## STATE OF ARKANSAS

DEPARTMENT OF POLLUTION CONTROL AND ECOLOGY 8001 NATIONA L DRIVE , P.O . BO X 8913 LITTL E ROCK , ARKANSA S 72219-8913



# RECOR D OF DECISIO N MONRO E AUT O PIT (Finc h Roa d Landfill ) SEPTEMBE R 1996RECOR D O F DECISIO N CONCURRENC E DOCUMENTATIO N FO R TH E MONRO E AUT O PI T SUPERPUN D SIT E (FINCH ROA

D LANDFILL)

. ^ ^

«r—————————^————————————————————————————^———— Sice Remedial Projec t Manaefer



# _^T^y^^^y__

Site Attorney

Wren Stenger, 1-Chief Arkansas/Oklahoma Section

Willia mHonker, Chie f Arkansas/Oklahoma/Texa s Branc h

Litigation an

d Enforcemen t Branc h 

# ^W^. G /^^JL ——y. ————y '<"————— Myron Knudson , Directo r Superfun d Divisio n

### DECLARATIO N FO RTH E RECOR

D OF DECISIO N (ROD ) SIT E NAME AND LOCATION Monroe Auto Pit Raragould, Arkansas STATEMENT OF BASI S AND PURPOS E Thi s decisio n document

presents the selected remedial actio n for the Monroe Auto Pit Superfundsite , i n Paragould , Arkansas , which was chose n i n accordanc e with the Comprehensive Environmental Response , Compensatio n andLiabilit y Ac t o f 1980 , a s amended, (CERCLA),42 U.S.C. §960 1 et.seq. and, to the extent practicable , the National Oi l andHazardous Substances Pollutio n Contingenc y Pla n (NCP) 4 0 CFRPar

t 300 . Thi s decisio n i s base d o n the Administrative Recor d for this site . ASSESSMEN T OF THE SIT E Actual or threatene d release s o

f hazardous substance s fromthis site , i f not addresse d by implementing the respons e actio n selected i n this ROD , may present an imminent

and substantial endangerment

to public health, welfare, or the environment. DESCRIPTIO N OF THE . RKMEDY 

### Thi s i s aROD for

Monroe Auto Pit, which consist s o f two major

elements . The function o f the soil andsludg e remed y i s to reduce the risk s associate d with exposur e to contaminated material s andprevent

potential groundwater

andsurface water

contamination. Th e second element o f the selecte

d remedy will addres s the contaminate d groundwater plume. Th e major components o

f the selected remedy include : Soil andSludg e

• Cappin g the sludg e disposa l are ai n accordanc e with RCRA Subtitl e C requirements.

• Installin g afrench drain aroundthe are ao f sludg e deposits . The french drain would intercep t perche d groundwater

before it enters the contaminate d area . The capture d groundwater

wouldb e transportedviaburie d pipin g to adischarge point locate d i n th e intermittent

strea msouthwest

of the site .
• Prohibitin g future development o f the site .
• Conducting environmental monitoring to ensure eflFectivenes s o f the remedia

l action . i i

### • Conducting environmental monitoring to ensure effectiveness o f th e remedial action. Groundwater

• Reducing contaminant concentrations through naturally attenuating processe s such a s biological/chemical/physical degradation, adsorption anddispersion.

• Placing groundwater use restrictions on th e site property.

• Conducting groundwater monitoring o f

on - andnear-site monitoring wells and residential wells.

• Implementing immediate an d secondar y contingency action s if

necessar y to protec t human health andth e en ironment. STATUTOR

Y DETERMINATIONS 

### The selecte d remedy for

soil/sludge andgroundwater i s protective o f

human health andth e environment, complie s with Federa l andStat e requirements that

ar e legall y applicabl e or relevant andappropriate to th e remedial action, andi s cost-effective. Th e selected remedy utilize s permanent

solution s an d alternative treatment to th e maximumextent

practicabl e for

thi s site. However, becaus e treatment o f th e principal threats a

t th e sit e was no t foundto b e practicable , thi s remed

y doe s no t satisfy th e statutory preference for treatment a s th e principal element. Becaus e thi s remedy will result i n hazardous substance s remaining on-sit e abov e health-base d levels , arevie w will b e conducte d within five years after commencemen

t of remedia l actio n to ensure that

th e remedy continues to provide adequate protection o f human health andth e environment.

/r^e^ 

### Regional Administrator DATE: September

26 , 199 6 / * / j ; , , „ 

# (X^/J^ f
. Randall E. Mathis Arkansas Department

of Pollutio n Contro l andEcolog y

11 1TABLE OF CONTENT S

1. 0 SIT

E NAME, LOCATION AND DESCRIPTION ............... . 1 1. 1 NAME AND LOCATION ........................ . 1 1.2 DESCRIPTION .............................. . 1 2.0 SIT

E HISTOR

Y AND ENFORCEMENT ACTIVITIE S ............. . 1 2.1 SIT

E HISTORY .............................. . 1 2.2 ENFORCEMENT ACTIVITIE S ..................... . 4 3.0 HIGHLIGHT S O F COMMUNITY PARTICIPATION .............. . 4 4.0 SCOP

E AND ROLE O F RESPONSE ACTIO N ................ . 5 5.0 SUMMARY O F SIT E CHARACTERIZATION ................. . 6 5.1 LAND USE/POPULATION ....................... . 6 5.2 CLIMAT

E ................................. . 6 5.3 SURFACE TOPOGRAPHY ........................ . 7 5.4 SURFACE HYDROLOGY ........................ . 7 5.5 GEOLOGY ................................ . 9 5.6 HYDROGEOLOGY ............................ . 9 5.6.1 Perche d Ground Water Zone s ................... . 9 5.6.2 Upper

Wilcox Aquifer

....................... . 1 3 5.6.3 Lowe

r Wilco x Aquifer

....................... . 1 7 5.7 NATURE AND EXTENT OF CONTAMINATION IN THE SLUDGE AND SOI L ............... . .............. . 1 7 5.8 NATURE AND EXTENT O F CONTAMINATION IN TH E GROUND WATE R................................ . 22 5.9 RESIDENTIA

L WATERSUPPLIE S ................... . 28 6.0 SUMMARY OF SIT E RISKS .......................... . 3 2 6. 1 HUMAN HEALTH RISK ASSESSMENT ................ . 3 3 6.1.1 Ground water

............................ . 3 3 6.1.1.1 Current

Exposures - Residentia

l Well s Off

Sit e ..... . 3 4 6.1.1.2 Hypothetical Future Exposures - Monitorin g Well s O n Sit e ............................. . 3 4 6.1.1.3 Hypothetical Future Exposure s - Modeled Ground Water Concentrations Off

Sit e .................. . 3 4 6.1.2 Sediment

.............................. . 3 5 6.1.3 Soils/Sludg e ............................ . 3 5 6.1.4 Summary o

f Human Health Ris k

................. . 3 6 6.2 Ecologica

l Risk Assessment

....................... . 3 6 i v7.0 DESCRIPTION O F ALTERNATIVE S ...................... . 3 7

7.1 Soi l and Sludge Remedial Alternatives .................. . 3 7 7.1.1 Alternative No. 1 : No Actio n .................. . 3 8 7.1.2 Alternative No . 2 : Acces s and Dee d Restrictions ........ . 3 9 7.1.3 Alternative No. 3 : Soi l and Vegetativ e Cover; Acces s ?ndDee d Restrictions ............................ . 3 9 7.1.4 Alternative No . 4A: Cap; Slurry Wall ; Acces s and Dee d Restrictions ............................ . 3 9 7.1.5 Alternative No. 4B : Cap; French Drain; Acces s and Dee d Restriction s ............................ . 4 0 7.1.6 Alternative No . 5 : Solidification/Stabilization ; On-site Landfill; Acces s and Dee

d Restriction s ................... . 4 1 7.1.7 Alternative No . 6 : Excavation ; Vapo r Extraction; Solidification/Stabilization on-site Landfill; Acces s an d Dee d Restrictio n ............................. . 4 2 7.1.8 Alternativ e No . 7 : Excavation ; Off-Site Transpor t and Disposa

l i n Subtitl e C or

D Landfill .................... . 43 7.2 GROUND WATERREMEDIAL ALTERNATIVE S ........... . 4 3 7.2.1 Alternative No . 1 : No Action .................. . 4 3 7.2.2 Alternative No. 2: Natural Attenuation and Degradation ; Ground Water Use Restrictions; Ground Water Monitoring and Residential Water

Supply Monitoring ............... . 4 5 7.2.3 Alternative No. 3 : Ground Water Extraction; Carbon Adsorption; Reinjection ...................... . 4 6 7.3 ARARS
.................................. . 4 6 7.3.1 Action-Specific ARARs for Soil/Sludg e ............. . 48 7.3.2 Action-Specific ARARs for Ground Water

............ . 4 9 8. 0 COMPARATIVE ANALYSIS OF ALTERNATIVE S .............. . 5 0 8. 1 NINE CRITERI

A ............................. . 51 8.2 COMPARATIVE ANALYSIS ....................... . 52 8.2.1 Sludg e Pi t

Are a.......................... . 5 2 8.2.2 Ground Water

........................... . 5 3 9.0 THE SELECTE

D REMEDY ........................... . 5 5 9.1 SOI

L AND SLUDGE REMEDIATIO N ................. . 5 5 9.2 GROUND WATERREMEDIATION ................... . 5 7 10. 0 STATUTOR

Y DETERMINATIONS ....................... . 5 8 10. 1 PROTECTION OF HUMAN HEALTH AND THE ENVIRONMENT . . 5 8 10.1. 1 Soi

l and Sludg e .......................... . 5 8 10.1. 2 Ground Water

........................... . 5 8 10. 2 COMPLIANCE WITH APPLICABL E ORRELEVANT AND APPROPRIATE REQUIREMENTS ................... . 5 910.2. 1 Soi l and Sludge .......................... . 5 9 10.2.2 Ground Water

........................... . 6 1 10.2.3 Action-Specific ARARs for Ground Water

........... . 6 1 10. 3 COST EFFECTIVENES S ........................ . 6 2 10.3.1 Soi l and Sludg e .......................... . 6 2 10.3. 2 Ground Water

........................... . 6 2 10. 4 UTILIZATION O F PERMANENT SOLUTIONS AND ALTERNATIVE TREATMENT TECHNOLOGIES TO THE MAXIMUM EXTENT PRACTICABLE .............................. . 6 3 10.4. 1 Soi l andSludge .......................... . 6 3 10.4. 2 Ground Water

........................... . 6 3 10. 5 PREFERENCE FORTREATMENT A S A PRINCIPAL ELEMENT . . 6 3 11. 0 DOCUMENTATION OF SIG-JIFICANT CHANGES ............. . 64 12. 0 RESPONSIVENESS SUMMARY ........................ . 6 4

VI

### LIS T O F FIGURE S
Titl e Pag e SIT E LOCATION MAP . ........................ . 2 SIT E TOPOGRAPHI C MAP. ..................... . 3 SIT E SURFAC E WATERFEATURES . .............. . 8 LOCATION O F CROSS-SECTIO N THROUGH THE SLUDGE DISPOSA

L AREA. ..................... . 1 0 CROS S SECTIO N THROUGH THE SLUDGE DISPOSA L AREA. .................................... . 1 1 REGIONAL GEOLOGIC CROS S SECTIO N ALONG AND ADJACENT TO CROWLEY'S RIDGE. ............... . 1 2 GROUNDWATERPOTENTIOMETRIC SURFAC E IN THE PERCHED GROUND WATERZONE - JUNE 1992 . ....... . 1 4 NORTH-SOUTH HYDROGEOLOGIC CROSS-SECTIO N IN THE SIT

E VICINITY (A-A'). .................... . 1 5 GROUNDWATERPOTENTIOMETRIC SURFAC E IN THE WILCOX AQUIFERUPPERZONE - MARCH 1993 . ...... . 1 6 GROUNDWATERPOTENTIOMETRIC SURFACE IN THE WILCO X AQUIFERLOWERZONE - MARCH 1993 . ..... . 1 8 ESTIMATE

D EXTENT OF SLUDGE DEPOSITS . ...... . 2 1 ORGANIC CONCENTRATIONS IN GROUNDWATERIN THE WILCOX AQUIFER. ...................... . 2 5 INORGANIC CONCENTRATIONS IN GROUNDWATER IN THE WILCOX AQUIFER. .................... . 29 ORGANIC AND INORGANIC CONCENTRATIONS IN RESIDENTIAL WELLS . ....................... . 3 1

vu

### LIS T O F TABLE S Title Pag e MAXIMUM CONCENTRATIONS DETECTE D IN SURFACE SOI

L SAMPLES . ..................... . 1 9

\ MAXIMUM CONCENTRATIONS DETECTE D IN SUBSURFAC E SOI

L AND SLUDGE SAMPLES . ....... . 2 0 SURFAC E WATERANALYTICAL DATA. .......... . 2 3 RANGES O F CONTAMINANTS DETECTE D IN UPPER WILCOX GROUNDWATERMONITORING WELLS . ... . 24 ORGANIC CONSTITUENT S IN THE GROUND WATERO F THE WILCOX AQUIFERUPPERZONE OVERTIME .... . 2 6 WILCOX AQUIFERLOWE RZONE GROUNDWATERANALYTICAL DAT A SUMMARY. ................ . 3 0 HEALTH RISKS . ............................. . 3 6 REMEDIAL ACTION GOALS . ................... . 3 7 SOIL/SLUDGE ALTERNATIVE COS T SUMMARY. ..... . 3 8 GROUNDWATERALTERNATIVE COS T SUMMARY. ... . 44

VlUTH E DECISION SUMMARY MONROE AUT O PI T
1. 0 SIT E NAME, LOCATIO N AND DESCRIPTIO N 1. 1 NAME AND LOCATIO N Th e Monroe Auto Pit

Superfund site , als o known as th e Monroe Finc h Roa d Landfill, i s locate d i n northeastern Arkansas i n unincorporated Green e County, approximately thre e mile s southwes t o f Paragould, a s shown on Figur e 1 . The sit

e lie s immediatel y wes t

o f Arkansas Highway 358 , approximr/sly three mile s wes t o f its intersectio n with U.S . Highway 49 . The site lie s i n th e Northwest Quarter o f the Northeast

Quarter o f Sectio n 17 , Township 1 6 North, Rang e 5 East, i n the Paragould Wes t P^-minute quadrangle. The southwestern comer o f the sit e i s a t latitude 36 ° 01 " 0' and longitude 90 ° 34 " 30' . 1. 2 DESCRIPTION The sit e i s ownedby Monroe Auto Equipment Company, On e International Drive , Monroe, Michigan . The property i s identified as parce l no . 4071- 1 i n the Green e County Ta x Assessor' s office. Th e lega l descriptio n provided i n the property deed i s "all that part o f the South Half

o f the Northwest

Quarter o f the Northeast

Quarter o f Sectio n 17 , Township 1 6 North, Rang e 5 Eas t

lying Wes t

o f the Highway No. 358 " (Warranty Deed 1973) . The sit e layout i s shown on the topographic map provided as Figure 2. Approximately four acre s o f the Monro e property , including th e sludge disposa l are athat cover s les s than one acr

e o f the site , i s currently surrounded by asix-foot tal l chain-link

fence toppe d with barbe d wire. Mos t o f the sit e i s cleare d o

f tree s and i s covere d with native vegetation .
2.0 SIT E HISTOR Y AND ENFORCEMENT ACTIVITIE S 2.1 SIT E HISTOR Y In 1973 , Monroe purchase d aseven-acr e trac t o f lan d i n Green e County, Arkansas. The sit e include d an inactiv e san d and grave l borrow pi t which was subsequentl y approve d by the Arkansas Department

o f Pollutio n Control and Ecology (ADPC&E) i n 197 3 for use a s a landfill . Approximately 15,40 0 cubic yards o f aluman d lim

e electroplatin g sludge/slurry fromth e wast

e water treatment

lagoon s at

Monroe's Paragoul d manufacturing plant wa s deposite d i n th e borrow pit between 197 3 and 1978 . Th e sludg e containe d approximatel y

### Figure 1 2

### 85% liquid . Th e present dewatere d volume i s about 10,80 0 cubic yards o

f sludge and contaminatedsoil . Based on boring samples, the sludge extends to an estimatedmaximumdepth o f 3 0 feet. Th e greates t

contaminant

concentration s andthe majority o f th e sludg e occur

i n an approximate interval o

f 5 to 2 5 fee t

belo w the surface. Approximately four

acre s o f the Monroe property, including the sludg e disposa l are athat cover s les s than one acre o f the site , ar

e currently surroundedby asix-foo t tal l chain-lin

k fence topped with barbe d wire . Th e sludg e i s covered with approximately thre e to five fee t o f soi l an d the sit

e i s vegetated . Th e sit

e has remaine d inactiv e sinc e 197 8 andacces s i s controlle d by the fence andalocked gate . Th e remaining thre e acre s within the fence are , for the most part, cleare d o

f tree s andcovere d with native vegetation . Under ADPC&E review , Monroe conductedaserie s o f investigation s a

t th e sit e between 197 9 and1990 . Thes e include d the installatio n o f groundwater

monitorin g wells , samplin g andanalysis o

f groundwater , soil , surface water , andsediment, andgeologica l surveys . Analysis o f the sample s collected frommonitoring well s a t the landfill indicate d the presenc e o f 1,1-dichloroethan e [100/zg/ L (1989) ] and1,2-dichloroethylen e [750/Ag/L (1988)] . Furthermore, aresidentia l wel l (Gann well ) locate d nea r the site als o showe d 1,1

- dichloroethan e [10/Ag/L (1987) ] and1,2-dichloroethylen e [145^g/ L (1987)] . The Environmental Protectio n Agenc y (ERA ) propose d that the sit e b e adde d to th e Nationa

l Prioritie s Lis t

(NPL ) i n 1989 . In August 1990 , the sit

e was adde d to the NPL. 2.2 ENFORCEMENT ACTIVITIE S A Potentially Responsibl e Part y (PRP ) search conductedi " 1990 under CERCLA Section 104(e) , indicate d that

Monroe Auto Equipment

was the only PRP for

thi s site . On March 14 , 1991 , EP

A issue d notic e o

f an impending Remedia

l Investigatio n andFeasibilit y Study ( RI/FS) to the PRP . Monroe Auto Equipment responde d to the notic e with agood faith offer to performthe RI/FS . On June 28, 1991 , EP A an d Monroe Auto Equipment entere d into an Administrative Order on Consent

for Monroe to performaRI/FS.

3.0 HIGHLIGHT S OF COMMUNITY PARTICIPATIO N 

### A Community Relation s Pla n for the Monroe Auto Pit

sit e was complete d i n June 1991 . Thi s Pla n list s contact s andintereste d partie s throughout government

an d th e loca

l community. I t als o establishe s communication pathways to ensure timel y disseminatio n o f pertinent information, andemphasizes the need for community involvement . A publi c work shop wa s
4

### hel d on February 24, 199 2 to discuss the progres s o f fieldwork

at the site andto inform the public o

f the availabilit

y o f aTechnica

l Assistance Grant

(TAG) for

the site . In May 1995 ADPC&E assumedthe rol e o f lea d agenc y for

the Monroe Auto Pit

site . The Propose d Plan was release d to the publi c by ADPC&E on July 17 , 1995 . Al l o f the site relate d documents are availabl e a t the Northeast

Arkansas Regional Library, locate d a t 12 0 North 12t h Street , Paragould, Arkansas. A public comment perio d on the Proposed Pla n was hel d fromJuly 1 7 to August 17 , 199 5 with an extension grante d until Octobe r 16 , 1995 . In addition, apublic meeting was heldon August 8 , 199 5 to present

the results o

f the Remedia

l Investigation/Feasibilit

y Study an d the Proposed Plan. Another open house was hel d Septembe r 12 , 199 5 to answer

any new questions andto explai n the detail s o f the plan . Al l comments received by ADPC&E prior to the en d o

f the comment

period , includin g those expresse d verball y a

t the publi c meeting , ar

e addresse d in th e Responsivenes s Summary sectio n o f this Recor

d o f Decision . 4.0 SCOP

E AND ROLE OF RESPONS E ACTIO N Thi s ROD addresse s the entire sit e a s one operabl e unit. The remedia l objectiv e that

i s addresse d i n this ROD is the reduction or elimination o

f the actua

l and/or potential ris k associate d with the sludg e pit andthe contaminants i n the groundwater . The objective s o

f this remedy are three fold, to prevent contac t with th e buried sludg e and contaminate d soil , to prevent infiltration o

f precipitation or

groundwater

i n the sludg e deposi t area, andto prevent

the contamination o

f the residential well water supply . Th e burie d sludg e was originall y 15,40 0 cubic yards o f alumandlime sludg e fromthe waste water treatment lagoons . Processe s relate d to shoc k absorber production contribute d to the wast e water . The sludg e wa s approximately 85% water . The present dewatere d volume i s about 10,800 cubic yards o

f sludge andcontaminatedsoil . Dermal contac t with, or ingestio n o f the sludg e andcontaminatedsoi l must b e preventedbecaus e contac t with the sludg e pose s acarcinogeni c andnon-carcinogeni c ris k level abov e that

recommende d by EPA . Th e sludg e was periodically covered with soil which absorbe d som e o f the water , but

was no t an effective barrier

to precipitation . Infiltration o f precipitatio n an d perche d groundwate r through the sludg e add s to the contaminant level s producedby th e initia l dewaterin g o

f the sludge . Future infiltration into the sludg e are ashouldb e prevented , thus cutting off the sourc e o f groundwater

contamination. The exact production zone s o

f all o f the private wells ar

e not known, but

most ar e assumed to produce fromthe lowe

r Wilco x aquifer. Becaus e this i s only an assumption, th e potential

### ingestio n or dermal contact

o f contaminatedgroundwater fromthe upper

Wilcox aquifer fromaresidential well or

fromawell place d on the sit e i n the futur e must

b e prevented. Monitoring o

f the on andnea

r site monitoring well s (8 8 samples ) shows adecreas e i n the contaminant

level s away fromthe sludg e area . Level s o f volatil e organi c compounds have decrease d ove

r time (first

monitoring 1988 ) andthis tren d shouldcontinue. Recent (1995 ) residential wel l water

samples do not

show contamination by volatil e organic s abov e analytical detectio n levels . Although modeling o f contaminant

movement

has been done , monitoring shouldbe continued. Th e remedie s evaluate d i n this ROD ar e measuredagains t

thes e objectives . Thos e remedie s meetin g thes e objective s are evaluate d further to determine the bes t

remedy for

thi s site . Th e ultimate objectiv e i s the protection o f human healt

h andthe environment.
5.0 SUMMARY OF SIT E CHARACTERIZATIO N 5.1 LAND USE/POPULATIO N The most predominant

landuse nea

r the sit e i s single-family residences . Based on afiel d survey conducte d i n 1992 , there are 5 2 single-family residence s andsix mobil e homes within aone-mil e radius o

f the site . Many o

f thes e are associate d with small farms an d relate d agricultural pursuits. Agricultural uses include cro p farming andlivestoc k production. The fieldsurvey identifiedfou r

commercial landuses. Thes e lan d uses were individual enterprise s andinclude d antique sales , convenienc e stores , andautomobile repair establishments . Industrial lan d uses are limite d to grave l quarries andan overhea d electrica

l powe r line . Ther e ar e no schools , nursing homes, churches, hospitals , or recreationa

l facilitie s within a one-mile radius o

f the site . In 1992 , the estimate d population within aone-mil e radius o f the Finc h RoadLandfill sit e was 15 9 persons , residing i n 5 8 households. Assuming the rate o f population increas e (from 1984 , til l 1992 ) remains constant there will b e an estimate d tota l o f 6 9 residence s and190 persons within aone-mile radius o f the site by the year

2000 . 5.2 CLIMATE Green e County has hot

summers, mil d winters , high humidity andabundant rainfall . Th e mean annual temperature i s 6 0 ° F with temperatures infrequently exceeding 100°F i n the summer or railin g belo w 1 0 ° F i n the winter . Precipitatio n average s 4 9 inche s per yea r with afairly even distribution throughout the year . In atypical year , April i s the wettes t month andOctobe

r i s the driest . Only minor amounts o

f snowfall contribute to the yearl y precipitation . In the averag e year , thunderstorms occu r on 5 5 days; however , damaging winds seldo maccompany these storms. The most intens e stor

meach yea

r average s 1. 4 inche s o f rai n i n an hour; the averag e yearly 24 hour maximumrainfal l i s between 3. 0 and 6

### 3.5 inches . Approximately 11 0 day s i n the yea r will have atotal precipitation greater than 0.01 inches. Th e mean annual windspee d average d through the afternoon mixing layer i s approximately 6 miles per

hour. 5.3 SURFAC E TOPOGRAPHY The lan d surface nea

r the site i s very irregular . The sit e topographic map, Figure 2, shows that the groundsurface slope s downwardfromHighway 35 8 o n the easter n sit e boundary, andthat the lan d i s relativel y flat ove r the sludg e disposa

l area . Tw o ravines , sloping southwesterly , lie wes t

o f the sludg e disposa

l are aandwithin ih e fencedarea . An intermittent

sprin g i s present

i n each o f the ravines . A shallo w seasona l pond i s als o present within the fencedarea, andi s foundnorthwest o f th e sludg e disposa

l area . Sit

e elevation s range fromapproximately 41 3 to 46 0 fee t abov e mean sealevel (MSL). 5.4 SURFAC E HYDROLOGY Surface water

i s intermittently present

a t three location s on the sit

e (Figure 3). A depression o n th e western edg e o

f the site , approximatel y 2 5 fee t in diameter, forms apondfromstor m water runoff during period s o

f heavy rainfall. The depressio n dries during period s o f lo w rainfall. Tw o intermittent

spring s i n the southwestern comer o f the sit e discharg e to asmal l stream. The spring s may b e discharge points for the perche d groundwater zone . Flo w rate s from the spring s have been observe d to b e greates t immediately following prolonge d period s o f heavy precipitation , andquickly decreas e after precipitatio n ends . Precipitatio n that

doe s not

run off either infiltrates, evaporates , or i s absorbe d by the vegetatio n on the site . Surface water a t the sit e ca n easily infiltrate the sandy loes s and grave l deposit s andmigrate to the perche d water zones . In afew area s o

f the site , cla

y nea r the surface prevents rapidinfiltration andpuddles ca n standfor

severa l day s i n thes e perche d zones . In summer

months, evaporatio n can reac h athirdo f an inc h per

day . Surface water

runoff leave s the site through two ravines , a s shown on Figure 3 . Surface water i n the ravines enter s an intermittent cree k that joins Villag e Cree

k nearl y amil e southwest o f th e site . The water

o f Villag e Cree

k enter s the St . Franci s rive r at it's confluence with Straight

Slough, ove

r 2 5 mile s southeas t

o f where surface water

runoff from th e sit e wouldenter

Villag e Creek . Secondar y contac t recreation , anddomestic , industrial, an d agricultural water

supplie s ar

e uses o f water s nea

r the site . Due to th e intermittent

nature o f the pondandsprings , the surface water exposure pathway i s incomplete . Th e only exposure possibl e wouldbe by persons comin g into contac t with surface water

o n site .

7

### Figures

### 5. 5 GEOLOGY

Pliocen e san dandgravel (Crowley's Ridg e deposits ) frombraide d andmeanderin g strea m environments overli e Eocene clay , silt , sandandlignit e deposits . In the sit

e area , the Crowley's Ridg e deposit s unconformably overli e the Eocene Wilco x Group. Th e Jackso n and Claibome Groups have bee n erode d away on the northern section s o f the Ridge . Figur

e 4 shows aregional cross-sectio n o f this area . At the site , the Crowley's Ridg e deposit s characteristicall y contain cobble s up to two inche s i n diameter, mixe d with sand, clayey sand, an d silt y sand. Th e deposit s ar

e up to 7 0 fee t i n thicknes s eas t

o f the site , where the deposit s have not been excavated . Thes e deposit s ar e 1 0 to 1 5 fee t

thick o n the sit

e where san dandgrave l excavatio n occurre d during quarry operations . In some grave l pits surrounding the site , thes e sand s andgravel s wer e excavate d to the top o

f the Wilco x Group. A cross sectio n through the sludg e disposa l are a(Figur

e 5 ) a t th e locatio n shown on Figure 6, shows the extent o f sludg e deposit s andcove

r material i n relatio n to the site lithology . At the site , individual thicknesse s o f san dandcla

y layer s in the Wilco x Group vary from les s than on e inch to severa l feet. However , aconsistent, very stiff cla y laye r i n the Wilcox Group correlate s betwee n borehole s acros s the site . The cla y laye r has an estimate d thicknes s o

f 4 0 to almos t

7 0 feet. Severa

l lignit e deposit s were als o encounteredi n this clay , which i s typica

l o f the Wilco x i n this area . Fine to medium-grainedsand s underli e the thick cla y a t all monitoring wel l locations . Other cross-section s ar

e includedi n the RI report. 5.6 HYDROGEOLOGY Tw o primary groundwater zone s have bee

n identifie d a

t the site : Th e upper

zone o f the Wilcox aquifer

andthe lowe

r zon e o f the Wilcox aquifer . Perche d groundwater has als o bee n identifie d i n some location s nea r th e sludg e disposa

l area . Th e followin g subsection s discuss the occurrence andhydraulic characteristic s o f these thre e zones . 5.6.1 Perche

d Groun d Wate r Zones Perche d groundwater

intermittently occur s acros s the site . Thi n layer s o f stif f clay , up to severa l inche s i n thickness, were observe d a t depths betwee n five fee t

and5 0 feet. After period s o f precipitation , the soil abov e thes e clay layer s has been foundto be saturated, creatin g localized zone s o

f perche d groundwater . During thes e high water period s (wate

r level s ca n chang e by as much a s 1 0 feet), water discharge s fromthe springs . Five monitorin g well s ar c installe d i n the perche d groundwater zon e a t the site . Water

leve l measurements were taken monthly for

one yea r to document

the seasona

l fluctuations. Thes e measurements indicat e that perche d groundwater

i s seasona

l andintermittent. The presenc e andamount o f perche d groundwater

ar c dependent

upon precipitation . Subsurface fieldinvestigation s hav e shown that on e localized perche d groundwater zon e mayREGIONAL GEOLOGIC CROSS SECTION ALONG AND ADJACENT TO CROWLEY' S RIDGE

APPROXIMAT E LOCATIO N O F TH E MONRO E AUT O PT T SUPERFUN D SfTEFigures 1 1Figure 6 1 2

### be continuous beneat h the are ao

f sludge/soil contamination. Th e elevatio n o f the perche d groundwater

surface has been recorde d a t approximately 41 6 to 42 7 feet abov e MSL (1 3 to 26 fee t belo w landsurface [bis] ) when present i n the monitoring wells . The perche d groundwater

gradient slope s i n the genera

l directio n o

f the ravines south-southwest o f the sludg e disposa

l area . Th e perche d groundwater

flow pattern, assuming that the perche d zon e i s continuous acros s the site , i s shown on Figure 7 . It i s believed that

this wate r may discharge through the spring s i n the two ravines. Perche d groundwater i s als o likely to percolat e into the underlying Wilcox aquifer

through discontinuities i n the underlying low-permeabilit y zone . A deepe r perche d zon e has bee

n identifie d on the northern portion o f the site . Th e ground water surface elevatio n i n this zone was measureda t approximatel y 38 1 fee t

abov e MSL (approximately 7 0 fee t

bis ) i n February 1992 . Thi s perche d zon e i s likel y formedfroma cla y lens that

was encountereda

t adepth o

f approximately 8 0 fee t

bis . Multiple perche d water zone s ar e typica l o f alluvial formations such as the Wilco x Group andi n area s where loca l infiltration i s the major

formo f recharge for

the aquifer. 5.6.2 Uppe r Wilcox Aquifer 

### Tw o groundwater

zone s wer

e encounteredi n the Wilcox aquifer through the total depth o f the subsurface investigatio n (Figur e 8) . The upper

zon e behave s as an unconfinedaquifer compose d o

f interbedde d san d andclay . Fiv e monitoring wel l cluster s andsi x singl e well s monitor the upper Wilco x aquifer. Thes e well s ar e designate d a s ES W ft

- 1 (lowe r part o f the upper aquifer) andES W if

- 3 or A (upper part o f the upper

aquifer). Exception s to these label s ar

e ES W 1A

- intermediate perche d zone, ES W 8 an d 9

- lowe r part o f th e upper aquifer, andES W 6
- the lowe r Wilco x aquifer. Approximatel y 1 0 to 7 0 fee t o f Crowley's Ridg e deposits overli e the Wilco x aquifer upper zon e i n the site area . A cla y laye r greate r tha n 4 0 fee t

i n thickness forms the bas e o f the Wilco x aquifer

upper zone . At th e souther

n boundary o

f the site , the surface o

f the cla y laye r was encountereda

t approximatel y 26 6 fee t abov e MSL (17 4 feet

bis). The groundwater

flow pattern i n the upper zone o f the Wilcox aquifer

i s shown on Figure 9 . The flow pattern i s see n to radiate fromthe western portio n o f the site towardthe northeast andsoutheas t

quadrants. Water

level s fluctuate by afew inche s up to on e foot seasonally . Th e hydraulic gradient i n the S E directio n (Ma

r '93 ) i s 0.00 5 ft/foot

andi n th e NE direction , 0.00 6 ft/foot. The saturate d thicknes s o f the upper

Wilco x aquifer

i s approximatel y 5 0 feet. A downwardgradient may exis t

i n the upper

zon e of th e Wilcox aquifer. Thi s vertica

l gradient i s due i n part

to the lo w hydraulic conductivity o f th e cla y andrecharg e fromthe overlyin g Crowley's Ridg e deposit s to the upper zon e o f th e Wilcox aquifer. Th e hydraulic conductivity i n th e vicinity o f ESW-13- 1 i s approximately 42 0 gallon s per da y per square foot

(gpd/ft 2 

### ) or

2.0 x 10 2 

### centimeter s per second (cm/s). Th e aquifer i s compose d o

f silt y sand, with lense s o

f sandy , silt

y clay .
1 31 41 5

### Figur e 9 1 65.6.3 Lower Wilcox Aquifer

A confined ground water

aquifer, the Wilco x aquifer lowe r zone, has been identified belo w the Wilcox aquifer

upper zone . Th e lowe

r zon e o f the Wilcox aquifer

i s separate d fromthe upper zone by aclay confining laye r more than 4 0 fee t

thick. Hydraulic conductivity test s performed on sample s o

f this cla y yielde d vertica

l hydraulic conductivity values on the order o f 10' 9 cm/sec. Fiv e monitoring well s monitor the lower

Wilcox aquifer. Thes e well s ar e designate d by ES W ff -2, except

for wel l ESW

- 6 . Th e lowe r Wilcox aquifer

i s compose d o

f fine to medium-grained san d and fine gravel , which coarsen s with depth. At the souther

n sit e boundary, thi s zon e i s approximately 3 6 fee t thick, extendin g from226 fee t abov e MSL to 19 0 fee t abov e MSL . Th e ground water

flow pattern i n the lowe r aquifer i s shown on Figure 10 . Th e ground water flow i s primarily t: the eas t and southeas t

fromthe site , and th e gradient appear s to be relatively smooth acros s the monitored area . Based o n aquifer pump test s (May '92) the hydraulic gradient

nea r ES W 13- 2 average s 0.002 ft/foot . The hydraulic gradient was calculate d a

t 5 6 ft/day (2.0 X 10- 2 cm/sec). 5.7 NATURE AND EXTEN T OF CONTAMINATIO N IN THE SLUDGE AND

SOI L Twenty one soil boring s wer e place d ove

r the sludge disposa

l area . Sample s o

f surface soil , shallo w subsurface soi

l nea r the inferred interface between th e soil/sludg e and the overlyin g fill material, an d sample s o f dee p subsurface sludg e and soil were analyze d for volatil e organi c compounds (VOCs), semivolatil e organics , and inorganics . Thre e VOCs, eigh

t semivolatil e organics , and four inorganic s wer

e detecte d i n surface soil sample s (les s than 2.5 fee t belo w the surface) a

t concentration s greate

r than twice thei r background concentrations. Maximumconcentrations detecte d i n the surface soi l ar e shown on Tabl e 1 . Thirteen VOCs, seve

n semivolatil e organics , and eightee n inoiganic s wer e detecte d i n shallo w subsurface soi

l ( adept h o f 2.5-7.5 feet) a

t concentrations greate

r than twice thei r

background levels . Fiftee n VOCs, eigh

t semivolatil e organi c compounds, and eightee n inorganic s wer e detecte d i n dee p subsurface soil/sludg e sample s (greater than 7.5 fee t

deep ) a t concentration s greate

r than twice thei r

background concentrations . Maximumconcentrations detected i n the subsurface soil/sludg e sample s ar e shown on Tabl e 2. Analyte concentration s ar e randomly distribute d acros s the site , an d the detected concentrations do no t

show th e existenc e o

f any spatia

l pattern. The estimate d horizonta l extent o f sludge deposit s is shown on Figure 11 . Th e horizonta l extent cover s approximatel y 1 71 8

### TABLE 1 MAXIMUM CONCENTRATIONS DETECTED IN

SURFACE SOI

L SAMPLESi Monroe Auto Pit

Superfund Sit

e (Finch Road Landfill) Parameter MaximumConcentratio n VOC s TC E 

### Ethylbenzene Tota l Xylenes 1 4 J ug/Kg 1. 0 Jug/K g 7.0 J ug/Kg Semivolatile Organics 2-Chlorophenol 1,2,4-Trichlorobenzene Naphthalene 4-Chloro-3-methylphenol 2,4-Dinitrophenol Fluoranthene Pyrene di-n-Octylphthalate Inorganics Chromium Lea d Manganese 1 2 J ug/Kg 1 0 J ug/Kg 1 4 J ug/Kg 1 4 J ug/Kg 2 7 J ug/Kg 5.0 Jug/K g 5.0 Jug/K g 1 0 J ug/Kg
60. 6 J mg/Kg 58 6 J mg/Kg 144 0 J mg/Kg
J - Estimate d Value 

### 1-0-2. 5 feet

belo w surface Sample s taken 1992-199 3 Complet e dat atable s that

include quantitation limits for all analyte s are provide d i n Appendi x H o f th e Remedia

l Investigatio n (RI ) 19TABL E 2 

### MAXIMUM CONCENTRATIONS DETECTE D IN SUBSURFACE SOIL AND SLUDGE SAMPLESi Monro e Auto Pi tSu^rfund Site (Finch Road Landfill) Parameter MaximumConcentration VOLATILE ORGANICS Vinyl Chlorid e 1.1-Dichloroethane 1.2-Dichloroethylen e 1,1, 1 -Trichloroethane Trichloroethyle" e Benzen e Tetrachloroethylene Toluene Ethylbenzene Total Xylenes SEMIVOLATILE ORGANICS bis(2-Ethylhexyl)phthalate Naphthalene di-n-Octylphthalate Phenol Phenanthrene INORGANICS Antimony Arsenic Beryllium Cadmium Chromium Lea d Manganese Mercury Nickel Zin c 

### Cyanide 31,OOOJug/Kg 66,000 ug/Kg 60.000 J ug/Kg 210 J ug/Kg 91 J ug/Kg 15 J ug/Kg 310 J ug/Kg 16.000 J ug/Kg 220J ug/Kg 6,70 0 ug/Kg 96,OOOJ ug/Kg 6400 J ug/Kg 550J ug/Kg 16.000 J ug/Kg 42,OOOJ ug/Kg 63. 1 mg/Kg 19.6 J mg/Kg 0.88 J mg/Kg 1. 2 mg/Kg 4.030 J mg/Kg 3.240 J mg/Kg 319 J mg/Kg 0.12J mg/Kg 23.8 J mg/Kg 50 8 mg/Kg 15. 7 mg/Kg Complete datatable s that

include quantitation limits for al l analytes are providedi n Appendix H o f th e Remedia

l Investigation (RI ) 2 0Figur

e 1 1

2 130,00 0 square feet, or approximately 0.7 acres . Th e sludg e extends to an estimate d maximumdepth o

f 3 0 feet, although the greates t contaminant

concentrations, an d the majority of the sludg e deposits , were identified through an approximate interval o f 5 to 2 5 feet. The depth o f the sludg e deposits ' botto msurface i s erratic . Bot h the tota

l depth and thicknes s vary greatl y betwee n boring locations . Th e total volume o f sludg e an d contaminated soi l i s estimate d to b e approximately 10,800 cubic yards . Variations i n the tota l sludg e dept

h an d thicknes s are to b e expected becaus e the sludg e was deposite d i n an abandoned quarry. An examination o

f other quarrie s i n the are ashow s that grea t variations i n excavatio n depths ar e common, a s excavatio n appear s to ceas e upon encountering cla y lense s i n the Wilcox deposits . 5.8 NATURE AND EXTEN T OF CONTAMINATIO N IN TH E GROUND WATER Contaminants i n the ground water move with the water . In the perche d zone , this wouldb e out through th e spring s or

downwardinto the upper Wilco x aquifer. In the upper Wilcox aquifer, the contaminants move i n anortheasterly and asoutheasterl y direction . The metal s have agreate

r affinity for

the fine graine d sediment s and wil l move slowe r than the organics , but i n the sam

e direction . A volume of

perche d water

sufficient for samplin g was present

at only on e monitoring wel l locatio n (ESW-2P , 1992) . No VOCs or semivolatil e organic s were detecte d i n aground water sampl e collected fromthis well. Inorganic concentrations were generally les s than those i n sample s fromthe Wilcox aquifer. Eight inorganic s were detecte d i n unfiltered sample s and si x i n filtered samples. I t must b e noted , however , that

thi s monitorin g wel l i s locate d on aside-gradient fromthe sludg e disposa

l area, i f acontinuous perche d zon e i s assumed to exis t

acros s the site . Some o f th e perche d water

appear s to discharg e through the springs following asignificant rai n event. Surface water representativ e o

f th e spring s i n the ravine s southwes t o f th e sludg e disposa l are awas als o sampled . Four volatile s organics , thre e semivolatil e organic s and nin e inorganic s were detecte d (Tabl e 3) . Sediment sample s fromthe cree

k showe d amarked decreas e i n contamination away fromthe site . Th e perche d water i s seasona

l an d its flow has alimite d extent . The maximumconcentrations o f contaminants detecte d i n the Wilco x aquifer upper zone i n 199 2 and 199 3 ar

c liste d i n Tabl e 4. The presenc e o f 1,1-DC A and 1,2-DC E ar c taken as indicator s o

f ground wate

r contamination becaus e thes e two compounds ar c consistently detecte d across the sit

e i n th e upper

Wilcox aquifer. Th e detecte d concentrations decreas e away fromthe sludg e disposa l are a(Figur

e 12) . A comparison o f April 199 2 dat ato previous dat a(1988-1990 , 6 6 sample s total ) sho w agenera l decreas e i n volatil e organi c concentrations (Tabl e 5). Dat afromwells installe d i n 199 2 i s insufficient to establis h a trend. Sample s containing elevated VOC and semivolatil e organic concentrations, a s compare d to 2 2

### TABLES SURFACE WATERANALYTICAL DATA Monroe Auto Pi t

Superfund Site (Finc h Road Landfill) Sampl e ID________________SW1-1 SW2- 1 SW3- 1 SW4- 1 PondRavine Ravine Ravine Volatil e Organic Compound s (ug/L ) Dilution Facto r

1. 0 1. 0 1. 0 1. 0 Carbo n Disulfide 1, 1 -Dichloroethan e 2-Butanon e Trichloroethylen e l.OU l.O U 0.3 J 0.03 J l.O U l.O U l.OU 1. 3 10 U 10

U 10

J 10

U l.O U 0.2 J l.OU l.OU Semivolatil e Organi c Compound s (ug/L ) Dilution Facto r

1. 0 1. 0 1. 0 1. 0 Diethylphthalate 10U J 0.1 J 0.1 J 0.2J di-n-butylphthalate 0.1J 0.1 J 0.1 J 0.3 J bis(2-Ethylhexyl)phthalate 10 U 10

U 10

U 15

J Inorganic s (ug/L) Arseni c Barium Chromium Manganese 6.6J 2.0UJ 2.0UJ 2.0U 49.6UJ 60.4J 71 . U 120 J 16.7 : 10.0

U 10.C U 10.0 U 98.6UJ 18. 5 24.9 35 3 NOTES : U - Undetected; quantity show n i s th e detection limit. J - Estimate d quantity. UJ - Undetected ; quantity show n i s estimate d detectio n limit . n a- Not

analyzed . Only th e analyte s detecte d i n dee p surfac e water

sample s are shown . Complete dat atable s that

include quantitation limit s for all analyte s ar

e provide d i n appendi x H o f th e Remedia l Investigatio n (RI) Data1992-199 3
2 3

### TABLE 4 RANGES OF CONTAMINANTS DETECTED IN UPPERWILCOX GROUNDWATERMONITORING WELLS Constituent

MaximumConcentration Volatil e Organi c Compounds (ug/L) Chlorethane 1,1-Dichloroethene 1.1-Dichloroethane 1.2-Dichloroethen e (total; ci s & trans) 1,2-Dichloroethan e Chlorofonn 2-Butanon c 1,1.1-Trichloroethane cis-1,3-Dichloropropcnc Carbo n Tetrachlorid c Trichloroethylen e Semivolatil e Compounds (ug/L) Nitrobeazene Isophorone Benzyl alcoho l Benzoi c aci d 4-Chloro-3-methylphenol Diethylphthalate Dimethylphthalate Di-n-butylphthalate bis(2-Ethylhexyl)phthalate Tota l (Unfutered) Inorganics (ug/L) Arseni c Bariu m Beryllium Chromium Lea d Manganese Mercury Zin c Dissolve d (Filtered ) Inorganic s (ug/L) Arseni c Bariu m Chromium Manganes e Zin c l.O J 4.0 42 \SO 2. 0 J 0. 5 N 3 2 NJ 2. 0 3. 0 0.3 J J.4 J 7 8 0. 2 J 0. 8 J 5. 0 J 0. 4 J 0.5 J 0.1 J 0. 4 J 44 J 12 2 1.290 12. 0 1,090 23 5 2,45 0 0. 4 4,22 0 5. 7 51. 3 14. 4 69. 3 22 1 Notes : J - Estimate d quantity. N - Presumptive evidence; presence of compoun d no t

confirmed. NJ - Presumptiv e evidence ; presenc e of compoundno t

confirmed. Quantity i s estimate d Only th e analyte s detecte d i n Wilco x groundwater sample s are shown . Complet e dat atable s that

include quantitation limit s for al l analyte s are aprovide d i n Appendix H Dan - 199

3 at a199 2 2 4Figur e 12TABLES Organic Constituent

s In the Groun

d Wate r o

f th e Wilcox Aquife r Upper Zon e Ove r Tim

e Monro e Auto Pi tSuperfund Sit

e
Paramet 1,1-Did Mar-8 8 Dec-8 8 Nov-89 Feb-9 0 Apr-92 Apr-93 Aug-9 3 1,2-Dichloroethylene (^g/1 ) Mar-88 Dec-8 8 Nov-8 9 Feb-9 0 Apr-92 Apr-93 Aug-9 3 er ilorocthan e (^g/1 )

(cis- ) (cis- ) (cis

- & trans-) (cis

- & trans- ) (cis

- & trans-) (cis

- & trans-) (cis

- & trans-) ESW-2A
9 7 7 7 10 0 9 3 4 2 n a 41
75 0 49 0 (5. 0 <5.0 18 0 n a 17 0 ESW-3 A

6. 0 8. 2 1 0 6.7 7. 0 N n a 6. 0
7. 8 1 1 <5.0 1 7 2 3 n a 1 8 ESW-4 A

1 7 21 2 3 14 0 4.0 N n a 11. 0
11 0 12 0 (5. 0 (5. 0 2 6 n a 3 9 ESW- 8

n i n i (5. 0 <5.0 (1.0 n a (1.0

n i n i (5. 0 <5. 0 (1. 0 n a 0. 2 J ESW- 9

n i n i (5. 0 (5. 0 <1.0 na (1. 0

n i n i (5. 0 (5. 0 (1. 0 n a (2.0 ESW-10- 1

n i n i (5. 0 (5. 0 (1. 0 n a (1. 0

n i n i <5.0 (5. 0 (1. 0 n a (1. 0 ESW-11- 1

ni n i ni n i 1. 0 N na 0. 4 J

n i n i n i n i 6. 0 n a 1. 8 ESW-H-3

ni ni ni n i (1.0 na (1. 0

n i n i n i n i <1.0 n a (1. 0

n i - Well no t

installe d n a- Not

analyze d J - Estimate d value N - Presumptiv e evidenc e R- Rejecte d data 2 6TABLES Organic Constituent

s in the Ground Water o

f the Wilcox Aquifer Uppe r Zon e Ove r Tim e Monroe Auto Pi tSuperfund Site

continue d

1-Dic h ar-8 8 ec-8 8 ov-8 9 sb-9 0 pr-92 pr-93 2-Dichloroethylene (^g/1 ) [ar-8 8 ec-8 8 ov-8 9 eb-9 0 pr-92 pr-93 e r iloroethan e (/^g/1 )

(cis- ) (cis- ) (cis

- & trans- ) (cis

- & trans- ) (cis

- & trans- ) (cis

- & trans- ) ESW-12

-

n i m n i n i 2. 0 na 1. 4

m n i n i m 5. 0 n a 5. 6 1 ESW-12- 2

n i n i n i n i 4.0 n a 2.0

n i n i n i n i 10. 0 n a 5. 5 ESW-13- 1

ni n i n i ni (1.0 na (1.0

n i n i n i n i (1.0 n a (1. 0 ESW-13- 3

m n i n i n i (1.0 na (1.0

n i n i n i n i (1. 0 n a (1. 0 $ ESW-14- 1

n i n i n i n i ni 2 5 J 7. 0

n i n i ni n i n i <1.0 49. 0 ESW-14- 3

n i n i n i n i n i 5 0 3.0

r ' n i n i n i ni 29. 0 J 16. 0 ESW-15- 1

n i n i n i n i n i <1.0 (1. 0
ni n i n i n i n i (1. 0 

### <i. o ESW-15- 3

ni n i n i ni ni (1.0 (1.0

n i n i ni ni n i (1.0 (1. 0 ESW-1 6

ni n i ni n i ni 12. 0 13. 0
ni n i n i n i n i 59. 0 J 94. 0

n i - Wel l no t

installe d n a- Not

analyze d J - Estimate d value N - Presumptive evidence R- Rejecteddat a 27background concentrations, di d not contain corresponding elevate d concentrations o f inorganics . Th e inorgani c concentrations detecte d i n ground water sample s (1992-93 ) showe d no pattern across the site , and did not always decreas e i n adown gradient directio n (Figur

e 13) . However , greate

r inorganic concentrations di d correspond to higher level s o f tota l dissolve d solid s measured i n the samples . Thi s fact, along with the much lowe r inorgani c concentrations i n filtered sample s as compared to unfiltered samples , indicate s that alarg e proportion o

f the tota l inorganic mass i n the ground water sample s i s due to soil particle s in the samples . Th e lac k o f aspatia l pattern i s probably due to natural variabilit y o f the Wilco x aquifer. Contamination appear s to b e confined to the upper Wilco x aquifer . Th e bes t water production and the depths o f the private well s indicat

e that most o f th e well s draw wate r fromthe lowe

r Wilcox aquifer. Th e upper Wilcox aquifer

i s considere d the most likely exposure route, but private well s are not

believed to produce fromthis zone . Thi s i s the only potentia

l exposure pathway. Ground water

sample s fn mthe Wilco x aquifer lowe r zone were no t

found to contai n detectabl e concentrations o f VOCs or

inorganics . Only one sampl e containe d detectabl e concentrations o

f semivolatil e organic s (Tabl e 6). Th e lowe r Wilco x aquifer

i s separate d fromthe upper

Wilcox aquifer

by approximately 4 0 fee t o f lo w permeabilit

y clay . Th e lowe

r Wilcox aquifer

i s not contaminate d and this exposure pathway i s not considere d further. 5.9 RESIDENTIA L WATERSUPPLIE S Residentia l water supplie s are obtained fromthe Wilco x aquifer. Th e production zone s ar e uncertain becaus e few drillin g log s or wel l construction record s were found, an d well owners had littl e or

no knowledg e o

f the wel l depths. I t

i s likel y that most well s are complete d i n the lowe

r zone becaus e monitoring well s at the site show that

this zon e provide s greater wel l yields than the upper zone . Well record s that coul d b e found indicate d that production from4 0 to 10 0 fee t bis. i n wells south o

f the site and 15 0 to 21 0 fee t bis . i n well s north o

f the site . Given the topography and th e high yields o f the well s sout

h o f th e site , all o f thes e well s could potentially b e in the sam e aquifer, the lowe

r Wilcox aquifer. Four VOCs, thre e semivolatil e organic compounds (SVOCs), and seve n inorganic s were detecte d i n residentia

l water supply sample s in 1992 . Th e VOC and SVOC level s ar e estimate d a s indicate d by the J qualifiers . Concentrations o f thes e contaminants ar

e belo w the Safe Drinking Water Act MaximumContaminant

Level s (MCLs). Concentration s o f organic s and inorganic s i n residential water supply sample s (1992 ) ar e shown o n Figur

e 14 . Th e wide dispersa

l pattern (up and down gradient o f the site ) and the lack

o f organi c contamination concurrent

with the metal s indicate s that the contamination i s no t

sit e related . Residentia l well samplin g sinc e the RI indicate that organics ar

e belo w the detectio n limi t if they ar e present and inorganic concentrations, when detected , remain a t about the same level . A comparison o

f the April 199 2 dat awith previous (1989 ) dat acollected prior to the CERCLA activitie s indicate s that the concentrations o

f VOCs and semivolatil e organic s hav e generall y remaine d stabl e ove r the monitoring period . The majority o f th e well s sho w concentrations o

f 28-N 100 (ee l SCALE 

### INORGANIC CONCENTRATIONS I N GROUNDWATER I N TH E WILCOX AQUIFER

MONRO E AUT O PI T SUPERFUN D SIT E (FINC H ROAD LANDFILL )
E S ENGINEERING-SCIENCE LEGEN D ESW-8 ^ Monitorin g Wel l Locatio n an d Numbe r Notes : 1 . All concentrations ar

e providedIn ug/L (ppb). 2 . When aduplicate sample was collected , the greatest value I s shown. 3 . J-estimated value. 4 . nd-no t detected . 5 . Samples frommonitoring well s with prefixes ESW-14, ESW-15 . andESW-16 were collecte d In 1993 . All other

samples were collecte d In 1992 .

### TABLE 6 WILCOX AQUIFERLOWERZONE GROUNDWATERANALYTICAL DATA SUMMARY

Monroe Auto Pi tSuperfun d Site (Finch Road Landfill) Sample ID_________ESW-6 ESW-10- 2 ESW-11- 2 ESW-12- 2 Volatil e Organic Compound s (ug/L ) No VOC s Detecte d Semivolatil e Organic Compounds (ug/L ) Pheno l 2 9 10U J 10

U 10

U 2-Methylphenol 1 7 10U J 10

U 10

U 4-Methylphenol 3 6 10U J 10

U 10

U 2,4-Dimethylphenol 5.0J 10U J 10

U 10

U Di-n-butylphthalate 0.2J 10U J 10

U 10

U Tota l (Unfiltered ) Inorganics (ug/L) No Inorganic s Detecte d Dissolve d (Filtered ) Inorganics (ug/L) No Inorganics Detected NOTES: U - Undetected; quantity shown i s the detectio n limit. J - Estimate d quantity. UJ - Undetected ; quantity show n i s estimate d detectio n limit. Only th e analyte s detecte d i n dee p surfac e water

sample s ar

e show n Complete datatable s that

include quantitation limit s for all analyte s ar

e provide d i n appendi x H o f

th e Remedia l Investigatio n (RI ) Data199 2 - 199 3
3 0

### ORGANIC AND INORGANI C CONCENTRATIONS IN RESIDENTIAL WELLS MONRO E AUTO PI T SUPERfUN D SITE ' (FWC H ROA D LANDFILL )

PW-S5 •- . . 1.::::::.•: TCE bis(2-Ethylhcxyl)phthal»le PW-S16~>| W O.IJ ,

l.OJ , / 

## ^

N 1 - ( N2 - 1 N3 - N 4 - N 5 - N6 - N 7 - 

### m • N9 - N10

- N1 1 • N1 2 N1 3 N1 4 Figure 1 4

Ml—— 3'Ncil Faulkner Halcomb Thompson. J Duncan Chafft n Merfdiih Henry • McAliSter MeCullT • Springsion •Gun n -Fah r • She ] io n

WWW* N1 5 •lohnson.G

Nl6-H*mp» n N17-L*dce y Nll-Johnson. M Sl •Clcvcl*n< i -S 2 -Kennedy S 3 - Templcto n S 4 -Hal e S 5 .Tolcr S 6 -Bcrodt S 7 -

S 8 - S 9 • SIO

Sll

S12

- S13 . S14 . S15 •Thompson, A S16 Robinson Hodse Dowlcr Wonh»m KJOSP El«m Not Assigned • Andcraon, D

• Hill, W LEGEN D

NOTES : i 199 2 samples Al l units i n u-f/L

(ppb) J Estimatedquantity 3 1 

# Q Pave d Highwa y Grave l Road o rDriv e Monro e Auto Propert y Fenc e PW-S1 Residenc e an d Private-wel l Locatio n Strea m Lakevolatil e organic s belo w the detectio n limits or not detecte d at

all . The concentrations exhibi t variations that

ca n b e considered normal under the samplin g and analytica l protocol s that were used. Variations in the inorganic concentrations an d their distribution ca

n b e attributed to natural variatio n within the Wilco x aquifer. No increasin g or decreasin g trends ar

e observe d i n the dat aove

r time (1989-1995) . Residential well s within one-hal f mil e o f the sit e are sample d semi-annually a t this time . They will continue to b e monitored, but th e frequency may change i n the future. Becaus e the volatil e organi c compounds move faster than the metal s and becaus e they move with the ground water flow, one wouldexpect

to se e the VOCs arriv e at

th e well s ahea

d o f the metals . Becaus e this relationship i s no t seen , the contaminants ar

e probably not

sit e related .
6.0 SUMMARY OF SITE RISKS An evaluatio n o

f the potentia

l risk s to human healt

h and the environment

fromsit

e contaminants was conducted in accordanc e wit h OSWE RDirectiv e 9285 , Ris k

Assessment Guidance for

Superfund, Volume 1 , Human Healt h Evaluatio n Manual (Par t A), a s part

o f the baseline risk

assessment. The results o f all the samplin g conducte d a t the sit e during the RI were used to evaluate the risk that the site pose s to human health and the environment. Th e objective s o

f the baselin e risk

assessment

were to (1 ) hel

p determine whether

additiona l respons e action s are necessar y a t the site ; (2) provid e abasis for determinin g remedia

l actio n goal s that

are adequately protectiv e o f human healt

h and the environment; and (3 ) provide abasi s for

comparing potential health impacts o f various remedial alternatives . Th e baselin e ris k

assessment

wa s divide d into two parts: 1 ) the human healt h evaluatio n an d 2) the ecologica

l evaluation . Human healt h risk s ar

e determined by evaluatin g chemica l exposure limit s and actual concentrations o f contaminants present

a t asite . Th e contaminant concentrations are compare d to the exposure concentration known or suspecte d to have a potential advers e impact. In the ris k assessment, carcinogeni c and non-carcinogeni c risk s arc calculated. Conservativ e assumptions that weigh i n favor

o f protecting human healt

h ar e used i n calculatin g risks . Th e environmental or ecologica

l risk assessment

i s conducte d to determine i

f there are any current

or potential impacts on ecologica l receptor s (such a s bird s or mammals) attributable to the unremediated site . The national risk, or

probability , that

an individual may develo p some formo

f cance r from everyda y sources , ove

r a70-yea r lif e span , i s estimate d a

t thre e i n ten. Activitie s such a s to o much exposur

e to sun, occupational exposures , or dietar y or smoking habits contribute to this high risk. Th e three i n ten probabilit y i s considere d the "natural incidence " o f cance r i n the Unite d States .

32To protec t

human health, arisk

rang e o f one i n ten thousand to one in one millio n exces s cancer risk has been se

t a s agoa l for Superfund sites . Thi s rang e may b e expresse d as 10 ^ to 10' 6

. For

example , arisk

o f 10' 6 means that

1 person out

o f one millio n could develo p cance r a s aresult

o f alifetime exposure to asite . The leve l o f concer n for non-carcinogeni c contaminants i s determined by calculatin g aHazard Inde x (HI) . Ther e may b e concer

n for potential exposure to asite where the HI values are greater than 1. 0 for

human populations who may reasonabl y be expecte d to b e exposed . Th e baselin e ris k

assessment

assumes ano-actio n alternative at the site . Baselin e exposure estimate s wer

e base d on future unrestricted access . Four acre s o f the site , including the pi t and seasona

l pond, are currently surrounded by alocke d chain-lin k fence . However , i t

was assumed that

th e sit e i s currently accessibl e to trespassers . Also , off-site residential well water was evaluate d for

risk s associate d with current domestic use. Th e future lan d use i s a^umeato be residential. Estimates were base d on the assumption that development

o f the Monroe site wouldresult i n unrestricte d public acces s and full use o f loca l resources by persons livin g on or nea r the site . An on sit

e occupational scenari o was also evaluateda s an alternative future case . Although the risk s fromboth the averag e (AVG) and reasonabl e maximumexposure (RME ) scenario s were calculate d i n th e ris k assessment, the RME risk s were used to evaluat e threats at the sit e becaus e the current

EP A polic y mandates the use o f the RME when evaluatin g the need for respons e actions at

Superfund sites. The difference betwee n the AVG and RME risk results fromusing different assumptions i n the equations utilize d to performthe ris k calculations . Fo r

example , the exposure frequency for AVG i s 27 5 day s per

yea r as oppose d to 35 0 day s per

yea r for RME, and the exposure durations i s 9 year s for AVG as oppose d to 3 0 year s for

RME. RME risk s are greater , and thu s more conservative , than averag e risks . Th e highly toxi c or

highly mobile sourc e materials that wouldpresent

asignifican t

ris k to human healt

h or the environment

should exposure occur

ar e considere d principa

l threa t wastes . On the other

hand, sourc e materials that generall y can b e reliabl y containe d and that wouldpresent

only alo w risk

i n the event

o f releas e are considere d lo w leve l threa t wastes . Th e National Oi

l and Hazardous Substance s Pollution Contingency Pla n (NCP), Section 300.430 , recommends treatment to address the principa

l threats pose d by asit

e whenever practicable , and engineering controls, such as containment, for waste that

pose s arelatively lo w long-ter

mthreat. 6.1 HUMAN HEALT H RISK ASSESSMEN T 6.1.1 Ground wate r Human healt

h risk s fromground water were calculate d for

thre e basic scenarios : current residential , future on sit

e residential , and future off site residentia

l use . Monitorin g well an d residentia l wel l results from199 2 were use d for current risks . Ground water

model s for 33

### transport

(MULTIMED , 1990 ) andinfiltration o f th e landfill cove

r (HELP , 1989 ) were used for future scenarios . Cancer slop e factors were fromIRIS , 199 2 andHEAST , 1992 . 6.1.1.1 Curren

tExposures - Residential Well s Off Sit e Current exposure ris k

was calculate d assuming that the residentia

l well s ar e connecte d to the upper Wilco x aquifer. Th e maximumdetecte d level s o f contaminants foundi n sample s o f eleven monitoring wells were used. Noncancer ris k fromexposure s to residentia l wel l water i s not significant

(les s than 0.01). Cancer risk fromresidentia

l wel l water

exposure (1X10" 8 

### for averag e an d IX 10 7 

### for

RME) is belo w the targe t risk rang e o f 1X10 ^ to 1X10- 6



### . No environmental threats fromresidential water supplie s have bee

n identified. 6.1.1.2 Hypothetical Futur e Exposures - Monitorin g Well s On Sit e Thi s scenari o assumes an on sit e residenc e with awel l i n the contaminated aquifer. I t i s als o assumedthat

the concentration o

f contaminants do not

decreas e ove

r time. Th^ , lif

e time exces s cancer

risk frommonitoring well water exposure i s within the targe t ris k range o f IXIO " to 1X10- 6 

### a

t 1X10^ to 1X1 0 - 5



### . Noncancer risk i s abov e the target

leve l o f ffl = 1 a t 3 0 base d on unfilteredmonitoring wel l samples . The greates t contribution to tota

l risk is fromingestio n o

f drinking water

andinhalation o

f vapor s while showering . The greates t contributor

to the ingestion risk

i s manganese; the greates t contributors to the inhalation risk are chlorobenzen e andnitrobenzene . Ther e i s slightl y les s risk

fromfilteredground water than fromunfilteredground water (Table 7) . 6.1.1.3 Hypothetical Future Exposures - Modeled Groun d Wate r Concentrations Off Sit e Thi s third scenari o i s for

ahypothetical residenc e 400 fee t down gradient

o f the sit e with a wel l i n the upper

Wilco x aquifer. Th e HELP model was usedto calculate the percolatio n rate through thre e types o

f landfill caps . Thes e three scenario s result i n percolatio n rate s o

f 0.0018 , 0.018 1 and10.0967 inche s per yea r through the sludge . Results o f the first two scenario s indicate d no contaminant releas e fromsludge to the groundwater for 3 0 years . Results o f the third scenario , which hadthe highest percolatio n rate through the cap and therefore the highest

potential for

leaching, contaminant

transport, andexposure , indicate d that benzene , 1,2-dichloroethene , andvinyl chlorid e wouldleac h into th e ground water , resulting in estimate d modele d concentrations o f 23.7 jug/L, 28.5 ^g/L an d 57.8 /-ig/L, respectively . Th e resultant risk indicate s anoncancer

risk o f 4X10 2 

### andacance

r ris k o f 1X10- 3 

### for

the RME. The sourc e o f the noncancer

risk i s 1,2-dichloroethene , andthe driving force o

f the cancer

risk i s vinyl chloride. Engineerin g Scienc e als o modele d th e transport o f 1,1-DC A and1,2-DCE i n the upper Wilcox aquifer

to arecepto r

700 fee t down gradient

using the PLUME 2D model. It i s assumedthat

biodegradatio n doe s not

occur . Monitoring wel l values (1992 ) were use d for the contaminant

concentrations . Modele d concentrations were predicte d to leve l off at 7 ppb and5 5 ppb respectively . Monitoring results o f residentia l well s i n 199 2 didnot

sho w thes e contaminants a

t concentrations abov e the detectio n limits.

34

### 6.1.2 Sediment

Risks o f cancer andnoncancer

resulting fromexposure o f apotential trespasser

to sediments ar c within acceptabl e ranges. The total RME cancer risk i s 1X10 6 

### , andthe total RME HI i s 1X10' 1



### . Residential risk to sediment

exposure also has acancer risk belo w the acceptabl e rang e (tota

l cancer risk = 1X10 5 

### ). 6.1.3 Soils/Sludge The soi l exposure pathway i s not

likel y to be significant

under current conditions sinc e the contaminants ar

e buried beneath 5 fee t

o f clea n fill that i s stabilized with vegetation . Future exposure ris k

was calculate d assuming that erosio n may bring the contaminants to the surface. ?'tf;Mt Lw d "ia i ' & iles^•i&'SffBft

A to 'iyf c "R^AKrforfi 'ccri

i '(A t "iW i ''aeituis^^ammi g ^rri i l 

### ave^toL' & production. Risk

estimate s ar

e base d on the assumption that development

o f the Monroe sit

e wouldresult

i n unrestrictedpublic acces s andfull use o f loca l resource s by person s living on or near the site . Th e potent

i \ 

### exposure pathways, a s aresult o f on-site residents , includ e (1 ) ingestio n o

f soil andgroundwater, (2 ) ingestio n o f contaminatedhome grown vegetables , meat, andmilk, (3 ) dermal absorption o f chemicals i n the soil , sediments, andgroundwater , (4 ) inhalation o

f VOC emissions fromgroundwater , and(5 ) inhalation o f VOC emissions anddust particulates fromthe soil . Th e noncancer

risk frompotential futur e residential exposure to soil s i s greate r than the target limit valu e o f HI=1 . Th e tota

l adult HI i s 5, resulting mostly fromdermal exposure . Th e chemica

l contaminant

i n soil that

i s most responsibl e for

this ris k i s antimony. Cancer risk for adults i s within the targe t risk range, but

i t i s a t the limit o f that range . Th e greates t risk s are fromdermal absorption o f contaminants i n soil ; the greates t contributor

to this risk i s vinyl chloride. Risk s to childre n are comparable to risks to adults, although they are higher for the soi l ingestio n pathway becaus e o f the greate

r ingestio n rate assumedfor children . Soil ingestion , however , was no t

the significant

pathway for

soil exposures . Risk s for workers o n th e site andapotentia

l trespasser

who climb s the fence andi s exposed to site soil s woul d be les s than that o f aresident. Th e risk s for these potential receptor s are les s than the residentia l risk s presente d here . Soi l andsludg e datawer

e combinedto obtain the tota l risk fromall soil s to which future residents a

t the site may be exposed . Fo r the ingestio n pathway , the noncancer ris k from sludg e alon e i s four

time s greater

than that fromsoi l mixe d with sludge ; the cance r ris k i s 1 0 times greater . The higher concentrations o

f contaminants i n the sludg e ar e responsibl e for this difference. Consequently, assuming the same exposure parameters for exposur e to sludg e a s were use d for

exposure to soil , the total noncancer andcancer

risk s for al l pathways associate d with sludg e ca n als o be assumedto be 4 and1 0 time s greater , respectively .

35

### 6.1.4 Summar y o f Human Health Risk Th e cumulative carcinogeni c risk s for the three mediabase d on reasonable maximum exposure concentration are shown i n Table 7 . Soil/sludge andunfilteredground water exhibite d cumulative carcinogeni c risk s greate r than 10^ , andnon-carcinogenic HI greater than 1 . Therefore , i n accordanc e with EPA's Risk Assessment

Guidance for

Superfund, only soil/sludge andgroundwater ar e considere d to present aconcern to human health.

Medi a Soil/Sludg e Ground water

-unfiltere d Ground water

- filtered Sedimen t 

### Tabl e 7 Cumulative Carcinogenic Ris k 3 x 10- 3 1 x 10-

4 8 x 10- 5 1 x 10- 5 Cumulative Non-carcinogeni c Risk 5 0 3 0 1 0. 1 

### Combining the contaminants and mediao f concern, the exposure pathways andreceptor s and the target goal s for

the contaminants o

f concern, remedia

l actio n goal s were establishe d (Tabl e 8) . Actual or threatene d release s o

f hazardous substances fromthis site , i f no t addresse d by implementing the respons e actio n selecte d i n this ROD , may present an imminent

and substantial endangerment

to public health, welfare, or , the environment. 6.2 Ecologica

l Risk Assessmen

t An ecologica

l ris k assessment

was conducted to evaluat e the threats the sit

e pose s to the environment. Based upon this study, EP A determine d that

it i s unlikely that

there ar e any significant impacts on surrounding ecosystem s a t the Monroe Auto Pi t

site . However , there may b e some localized impacts on the site . Severa l contaminants o

f concern - iron, chromium, lea d andmercury - actuall y or potentiall y excee d eithe r sediment or water qualit y criteri aand, therefore, pos e an ecologica l risk to the amphibians using the ponds or seeps . Th e releas e o

f chemical stressor s fromthe landfill may have achronic impact

on the seep s andany wildlife that may use them.

36Table 8 REMEDIA L ACTIO N GOAL S

Contaminant

o f Concern Soil/Sludg e Triehloroethylene Vinyl chloride Antimony Arsenic Beryllium ChromiumVI Lead Groun d wate r cis-1,2-Dichloroethylene trans-1,2-Dichloroethylene bis(2-Ethylhexyl)phthalate Beryllium Chromium Lea d Manganese Target Goal Basis

0.1-10 mg/Kg Carcinogenic Risk 20-2,00 0 mg/Kg Carcinogenic Risk 6 mg/Kg Noncarcinogenic Effects 0.02- 2 mg/Kg Carcinogenic Risk 0.07- 7 mg/Kg Carcinogenic Risk 3-30 0 mg/Kg Carcinogenic Risk 50 0 mg/Kg EPA Guidance

7 0 ftg/L MCL 10 0 ^g/L MCL 6 (ig/L MCL 4 ^g/L MCL 5 0 ^ig/L MCL 1 5 ^g/L SDWA Action Level 200 (xg/L MCL
7.0 DESCRIPTIO N OF ALTERNATIVE S 7.1 Soi l and Sludge Remedial Alternative s Alternativ e 1 : Alternativ e 2 : Alternativ e 3 : Alternativ e 4A: Alternativ e 4B : Alternativ e 5 : Alternativ e 6 : Alternative 7 : Soil/sludge Alternative s

No actio n Acces s and deed restrictions Soi l and vegetativ e cover ; acces s and deed restriction s Cap; slurry wall ; acces s and deed restriction s Cap; french drain; acces s and dee d restriction s Solidification/stabilization ; on-site cap ; acces s and deed restriction s Excavation ; vapo r

extraction; solidification/stabilization ; on-sit e cap ; acces s and deed restrictions Excavation; off-site transport an d disposa

l i n Subtitle C or

D landfill. 3 77.1.1 Alternativ e No . 1 : No Action

No remedia

l action s will be conducted under this alternative, and no limitation s wil l b e place d o n future uses o

f the site . Al l contaminated soil/sludg e i s within the sit e boundaries and acces s i s physically restricte d through an existin g chain link fence. Th e sludg e i s covere d by thre e to five fee t o f fill, currently preventin g direc t contact. Implementing no remedia l activitie s at

the sit e allow s the existin g contaminant source to remain i n place . The potential for

exposure to contaminants i s not reduced i n this alternative . Th e present

worth cos t

estimates for

this and other

alternatives ar

e summarized i n Table 9 . TABLE 9 SOIL/SLUDGE ALTERNATIVE COS T SUMMARY Alternativ e 2 3 4 a4b 5 6 7 Acces s and ;>oil and Multi-laye r Multi-laye r

Solidification /

V ap o r

Off-sit e Dee d Vegetativ e Cap; Slurry Cap ; stabilization extraction ; disposa l Restriction Cover

Wall Frenc h solidification/ ( RC RA Drain stabilization landfill ) 0 ff - s i t e disposa l (sanitary/ industria l landfill ) Capita l Lo w Estimate 0.0 0 27 6 58 8 73 3 3,03 7 3,339 4,60 0 1,900 High Estimate 0.0 0 33 0 81 7 1,46 0 7,879 8,418 10,000 3,70 0 0& M Lo w Estimate 10

7 13 4

13 4 13 4 13 4 13 4 High Estimate 11 7 13 4 13 4 13 4 13 4 13 4 Tota l Cost Lo w Estimate 10

6 41 0 72 2 86 7 3,17 1 3,473 High Estimat

e 11 7 46 5 95 1 1,59 4 8,01 3 8,552 Notes : I . Costs ar

e i n thousands o

f dollar s 2. No cost s ar

e incurred for

Alternative 1 - No Action 3 . N/A - Not

applicabl e

38 N/A N/A N/A N/A
4,600 1,900 10,00 0 3,70 0

### 7.1.2 Alternativ e No . 2 : Access and Deed Restriction s

Under this alternative, the current coye r will remain in place . Periodi c inspection s will be conductedan d maintenance wouldbe performed to help ensure that the cove r remains intact . Maintenance , as needed , will consist o f semi-annual mowing andrepair o f damage d fencing. Minor drainin g modifications may be conducteda s neede d to prevent ponding andpromote surface water

runoff . Limitations will b e place d on future uses o f the site . A survey plat

indicatin g the locatio n o f th e waste disposa

l are awith respect

to permanently surveye d benchmarks wil l b e prepare d andfiledwith the loca

l zonin g authority. The plat will contai n anote , prominently displayed , which state s the owner's obligatio n to restric t disturbance o

f the waste . 7.1.3 Alternativ e No . 3 : Soi l and Vegetativ e Cover ; Acces s and Dee d Restriction s The existin g cove

r will b e augmentedby the addition o f clea n soil . The soil wil l b e obtaine d locally an d use d to create auniformslop e acros s the site to promote drainag e off o f the sludg e disposa

l area . After

the cove r has bee n improve d to provide adequate drainage , aminimumsix-inc h laye

r o f topsoi l wil l b e adde d to promote vegetativ e growth. The cove r will be seede

d with native grasse s to reduce future erosion . Periodi c inspection s will b e conductedandrepair s performed to ensure that the cove r remains intact. Repairs , a s needed , will consist o f replacin g erode d topsoil , reseedin g bare areas , semi-annual mowing, andrepair o f damagedfencing. Th e improve d cove

r will b e maintained. Limitations will be place d on future uses o f the site . A survey pla

t indicatin g the locatio n o f the wast e disposa l are awith respec t

to permanently surveye d benchmarks will b e prepare d andfile d with the loca l zoning authority. The pla t will contai n anote , prominently displayed, which states the owner's obligatio n to restric t disturbance o

f the waste . 7.1.4 Alternativ e No . 4A : Cap ; Slurry Wall; Access an d Deed Restrictions A bentonite slurry wal l will b e constructed surrounding the are ao f sludg e deposits . The three-foot wide slurry wal l wil l b e installe d to adepth o f approximately 3 0 fee t

andwil l tota

l approximately 210 0 fee t

i n length. The bottomo f the wal l wil l be belo w the tota l dept h o f the sludg e deposits . However , slurry wall s are most effectiv e when they ar

e tie d into an impermeable layer . At

the Monroe Superfundsite such an impermeabl e cla y laye r i s about 15 0 fee t belo w the surface. Sit e soil s displace d as aresul t o f excavatio n o

f the trench wil l b e sprea d ove r th e sludg e area , andb e covered by the cap . Al l excavatio n wil l b e planne d i n uncontaminated areas . If staine d soil s exhibitin g possibl e contaminant characteristic s ar

e encountered, they wil l b e segregate d andshippe d for off-site disposal . Th e slurry wall will b e designe d to provide alow-permeability barrier to restric t

the movement o f perche d ground water

into the sludge. Normally aslurry wall i s tie d into a

3 9

### lo w permeabilit y laye r a t its base . Becaus e the shallowes t continuous cla

y laye r i s ove r 10 0 fee t belo w the surface, this slurry wal l will hang to adepth o f 3 0 feet, which i s belo w the level o f the sludge . This will mitigate to some extent perchedwater

fromenterin g the sludg e frombelo w the wall . A cap meetin g the genera l desig n requirements o f the Arkansas Hazardous Wast e Management

Regulation 2 3 § 264.310 wil l be constructed. The ca p evaluate d under

this alternativ e includes a24-inch thick uncompactedsoil laye

r comprise d o

f si x inche s o

f uniformly distributedtopsoi l ove r 1 8 inches o

f sandy soil . Th e 24-inch soi l layer s wil l be underlain by a24-inch compacte d cla y layer . Components andthicknesse s o f the ca p specifie d her

e d o not necessarily represent

the final desig n parameter s under thi s alternative . If thi s alternativ e i s implemented, adetaile d desig n will b e submittedandthe cappin g parameter s will b e further

refined. Dee d restriction s wil l prohibit futur e development

o f th e site . A survey plat

ind"'atin g th e locatio n o f the wast e disposal are awith respec t to permanently surveye d benchmarks would b e prepare d andfile dwith the loca l zoning authority. Th e plat wil l contai n anote , prominently displayed , which state s the owner's obligatio n to restric t disturbance o

f the waste . In additio n to the cap , these restriction s wil l eliminate the risk o f long-ter mcontac t with contaminatedmedia. Th e baseline ris k assessment

assumedafuture residentia l lan d use scenari o for

the calculation o

f future risks . Th e ca

p anddeed restriction s wil l eliminat e the possibilit y o f residential lan d use a

t the site . The multilayer

cap wil l be periodicall y inspecte d for signs o f erosion , subsidence , or

damage cause d by frost

or burrowing mammals. Damage d area s wil l b e repaire d to restor e th e cap . The vegetatio n wil l b e maintainedthrough periodi c mowing andreseedin g o f bare areas . 7.1.5 Alternativ e No . 4B : Cap ; Frenc h Drain ; Acces s and Deed Restriction s A french drain will b e constructedsurrounding the are ao f sludg e deposits . Th e three-foo t wide french drain will b e installe d to adepth o f approximatel y 3 0 fee t

andwil l tota

l approximatel y 210 0 fee t

i n length . The bottomo f the french drain will be belo w the tota l depth o f the sludge deposits , andwill extendthrough the perchedzon e into the underlying unsaturatedzone . Sit

e soil s displace d a s aresult o f excavatio n o

f the trench wil l b e sprea

d ove r the sludg e are aandcovere d by the cap . All excavatio n wil l b e planne d i n uncontaminatedareas , but

i f staine d soil s exhibitin g possibl e contaminant characteristic s ar

e encounteredthey wil l b e segregated andshippe d off-site for disposal . The french drain wil l intercep t perche d groundwater

before i t enter s the contaminate d area . Th e capture d groundwater wil l b e transportedviaburiedpiping to adischarg e point located i n the intermittent

strea msouthwes t

o f the site . A french drai n suitabl e for this site will b e constructedby excavatin g a30-foo t dee p trench 4 0

### an d installin g impermeable plasti c sheeting along the sludg e deposit side o f the trench. A one - to two-foot

thick grave l base wil l b e place d in the trench; slotte d PVC piping will be installe d abov e the grave l base , andgrave l fil l will b e installe d to ground surface. The trench parameters andit s constmction methodwill be further refinedi n the detaile d design proces s to provide improve d performance. A cap meeting the genera l design requirements o f the Arkansas Hazardous Wast e Management

Regulation 2 3 § 264.310 will be constructed. Th e ca p evaluate d under

this alternative includes a24-inch uncompacted soil laye r comprised o

f six inche s o

f uniformly distributed topsoi l ove

r 1 8 inche s o

f sandy soil . The 24-inch soil laye r wil l b e underlain by a24-inch compacte d cla

y layer . Components and thicknesses o f the cap specifie d here do not necessarily represent

the final desig n parameters under this alternative . If

this alternativ e i s implemented, adetaile d desig n will b e performed andthe cappin g parameter s wil l b e further refined. Dee d restriction s wil l prohibit future development

o f the site . A survey plat

indicatin g the locatio n o f the wast e disposa l are awith respec t

to permanently surveye d benchmarks wil l b e prepare d andfiledwith the loca l zoning authority. The plat will contain anote, prominently displayed , which state s the owner's obligatio n to restrict disturbance o

f the waste . In addition to the cap , these restriction s will eliminate the risk o f long-termcontact

with contaminated media. The baselin e risk assessment

assumedafuture residential lan d use scenari o for

the calculation o

f futur e risks . Th e ca

p anddeed restrictions will eliminate the possibilit y o f residential landuse at

the site . Th e multilayer

ca p andthe french drain outle t will b e periodicall

y inspecte d for

signs o f erosion, subsidence, or

damage cause d by frost

or burrowing mammals. Damage d area s wil l b e repaire d to restore the cap . The vegetatio n will b e maintained through periodi c mowing andreseeding o

f bare areas . 7.1.6 Alternative No . 5 : Solidification/Stabilization; On-site Landfill; Access and Dee d Restriction s 

### Solidification/Stabilizatio n wil l involv e excavatio n andremova l o f soil andsludge containin g contaminants that

excee d remedia

l actio n goals . The tota l volume o

f soi l andsludg e requirin g excavatio n i s estimate d to b e betwee n 11,000 and20,00 0 cubic yards. Temporar y erosio n contro l measures will b e implemented to isolat e the disposa

l pit are aan d displace d soil/sludg e fromthe intermittent cree k andsprings . Impermeable tarps wil l b e place d on the groundsurface prior

to placement

o f the excavate d material andsimila r tarps wil l als o b e place d ove

r the individual pile s to avoi dproducing airborn e particulates andcontaminate d runoff. Othe

r erosion contro l measures will b e implementedas necessary . Soil andsludge wil l b e excavate d fromthe disposa l pit by backho e or

simila r means. Thi s material wil l b e staged i n pile s locate d i n the northern fencedportion o f the sit e pendin g treatment. Soil samplin g will be conductedwithin the excavatio n to confirmcomplete excavation . 4 1

### A hazardous waste landfill, meeting the general design requirements o f the Arkansas Hazardous Wast

e Management

Regulation 23 §26 4 Subsection N, wil l b e constructed i n the excavatio n area. Treate d material will be place d into the landfill andaca p wil l b e constructed ove

r the landfill. Periodi c inspections o f the cap andfence will b e performed to identify area s on the fence andcap that nee d maintenance. Maintenance will include fence repairs , periodicall y mowing the cap , reseedin g bare spot s on the cap , andrepairin g erosion areas . Dee d restrictions will als o be place d on th e parce l o f lan d that wil l limit future development o f the sit e i n the even

t Monroe relinquishe s th e site to another party . Acces s wouldcontinue to b e restricte d by the existing fence. A survey pla t indicatin g th e locatio n o f the waste disposa l are awith respec t

to permanently surveye d benchmarks will b e prepare d andfiled with the loca

l zonin g authority. The plat will contain anote, prominently displayed , which state s the owner's obligatio n to restric t disturbance o

f the waste. 7.1.7 Alternative No . 6 : Excavation ; Vapo r Extraction ; Solidification/Stabilization on-sit e Landfill; Access an d Deed Restrictio n Alternative No . 6 will require excavatio n andremoval o f an estimated 11,000 to 20,00 0 cubic yards o

f soi l andsludg e containin g contaminants that excee d remedia l actio n goals . Soi l samplin g will b e conductedwithin th e excavatio n to confirmrequire d excavatio n depths within the sludg e pit. Th e excavate d material will b e stage d i n pile s locate d i n the northern fencedportio n o

f the site pending treatment. Initial treatment

will employ vapor

extraction for

organic s removal. Excavate d soi l and sludg e wil l b e place d i n pile s on an impermeabl e barrier . Perforatedpipe s wil l b e place d i n the pile s and vacuumpumps will pull ambient ai r through the contaminate d soil/sludge , volatilizin g VOCs fromthe soil . Air pollution control requirements under thi s alternativ e ar

c not anticipate d to b e necessary , but couldbe adde d if

needed . Due to spac e limitations onsite , excavate d soils/sludge will b e treate d i n batches . Followin g the vapor

extractio n treatment, the soil/sludge will be solidifie d to immobiliz e the inorgani c contaminants. While one batch i s bein g solidified , another batch wil l b e excavate d andtreate d by vapor

extraction. A hazardous waste landfill, meetin g the genera l desig n requirements o

f the Arkansas Hazardous Waste Management Regulation 2 3 §264 Subsection N, wil l b e constructed i n the excavatio n area . Treate d material will be place d into the landfill andaca p will be constructed ove

r the landfill. Solidification/Stabilizatio n o f the soil s andsludg e will b e conducte d by mixing th e soil/sludg e with Portlan d cement, resultin g i n amixture that wil l physicall y immobiliz e the inorgani c contaminants. Solidification/Stabilizatio n will b e conducte d a s describe d i n Alternativ e No 5. Excavatio n will b e limite d to soils/sludg e containing inorganic s i n exces s o f remedia l actio n goals ; the volume o f soil/sludge to b e treate d i s estimate d to b e betwee n 11,00 0 and 20,00 0 cubic yards.

42Maintenance o f the ca p and fence will b e conducted through periodi c inspections performed to identify area s on the fence and cap that nee d maintenance. Maintenance will include fence repairs , annual mowing o f the vegetativ e cover , reseedin g o f bare spot s on the cap , and repairin g erode d areas . Implementation o f this alternative may require construction o f temporary erosion control structures, repair of erode d areas , and reseeding . Deed restrictions will als o be place d on the parce l o f lan d that will limi t

future development o f the site i n the event

Monroe relinquishes the site to another party. Acces s wil l continue to b e restricte d by the existin g fence. A survey plat indicatin g the locatio n o f the waste disposa l are awith respec t

to permanently surveyedbenchmarks wil l b e prepare d an d filed with th e loca

l zonin g authority. Th e pla t wil l contain anote , prominently displayed , which state s the owner's obligatio n to restric t disturbance o

f the waste . 7.1.8 Alternativ e No. 7 : Exca - ition; Off-Site Transpor tand Disposa

l in Subtitl e C or D Landfill Thi s alternativ e require s excavation , by backho e or simila r means, and remova

l o f an estimate d 11,000 to 20,000 cubic yards o f soil and sludg e containin g contaminants i n exces s o f remedial action goals . Soi l sampling will be conducted i n the excavatio n to confirm remova l o f contaminate d soi l and sludge . Th e excavate d material will b e loade d without any treatment into line d dump trucks and transported to either aregiona

l sanitar y landfill (such a s the Greene County landfill) or to aRCRA-permitted hazardous wast e landfill. Uncontaminated soil s fromloca l borrow pits will b e used to backfill the excavation . The site will subsequently b e graded, covere d with a12-inc h topsoi l layer , an d vegetated . No acces s controls or

deed restriction s will b e necessar y following completio n o f these actions . I f the delistin g petitio n was approve d by EPA, the deliste d waste could then b e dispose d i n asanitar y or industrial landfill. I f

adelistin g petitio n was no t approved , pretreatment

o f the waste might

b e necessar

y to meet Land Disposa

l Restrictions (LDRs ) before the waste coul d b e dispose d o

f in ahazardous waste landfill. 7.2 GROUND WATERREMEDIA L ALTERNATIVE S Alternative 1 : No actio n Alternativ e 2: Natural attenuation; ground water and residentia

l water supply monitoring; ground water

use restriction s Alternativ e 3 : Ground water extraction ; carbo n adsorption; reinjection. 7.2.1 Alternative No . 1 : No Action Under thi s alternative , no actio n will b e taken a t the sit e and no ground water

monitoring o f the existin g well s will b e performed. Reduction o f the ground water

contaminant

level s will occur through natural processe s such a s biological , chemical, an d physica l degradation, adsorption and dispersion. The present

worth cos t

estimates for

this and other

alternative s ar

e summarized i n Tabl e 10 . 43TABL E 1 0 GROUND WATERALTERNATIVE COST SUMMARY Alternativ e No Action Natural Attenuation, Monitoring, Use Restrictions Ground water

Extraction, Carbon Adsorption, Reinjection Capital Lo w Estimat

e Hig h Estimate O&M Lo w Estimate High Estimat

e Tota l Cos t Lo w Estimate 0 0

0 High Estimate 0 Notes : 1 . Costs ar

c i n thousand dollars . 

### 7 0 7 1

68 6 111 4

75 7 1186 47 2



### 60 8
2656 283 0

3129 343 8

4 47.2.2 Alternativ e No . 2 : Natural Attenuation an d Degradation ; Ground Wate r Use

Restrictions ; Groun d Wate r Monitorin g and Residential Water Suppl y Monitoring Under thi s alternative , contaminant reduction will occur

through natural processe s such a s biological , chemical and physical degradation, adsorption, and dispersion . Th e use o f potentiall y contaminated ground water wil l b e restricte d by placin g ground water use restriction s on the site property . Ground water monitoring o

f on and nea

r site wells and residentia l well s will be conducted. Initially , ground water

use restriction s wil l b e place d only o n the site property . Residentia l well s within one-hal f

mil e o f the sit e will be sample d regularl y for VOCs, semivolatil e organics , and inorganics , a s currently conducted. Ground water from monitoring well s on and nea r the sit e will b e sample d regularl y for VOCs, semivolatiles , an d inorganics . The samplin g datawil l b e reviewe d to evaluat e trends i n ground water quality an d to determine the effectiveness o f natural attenuation. Initially , residentia l well s will b e sampled semiannually. Monitorin g well s will b e sample d semiannuaiiy until four rounds o f samplin g ar

e accomplished. At

that time, the dat awill b e evaluate d an d the monitoring frequency could b e changed to annually. Existin g well s that have samplin g dat afor

four samplin g rounds for

VOCs, semivolatile s (including BEHP), and inorganic s wil l continue to be sample d annually. To better insure the possibilit

y o f obtainin g asample , samplin g should b e schedule d during the "wet" season . Samplin g protocol wil l follow that

i n th e Statement

o f Work. Onc e atrend has been defined, sampling may b e conducted on ales s frequent basis . A Statement

o f Work, including a Sampling and Analysis Plan will b e submitted by Monroe and approve d by ADPC&E. Should monitoring indicate adegradatio n o f residential water

supplie s due to sit

e contaminants, by an increas e o f five times the previous reading, or the occurrence o

f a previously non-detecte d constituent abov e the MCL level , the affectedresident s will b e put on bottle d water

or apoint o f use water

supply treatment, and the well(s ) wil l b e immediately resampled . I f achange i n ground water quality i n the monitoring well s i s indicate d by an increas e o f two times for

constituent

level s a t or abov e 10/xg/l an d afive times increas e for

constituent

level s les s than 1 0 ^g/1 , the affectedwell s wil l immediatel y be resampled . If

any change s are verified, more frequent samplin g should b e performed. I f necessary , activ e remediatio n or physical/ hydraulic containment

measures wil l b e evaluated . Should activ e remediatio n or containment

measures become necessary , aROD amendment

or explanatio n o

f significant

differences will be issued. A monitoring plan i n the Statement o f Work will addres s the monitoring criteria . Samplin g wil l most

likely b e conducte d by Monroe, but could als o b e conducte d by a contractor to Monroe , aregulator

y agenc y or

agenc y contractor . In the past, residentia l well s have been sample d by the Arkansas Department o f Health, a s wel l as Monroe contractors . Based on ground wate

r modeling , it

i s assumed that

the contaminant

concentrations wil l not excee d the Remedia

l Action Objective s (RAO) target goal s or the MCLs a

t the 4 5residentia

l wells . Becaus e al l modeling i s based on some assumptions about the aquifer, contingency plans are included i n this ROD . The performance standards will b e met by this alternative . Ground water use restrictions on the sit e will prevent

future exposure to o n sit e wate r users (residents) . Monitoring o f the residentia

l wells and monitoring well s will prevent

potential future threats to residential water supplies . Immediate and secondary contingency actions are included to protect human health and th e environment. Thi s alternative could b e easil y implemented a s contractors, supplies , and equipment are availabl e locall y or

fromregiona

l vendors . The residential well s are currently bein g sample d and the samplin g could b e expande d to include the site well s with afew months notice . Cos t

for this alternative i s include d i n Tabl e 10 . Maintenance wil l include well upkeep , samplin g analysis , dat avalidation, and reporting . Th e estimate d present

worth for

this iltemative, including capita l cost s and 3 0 year s o

f O&M costs , range s from$760,00 0 to $1.2 million . 7.2.3 Alternativ e No . 3 : Ground Water Extraction ; Carbo n Adsorption ; Reinjection Thi s alternativ e require s extractio n o f ground water

fromthe Wilco x aquifer

upper zon e by strategi c placement

o f ground water

recover y wells . The extracte d ground water wil l b e passe d through atreatment unit locate d onsite. I f

RAO target

goal s ar e exceede d offsite , temporary restrictions will be place d on ground water use. Thes e restrictions wil l remain i n effect

until targe t

goal s are met. The extraction wel l location s and pumping rate s wil l b e determine d during the desig n phase. Collectio n o

f additional dat aduring the design o f aremediatio n systemmay b e necessar y i n order

to further

characteriz e the hydraulic nature o f the aquifer

i n the are ao

f the recover

y and injection wells. Followin g treatment, ground water meeting RAO target

goal s will b e reinjecte d into the Wilco x aquifer

up gradient

o f the contaminant

plume. Monitoring o

f th e treate d effluent will b e conducted to assure that reinjecte d ground water

complie s with RAO target goals . Maintenance will include syste moperation, sampling, analysis , dat avalidation, and reporting . The estimate d present

worth for

thi s alternative, including capita l cost s and 3 0 year s o

f O&M costs , range s from$3. 1 millio n to $3.4 million . 7. 3 ARARS CERCLA, Section 121 , and the National Contingenc y Pla n (NCP), 4 0 CFRPar

t 300 , (revise d March 8 , 1990

) require an assessment

o f alternativ e sit

e response s to determin e whether they attai n applicabl e or relevan t and appropriate federal and stat e environmental and public healt

h requirements (ARARs) or provide grounds for

invokin g one o

f the identifie d waivers . 4 6

### Identification o f ARARs must

be done on asite-specifi c basis . Th e NCP andCERCLA do not provide across-the-boardstandards for determining whether

aparticular

remedial action will produce an adequate remedy a t aparticular

site . Rather, the proces s recognize s that

eac h sit e will have unique characteristic s that must b e evaluate d and comparedto those applicabl e andrelevant requirements that

apply under

the given circumstances. In accordance with the requirements o f th e NCP Sectio n 300.400(g) , the remedia l actio n selected must

meet al l ARARs unless awaiver fromspecifi c requirements ca n b e granted. For remedia l action s performedunder

CERCLA Sectio n 121(e) , permits for complianc e with the Resourc e Conservatio n andRecover y Ac t (RCRA), National Pollutant Discharg e Eliminatio n System(NPDES), andthe Clea n Air Ac t (CAA ) regulation s for

onsit e remedia l action s ar

e no t required . However , CERCLA Sectio n 121(d ) require s that

the selected alternative meet

relevant andappropriate regulatory standards or performance level s where possible , even though apermit i s not required . Relevan

t andappropriat

e regulator y standard s addres s problems or situations sufficiently simila r to those encountereda

t aCERCLA-regulatedsite ; therefore, thei r use i s well-suite d to the particular site o f concern. ARARs ar

e defineda s follows:

• Applicabl e requirements ar e those cleanup standards , standard s o f control, and other substantive environmental protectio n requirements , criteria , or limitation s promulgatedunder

federa l environmental, stat

e environmental, or

facility sitin g law , that specificall y address ahazardous substance, pollutant, contaminant, remedial actio n location, or other circumstance founda

t aCERCLA site .

• Relevant

andappropriate requirements are those cleanup standards , standard s o f control, andother

substantive environmental protection requirements, criteria , or limitation s promulgatedunder federal or

stat e la w that, while not

"applicable " to ahazardous substance, pollutant, contaminant, remedia l action, location , or other circumstance a

t aCERCLA site , addres s problems or situation s sufficiently similar

to those encountereda

t aCERCLA site . ARARs may b e divide d into the following categories :

• Chemical-specifi c requirements are health- or risk-base d concentratio n limit s or range s i n various environmental mediafor specifi c hazardous substances , pollutants, or contaminants. Thes e limit s may tak e the formo

f actio n level s or

discharg e levels .

• Location-specifi c requirements ar e restriction s o n activitie s that ar e based o n the characteristic s o

f asit e or it s immediate environment. An exampl e woul db e restriction s o n wetlands development.

4 7• Action-specific requirements are controls or restrictions on particular types o f activitie s i n relate d area s such as hazardous wast e management

or waste wate

r treatment. An exampl e wouldb e RCRA incineratio n standards . 7.3.1 Action-Specific ARARs for Soil/Sludge ADPC&E Regulation No . 23 §264.11 1 - requires that closure o f the landfill must

b e conducted i n amanner

that minimizes the nee d for

further maintenance an d controls, minimize s or

eliminates escap e o

f hazardous waste . \ ADPC&E Regulatio n No . 2 3 §264.11 4 - require s that contaminated equipment, structures, and soil s b e properl y dispose d o f or decontaminated . ADPC&E Regulatio n No. 23 §264.25 1 - The wast e pile s should b e constructed an d operate d i n amanner

that complie s with ADPC&E Regulatio n No . 23 §264.251 , which specifie s waste pil e design and operating requirements. ADPC&E Regulation No. 23 §264.25 8 - The waste pile s should b e closed i n compliance with thi s regulation which provides requirements for the closure o

f waste piles . ADPC&E Regulatio n No . 23 §26 8 - Monroe Auto Equipment dispose d wast

e water treatment sludg e fromelectroplatin g operatio n (F00 6 waste) a t the sit e betwee n 197 3 and 1978 . Sinc e the specifi c sourc e o f the sludge a

t the landfill i s known, the time a t which the waste was dispose d doe s not affect the waste listin g and the waste wouldb e subject to land disposa

l restrictions, if

excavate d and treated . ADPC&E Regulatio n No. 2 ARARs - Stat e standards under

Regulatio n No . 2, Regulatio n Establishin g Water

Quality Standards for

Surface Water s o

f th e Stat e o f Arkansas, ar

e ARARs for

remedia l actions involvin g discharg e o f treate d ground water . The standard s may b e applicabl e if

discharges are expected to affect surface water s addresse d under thi s regulation. I f

not applicable , portions o

f this regulation may b e relevant and appropriate i f the regulation was intended to address conditions simila r to those pose d by some o f the remedia l action s that

are under

consideration. Stat e standard s under

the Arkansas Underground Injectio n Control Code are ARARs i f treate d ground water

i s reinjected to the aquifer. The standard s may b e applicabl e if ground wate

r i s reinjecte d into ground waters addresse d under these regulations . If

no t applicable , portion s o

f this regulatio n may be relevant and appropriate if

the regulatio n was intended to addres s conditions simila r to those pose d by some o f the remedia

l action s that ar e under consideration. Clea n Air Ac t (CAA) 4 0 CFR, Par

t 6 1 - Nationa

l Emission Standards for

Hazardous Air

Pollutant s (NESHAPs )

- provides standard s for

emissions o

f particular

ai r pollutants fromspecifi c sources . Part s o f NESHAP s may b e relevant and appropriate i

f treatment

results i n releas e o

f a regulate d pollutant. 48Clean Water Ac t (CWA) Th e Clea n Water Act (CWA) requirements may be applicabl e because treatment may generate fluids that

nee d to b e treate d and discharged. The CWA applie s to point-source direc t discharge s into navigable water s and indirec t discharge s to apublicly owned treatment work s (POTW). In the cas e o f indirec t discharge s to aPOTW , the POT W set s forth pretreatment

standards. Arkansas Water

and Air Pollution Control Ac t Arkansas air

and water

quality regulations resemble the national standard s se t forth by the U.S . EP A under the Clea n Air and Clea n Water Acts, but require preconstruction revie w by the state . In addition. Sectio n 5 o f the Arkansas Air

Pollutio n Contro l Regulation s outline s specifi c limitation s for paniculate emissions fromne w or modified sources . Thes e limit s are base d solely o n the amount o f material being processe d (Ib/hr). Arkansas NoncriteriaA^ Pollutants Control Strateg y ADPC&E has implemente d an evaluatio n o f the emission s o

f noncriteri aai

r pollutants fromall source s i n order

to determine i f

apermit shouldb e issue d or

i f an existin g sourc e should be require d to retrofit contro l equipment. Th e Noncriteri aAir Pollutant s Control Strategy (NAPCS) i s base d upon Threshol d Limit Value s (TLVs ) for

chemica l substances adopte d by the American Conference o f Governmental Industrial Hygienist s (ACGIH). According to NAPCS, the predicte d ambient ai r concentration o

f gase s and vapor s i s considered acceptabl e if i t i s les s than 1/10 0 o

f the ACGIH TLV . Th e ambient concentration i s determine d by using appropriate atmospheric dispersio n models ove r a24- hour average . Th e spacin g between receptor s used in th e model i s 10 0 meter s (i n the are ao f the highest

concentration). The NAPCS may consider 8 and 24-hour

averages , first highs, a s wel l as annual average s for use i n assessin g risk. A s state d i n the NAPCS, when the substance emitte d i s apaniculate compound an d persistenc e i n the environment i s expected , the predicte d annual averag e concentratio n i s considere d acceptabl e i f

i t doe s not excee d the dosag e mass o

f the LD5 o (lethal dos e for 50%) expression divided by 10,000 . DO T ARAR s Department

o f Transportation requirements for the transportation o

f hazardous wastes on publi c highway s (4 9 CFR171. 1 - 172.558 ) are applicabl e to the off-site transport o f hazardous waste . Stat

e requirements for

manifesting waste s and notifying th e Stat e o f out-of-state shipments o

f wastes are als o applicable . 7.3. 2 Action-Specifi c ARARs for Ground Wate r CAA ARARs National emission standards for hazardous air

pollutants (NESHAPs ) establishe d under 4 0 CFR, Part

61 , ar e not applicabl e becaus e the site doe s not contain any o

f the sourc e categorie s regulate d under this program. Parts o

f the NESHAP s may b e relevan t and appropriate , however , i f

remediatio n such as ground water treatment, results i n the releas e o f asubstanc e regulate d under the NESHAPs . 4 9CWA ARARs



### Discharges o

f treate d groundwater

to the intermittent

streamon the site may render requirements o

f 4 0 CFR, Par

t 125 , relevant

andappropriate . Thes e regulations addres s criteri aandstandards for

the national pollutant

discharge elimination system(NPDES) . Although an NPDES permit wouldnot

b e require d for

this discharge, parts o

f 4 0 CFR, Par t 125 , may contain substantive requirements that couldbe relevant

andappropriate because the remedial actio n wouldb e similar to the actio n that

the requirements were meant to address . ADPC&E ARARs 

### Stat e standard s under

Regulatio n No. 2, Regulation Establishin g Wate r Qualit y Standards for Surface Water s o

f the Stat e o f Arkansas, ar

e ARARs for

remedia l action s involvin g discharg e o

f treate d groundwater . The standard s may b e applicabl e i f discharge s ar

e expected to affect

surface water s addresse d under this regulation. I f

no t applicab's , portions o f thi s regulation may b e relevant andappropriat

e if the regulatio n was intended to addres s conditions similar to those pose d by some o f the remedia

l action s that

are under consideration. Stat e standard s under

the Arkansas UndergroundInjection Contro l Code ar e ARARs i

f treate d groundwate

r i s reinjecte d to the aquifer. Th e standard s may b e applicabl e i f groundwater

i s reinjecte d into groundwater s addresse d under these regulations . If

no t applicable , portions o

f this regulation may b e relevant an d appropriate i

f the regulatio n was intendedto address conditions similar to those pose d by some o f th e remedia

l action s that are under consideration. Locatio n Specifi c ARARs ADPC&E Reg . 23§264.310, Closure andPost-Closure Care o f aLandfill. The standard s may b e applicabl e to the close d landfill. If not applicable , portions o

f this regulatio n may be relevant

andappropriate if

the regulation was intendedto address conditions simila r to those pose d by some o

f the remedial actions that

ar e under consideration.

8.0 COMPARATIVE ANALYSI S OF ALTERNATIVE S 

### Th e stat e i s require d to use certai n criteri ato evaluate alternative s for addressin g a Superfundsite . Thes e nine criteri aar e categorize d into thre e groups: threshold, primary balancing , andmodifying. Th e thresholdcriteri amust b e me t i n orde r for an alternativ e to b e eligible for

selection . Th e primary balancing criteri aar e use d to weig h major tradeoffs among alternatives . The modifying criteri aare taken into account after publi c comment i s received o n the preferredalternative as identifie d anddescribe d i n th e Propose d Pla

n o f Action.

508.1 NINE CRITERI A 

### Th e nine criteri ausedi n evaluating all o f the alternatives ar

e a s follows: ThresholdCriteri a

• Overal l Protectio n o

f Human Health andthe Environment addresses the way that

an alternativ e wouldreduce, eliminate , or contro l the risk s posed by the sit e to human healt h andthe environment. Tota l elimination o

f risk i s often impossibl e to achieve . However , aremedy must

minimize risk s to assure that human healt

h andthe environment

are protected .

• Complianc e with ARARs. or "applicabl e or

relevan t andappropriate requirements," assures that

an a^ernative wi 1 

### ! meet

all relate d federal, state , andloca l requirements. Primary Balancing Criteria

• Long-termEffectiveness andPermanence addresses the abilit y o f an alternativ e to reliabl y provide long-termprotection for human health andthe environment after the remediatio n goal s have been accomplished.

• Reduction o

f Toxicity . Mobility , or

Volume o f Contaminants through Treatment assesse s how effectively an alternative wil l addres s the contamination on asite . Factor s considere d include the nature o f the treatment

process; the amount

o f hazardous materials that

will be destroye d by the treatment process ; how effectively the process reduce s the toxicity , mobility, or volume o f waste; andthe type and quantity o f contamination that

will remain after

treatment.

• Short-termEffectiveness addresse s the time i t take s for remedy implementation. Remedie s often require severa l year s for implementation. A potential remedy i s evaluate d for

the lengt h o f time require d for

implementation an d the potentia l impac t on human health andthe environment during implementation.

• Implementability addresse s the eas e with which an alternativ e ca n b e accomplished . Factor s such a s availabilit

y o f materials andservice s andother obstacle s ar

e considered .
• Cost (includin g capita

l costs andprojectedlong-termoperatio n andmaintenance costs ) i s considere d andcompare d to the benefit that will result

fromimplementing th e alternative . Modifying Criteri a

• EP A Acceptanc e addresse s whether EP A agree s with, opposes , or has no comment

on the propose d remedy . 5 1• Community Acceptanc e addresses comments and concerns raise d by the community

and other members o

f th e public during the public comment period for

the Propose d Pla n and Administrative Record. The Stat e considers these comments i n making it s final remedy selection . Th e comments arc addressed i n the responsivenes s summary that i s part o f this ROD . 8.2 COMPARATIVE ANALYSI S 8.2.1 Sludg e Pi tArea Overall Protectio n o

f Human Healt

h and the Environment

• Alternativ e 1 (no action ) wouldresult

i n exposure and an increase i n contaminant migration a s th e existin g cove r erode s or i f the site i s developed . Becaus e the no actio n alternativ e i s not protectiv e o

f human health and the environment, i t wil l not be considere d further

i n the evaluatio n process . Alternative s 2 through 6 offer the sam e leve l o f protectio n to human healt h becaus e each alternativ e incorporate s aca p or cove r to prevent

exposure , and becaus e sit e acces s restriction s and deed restriction s wil l prevent future development

o f the site . Alternativ e 7 offers additiona

l protection even i n the absence o f maintenance and site acces s restrictions . Compliance With ARARs • Al l alternatives comply with all identified ARARs provide d they ar e properly implemented. Long-termEffectiveness and Permanence • Alternativ e 7 provide s the greatest long-term protectio n becaus e waste s are remove d fromthe site . Alternative s 4 through 6 offer greater reliabilit y o f protectio n agains t

future migration o

f waste constituents through the use o f physica l barrier s or

treatment o f the waste . Of

these , alternativ e 4B provide s greater reliability . Th e french drain provides ahigher leve l o f protectio n than aslurry wal l becaus e ground water i s les s likel y to contac t

contaminated soi

l and sludge . Bot

h alternatives 4A and 4B offer reliabilit y i n tlie formo

f an improve d ca

p to hinder infiltration. Alternatives 5 and 6 provide reliabilit y i n the control o

f contaminant migration through the use o f treatment. Alternatives 2 and 3 offer the leas t long-ter m effectiveness . Under

alternative s 2 and 3, the potential threat o f leachin g o

f the wast e constituents into the ground water wouldremain a

t the site . Reductio n o

f Toxicity . Mobility , or

Volume Through Treatment • Onl y Alternative s 5 and 6 utiliz e treatment

a s amechanismto achiev e reductio n i n mobility . Alternativ e 6 utilize s treatment

as amechanismto achiev e reductio n i n toxicit y and mobility , but

bot h Alternatives 5 an d 6, result in an increase in volume o f contaminated material. Short-termEffectiveness • Implementation o f alternatives 2, 3, 4A, and 4B , pos e no threa t o f exposure to workers or

to the community, and they pose no environmental

52threat. Implementation o f alternatives 5 , 6, and 7, present threats o f exposure to workers, the community, and th e environment becaus e the waste wouldb e excavated . Thes e alternatives wouldrequire worker protectio n and monitoring to ensure protectio n o f human health. Implementability • No limitations have bee n identified for implementation o

f Alternatives 2 and 3 . Alternatives 2 and 3 ca n be implemented with loca l or regional equipment, personnel, and materials. Alternatives 4A, 4B , 5 , and 6 may be more difficult to implement becaus e these service s ar e offeredby fewer

contractors and ar

e not availabl e locally . Alternativ e 7 require s acceptanc e o f the waste by off-site disposa l facilities . If the material i s dispose d o f a s ahazardous waste , i t

wouldhave to b e transported out o f state for disposal . Cost • Cos t comparisons are shown i n Tabl e 9. It shouldb e note d that

cost s associate d with Alternative s 5 and 6 assume that the waste i s i n complianc e with RCRA land disposa l restrictions . EP A Acceptanc e • EPA s comments on the draft propose d plan were incorporated into the final propose d plan prior

to the public comment

period. Community Acceptanc e • All comments received hav e been addresse d i n the responsivenes s summary, which i s attache d to this Recor d o f Decision . The public , i n general, would prefer

to se e Alternative 7 implemented becaus e aremova l o f the sludg e fromthe pit

will permanently eliminate the human health andenvironmental threats from the site . The sit

e could then b e developed into aresidentia l settin g and may result

i n an increas e o f the neighboring property values. Th e residents believe that the french drai n wouldresult

i n further

migration o

f the contaminants fromthe sit e into surface water . However , the french drain wouldcapture ground water flow before i t

reache s the sludg e deposits . To ensure that

no contaminated water

i s discharge d to surface water , the water fromthe french drain discharge point would b e analyzed and, i f necessary , treate d to mee t the Arkansas surface water quality standards. 8.2.2 Ground Wate r Overal l Protectio n o

f Human Health and the Environment • All alternative s offer

the sam e immediate protection . Alternative No. 2 restrict s the use o f onsite ground water and includes monitoring that wouldprovide earl y detectio n o f contaminant

migration or degradatio n i n the quality o f residential water

supplies . Alternativ e No . 3 would effectively reduce the tota l mass o f contaminants. Alternative No. 3 would decreas e the time necessar

y for mass reductio n as compared to that achieve d under

Alternativ e 1 or

2, but may not significantly lessen the time for attainment

o f the ARARfor

BEHP ove

r the time require d for

natural attenuation alone . Alternative No . 1 doe s no t include monitoring, s o contaminant migration or

attenuation cannot

be evaluated . Complianc e With ARARs • Al l alternatives ar e expected to result

i n long-termcomplianc e 5 3with ARARs i n the residential water supplies. Natural attenuation and degradation , which wouldoccur

under all alternatives, are expecte d to result i n ARARcomplianc e for 1,2- DCE and for

BEHP . Long-termEffectiveness and Permanence • Al l alternatives ar e predicte d to result

i n a reduction i n risk

and are expecte d to result in complianc e with ARARs i n residential water supplies . Alternative 2 offers the additional protection o f restriction s on uses o

f ground water

a t the site . Alternative 3 wouldreduce the tota l mass o f contamination i n the aquifer

i n les s time than Alternative s 1 and 2. Reductio n o

f Toxicity . Mobility , or

Volume Through Treatment • Onl y Alternativ e 3 employs treatment. Under Alternativ e 3, the mass o f contaminants i n the aquifer would b e reduced. Thes e contaminants wouldb e transferred to activate d carbon, which would require regeneratio n or

disposa l a t an off-site facility. Short-termEffectiveness • None o f th e alternatives pos e athrea t to the loca

l community. Alternativ e 3 pose s apotential threat to sit e worker s who ar

e expose d to contaminate d ground water , but

these threats wouldb e mitigate d by the use o f protectiv e equipment. Implementability • Alternative 1 requires no action. Alternative 2 i s easily implementable and service s ar

e availabl e locall

y or regionally . Alternative 3 i s easily implementable with commercially availabl e products and services . Thi s alternativ e would, however , require extensiv e O&M activities . Cos t • Cost comparisons are shown i n Tabl e 10 . Alternativ e 2 would b e the most cos t effective . Alternativ e 3 may result i n ashortene d remediatio n time, but the lo w concentration s o

f the contaminants i n ground water and the larg e volume o

f water (estimate d a

t 4 0 million gal./yr.) that

would nee d to b e treated , make alternativ e 3 inefficient. Alternative 3 would als o require disposa l or renewa l o f carbon filters a

t an adde d cost . Alternative 1 i s the leas t costly . The difference i n time require d for remediation doe s not

justif y the additional cos t

o f treatment. EP A Acceptance • EPA s comments on the draft propose d plan were incorporate d into the final propose d plan prior

to the public comment

period . Community Acceptanc e • Public comments and response s to those comments ar e include d i n th e responsivenes s summary. Th e public wouldprefer alternativ e 3, treatment, or bein g connecte d to th e Raragouldpublic water suppl y system . Th e residents believe that thei r water i s contaminated, when i n fact, test s sho w that the water

meets the criteri afor safe drinkin g water .

549.0 THE SELECTE D REMEDY 

### Base d upon consideration o f the requirements o

f CERCLA, adetailed analysis o f the alternatives using the nine criteria , andpublic comment; both EP A andthe Stat

e have determinedthat

acombination o

f alternative 4b for

soil/sludge , afnench drain andacap , andalternativ e 2 for

groundwater , natural attenuation anddegradatio n with monitoring, i s the most appropriate remedy for

the Monroe Auto Pit

Superfundsite i n Raragould, Arkansas. 9.1 SOI L AND SLUDGE REMEDIATIO N 

### Th e selecte

d remedy for

addressing the contaminatedsoil/sludg e i n th e pit are ai s Alternativ e 4b. The origina l waste containe d ahigh volume o f liquids , which i s believed to have been the primary source for groundwater

contamination a

t the site . Sludge sample s collected during the RI containedno free liquids. Analytical dat afromtestin g o f leachat e producedby the toxicit

y characteristic leachin g procedure (TCLP) sho w ver y lo w leachabilit y o f the contaminants i n the soil andsludge . (The TCL P dataar e presentedi n Sectio n 4 o

f the RI). In accordanc e with the NCP Sectio n 300.43 0 andOSWER Directives , the Stat

e has determine d that

the soil/sludg e deposit s i n the pit are apos e a relativel y low , long-ter

mthreat; andthat

through the use o

f engineering controls (such a s containment) anddeed restrictions the soil/sludg e material ca n b e reliabl y contained . A french drai n will b e constructedsurrounding the are ao f sludg e deposits . Th e three

foot wide french drai n will be installe d to adepth o f approximately 3 0 fee t

andwil l tota

l approximatel y 2100 fee t

i n length. The bottomo f the french drai n will b e belo w the tota l dept h o f the sludg e deposits , andwill extendthrough the perche d zon e into the underlying unsaturatedzone . Site soil s displace d a s aresult o f excavatio n o

f th e trench will b e sprea

d ove r the sludge area, andb e covere d by the cap . Al l excavatio n wil l be plannedi n uncontaminatedareas ; but if staine d soil s exhibitin g possible contaminant characteristic s ar

e encounteredthey will be segregate d andshippe d off-site for disposal . A french drain wil l restric t groundwater

movement

into the are ao

f contaminatedsoi

l an d sludge . The french drai n wil l also intercep t perche d groundwater

before i t enter s the contaminatedarea . Th e capturedgroundwater will b e transporte d viaburie d pipin g to a discharge point

locate d i n the intermittent strea msouthwest

o f the site . Water

fromthe french drain wil l b e teste d to ensure the Arkansas surface water quality criteri aar

e met. A french drain suitabl e for this site will be constructedby excavatin g a30-foo t dee p trench andinstallin g impermeable plasti c sheeting alon g the sludg e deposi t side o f the trench. A one - to two-foot thick grave l base will be place d i n the trench; slotted PVC piping will b e installe d abov e the grave l base , andgrave l fill wil l b e installe d to ground surface. Th e trench parameters andits construction methodwill b e further refinedto provide improve d performance i n the detaile d design process . 55

### The cap evaluate d under this alternative includes a24-inch uncompactedsoil laye r comprise d o

f six inches o

f uniformly distributedtopsoi l ove r 1 8 inches o

f sandy soil . Th e 24-inch soil layer

will be underlain by a24-inch compacte d clay layer . Components andthicknesse s o

f the cap specifie d here do no t necessaril y represent

the final desig n parameters under

this alternative . I f

this alternative i s implemented, adetaile d design will b e providedandthe capping parameters will b e further refined. Dee d restrictions will prohibit future development

o f the site . A survey pla

t indicatin g the locatio n o

f the waste disposa

l are awit h respec t

to permanently surveye dbenchmark s wouldb e prepare d an d filedwith the loca l zoning authority. Th e plat wil l contai n a note, prominently displayed , which state s the owner's obligatio n to restric t disturbanc e o

f the waste . In addition to the cap , thes e restriction s will eliminate the risk o f long-termcontact

with contaminate d media. Th e baseline risk assessment

assumedafuture residentia l landuse scenari o for

the calculatio n o

f future risks . The cap anddeed restrictions will eliminat e the possibility o

f residential lan d use at

the site . Th e multilayer

cap andthe french drain outle t will b e periodically inspecte d for sign s o f erosion , subsidence , or

damage cause d by frost

or burrowing mammals. Damage d area s wil l b e repaire d to restore the cap . The vegetatio n will b e maintainedthrough periodi c mowing andreseedin g o

f bare areas . ADPC&E believe s that

base d on the current

information the selected remedy wil l provide the bes t balance among the alternative s with respec t to the two thresholdandfive primary balancin g criteria . Th e alternativ e will: (1 ) prevent direc t contact, ingestio n an d inhalatio n o f contaminants in the sludg e andancillary contaminatedsoil anddebris ; (2) prevent the future migratio n o

f contaminants fromthe sludge are ato the surface; and(3 ) prevent the potentia l for future migration o

f contaminants to the groundwater . Th e selecte d remedy i f implementedproperly , will comply with al l applicabl e andrelevant or appropriate requirements identifiedfor

the site . Th e alternativ e wil l achiev e long-termpermanence andeffectiveness . The ca p combine d with the french drain will permanently isolat e the contaminants i n the sludg e pi t are afrom surrounding media. Ther

e ar e no expected unmanageable short-termrisk s associate d with thi s alternative . Th e alternative i s implementable andcos t effective . Even though a residential scenari o was utilize d to calculate the risk s associate d with the contaminants a t th e site , none o

f the alternatives , with the exceptio n o f Alternativ e 7, will allo w the residential development

o f the sit e to occur . Th e estimate d capita

l cos t to implement

the selected remedy ranges from$730,00 0 to $1. 5 million . The capita

l cos t includes engineering , equipment andmaterials , testing , an d sit e support. Th e annual O&M cost s i s estimateda t $14,00 0 per

yea r i n 199 3 dollars . The estimate d present

worth for the selected remedy, including capita l cost s an d 3 0 year s o f O&M costs , range s from$870,00 0 to $1.6 milFon. 569.2 GROUND WATERREMEDIATIO N

The selected remedy addresses the ground water contamination through natural attenuation, degradation, and monitoring. The sourc e o f the contamination i s the liquid s that were part o f the origina

l sludge deposite d in the pit. When first deposited, the sludge was about 85% liquid. Thes e liquids migrated into the ground water where we findthem today . In this respect , the sourc e o f continuing contamination has bee n removed. Th e level s o

f the contaminants o

f concern see

n i n the upper

Wilco x aquifer

on the sit

e decreas e away fromthe sludg e pi t area . I t i s expected that

this tren d o

f decreasin g value s wil l continue . Regula r monitoring o

f the monitoring well s and the residentia l well s will provid e continuous evaluatio n o f the effects o

f natural attenuation an d degradatio n i n the ground water

system. In the unlikely event that monitoring indicate s adegradatio n o f residentia l wel l water , by an increas e o f five times the previous reading , or the occurrence o

f apreviously non-aetecte d constituent abov e the MCL level , the affected residents wil l be put

on bottle d water

or apoint o f use water

supply treatment, and the well(s ) will b e immediately resampled . If achange in ground water quality i n the monitoring wells i s indicate d by an increase o f two times for

constituent

level s a t or abov e 10/xg/l and afive times increas e for constituent

level s les s than 1 0 /zg/1 , the affectedwell s will immediately b e resampled . I f any changes ar

e verified, more frequent samplin g should be performed. If necessary, activ e remediatio n or physical/ hydraulic containment

measures will be evaluated. Should these measures become necessary , a ROD amendment

or an explanation o

f significant

differences will b e issued. Ground water

use restrictions will be i n plac e on the site until the contaminant level s ar e belo w the remedia

l actio n goa

l levels . Monitoring well s to b e sample d wil l b e sufficient i n number

an d locatio n to delineat

e the contaminant

plume and to detec t

contaminant migration. Contaminated ground water must b e kep t within the lega

l sit e boundaries . Th e exac t monitoring well s and their location s will be determine d a s part o f the desig n phase for th e french drain. Monitoring shall b e semi-annually for two year s or

until four sample s have been take n for volatiles , semi-volatile s (including BEHP), and metal s for statistica l analysis . Th e statistica

l method used will b e a s specifie d i n the Statement o f Work. Monitoring coul d b e require d for 3 0 year s or

more. Capital cost s for

this alternative are estimate d from$70,00 0 to $71,000
. Thi s would includ e development

o f asamplin g plan and abandonment o f well s not

kept i n the monitoring system . Operatio n and maintenance cost s for this remedy include sampling , analysis , dat avalidation , and reporting . Th e cos t i s estimate d a

t $73,00 0 to $120,00 0 per yea r i n 199 3 dollars . Thi s figure assumes that the current

monitoring plan doe s no t change . Th e estimate d present worth including capita

l cost s and 3 0 year s o

f O&M cost s i s from$760,00 0 to $1.2 million.

5710. 0 STATUTOR Y DETERMINATION S 

### Th e primary responsibilit

y at Superfundsite s i s to select remedia l actions that

ar e protective o

f human healt

h andthe environment. Sectio n 12 1 o f CERCLA als o require s that the selected remedia

l action comply with applicabl e or relevant andappropriate environmental standards establishedunder federal andstate environmental laws , unless a waiver i s granted. Th e selecte d remedy must be cost-effective andutiliz e permanent solution s andalternative technologie s or resource recover

y technologie s to the maximum extent practicable . The Statute also contains apreference for remedie s which emplo y treatment that permanently andsignificantly reduce the volume, toxicity , or mobilit y o f hazardous wastes a s aprincipa l element. The following section s discuss ho w the selected remedy meet s the statutory requirements. 10. 1 PROTECTION OF HUMAN HEALT H AND THE ENVIRONMEN T 

### 10.1. 1 Soi l an d Sludg e The soil/sludge selected remedy meets all o f the soil andsludge remedial actio n objective s through limitations on site development andinadvertent

access , andby eliminatin g the potentia l for long-termdirec t

contac t with contaminatedsoil

/ sludge . Contaminant

mobilit y wil l b e minimizedor

prevente d becaus e the french drai n wil l isolat e the contaminate d soil/sludge fromthe perche d groundwater tabl e andthe cap wil l minimiz e infiltration and erosion . Deed restrictions andsit e acces s restrictions will prohibit any use o

f the site that wouldresult

i n contact

with contaminatedmedia, andwill limi t any human or environmental contac t

with contaminatedmedia. Short termrisk s associate d with the selecte d remedy can b e controlle d by proper desig n andimplementation. No advers e cross medi aimpacts ar e expected fromimplementatio n o f the selected remedy. 10.1. 2 Ground Wate r Becaus e the onsite contamination i s i n the upper Wilcox aquifer

andthe private well s are believed to produce fromthe lowe r Wilco x aquifer, acomplete exposure pathway doe s not exis t a t thi s time. A cap on the sludg e deposi t are aandafrench drain wil l prevent infiltration o

f precipitatio n andperche d groundwater into the sludge . Th e selected remedy wil l protec t

human health andthe environment by natural attenuation an d degradatio n o

f the contaminants o

f concern . Groundwater

use restriction s for

th e on sit

e groundwater

wil l prevent

contac t with contaminatedgroundwater . Monitorin g o f th e residentia l well s wil l provide continuous assessment o f the effects o

f natural attenuation an d i n thi s way protec t

human healt

h andthe environment. Ther e are no short-term threats associate d with the selecte d remedy for groundwater

that canno t be readily controlled . In addition, no adverse cross-medi aimpacts ar e expecte d fromthe remedy .

5810. 2 COMPLIANC E WITH APPLICABLE ORRELEVAN T AND APPROPRIAT E REQUIREMENT S The selected remedy o

f cap , French drain, acces s and deed restrictions for soi l and sludg e and natural attenuation and degradation, ground water use restrictions , and ground water monitoring for

ground water

remediation will comply with al l applicabl e or relevant and appropriate requirements (ARARs), if properly designe d and implemented. Th e ARARs for the selected remedy are presented below . 10.2. 1 SoU an d Sludg e Action-Specifi c ARARs ADPC&E Regulation No . 23 §264.111 - closure o f th e landfill, must

b e conducte d i n a manner that minimizes the need for

further maintenance and controls, and minimize s or eliminate s escap e o

f hazardous v'aste. ADPC&E Regulatio n No. 23 §264.11 4 - requires that contaminated equipment, structures, and soil s b e properl y dispose d o f or decontaminated. ADPC&E Regulation No. 23 §264.251 - The wast e pile s should be constructed and operate d i n amanner

that complie s with ADPC&E Regulatio n No . 23 §264.251 , which specifie s wast

e pil e desig n and operatin g requirements. ADPC&E Regulation No . 23 §264.25 8 - The waste pil e shouldbe closed in complianc e with this regulation which provides requirements for the closure o

f awast e pile . Regulatio n No . 23 §26 8 - Monroe Auto Equipment dispose d o

f waste water

treatment sludg e fromelectroplating operation s (F00 6 waste ) at the site between 197 3 and 1978 . Sinc e the specifi c source o f the sludg e a

t the landfill i s known, the time a t which the waste was dispose d doe s not affect the wast e listin g and the waste would be subject to land disposa

l restrictions, i f

excavate d and treated. Clea n Air Ac t (CAA) 4 0 CFR, Par

t 6 1 - National Emission Standards for Hazardous Air

Pollutants (NESHAPs )

- provides standards for

emission s o

f particular

air pollutants fromspecifi c sources . Parts o f NESHAP s may be relevant and appropriate if

treatment

results i n releas e o

f a regulate d pollutant. Clea n Water Ac t (CWA) Th e Clea n Water Ac t (CWA) requirements may b e applicabl e becaus e treatment may generate fluids that

nee d to be treate d and discharged . Th e CWA applie s to point-sourc e direc t discharge s into navigabl e water s and indirec t discharge s to apublicly owned treatment works (POTW). In the cas e o f indirec t discharge s to aPOTW , th e POT W set s forth pretreatment

standards .
59Arkansas Water and Air Pollution Control Ac t Arkansas air

and water

quality regulations resemble the national standards se t forth by the U.S . EP A under the Clean Air

and Clean Water

Acts , but require preconstruction revie w by the state . In addition, Sectio n 5 o f the Arkansas Air

Pollution Control Regulation s outlines specifi c limitations for particulate emissions fromnew or modified sources . Thes e limits are base d solely on the amount o f material being processe d (Ib/hr). ADPC&E ARARs State standards under

Regulation No . 2, Regulation Establishin g Water Quality Standard s for Surface Water s o

f the Stat e o f Arkansas, are ARARs for remedia l actions involvin g discharg e o

f ground water . Th e standard s may b e applicabl e i f discharge s ar

e expected to affect surface water s addresse d under this regulation . If

not applicable , portion s o

f this regulation ar

e relevant

and appropriate to addres s conditions simila r to thos e pose d by some o f the remedial actions that are under

consideration. Arkansas NoncriteriaAir

Pollutants Control Strategy ADPC&E has als o implemented an evaluation o f the emissions o

f propose d emission o

f noncriteri aai

r pollutants fromall source s i n order to determine i

f apermit should b e issued or i f an existin g sourc e should b e require d to retrofit contro l equipment. The Noncriteri aAir

Pollutants Control Strategy (NAPCS) i s base d upon Threshol d Limit Values (TLVs ) for

chemica l substance s adopte d by the American Conference o f Governmental Industrial Hygienist s (ACGIH). Accordin g to NAPCS, the predicte d ambient air concentration o

f gase s and vapor s i s considere d acceptabl e if

it i s les s than 1/10 0 o

f the ACGIH TLV . Th e ambient concentration i s determined by using the spacin g between receptor s use d i n the model o f 10 0 meter s (i n the are ao

f the highest

concentration). Th e NAPCS may consider 8 an d 24-hour averages , first

highs, as wel l a s annual average s for use i n assessin g risk. A s state d i n the NAPCS, when the substance emitte d i s aparticulate compound and persistenc e i n the environment i s expected , the predicte d annual averag e concentration i s considere d acceptabl e if

i t doe s not excee d the dosag e mass o

f the U^o (letha

l dos e for 50% ) expressio n divide d by 10,000 . DO T ARAR s Department

o f Transportation requirements for the transportation o

f hazardou s waste s o n public highways (4 9 CFR171. 1 - 172.558 ) ar e applicabl e to the off-site transport o f hazardous waste . Stat

e requirements for

manifesting waste s an d notifying the Stat e o f out-of-state shipments o

f wastes ar

e als o applicable .

6 0ADPC&E ARARs

Stat e standard s under

Regulation No. 2, Regulation Establishing Water Quality Standard s for Surface Water s o

f the State o

f Arkansas, are ARARs for remedial actions involvin g discharg e o

f treate d ground water . The standards may b e applicabl e if discharge s ar

e expecte d to affect

surface water s addresse d under this regulation. I f

no t applicable , portions o f thi s regulation may b e relevant and appropriate if

the regulation was intende d to address conditions similar to those pose d by some o f the remedia

l actions that

ar e under consideration. Stat e standard s under

the Arkansas Underground Injection Control Code are ARARs i f treate d ground water

i s reinjecte d to the aquifer. Th e standard s may b e applicabl e i f ground water

i s reinjecte d into ground water s addresse d under thes e regulations . If

not applicable , portions o

f this regulatio n may b e relevant and appropriate i

f th e regulatio n was intende d to address conditions sinrlar to those pose d by some o f the remedial action s that ar e under consideration. 10.2.2 Ground Wate r The selected remedy meets all action and locatio n specifi c ARARs. Chemical specifi c ARARs wouldnot

b e immediately met

under thi s remedy . Groundwater modeling predict s that

for 1,2-DCE concentrations ARARs wouldb e attaine d within one year . ARARs for

BEHP will b e met

i n the future, possibly within 3 0 years . ARARs are no t expected to b e exceede

d i n residential wate

r supplie s a

t any time . 10.2.3 Action-Specific ARARs for Ground Wate r CAA ARARs National emission standards for hazardous ai

r pollutants (NESHAPs ) establishe d under 4 0 CFR, Par t 61 , are no t

applicabl e becaus e the site doe s no t contai n any o

f the sourc e categorie s regulate d under this program. Parts o

f the NESHAP s may b e relevant and appropriate , however , i

f remediatio n such as with ground water treatment, results i n the releas e o f asubstance regulate d under the NESHAPs . CWA ARARs Discharge s o

f treate d ground water

to the intermittent

strea mon the sit

e may render requirements o

f 4 0 CFR, Par

t 125 , relevan

t and appropriate . Thes e regulations addres s criteri aand standards for

the national pollutant

discharge elimination system(NPDES). Although an NPDE S permit would no t

b e require d for

thi s discharge , parts o

f 4 0 CFR, Par t 125 , may contain substantive requirements that could b e relevant

and appropriate becaus e the remedia

l actio n wouldb e similar to the actio n that

the requirements wer

e meant to address . ADPC&E ARARs Stat e standard s under

Regulation No . 2, Regulation Establishin g Water Qualit y Standards for Surface Water s o

f the Stat e o f Arkansas, are ARARs for remedial action s involvin g discharge o

f treate d ground water . Th e standards may b e applicabl e i f discharge s are 6 1expecte d to affect surface waters addresse d under this regulation. I f

not applicable , portions o f this regulation may be relevant and appropriate i

f the regulation was intended to addres s conditions similar to those pose d by some o f the remedial action s that are under consideration . State standards under

the Arkansas Underground Injection Control Code ar e ARARs i

f treate d ground water

i s reinjected to the aquifer. Th e standards may b e applicabl e i f ground water

i s reinjected into ground waters addresse d under these regulations. I f

not applicable , portions o

f this regulation may be relevant an d appropriate i f

the regulatio n wa s intende d to address conditions simila r to those pose d by some o f th e remedia

l action s that ar e under consideration . Locatio n Specifi c ARARs ADPC&E Reg . 23§264.3JO, Closure ind Post-Closure Care o f aLandfill. Th e standards may b e applicabl e to th e closed landfill. I f not applicable , portions o

f this regulatio n may be relevant

and appropriate i

f the regulation was intended to addres s conditions simila r to those pose d by some o

f the remedial actions that are under

consideration. 10. 3 COS T EFFECTIVENES S 10.3. 1 SoU and Sludg e ADPC&E believe s that

the selected remedy for

soil and sludg e will eliminate th e risk s to human health a

t an estimated cos t

o f $870,00 0 to $1.6 million . Even though the selected remedy doe s not

provide for

areduction i n the toxicit y or volume o

f contaminants i n the soi l and sludge, the cappin g and the french drain will substantially reduce the mobility o f the contaminants. Th e selecte d remedy provides an overall effectiveness proportionate to its costs , such that

it represents areasonable value for the money that

wil l be spent. 10.3. 2 Ground Wate r Th e lo w concentrations o

f contaminants i n the upper Wilco x aquifer

and the lack

o f a complete contaminant

pathway make the selected remedy the most cos t effectiv e remedy for ground water . ADPC&E believe s this remedy wil l eliminat e the risk s to human health and the environment at an estimated cos t

o f $760,00 0 to $1.2 million, therefore the selected remedy provides an overal l effectiveness proportionate to its cost , such that it represents areasonable value for the money that

will b e spent . Th e difference i n time require d for

remediation doe s not

justify the additional cos t o f treatment.

6 210. 4 UTILIZATIO N OF PERMANEN T SOLUTION S AND ALTERNATIVE TREATMENT TECHNOLOGIE S T O TH E MAXIMUM EXTENT PRACTICABLE 10.4. 1 Soi l and Sludg e ADPC&E has determine d that the selected remedy represents the maximumexten t to which permanent

solutions an d treatment

technologie s ca

n be utilize d i n acost-effectiv e manner for contaminated soil and sludge . Of those alternatives that

ar e protectiv e o

f human health and the environment and comply wit h ARARs, ADPC&E has determine d that the selected remedy provides the bes t balanc e i n terms o

f long-tsrmeffectiveness and permanence ; reductio n in toxicity , mobility , or volume achieve d through treatment; shorttermeffectiveness; implementability; and cos t while als o considerin g the statutory preferenc e for

treatment as aprincipa

l element and considering EP

A and community acceptance . 10.4. 2 Ground Water Al l o f the ground water

alternatives are equa

l with respec t

to long-termeffectiveness and permanence, short-termeffectiveness and Implementability . AH o f the alternatives wil l mee t the actio n and chemica

l ARARs a

t some futur e date . Alternative 3 i s the only alternativ e to emplo y treatment o f the ground water . Balancin g cos t effectiveness agains t treatment, alternative 2 achieve s the same goal s with les s cos t and aminimal increas e i n time. Becaus e acomplete contaminant pathway may or

may not exis t a t this time, ADPC&E believe s alternative 2 i s the appropriate remedy for this site . 10. 5 PREFERENC E FO RTREATMENT A S A PRINCIPA L ELEMENT Th e selected remedy for

soil/sludg e and ground water i s protectiv e o

f human health and the environment, complie s with federa l and stat e requirements that

are legall y applicabl e or relevant an d appropriate to the remedia l action, and i s cost-effective . The selected remedy utilize s permanent solutions and alternative treatment to the maximumextent practicabl e for

this site . However , becaus e treatment o f the principal threats o

f the sit e was not found to be practicable , this remedy doe s no t satisfy the statutory preference for treatment a s the principal element. Becaus e thi s remedy will result i n hazardous substances remaining on-site abov e health

base d levels , arevie w will b e conducted within five year s after commencement

o f remedia l actio n to ensure that

the remedy continue s to provid e adequate protectio n o f human health an d the environment.

6 311. 0 DOCUMENTATIO N OF SIGNIFICAN T CHANGE S



### The Propose d Pla

n for the Monroe Auto Pi t

site was released for

public comment

i n July 1995 . Th e Propose d Pla

n identifiedalternative 4b , cap , french drain, acces s anddeed restrictions , a s the preferredalternative for soil andsludge remediatio n andalternative 2, natural attenuation, groundwater andresidential water

supply monitoring, andground water use restrictio n as the preferredalternative for the groundwater

remediation . ADPC&E reviewe dal l written andverbal comments submittedduring the public comment period . Upon revie w o

f these comments, i t

was determine d that

no significant

change s to the remedy, a s originall y identifiedin the Propose d Plan, were necessary . 12. 0 RESPONSIVENES S SUMMARY Thi s Responsivenes s Summary has been prepare d to provid e written response s to comments receive d at

the public meeting andduring the Publi c Comment Perio d for

th e Propose d Pla

n o f Action for

the Monroe SuperfundSite . On e public meetin g was conductedon August

8 , 199 5 during the Public Comment Period . Th e transcript

o f this meetin g i s includedin the Administrative Record . Written comments on the Propose d Plan were submittedby Monroe Auto Equipment Incorporated, McMath Law Firm, P.A., andafew concerne d citizens. Commen tffl Everyone I know i n thi s are ai s having to use bottle d water for drinkin g an d cookin g now . The recommendedactio n will do nothing to improv e thi s situatio n except wai t and hope it goe s away . Respons e ff

1 The private well s within al 

### /^mile radius o f the site have been andwill continue to b e tested . All results obtaine d to date indicate that the concentratio n o

f contaminants i n these well s ar

e belo w MCLs . Thi s means that the water fromprivate well s i s safe to drink. In addition, this Recor d o f Decisio n provide s the means by which to ensure th e safet y o f the drinking water

i n the future. The decisio n by are aresidents to use bottle d water to cook anddrink

i s voluntary. Groundwater model s indicat

e that th e contaminants will degrad e naturally to safe level s before they coul d possibl y reac h any o f the residentia

l wells . Commen tffl Environmental laws/processe s focus on environmental andhealt h issues . In doing this , 6 4economic issue s (such as property values) may b e indirectly impacted, but these types o

f economic issue s do not

directly influence the decisio n making process . I sa w severa l references to cos t

benefits. I t

wouldsee

mthat i f you determine that

the cos t i s too high to do anymore than outlined, you wouldspecif y that some o f the saving s b e directe d towardrectifying damages. Respons e ff2 Th e cos t o f aremedy i s jus t

on e o f the nin e criteri aconsidere d i n the remedy selection process . The two threshold criteri a1 ) overall protectio n o f human healt

h and th e environment, an d 2 ) complianc e with ARARs (applicabl e or relevan t and appropriat

e requirements o

f federal and stat

e environmental statutes), must b e met prior to other considerations . ADPC&E believe s that th e selected remedy for

the Monroe Auto Pit provide s the best

balance among the alternative s with respect to the threshold and primary balancing criteria. Therefore i t i s not justifiable to choos e amore expensiv e remedy when ales s expensiv e remedy ca n meet all the objectives . Commen tff3 It i s difficult

to understand how this Frenc h Drai n optio n i s goin g to do anything except catc h all the pollutio n and put it i n the creek . I certainly wouldnot allo w thi s to happen to my property . Respons e #3 The purpose o

f placing afrench drain around the sludge pit i s to intercep t

the perche d ground wate

r before i t enter s the contaminated area . The perche d ground water collected a t the french drain i s expected to b e "clean." However , the water will b e teste d and, i

f necessary , treate d to ensure that the State's surface water quality criteri aare met. Commen t#4 A s I understand the actio n that you inten d to take , no solidificatio n o f the contaminated materia l wil l tak e plac e and no effort

to filter the hydrocarbons out

o f the aquifer

wil l tak e place . I d o no t

think this i s goo d enough. Respons e #

4 A s part o f the Remedia

l Investigation/Feasibilit

y Study (RI/FS), Monro e conducte d a Treatabilit y Study o n severa

l treatment

technologies . Solidification/Stabilizatio n was one o f the technologie s investigate d in that study. In general, solidificatio n i s used to reduce/eliminate the rate a t which contaminants leac h 6 5fromacontaminate d matrix. One way to measure the performance o f solidification/stabilization i s for the solidifie d matrix to pass the TCLP test. In Monroe's case , however , the study indicate d that prior to any treatment, sludge/soil present a t the pit wouldpass the TCL

P tests . The chlorinated hydrocarbons present i n the on-site ground water will degrade by natural processes . Base d on ground water modelin g and the analytical dat afromthe monitoring well s and private wells to date , it appear s that

the contaminant

level s will degrad e naturally within areasonable time perio d without endangerin g human health or the environment. Filterin g contaminants out (pump and treat) may reduc e the time necessar y to meet Target RAOs. Th e level s o

f contamination that

we se e a t the site ca

n easily degrad e before they reac h any off site wel l locations . Thi s short time decreas e doe s not warrant the extr aexpense . Commen t#5 I had nothing to do with the illega l dumping o

f the chlorinate d hydrocarbons i n the pi t anddo no t

understand why we must stil l have thi s problem. Respons e ff5 At the time , when Monroe dispose d o f it s sludge into the pit, most o f the environmental laws that are in-plac e today were nonexistent. Thus, Monroe di d not dispos e o

f the sludg e into the pi t

illegally . Th e selected remedy specifie d i n this ROD , i f designe d an d implemented properly , will provide adequat e protectio n o

f the human healt

h and the environment. Commen tff6 I formally reques t

a t leas t asix month dela

y before afinal action decisio n i s made. Respons e ff6 Th e Superfund Programemphasize s the importance o f community involvement. Therefore, prio r

to th e releas e o

f the Propose d Plan, EP

A had conducte d an ongoing community relations programto ensure that the citizen s had ampl e opportunity to voic e opinions , receiv e answers to thei r questions, and provide meaningful input into the decisio n making process . Base d on anumber

o f requests , atwo month extension o f the comment

perio d on th e Propose d Pla

n o f Actio n was granted. Thi s made the comment perio d on the Propose d Pla n atota l o f thre e (3 ) months. ADPC&E believe s thre e months was sufficient for the comment period .

6 6Commen

t#7 

### I amsendin g this written comment since it was requested, but

I have no confidence that any change i n the plannedaction will tak e place; I hope I amwrong. Respons e ff7 After careful consideration o

f all public comments on the Propose d Plan, ADPC&E determine d that

no significant

change s to the preferredremedy ar e necessary . Commen tffS When I move dher

e this are awas apremier

home site , no w it

i s practicall y worthless . I was expectin g som

e help from^e government; I do not se e i t yet. Respons e ff8 Various element s couldaffect the property value a

t agiven location . One such element i s nearness to aSuperfundsite . Even though aSuperfundsit e may not physically affect

a give n neighborin g community i n any way or fashion, the badperceptio n o f livin g clos e to aSuperfundsit

e i s on e which canno t

be easil y altered . In thi s particular situation , a s soo n as all remedia

l objective s are met, the State wil l make efforts to delet e the sit e from the National Prioritie s Lis t (NPL ) in an expedite d manner. We hope that this action wil l provide som

e relief to property value s surrounding the site . Commen tff9 When we wouldge

t results on our

wel l water , andalette

r fromMonroe , sayin g everythin g check s out

"fine". We trusted Monroe . We hadno ide awhat the result s showed. But

after we received acopy o

f the Propose d Pla

n o f Action , we got

all our results out an d starte d comparing them. Ther e i s none o

f themthe same , andif

there was ahigher amount foundfromone time to the next. Th e limits g o up, fromwhat we understandby comparing them, we have question about the limits? For example: Surrogate % Recover y Q.C. Limits 12/6/94 Bromo-1-chloropropan e 8 1 5 0 12 5 Flurobenzen e 10 4 5 0 12

5 6/30/94 

### l,4,Dichlorobutane 6 8 5 0 12 5 Flurobenzen e 10 2 5 0 12

5 Doe s thi s mean we are i n the limits ? If it does , we sure are clos e to ove r goin g the limits . 6 7

### Respons e ff9

Above is an exampl e o

f laboratory QA/QC information. Laboratory QA/QC sample s are measures o

f instrument

andlaboratory performance. They provide dat athat i s necessar

y to determine the quality o

f sampl e analyses . In thi s instance, laboratory grade water i s spiked with the analyte o

f interest to monitor

the accuracy o

f analysi s o

f the laboratory performance methodused. The concentration o

f contaminants shown on your reports provide the necessar y information i n relatio n to quality o f the water and, therefore, wouldbe o f significanc e to the wel l owners . Commen tfflO My husbandneve

r coul d drink

our wel l water . It

alway s made hi msick . We neve r realized takin g ashowe

r may be harmful to my family. We stil l wouldn't hav e known i

f we hadn't went to the librar

y andlooke d up all these words, andthey all mea n the same . The y ar e all , very much adange

r to human health. S o takin g all this andmore into consideration, we feel we really need more time to really look a t al l this with our

eye s open. Response fflO Th e concentration o

f contaminants in private well water s are belo w MCLs andtherefore the water fromthe private well s i s safe to drink. Thi s als o implie s that the wate r i s not harmful to human health when takin g ashower , washing dishes , or for any other domesti c use . Commen tffll 

### Alternativ e No . 2 i s not

aggressiv e enough a

t cleanin g up this sit

e andprotecting human health an d the environment. It wouldsee

mmuch more appropriate to implement a combination o

f groundwater

Alternative s No . 2 andNo . 3 andremov e an d trea t ground water fromall contaminate d zone s a t leas t i n the sourc e are aandimmediatel y downgradient. Well s place d strategicall y downgradient o f the sit e couldb e operate d periodicall y to remov e a s much contaminants a s possible , prevent contaminant

migration andresult i n much better

protectio n o

f human healt

h andthe environment

a t areasonabl e cost . Respons e ffll Th e upper Wilcox aquifer

andthe perche d aquifer

are the only zone s to sho w contamination. Th e perche d water zon e has not

produce d enough water

to sufficiently test, but becaus e o

f its contac t

with the sludg e when i t

was deposited, an d becaus e i t appear s to b e linke d hydraulically to the upper Wilco x aquifer, we have assumedthat i t 68has bee n contaminated a s well. The level s of contamination that

we se e at the sit e ca n easily degrade before they reach any off site well locations. Th e private well s produce fromthe lowe

r Wilco x aquifer

which i s not

contaminated by the Monroe site . Ground water models have shown that

with aca

p o f lo w permeabilit

y soil , that

after 3 0 year s th e concentration o

f contaminants o

f concern 400 fee t

fromthe sit

e are equa

l to zero . The RCRA type ca

p that i s recommended for

this site wouldallo w even les s infiltration than that o f the model. Based on the ground water modeling and the analytical dat afromthe monitoring well s and private well s to date , i t appear s that

the contaminant

level s wil l degrad e naturally within areasonabl e time perio d without endangerin g human healt h or th e environment. Pumping o

f the contaminated water

may decreas e the amount o f time necessar

y to reduc e the contaminant

level s for

volatil e organics , but

only by one yea

r a s compared to two year s for natural degradation . Thi s short time decreas e doe s not

warrant the extr a expense . Commen tftll The planned cappin g o

f Alternativ e 4- B will no t

prevent leaking into the sludg e and, a s a result, there will b e significant pressure agains t

the line r i n the french drain. All cap s lea k to some degree . I t

wil l b e nearly , i

f not totally , impossibl e to construct awatertight "plasti c sheeting " a

t such depths, s o the hydrostati c pressure fromsludge area s can migrate into the French drain. In addition, Alternativ e 4-B wil l not reliev e the ground water leadin g to deepe

r aquifers which show som e contamination. Th e desig n o f Alternative 4- B will actually serv e a s asystemto confine more pressure i n acolumn ove r the sludge are aand into the lowe r units sinc e no ca

p i s impervious. For the reason s presented here, the ground water must b e remove d and treated . Otherwise, lo w level s o

f contaminants ca

n continue to leac h out

and, onc e discovere d i n private dee

p wells, the plume o

f unacceptable contaminant level s could b e very large , and very expensiv e to clea

n up. Response ffl2 ADPC&E disagree s that

implementatio n o

f Alternativ e 4b wouldresult i n continue d leachin g o f contaminants into the ground water . Th e ca p intende d for

the Monroe Auto Pi t

shal l b e designe d and constructe d to mee t th e requirements o

f Arkansas Hazardous Waste Management Regulatio n 23 § 246.310 . Thi s lo w permeabilit

y ca p minimize s infiltration o f surface precipitatio n into the sludg e pi t and direct s surface water

away fromthe pit

area . Thus, infiltration through the cap and into the sludg e i s insignificant.
6 9In addition, gravitational force woulddirec t the effluent

fromthe french drai n to asurface discharge point. Such adischarge must meet the Arkansas Surface Water Quality Standards. Also, i t i s important

to remember

that the analytical datafromtesting o f leachate produce d by the toxicity characteristi c leachin g procedure (TCLP) show very lo w leachabilit y o f the contaminants fromthe sludge and that the sludg e even in its present condition i s no longe

r aprimary sourc e o

f ground water

contamination. Commen t#1 3 I amver y disappointe d with this pla n and I fee l i t

should b e taken out

o f th e are a completely an d all well s (residential ) should b e replace d by Monroe and/or arural water systemplace d i n the are aan d Monro^ pays for all expense . Respons e #1 3 A complet

e remova l o f the sludge fromthe site has anumber o f advantage s that

other alternative s do not

provide . Th e remova

l alternativ e offers additional overall protectio n o f human healt

h and the environment, provide s the greates t long-ter mprotection , and i s th e only alternative that, if

implemented, would not require site acces s restrictions (fence) an d site maintenance. Th e site could actually become aresidentia l area. However , the relatively lo w long-termthreat pose d by the soil/sludge deposit s i n th e pi t area, combine d with the agency's preference for on-site remedie s are among the main factors that hamper selectio n o

f atreatment/removal remedy . The Stat e would certainly entertai n the removal optio n i f Monroe volunteer s to d o so . In the absenc e o

f this voluntary action, the Stat e cannot justify the recommendation that removal b e th e preferre d remedia l action. Residentia l wel l water meet s the safe drinking water standards . Replacement

o f residentia l well s and/

or an extensio n o

f the rural water

systemto the area s nea

r the sit e by Monro e i s neither

necessar y nor justified. Commen t#1 4 I hav e aslim

e that forms in our

bathroomeveryda

y and you ca

n not tel l me where i s it coming from! Pleas e help us i n this matter! We need suitabl e drinking water , now! Respons e #1 4 Th e Arkansas Department o f Healt h investigate d the slim

e issue and found no bacteri ai n the wel l water . Th e slim e i n the bathroommust

have another

source . The residentia

l well water

i s asuitabl e sourc e o

f drinkin g water .

7 0Commen

t#15 We ca n not sel l our homes and move - becaus e the mortgage companie s wil l not loa n money on thi s area . Homes and propertie s will no t sel l i n this area . Respons e ffl5 Th e State ca

n only provide information regardin g the status o f the site to the mortgag e company. Th e impac t

o f the site information on mortgag e company decision s i s out o f the control o f ADPC&E. Pleas e se

e Response #2. Commen t#16 We own 4 0 acre s o

f land joining S- 9 Dowler and S-1 1 Krosp property . We arc very much intereste d i n having the cree k water and pon d water

o n our property tested . Ther

e has been an incident

with alaye

r o f oily residu e showing up o n top o f the ground as we trie d to plant

atre e o n our

property . Pleas e le

t us know how to ge

t the water

teste d and soil sample s taken. Response #16 Water has been observe d to flow fromasprin g located i n the ravine s on th e southwestern portion o f the sit e for 1 2 to 24 hours following heavy or extende d precipitation . Water fromthis sprin g and runoff fromthe sludg e pi t

are aenter s th e ravine s an d flows into an intermittent

strea mthat leave s the site a

t the southwestern sit

e boundary and joins Villag e Cree k nearl y amil e southwest

o f the site . During the sit

e investigation , i n general , the greates t surface water

and sediment

contaminant

concentrations were observe d nea r the site . Thes e concentrations decrease d downstreamo f the site . In addition, th e abov e property appear s to b e a

t leas t 100 0 fee t eas t o f this intermittent

stream. Therefore , the suspecte d contaminants on the sai d property ar e no t sit e related . ADPC&E doe s not pla n to performsampling a

t this time. If

you wish, you may contact acertified laborator

y i n your are afor sampling information. Commen

t #17 Som e o f our property i s within the one hal f mil e radius o

f the Monroe Auto Superfund site , but we hav e neve

r been contacte d by Monroe, EPA, or ADPC&E. We would appreciat e receivin g any previous correspondenc e a s well a s any future correspondence . Also , we would lik

e to reques t

our water b e teste d a s quickly as possible . Respons e #17 Based on provisions se

t forth i n this Recor

d o f Decision , all residentia

l well s that

ar e locate d within on e half

mil e radius o

f the sit e wil l be periodically tested . 7 1

### Al l future correspondenc e will b e maile d to persons wh o are on the site's mailing list .

Previous information on the site ca n be accesse d at

Northeast

Arkansas Regional Library i n Paragould, Arkansas. Commen t#1 8 We fee l that

the propose d solution to this problemi s unsatisfactory becaus e i t leave s the Monroe Auto Pit

intact.
s 

### Response ffU Analytica l dat afromtesting o

f leachat e produced by the toxicit

y characteristi c leachin g procedur e (TCLP) sho w very lo w leachabilit y o f the contaminants i n the sludge . Therefore , the sludge/soi l deposit s i n the pit pos e alo w long-termthreat. Thi s lo w long

termthreat

ca n b e reliably containe d by the engineerin g controls , namely, constn""tio n ur afrench drain and placement o f an impermeabl e ca

p ove r th e sludg e deposi t

area . ADPC&E i s committed to safeguardin g human healt h and the environment

agains t any possibl e advers e effect

fromthis site and believe s that the selected remedy will fully satisfy the abov e objective . Commen t#19 As lon g a s the fence and the sign s remain our property we be devalued. Pleas e se e Respons e #2. Respons e ffl9 ADPC&E agree s that

the fence andsigns coul d adversely impac t the property values . Despit e thi s acknowledgment, sit e restrictio n will remain a s part o f the selected remedy . Commen t#2 0 We reques t

an extensio n to the August 1 7 deadline , sinc e we have not previously been aware o f the seriousnes s o

f thi s problem. We need more time to study the proposals . Respons e #2 0 A two month extensio n to the August 1 7 deadlin e was granted . Pleas e se e Respons e ff6. Commen t#2 1 I' mreally disappointe d that no actio n i s reall y bein g taken to solv e the drinking water problem. Rea

l or imaginary, everybody i n the are afeel s lik e we've go t

problems with th e water . Mos t

everybod y i s drinking bottle d water . We ar e really concerne d about

the healt h o f our children and our

families. 7 2Respons e ff21

ADPC&E disagrees . The residential well s within ahal f mil e radius o

f the sit e wil l continue to b e analyzed to ensure that residentia

l well s meet

the drinking water

standards . In addition, i n the unlikely event that monitoring indicate s adegradatio n o f residentia

l water well quality due to sit

e contaminants, proper

contingency action s wil l b e implemented. Analytica l results fromresidentia

l well s nea

r the sit e meet the safe drinking water standards . Therefore , consumption o f water fromthes e well s should not caus e any advers e healt

h effect to childre n or

adults. Commen t#22 I believ e that

failure to remove or

solidif y that sludg e i s goin g to en d up bein g astigm a on the community and remain to b e adrai n on property values i n the are afor ages . Pleas e se e Respons e ff2. Respons e ff22 Th e impac t

o f an alternativ e on the property values i s not one o f the criteri awhich would directl y influence selectio n o f aremedial alternative . Th e Stat e agree s with the respondent

that the remova

l alternativ e wouldhelp to improv e the property value s i n thi s area . Th e solidification/stabilizatio n alternative wouldenlarg e the size o f the landfill and i t

i s unlikely that

it wouldimpac t

the property values any differently than the selected remedy . A s to why aremova

l alternativ e was not

chosen, pleas e refer

to comment

^13 . Commen tff23 Thi s i s an earthquake area . It has avery destabilizin g effect on some o

f these drains and cap s and s o forth and I' mrea l concerne d that

reall y hasn't

been taken into consideratio n carefully enough. Response ff23 The Arkansas Hazardous Waste Management, Regulatio n 23, Section 264.18(a) states : (a) Seismi c consideration . (1 ) portions o f new facilitie s where treatment, storage , or disposa l o f hazardous waste wil l be conducte d must not b e locate d within 6 1 meter s (20 0 feet) o f afault which had displacement

i n Holocene time. Such afault

doe s not exis t within the specifie d are ao f the site . Therefore , seismi c consideration s ar

e not applicabl e to this site .
7 3Commen

tff24 The ide ao

f drainin g afrench drain into the cree k jus t sounds ridiculous to me. I don't se e how the contaminants i n that french drain is not

jus t goin g to ge

t into the cree

k and b e abigge

r hazard than we have right now . Respons e ff24 As an adde d precaution, acap and french drain will be place d around the sludge pit. Th e ca p will prevent

infiltration o

f rainfall and run off. Th e french drai n wil l direc t the perche d water

away fromthe sludge . Th e perche d water wil l be intercepte d before it comes i n contac t

with th e sludg e and will therefore b e "clean" when it i s discharge d to the stream . Commen t#2 5 At Time s Beach, Missouri, becaus e o f throwing out

just plai n ol d oil , they bought the town out. The sludg e i n Monroe Auto Pi t came frompaint

booths, contaminants from there, plus some other

waste water . Waste water means i t came fromwherever

Monroe had grinding . And bein g amachinis t and everything , you don't know what

material s you have i n alloys . Whatever

Monroe doe s to this property i s not goin g to eliminat

e contamination i n the future. Th e health effect of contaminants ar

e no t fully known. At one time the Ocea

n Spray Cranberry Sauc e was considere d safe to eat, later i t becam e known that

i t could cause cancer . So , the number one concer

n i s health . Respons e ff25 The sludg e a

t the pi t contains anumber

o f organi c and inorgani c contaminants. Th e remedia l investigatio n repor

t provides information to the extent and amount

o f these contaminants. At

Time s Beac h the oi l containe d some o f the most toxi c substance s known to humans (dioxin) . Moreover , becaus e it was sprea

d on roads and street s to suppres s dust, the public was i n direc t contac t with these contaminants. At Monroe Auto Pit, however , the public has not been directly expose d to the contaminants. Addition o f the cap and French drain, a s i t i s specifie d under

the preferred remedy, will isolat e the sludg e pit. Thi s isolatio n will eliminate any possible mingling o f contaminants i n the sludg e with other

medi a(soil , water , and air). Protectio n o f the public healt

h and the environment

throughout

the stat e o f Arkansas i s als o aconcer n o f ADPC&E. ADPC&E believe s that

the selected remedy will provide adequat e protectio n agains t

any advers e health effect

which may b e cause d by the site . Commen tff26 We ar e in the earthquake are aand the New Madrid Faul t i s not too far away from Greene County. S o whatever Monroe doe s to thi s property out there i s not

going to eliminate contamination i n the future for that. 7 4Respons e #2 6

Se e response #23. Commen t#2 7 I t makes adifference i f

you are i n an are athat

has bee n contaminated with acontaminant that was jus t freely thrown out

becaus e it

was accounting by abi g manufacturing firm that employs alo t

o f people . We don't

lik e things thrown out

and no t taken car

e of. What are we goin g to do about it ? According to this report, we're goin g to le t it drain off into our water naturally. Respons e #2 7 The contaminants present

i n th e on sit

e monitoring well s ar

e i n the upper

Wilcox aquifer. Thes e contaminants wer

e originally i n the sludg e that was deposite d i n th e pit

by Monroe Auto Plant

i n Paragould. Ove

r time the liquid s i n the sludg e leache d out an d travele d down to the water

table and into the water

of the upper

Wilcox aquifer. The monitoring wells on the sit

e and those surrounding the site have been use d to monitor the movement o f contaminants i n the ground water . Fromthese analyses , the contamination i s confined to the Monroe property at thi s time. Using this dat aand information about how water

move s i n the aquifer, models o f the expecte d movement

o f contaminants and how the contaminants chang e ove r time were developed . Using thes e models , contaminants are expecte d to degrad e (change ) and th e level s lowe

r naturally ove

r time before they become athreat to residentia

l wells . Commen t#2 8 What els e ca n you do , other

than try to lift

every bit o f it (sludge ) out

o f there (pit) and carry i t off? Respons e #2 8 Pleas e se e respons e #18. Commen t#2 9 What i s going to happe n to our property valu e i n thi s area ? What type compensatio n ar

e the lan d owners goin g to ge t out o f this or their property i n the future becaus e you hav e none.

7 5

### Respons e #29

Contaminants release d to mediaoutside the site boundary ar e belo w the federal andstat e regulatory action levels . CERCLA doe s not

authorize compensation foor areduction i n property value, base d on stigm ao f its nearness to aSuperfundsite . Pleas e se e respons e ft2. Commen tff3Q Now , most

streams that

you'll se e has got clea r water , yo u know , but

now I've got

two or thre e place s that

stuff runs out andit' s amilky looking andoily looking stuff that's comin g out

o f there . That's not

clea r water . I don't

know what

i t i s andhadn't

nobody tol d me anything andI hadn't reall y knew who exactl y to ask, but I just kin d o f Like to wonder what i t is , how dangerous it

is , andi f i t couldb e cleane d up. What couldbe done to it ? Respons e ff30 Surface water

studie s o n the sit

e sho w that

any contaminatio n that

coul d be carrie d by run off wouldenter

the intermittent

cree k southwes t o f the sit e andthat the level o

f contamination foundi n cree k sediment decrease s rapidly away fromthe site . Given thi s information, the site i s probably not causing the cloudy or

oily effects i n your

streams . Commen tff31 ...this pamphle t

i t say s "The majority o

f the liquid s migrate d into th e groundwater during the 1970' s when the landfill was active andi s believe d to b e amajor sourc e o f groundwater

contamination a

t this site . Th e primary sourc e o f groundwater contamination no longe

r exist s a t the site." Well , my nex t questio n is , where di d this contamination g o to ? I f

it's not on the site , i t

look s to me lik

e it' s hadto went somewhere. It's hadto drain down, andthat's why I think it's probably o n this plac e o f mine andmaybe on surrounding areas . Respons e #31 Presently , th e contamination i s i n the groundwater . The contaminants that wer e leachabl e fromthe sludg e have left the sludg e an d ar

e now i n the groundwater . The contaminatedgroundwater i s stil l within the sit

e boundaries a s indicate d by the sampl e results fromthe monitoring wells . Monitoring wells have been place d aroundthe sit e perimeter andi n all thre e aquifers to monitor th e movement

o f the contaminatio n plume. Thi s monitoring wil l continue to kee p us up to date on how degradatio n o f the contaminants i s progressing.

7 6

### Commen

t#3 2 I have severa

l concerns. Firs t

i s surface water

contamination andI have aske d for testing andwhatever

andhaven't

hadany results or

any satisfactio n about

what studie s have been made about

surface water

contamination andany results o f that. AndI have , I gues s the major cree k that runs north o

f the dump sit

e andi t drains quite abit

o f acreag e wes t

and some south towardthe dump sit e through my property. Respons e #3 2 Fromlookin g a

t atopographi c map, the cree k that you mentione d drains an are anorth o f the site . The topography a t the site i s such that

surface run off

travel s to the southwes t an d south fromthe sludg e area . Th e sit e drainag e are aandth e drainag e are ao f your streamar e separate and do not

run together. Commen t#33 ...What do you plan to do i n the Remedia l Action Pla

n that may involv e extractio n o

f any water fromthe site andwhere you propose to put that. Respons e #3 3 Th e selected remedy wouldinvolv e afrench drai n that wouldcapture perche d water and releas e it to the intermittent

strea mthat flows southwest

o f the site . I f

apump andtreat methodi s implemente d for the ground water

remediation, the water

woul d b e treate d and put back into the aquifer

by well s to enhance the remediation . Commen t#3 4 ...I fee l lik

e we need more time to evaluate what we're lookin g a

t andwhat the solution s are . ...And I don't

know what's availabl e through EPA, if the consultant

route i s stil

l availabl e to us. Respons e #3 4 A two month extensio n o

f the public comment

perio d was granted . B y "consultant route", i f i t means aTA G grant, such agrant i s not availabl e a

t thi s stag e o

f the remediation . Commen t#3 5 Monroe has not

bee n very responsive to the property owners i n thi s area . I've see n no studie s to evaluat

e property values . All we ca n se e i s property value s bein g devalued .

7 7Respons e #35

The Superfund remediatio n proces s doe s not authorize studie s on property values . Th e impact o f the superfund remediation on the property value s i s not controlle d by the State . Pleas e se e Response ff2. Commen tff36 ...after looking a

t that (report) it

look s lik e something around thirtee n out o f twenty-six wells have shown sign s o

f the contaminants that

ar e on the sit

e ar e now i n the ground water i n the surrounding area . We were originall y told that the Gai mwell was the only wel l that wa s contaminated. Respons e ft36 Th e figure you ar

e referring to shows the concentration s o f organics and inorganic s (metals ) that

were found in the residentia l samples taken i n Apri l 1992 . Many metals ar e naturally occurring. The organi c value s are quantified a s estimate d values , which means that the actual values could b e lower . The contamination i n the Gann wel l showe d level s that were 1 0 to 10

0 times greater . The monitoring well s that were place d adjacent

to the Gann well continue to show level s o f the same contaminants, but a t lowe r levels . The contamination i s confined to the upper Wilco x aquifer. The Gann wel l remains th e only residentia l wel l that

has shown sign s o

f contamination. Commen t^3 7 Th e solution, a s I mentioned, i s unacceptabl e for fair peopl e and we'd lik

e to as k that we have additional time to study this report, to get som e technica l expertis e to explain to us, collectively and individually , what our, the impact

o f this sit e has on us. Respons e ff37 The selected remedy i

f designe d and implemented properly wil l provide protectio n o f the human healt

h and the environment. A two month extension o f the public comment

perio d was granted. Commen tff3S People won't

fish i n my pon d that

I built. They won't

ea t the fish. Respons e ff3S Surface water

drainage into your

pond doe s not

appea r to come fromthe site . Villag e 78Cree

k i s the surface water

connection fromthe sit

e to your pond; however , your

pond drains into Villag e Creek. No contamination fromthe site shouldb e i n your pond. Commen t #3 9 So I think we need alittl e more time to investigat e this becaus e this stuff

i s coming out through everybody's water, I know it is , and I think

there shouldb e more well s checke d to se e how much contamination there actually is . Respons e #3 9 Sampling to date indicate s that trace amounts o

f contaminants occur

i n some wells . Th e distribution o

f contaminants doe s not

indicate i

f the contamination i s fromthe sit e or not fromthe sites . Th e highest concentration s o

f contaminants o

f concer n occur on the site . In general , contaminants wil l mov e fromarea s o f high concentratio n to area s o f lowe r concentration. The highes t reading s will b e nea

r the sourc e o

f contamination and decreas e away fromthe source o f contamination. Monitorin g well s have bee n place d around the border

o f the sit e to monitor

any increase s i n contaminant levels . Continued monitoring will b e apart o f the remediation plan. Commen t#4 0 ...I objec t to leavin g this pit

to b e acontinuing problemfor no telling how long . Eliminate the problem. Eliminate the problem. Cos t should no t

be even considered . Monroe put

i t there , Monroe can remove it. Respons e #4 0 Th e Stat e i s require d to use nine criteri ato evaluate alternative s for addressin g a Super-fundsite . Sinc e cos t i s one o f the nine criteria , it

cannot b e ignore d a s the respondent

has suggested . Th e rational e for no t choosin g aremova

l option i s explaine d i n respons e to comment

#13 . Also , pleas e note that even acomplet

e removal o

f the sludg e wil l not eliminate th e problems with the ground water immediately . Commen t#4 1 I'd lik e to know why I haven't

receive d no paperwork

on thi s stuff? Respons e #4 1 The mailin g lis t

i s compile d fromattendance sheet s a t previous meetings , those persons submitting comments, and those person s who have requeste d to be place d on the mailin g lis t either through Monroe , the Stat e Department

o f Pollutio n Control and Ecology , or through EPA . A s aresul t o f attending this meetin g your name wil l b e place d o n the 7 9mailing list . All o f the public record s arc accessibl e a t the Northeast

Arkansas Regiona

l Library i n Paragould, Arkansas or in our central files in Littl e Rock, Arkansas. Commen t^4 2 ...there's one thing I haven't heard mentioned tonight

i s peopl e that

i s gettin g sic

k from the wel l water . People that tak e ashowe r break out i n rashes . The y ge

t fumes that makes themsick . And that i s gettin g farther

away fromthat

all the time, and you're not goin g to make anybody i n here believ e it' s not coming out

o f those wells , because,it

is . Respons e #4 2 The only recorde d incident of rashes fromwater

use or fumes fromthe water

ar e relate d to the Gann well . A s state d earlier , the la b results fromprivate wel l samplin g indicate that the water

i s safe for

drinking an d other

domestic uses. Commen tff43 ...m y concer

n is , I have two small children and I want to know i

f that water out there's goin g to kil l themlik

e it did the frogs? Respons e ff43 Th e frogs you sa

w at the sit e were i n the decontamination tank. The chemicals use d to decontaminate the drillin g equipment wouldb e toxi c to frogs. Th e decontamination water i s siphone d fromthi s temporary tank into aholding tank

a t th e site for

proper disposal . Commen t^4 4 The y (residents) have afear o f the unknown. They have area l concer n about the health, not only acute but

als o chronic . Respons e ff44 The stat e understands the concerns o f the loca l residents . Th e protectio n o f human healt

h i s the top priority o

f the State . Commen tff45 And another

thing surfaces, maybe not a s strong a s the res t

o f it but certainly a diminution i n their

property valu e ove

r aperio d o

f time . Respons e ff45 The impac t

o f aSuper-fundsit

e on property values i s not controlle d by th e Stat

e or the EPA. Pleas e se

e Response ftl. 8 08 1Commen

t#4 6 They (th e residents) have aske d that I ask you folks to giv e theman extension o f time on the comment

perio d to consider

either , hopefully, under

the TA G program, hirin g a consultant ...t o come i n and help themthrough this process . Respons e ff46 A two months extension perio d was granted. The TA G programi s not availabl e a

t this stag e o f the remediation process. Pleas e se e Response ff6. Commen tFro m Monro e Aut

o Equipment Monroe believe s that

the propose d plan will adequately protec t human healt

h andthe environment. Monroe agree s that i t i s appropriate to leav e the contaminated sludge/soi l i n plac e a t the site . Th e installatio n o f aca p wil l minimiz e infiltration an d erosio n while the Frenc h drai n will isolate the contaminated soil/sludg e fromthe perche d ground water . Periodi c maintenance o

f the cap wil l assure the long-termintegrity o f the cap . Dee

d restrictions and site acces s restriction s will further limit any potentia

l contac t with contaminate d media. Becaus e the primary sourc e o f ground water

contamination no longe r exist s a t th e site , the concentrations o f contaminants i n the ground water wil l decreas e through natural attenuation and degradation. Ground water use restriction s on the sit e an d periodi c monitoring o f residential well s and monitoring well s wil l further protec t public health. Although off-site migration o f contaminants i s no t

expected , th e periodi c monitoring wouldprovide notice o f migrations should i t

occur . Respons e The Stat e agrees .

82