionAlternative 6BSourceContainment:Leac f ia t eExtraction,Treatment andDischargeT e c h n o l o g y Types:AccessRestrictions,M o n i t o r i n g ,C a p p i n g andS l u r r y W a l l

itsier«eBO»>Noi«»s»i»Overall Protectionof Human H e a l t hand the- Environment

Land use restrictionsand capping wouldprevent direct contactwith leachate and wastepit soils. H y d r a u l i ccontainment of leachatewould provide long-termprotec t ion of humanh e a l t h and theenvironment f r o msource contaminants.Contaminants I n al luvialgroundwater wouldpresent a minimal risk tohuman hea l th and theenvironment that wouldbe addressed t h r o u g hnatural a t t enuat ion.

^iggfiiertor**<o*i3isii«jCompliance withA p p l i c a b l e orRelevant andA p p r o p r i a t eRequirements

Chemica l- spe c i f i cA R A R s f o r groundwaterquality may not be metC h e m i c a l - s p e c i f i cA R A R s f o r treatment o fleachate prior to surfacewater or POTWdischarge are expec t edto be metA c t i o n - s p e c i f i c A R A R sshould be met by thi salternative.Loca t i on- sp e c i f i cARARs should be metby thi s alternative.

gpsw6rftafioivf<a^s*si*

Ldng-TermEf f e c t i v ene s s andPermanenceThe long-terme f f e c t i v e n e s s o f thisal t ernat ive I scomparable toA l t e r n a t i v e 6A.Long-term sourcecontainment of leachateand waste pit s o i l s isprovided by thi salternative.I f p r o p e r l y I m p l e m e n t e d ,long-term e f f e c t i v e n e s sis high.

|p«|prtts|j«>r*if0sal!5ii«s-: Reduction of; Toxi c i ty , M o b i l i t yand Volume: T h r o u g hTreatmentT h e volume, m o b i l i t y ,and toxici ty ofcontaminants inleachate would bereduced t h r o u g hco l l e c t i on and treatment.T h e volume, mob i l i ty ,and toxicity ofcontaminants I n alluvialgroundwater would notbe ac t ive ly reduced bythis al ternative.

lisasemerior* Ncfcs.;^

S h o r t - T e r mE f f e c t i v e n e s sThis a l t ernat ive ise f f e c t i v e I n t h eshort-term. Risks toworkers would be s i m i l a rto A l t e r n a t i v e 6A.D r i l l i n g w e l l s t h r o u g h t h el a n d f i l l c on s t i tu t e sgreater risk to workersthan A l t e r n a t i v e 4A and5A. Risks to thecommuni ty would ben e g l i g i b l e . Remedialaction could causeenvironmental impacts.E f f e c t i v e in prevent ingexposure to human andenvironmentalreceptors.

iKmGfi&ftOK NQKfts ««*

I m p l e m e n t a b i l i t yT e c h n i c a l l y f e a s i b i l i t y i sgood. A d m i n i s t r a t i v ef e a s i b i l i t y i s fair to good.

s f eCfi t eaooNos^s*

Costs(Capi ta l and O&M)The 1991 presentnet worth is$5.3-21.1 m i l l i o n ,I n c l u d i n g c a p p i n go p t i o n s 1 , 2, and 4;and, d i s charge toa POTW or surfacewater under anN P D E S Permit.

•fcmw«0BOttN0iim»?pJ

S t a t e AcceptanceThe state has shown nopre f e r enc e amongstalternatives. T h ea c c e p t a b i l i t y o fa l t e rna t iv e s will beassessed f o l l o w i n gcomment on theF e a s i b i l i t y S t u d y Report.

s ^ s C H l e r l o n s N O S S f t s f e :

CommunityAcceptanceThe community hasshown no pr e f e r enc eamongst alternatives .The ac c ep tab i l i ty ofal t ernat ive s will beassessed f o l l o w i n gcomment on theF e a s i b i l i t y S t u d y Report.

AUGUST 1901 PAGE 5 OF 9

0 0 6 3 0 2

TABLE 3-2E V A L U A T I O N O F R E F I N E D A L T E R N A T I V E S A G A I N S T T H E N I N E C R I T E R I A! | * ** §$M ~ltI

AlternativeDescriptionAlternative 7ASourceContainment:GroundwaterExtractionand Discharge;L e a c f i a t eExtraction,Treatment andDischargeTechnology Types:C a p p i n g ,AccessRestrictionsand M o n i t o r i n g

P i j s f i t B f W w s p i i i i iOverall Protectionof Human HealthandtheEnvironment

Land use restrictionsand capp ing wouldprevent direct contactwith waste. Hydrauliccontainment of ieachateand al luvia l groundwaterwould provide long-termprotect ion of humanhealth and theenvironment Remedialaction would remediategroundwater near thel a n d f i l l .

iifiPrnai»R>N<»!8i!;RiiCompliance withA p p l i c a b l e orRelevant andA p p r o p r i a t eRequirements

C a p a b l e of meetingch emica l- sp e c i f i cA R A R s f o r groundwaterquali ty. Expected tomeet ch emi ca l - sp e c i f i cARARs for treatment o fIeachate and dischargeto surface water orPOTW. May not meetchemica l- spe c i f i cARARs for discharge o funtreated groundwaterto a POTW.A c t i o n - s p e c i f i c A R A R sunder the CWA andRCRA may not be met.L o c a t i o n - s p e c i f i c A R A R ishould be met by thi sal ternative.

sf|giiSSrfte«CB!R0s^Si

Long-TermEff e c t iv ene s s andPermanenceThe long-terme f f e c t i v e n e s s of thisal ternative is e s s e n t i a l l ythe same as A l t e r a t i v e6A. Long-termcontainment ofgroundwater and Ieacha t eis provided by thi salternative. I f p r o p e r l yi m p l e m e n t e d , long-terme f f e c t i v e n e s s is high.

llli;£ansr»(««osipi:ii: Reduction ofT o x i c i t y j Mobi l i tyand VolumeThroughTreatment

The volume, m o b i l i t y ,and toxicity ofcontaminants ingroundwater andI e a c h a t e would bereduced throughc o l l e c t i o n and treatment

s fSier i t enof t iNossr-^s*

S h o r t - T e r mE f f e c t i v e n e s sThis a l t e r n a t i v e i se f f e c t i v e in theshort-term. Risk s toworkers would becomparab l e toA l t e r n a t i v e 6A. Risks tothe community would ben e g l i g i b l e . Remedia lactions could causeenvironmental impacts .E f f e c t i v e in p r e v e n t i n gexposure to human andenvironmentalreceptors.

l£ iS%cmerwnsNCKi6*iav

I m p l e m e n t a b i l i t yT e c h n i c a l l y f e a s i b i l i t y i sgood. A d m i n i s t r a t i v ef e a s i b i l i t y I s f a i r t o good.

s a c n t e H o B i N O s s ^ f ' i s

Costs(Capi ta l and O&M)The 1991 presentnet worth is$3.5-22.8 m i l l i o n ,i n c l u d i n g c a p p i n go p t i o n s 1 , 2, and 4:and, d i s charge toa POTW or surfacewater under anN P D E S Permit.

v«|s:CrttsrWr*:NO!i-8;«Ef

Stat e AcceptanceThe s tate has shown nop r e f e r e n c e amongstalternatives. T h ea c c e p t a b i l i t y ofalternatives will beassessed f o l l o w i n gcomment on theF e a s i b i l i t y S t u d y Report.

f ; :s:«creertonsNos5SBB?*.

CommunityAcceptanceThe community hasshown no p r e f e r e n c eamongst alternatives.The a c c e p t a b i l i t y o fal ternat ive s will beassessed f o l l o w i n gcomment o f t h e R I / F S .be assessed f o l l o w i n gcomment on theF e a s i b i l i t y S t u d y Report.

AUGUST 1901 R A G E 8 O F 9 903-2223

^ 0 0 6 3 0 3

TABLE 3-2E V A L U A T I O N O F R E F I N E D A L T E R N A T I V E S A G A I N S T T H E N I N E C R I T E R I A

AlternativeDescriptionAlternative 7B:SourceContainment:GroundwaterExtraction andDischarge;LaachateExtraction,Treatment andDischargeTechno l ogy Types:AccessRestric t ions,M o n i t o r i n g ,C a p p i n g andS l u r r y wall

iii!pmea<ms«<^BiiOverall Protectionof Human H e a l t hand theEnvironment

Land use restriction andc a p p i n g would preventdirect contact withwaste. H y d r a u l i ccontainment of leachateand a l luv ia l groundwaterwould prov id e long-termp r o t e c t i o n of humanh e a l t h and theenvironment. Remedialaction would remediategroundwater near thel a n d f i l l . T h i s al ternativeprovides an a d d i t i o n a lmeasure of protec t ionover A l t e r n a t i v e 7Athrough containment ofl eachate by a slurry wall.

i S « p r f l » O W ? N O S 2 S ! i f sCompl iance withA p p l i c a b l e orRelevant andA p p r o p r i a t eRequirements

C a p a b l e of meet ingchemica l- spe c i f i cA R A R s f o r groundwat erquality. Expec ted tomeet c h e m i c a l - s p e c i f i cARARs for treatment o fleachate and di s chargeto sur fac e water orPOTW. May not meetchemica l- spe c i f i cA R A R s f o r di s charge o funtreated groundwaterto a POTW.A c t i o n - s p e c i f i c A R A R sunder the CWA andRCRA may not be met.L o c a t i o n - s p e c i f i cARARs are expec ted tobe met by th i sa l t ernat ive .

i s s iqr t ta iHonifwi ip i i s s

Long-TermEf f e c t i v ene s s andPermanenceT h e long-terme f f e c t i v e n e s s of th i sal ternative is comparableto A l t e r n a t i v e 7A.Long-term containmentof groundwater andleachate is prov ided bythi s alternative. Thea d d i t i o n of a s lurry wallimproves the long-terme f f e c t i v e n e s s o f t h i sal t ernat ive overAlt erna t iv e 7A throughincreased containment ofsource contaminants.

S S i s S f S s r l o m N ^ i S f i i WReduction ofT o x i c i t y , M o b i l i t yand VolumeT h r o u g hTreatment

T h e volume, m o b i l i t y ,and t o x l c l t y ofcontaminants ingroundwater andleachate would bereduced throughc o l l e c t i o n and treatment.

' ^ I K i ^criterion No;-5 : SK

S h o r t - T e r mE f f e c t i v e n e s sThis a l t ernat ive i se f f e c t i v e in theshort-term. Risks toworkers wou ld be s i m i l a rto A l t e r n a t i v e 6B. Risksto the community arecons idered n e g l i g i b l e .Remed ia l actions couldcause environmentalimpact s . T h e s e impac t scould be greater for th i sa l t e r n a t i v e than f o rA l t e r n a t i v e 68. E f f e c t i v ein p r e v e n t i n g exposureto human andenvironmentalreceptors .

S M s e n t e n o r S N o J ' S ' M - P

I m p l e m e n t a b i l i t yT e c h n i c a l l y f e a s i b i l i t y I sgood. A d m i n i s t r a t i v ef e a s i b i l i t y i s f a i r to good.

rsCntsnon NO»7R:

Costs(Capital and O&M)The 1991 presentnet worth is$5.4-22.1 m i l l i o n ,i n c l u d i n g c a p p i n go p t i o n s 1, 2, and 4;and, d i s charge toa POTW or sur fa c ewater under anN P D E S Permit.

w ^ e m s r i o m N o s a s ' s *

Stat e AcceptanceThe state has shown nop r e f e r e n c e amongstalternat ive s . Thea c c e p t a b i l i t y o fal t e rna t iv e s w i l l beassessed f o l l o w i n gcomment on theF e a s i b i l i t y S t u d y Report.

i s s c m e r i o r w o f e s ^ ' i s ; ?

CommunityAcceptanceThe community hasshown no pr e f e r enc eamongst al t ernat ive s .The a c c e p t a b i l i t y o falternatives w i l l beassessed f o l l o w i n gcomment on theF e a s i b i l i t y S t u d y Report.

A U G U S T 19C1 PAGE 7 OF 9 903-2223

0 0 6 3 0 4

TABLE 3-2E W - U A T t O N O F R E F I N E D A I J E R N A T I V E S A G A I N S T T H E N I N E C R F T E R I A

Alternat iveDescriptionAlternative 8ASourceContainment:Groundwat erand Leachate,Extraction,Treatment andDischargeTechnology Types:C a p p i n g ,AccessRestrictionsand M o n i t o r i n g

P f ^ p r f f B r j o f t N e a s f t g iOverall Protectionof Human Healthand theEnvironment

Land use restrictionsand c a p p i n g wouldprevent direct contactwith waste. Hydrauliccontainment of leachateand a l l u v i a l groundwaterwould provide long-termprotec t ion of humanhealth and theenvironment. Remedialaction would remediategroundwater near thel a n d f i l l .

i f«^te f lOifcNeeizBis iCompliance with: A p p l i c a b l e orRelevant andA p p r o p r i a t eRequirements

C a p a b l e o f mee t ingc h e m i c a l - s p e c i f i cA R A R s f o r groundwaterquality. Expected tomeet c h e m i c a l - s p e c i f i cARARs for treatment o fl eachate andgroundwater prior todischarge to surfacewater or POTW.A c t i o n - s p e c i f i c A R A R sare expected to be met.L o c a t i o n - s p e c i f i cARARs are e xpe c t ed tobe met.

i g g f j C n i e o o j p ^ a i M i p

Long-TermE f f e c t i v e n e s s andPermanenceThe long-terme f f e c t i v e n e s s of thisa l t ernat ive is comparableto A l t e r n a t i v e 7A.Long-term containmentof groundwater andleachate is provided bythi s alternative. I fp r o p e r l y i m p l e m e n t e dlong-term e f f e c t i v e n e s s ish igh.

s«asrRarwi«*oe;*«iiiReduction ofT o x i c f t y , M o b i l i t yand VolumeThroughTreatment

T h e volume, m o b i l i t y ,and tox i c i ty ofcontaminants ingroundwater andleachate would bereduced throughc o l l e c t i o n and treatment.

« f c £ r i i e n o m N Q s ; 5 f S i s K

S h o r t - T e r mE f f e c t i v e n e s sThis a l t ernat ive ise f f e c t i v e in theshort-term. Risks toworkers would be s imilarto A l t e r n a t i v e 7A. Risksto the community wouldbe n e g l i g i b l e . Remedialactions could causeenvironmental impacts.E f f e c t i v e in pr ev en t ingexposure to human andenvironmentalreceptors.

ajpgoter iore N O & e s e s

I m p l e m e n t a b i l i t yT e c h n i c a l l y f e a s i b i l i t y i sgood. A d m i n i s t r a t i v ef e a s i b i l i t y i s f a i r to good.

; « C f i t e r t o r t i N o » ' » - *

Costs(Capi ta l and O&M)The 1 991 presentnet worth is$3.6-23.3 m i l l i o n ,i n c l u d i n g c a p p i n go p t i o n s 1 , 2, and 4;and, discharge toa POTW or surfacewater under anN P D E S Permit .

-swa c r a e n o R ' N o w p i P

State AcceptanceThe state has shown nop r e f e r e n c e amongstal t ernat ive s . T h ea c c e p t a b i l i t y ofal t ernat ive s will beassessed f o l l o w i n gcomment on theF e a s i b i l i t y S t u d y Report.

MSCrtte i t omN^te*

CommunityAcceptanceThe community hasshown no p r e f e r e n c eamongst al ternatives .The a c c e p t a b i l i t y o fal ternatives will beassessed f o l l o w i n gcomment o f t h e R I / F S .be assessed f o l l o w i n gcomment on theF e a s i b i l i t y S t u d y Report.

AUGUST 1891 PAGE 8 OF 9 903-2223

0 0 6 3 0 5

TABLE 3-2E V A L U A T I O N O F RERNED A L T E R N A T I V E S A G A I N S T T H E N I N E C R I T E R I A

t - -s " ^

Alternat iveDescriptionAlternative SB:SourceContainment:Groundwater andLeachateExtraction,Treatment andDischargeTechnology Type s:AccessRestrict ions,Moni tor ing ,C a p p i n g andS l u r r y wall

Pli5f j injer jore;N(w»$»|Overall Protectionof Human Healthand theEnvironment

Land use res trict ionsand c a p p i n g wouldprevent direct contactwith waste. H y d r a u l i ccontainment of l eachateand alluvial groundwaterwould provide long-termprotec t ion of humannea l th and theenvironment Remedialaction would remediatej r oundwat er near thea n d f i l l .

il«srft9rton>$o^p«8>i • .- . ..Compl iance withA p p l i c a b l e orRelevant andA p p r o p r i a t eRequirements

C a p a b l e o f meet ingc h e m i c a l - s p e c i f i cA R A R s f o r groundwaterquality. Expected tomeet c h e m i c a l - s p e c i f i cA R A R s f o r treatment o fleachate andgroundwater pr ior todischarge to surfacewater or POTW.Action- spe c i f i c A R A R sare expected to be met.Loca t i on- sp e c i f i cARARs are expec ted tobe met.

»s»3f!p«onx8!ov^»

Long-TermE f f e c t i v e n e s s andPermanenceT h e long-terme f f e c t i v e n e s s of thisa l t ernat ive is comparableto Alternat ive 7B.Long-term containmentof groundwater andleachate is provided byth i s alternative. Theaddi t i on of a slurry wallimproves the long-terme f f e c t i v e n e s s o f th i sal t ernat ive overA l t e r n a t i v e 8A throughincreased containment ofsource contaminants.

jBpsmsnonsNepipawReduction ofToxicity, Mobi l i tyand VolumeT h r o u g h :Treatment

The volume, m o b i l i t y ,and t o x i c i ty ofcontaminants ingroundwater andleachate would bereduced throughc o l l e c t i o n and treatment.

• s i ! j ! r : i C r i t e r l d r r , N O j s S s f = : ; ' ^

Snort-TermE f f e c t i v e n e s sThis a l t ernat ive i se f f e c t i v e in theshort-term. Risks toworkers would be s imilarto A l t e r n a t i v e SB. Risksto the community wouldbe n e g l i g i b l e . R e m e d i a lactions could causeenvironmental impacts.E f f e c t i v e in prevent ingexposure to human andenvironmentalreceptors.

« s C n t 0 r t o r J ; N O J . 6 sv*

I m p l e m e n t a b i l i t yT e c h n i c a l l y f e a s i b i l i t y i sj o o d . A d m i n i s t r a t i v e' ea s i b i l i ty i s f a i r t o good.

»; Criterion. N o i l : - : .

Costs(Capi ta l and O&M)The 1991 presentnet worth is$5.4-22.2 m i l l i o n ,n c l u d i n g c a p p i n go p t i o n s 1 , 2, and 4;and, di scharge toa POTW or s u r f a c ewater under anN P D E S Permit .

f e i S C m ' e H r o - N o s S i s ' *

S t a t e AcceptanceThe state has shown nopre f er enc e amongstalternatives. T h ea c c e p t a b i l i t y ofal t ernat ive s w i l l beassessed f o l l o w i n gcomment on theF e a s i b i l i t y S t u d y Report .

^ - ' ' C r K s H o w - N o i r S w i i w

CommunityAcceptanceThe community hasshown no pre f er enc eamongst alternatives.The a c c e p t a b i l i t y ofalternatives wi l l beassessed f o l l o w i n gcomment on theF e a s i b i l i t y S t u d y Report.

AUGUST 1981 P A G E 9 OF 9 903-2223

; OO 6 3 0 6

TABLE 4-1ROLE O F T H E N I N E E V A L U A T I O N C R I T E R I A D U R I N G REMEDY S E L E C T I O N

• How A l t e r n a t i v e Provides H u m a n Heal th and Environmental Protect ion • T h r e s h o l d "Factor s

C o m p l i a n c e wi th C h e m i c a l - S p e c i f i c A R A R s .• C o m p l i a n c e w i th A c t i o n - S p e c i f i c A R A R s

C o m p l i a n c e wi th L o c a t i o n - S p e c i f i c A R A R sC o m p l i a n c e with Other C r i t e r i a , Advi sor i e s , and Guidance s

I• M a g n i t u d e of Res idual Risk• A d e q u a c y and R e l i a b i l i t y of C o n t r o l s

i• T r e a t m e n t Process Used and M a t e r i a l s Treat ed• A m o u n t s of H a z a r d o u s M a t e r i a l s Destroyed or Treated• Degree of E x p e c t e d Reduc t i on s in T o x i c i t y , Mobili ty, and V o l u m e• Degree to W h i c h T r e a t m e n t is I r r e v e r s i b l e• T y p e and Quant i ty of Residual s Remaining a f t e r Trea tment

i• P r o t e c t i o n of C o m m u n i t y d u r i n g Remedial A c t i o n s• Pro t e c t i on of Workers d u r i n g Remedial A c t i o n s• Environmenta l I m p a c t s• T i m e u n t i l Remedial A c t i o n Obj e c t iv e s are Achieved

i• Abili ty to Cons truc t and Operate the T e c h n o l o g y• R e l i a b i l i t y o f th e T e c h n o l o g y• Ease o f U n d e r t a k i n g A d d i t i o n a l Remedial A c t i o n s , i f Neces sary• Abi l i ty t o M o n i t o r E f f e c t i v e n e s s o f Remedy• Abi l i ty t o Obtain A p p r o v a l s f r o m Other A g e n c i e s• C o o r d i n a t i o n wi th Other A g e n c i e s• A v a i l a b i l i t y o f O f f - s i t e T r e a t m e n t , S t o r a g e , a n d Dispo sa l Servicesand C a p a c i t y• Availabi l i ty o f Nece s sary E q u i p m e n t and S p e c i a l i s t s• Avai lab i l i ty o f Pro sp e c t iv e T e c h n o l o g i e s

' P r i m a r y Balancing*Factor s

r-orovDOo

i C a p i t a l Costs< O p e r a t i n g and M a i n t e n a n c e Costs> Present W o r t h Costs

1 T h e s e cr i t er ia are assessed f o l l o w i n g comment on the FS report.Reference: G u i d a n c e for C o n d u c t i n g Remedial I n v e s t i g a t i o n s and F e a s i b i l i t y S t u d i e s U n d e r C ERG LA.

G o l d e r Asso c ia t e s

' M o d i f y i n g * Cons iderat ions

A u g u s t 1991 903-2223

,JK*.- R E T E N T I O N P O N D-s--' t/ *

SOURCES: 1888 USQS TOPOQRAPHIC MAPS1989 AERIAL PHOTOGRAPH \. ,O K L A H O M A O E C ' - O Q I C A L S U R V E Y (1966). I M '

: / " ' • & ' ' ' l l ' ~ ' \ " i£Sp" ' v - ' / ^ \....,!____y • ; . , - • ' : i u ^ - J i v . ; r i ' -n?^--- > : - . - - f e — / • ' - \ —-• ------T - (T^^^r7 -:.,..p=?s5E;. ,/,/T^ ^( r-• -^ ——— -— -. WASTE MANAGEMENT OF OKLAHOMA

M O S L E Y R O A D S A N I T A R Y L A N D F I L Laam BDL

--„ ' is ;t . ^ T j r i ] 5 . . . . . i ^C o l d e r A s s o c i a t e s I n c .

D e n v e r , C o l o r a d o~~ W I I W V I , \ « W I U I « U V

p a . j p W H [RENEWED J R ° » T E g E p T 199Q [^oi^ S H Q W N pNO. 9 Q 3 _ 2 g 2 3

L E G E N D :

' M O S L E Y R O A D L A N D F I L L B O U N D A R Y

APPROXIMATE LOCATION OF BURIEDCRUDE OIL PIPELINEAPPROXIMATE LOCATION OF BURIEDP E T R O L E U M P R O D U C T S P I P E L I N E

1200'S C A L E I N F E E T

TOPOGRAPHY BASED ON SEPT. 1889 AERIAL PHOTOGRAPH

S I T E L O C A T I O N M A P™*« 1_1

0 0 6 3 0 8

E A S T Q A K S A N I T A R Y L A N D F I L L J I

1086 U S Q S T O P O O R W H C MAPS \ T

1 8 B 9 A E B I U . P H O T O Q B A P H \OKLAHOMA G E O L O G I C A L SURVEY (18BW, *

C L I t N T / P R O J E C TVWVSTE MANAGEMENT OF OKLAHOMA' M O S L E Y R O A D S A N I T A R Y L A N D F I L L

BDL ' W H ' JR

C o l d e r A s s o c i a t e s I n c .D e n v e r , C o l o r a d o

E S E P T 1990 [ " ' " A S S H O W N l*g(&-2223

L E G E N D :H O R I Z O N T A L E X T E N T O F W A S T EPIT BASED ON NOVEMBER 1S/6AND OCTOBER 1976 AERIALP H O T O G R A P H S .

BH-106 W A S T E P I T B O R I N G L O C A T I O N& M O S L E Y R O A D L A N D F I L L B O U N D A R Y

— - — •— APPROXIMATE LOCATION Of BURIEDCRUDE OIL PIPELINE— — — — — APPROXIMATE LOCATION OF BUREDP E T R O L E U M P R O D U C T S P I P E L I N E

600'iCt

1200'S C A L E I N FEET

. TOPOORAPHY BASED ON SEPT. 1969 AERIAL PHOTOGRAPH.

W A S T E P I T B O R I N G L O C A T I O N S1-2

0 0 6 3 0 9

golder associates inc. · 2020. 11. 25. · golder associates inc. consulting engineers final...

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