SOD 001 OOOS55

ENFORCEMENTRECORD OF DECISION

REMEDIAL ALTERNATIVE SELECTION

SODYECO SITECHARLOTTE, MECKLENBURG COUNTY

NORTH CAROLINA

PREPARED BY:

U.S. ENVIRONMENTAL PROTECTION AGENCYREGION IV

ATLANTA, GEORGIA

SOD 001 000856

DECLARATION FOR THE RECORD OF DECISION

Site Name and Location

SodyecoCharlotte, Mecklenburg County, North Carolina

STATEMENT OF PURPOSE

This decision document represents the selected remedial action for this sitedeveloped in accordance with CERCLA, as amended by SARA, and to the extentpracticable, the National Contingency Plan.

The State of North Carolina has concurred on the selected remedy.

STATEMENT OF BASIS

This decision is based upon documents which make up the site AdministrativeRecord. The attached index identifies items which comprise the AdministrativeRecord.

DESCRIPTION OF THE SELECTED REMEDY

GROUNDWATER- Extraction of contaminated groundwater- On-site treatment of extracted groundwater- Discharge of treated groundwater to off-site stream- Groundwater remediation will be performed until all

contaminated water meets the cleanup goals specified in the attachedSummary of Alternative Selection

SOIL

- Asphalt cap of Area B (Truck Staging Area)- Excavation and off-site incineration of contaminated soil in AreaD (Settling Pond Area)

- On-slte treatment of contaminated soil In Area C (Trench Area) to removeorganic contaminants

IMPLEMENTATION

The Remedial Design and Remedial Action will be conducted under an amendment tothe Resource Conservation and Recovery Act (RCRA) Part B Permit NumberNCD001810365, Issued March 31, 1987. Personnel In EPA's RCRA program willoversee the vork to be performed.

SOD 001 000857

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DECLARATION

"The selected remedy is protective of human health and the environment, attainsFederal and State requirements that are applicable or relevant and appropriate,and is cost-effective. This remedy satisfies the preference for treatment thatreduces toxicity, mobility, or volume as a principle element. Finally, it isdetermined that this remedy utilizes permanent solutions and alternativetreatment technologies to the maximum extent practicable."

Lee A. DeHihns, IIIActing Regional Administrator

SOD 001 OOOS58

SUMMARY OF REMEDIAL ALTERNATIVE SELECTION

SODYECO SITECHARLOTTE, MECKLENBURG COUNTY, NORTH CAROLINA

PREPARED BY:

U.S. ENVIRONMENTAL PROTECTION AGENCYREGION IV

ATLANTA, GEORGIA

SOD 001 °00859

TABLE OF COKTENTS

1.0 Introduction.............................................................. 11.1 Site Location and Description..............................,..........!1.2 Site History..................................................... ......A

2.0 Enforcement Analysis....................................................... 7

3.0 Current Site Status.......................................................73.1 Hydrogeologic Setting.................................................73.2 Site Contamination....................................................83.3 Receptors............................................................17

4.0 Clean-Up Criteria........................................................ 184.1 Groundwater Remediation..............................................184.2 Soil Remediation.....................................................224.3 Surface Water Remediation............................................22

5.0 Alternative Evaluation...................................................225.1 Alternatives.........................................................28

6.0 Recommended Alternatives.................................................336.1 Description of Recommended Remedy....................................336.2 Operation and Maintenance............................................336.3 Cost of Recommended Alternatives..................................... 336.4 Schedule............................................................. 346.5 Future Actions.......................................................346.6 Consistency with Other Environmental Laws............................34

7.0 Community Relations......................................................35

SOD 001 000860

LIST OF FIGURES

Figure 1 - Site Location Map.................................................2Figure 2 - Site Vicinity Map.................................................3Figure 3 - CERCLA Areas at the Sodyeco Site..................................5Figure 4 - Analyte Concentrations in Groundwater and Soil Samples

from Areas A & B.................................................. 9Figure 5 - Location of Groundwater Sampling Wells Where Organic

Compounds Were Not Detected...................................... 11Figure 6 - Analyte Concentrations In Groundwater and Soil Samples

from Area C...................................................... 12Figure 7 - Analyte Concentrations In Groundwater and Soil Samples

from Area D......................................................13Figure 8 - Analyte Concentrations in Groundwater and Soil Samples

from Area E...................................................... 15Figure 9 - Analyte Concentrations in Surface Water and Sediment

Samples at the Sodyeco Site...................................... 16Figure 10 - Off-Site Water Supply Wells Within One-Half Mile of

CERCLA Areas..................................................... 20

LIST OF TABLES

Table 1 - Groundwater Cleanup Goals........................................21Table 2 - Preliminary Screening of Treatment and Disposal Technologies.....23Table 3 - Preliminary Screening of Containment and Migration Control

Technologies..................................................... 27Table 4 - Preliminary Screening of General Alternatives Based on

Effectiveness, Implementability, and Cost Criteria...............29Table 5 - Summary of Screening Criteria for Comparing Soil Alternatives ....31

SOD 001 000861

ENFORCEMENTRECORD OF DECISION

SUMMARY OF REMEDIAL ALTERNATIVE SELECTIONSODYECO SITE

CHARLOTTE, MECKLENBURG COUNTY, NORTH CAROLINA

1.0 Introduction

The Sodyeco Site was proposed for inclusion on the National Priorities List(NPL) in December 1982 and ranks 146 out of 703 NPL Bites. The Sodyeco Sitehas been the subject of a Remedial Investigation (RI) and Feasiblity Study (FS)performed by the responsible party, Sandoz Chemicals Co., under anAdministrative Order by Consent, dated February 10, 1986. The RI report, whichexamines air, sediment, soil, surface water and groundwater contamination atthe site was completed on August 17, 1987. The FS, which develops and examinesalternatives for remediation of the site, was issued in draft form to thepublic on August 19, 1987.

This Record of Decision has been prepared to summarize the remedial alternativeselection process and to present the selected remedial alternative.

1.1 Site Location and Description

The Sodyeco Site is located in Mecklenburg County, North Carolina,approximately 10 miles west of Charlotte (Figure 1). The City of Mount Hollyis located across the Catawba River west of the plant. The plant site consistsof roughly 1300 acres (Figure 2). It extends over 2000 feet north of StateHighway 27, south past Long Creek, over 500 feet east of Belmeade Drive and isbounded on the west by the Catawba River.

Of the approximately 1300 acres at the Sodyeco Site, about 20 percent isoccupied by production units and the waste water treatment facility. Themajority of the remaining acreage Is undeveloped.

The Sodyeco Site contains an operating manufacturing facility consisting ofproduction units, a waste water treatment area, and material storage areas.The facility la partially fenced along open road frontage areas and a securityclearance is required for entrance*

The area in the vicinity of the Sodyeco plant is gently rolling, withelevations ranging froa about 570 feet NGVD (National Geometric Vertical Datumof 1929) near the river to 670 feet east of the plant area. The originaltopography of the plant has changed considerably during its operation as theresult of various grading and landfilllng operations in conjunction with theconstruction of new facilities.

As a result of previous studies, five CERCLA areas were identified, whose usedates back to the late 1930's. In addition to the CERCLA areas, a RCRA permithas been Issued for the treatment, storage, and disposal of hazardous wasteon-site. Waste water treatment and discharge activities are regulated underthe NPDES program.

SOD 001Figure 1

Site Location MapSodyeco Site

Mecklenburg County, North Carolina

NORTH CAROLINA

MecklenburgCounty

SODYECO SITE..Iti

-2-

SOD 001 000863Figure 2

Sodyeco Site Map

-3-

SOD 001 OOOS64

-4-

The areas surrounding the Sodyeco Site are primarily undeveloped woodland,sparse residential and light industrial areas. To the north of the plant (andNC Highway 27) is an area of primarily undeveloped woodland. A conveniencestore, located immediately north of Highway 27, is not owned by Sandoz. Thearea to the east is primarily agricultural with sparse residential and lightindustrial areas. The area west of the Catawba River, which forms the westernsite boundary, encompasses the outskirts of the town of Mount Holly andincludes a power substation, sewage disposal plant, industrial facilities and•ome residential areas. Approximately 20-30 residents are estimated to residewithin a one-quarter mile radius of the site. Because the Sandoz ChemicalsCorporation is one of the largest employers in the area, many residents,including residents of Mount Holly and Belmont, commute daily to the plane.The most recent census (1980) gives a population of 4,530 for the city of MountHolly and 4,607 for the city of Belmont.

1.2 Site History

The Southern Dyestuff Company (Sodyeco) began operations at the currentlocation in 1936. Initially, the plant produced liquid sulfur dyes frompurchased raw materials. American Marietta (which became Martin Marietta in1961) purchased the Sodyeco site in 1958. In the early 1960's, the company'sproduct lines expanded to include vat dyes and disperse dyes. Since that time,the company has produced specialty chemical products for the agrochemical,electronic, explosive, lithographic, pigment, plastic, rubber and generalchemical industries. Sandoz purchased the Sodyeco Plant from Martin Mariettain 1983.

The Sodyeco Site contains five CERCLA facilities, identified as Areas A, B, C,D and E (Figure 3). The following is a description of these CERCLA area;;:

Area A - This landfill's use began in the late 1930's. Waste materialsdisposed of at this facility included sulfur dye clarification residues,off-specification sulfur and disperse dyes, filter cloths, empcy metal andcardboard drums and cartons, small amounts of non-acidic, non-flammablediscarded chemicals and chemical wastes, and construction debris. Thelandfill was closed sometime between 1973 and 1974. Most of the areaabove the facility is now covered with asphalt and buildings.

Area B - This landfill operated between 1973 and 1978 and received wastesthat had previously been disposed in Area A. The area Is presentlycovered with gravel and used as a truck staging area.

Area C - This area originally consisted of three covered trenches thatcontained the remains of laboratory and production samples, distillationtars, and waste solvents. The two northern pits were excavated in March1981 and the contents were trucked off-site to a landfill in Pinewood,South Carolina. Removal of the remaining pit was conducted in 1983,After excavation activities, Area C was regraded and grassed.

CERCLA AREAS ATTHE SODYECO SITE

LEGENDEB CERCLA ATM

00

OoOooenCJ1

*nMO

SOD 001 000866-6-

Area D - This area formerly contained two wastewater settling ponds. Theponds were taken from service in 1966; one was cleaned out in 1973 and theother between 1976 and 1977. This area currently holds a lined fresh waterpond and a fuel oil storage tank. A French drain is located immediatelydowngradient of the area to intercept shallow groundwater.

Area E -No wastes are known to have been disposed of in this area whichlocated downgradient of the old plant manufacturing area.

The first indication of potential groundwater contamination at the Sodyeco Sitewas the discovery of organic solvents in the company's potable water well inSeptember 1980. Contaminated groundwater was also detected in water supplywells adjacent to the plant. Residents of five homes were vacated and theplant water supply was changed from groundwater to surface water (CatawbaRiver).

In June 1982, a hazardous waste site investigation of the Sodyeco Site wasconducted by EPA. Results of surface water, groundwater and sediment samplesrevealed the presence of organic contaminants in the groundwater and smallamounts in the surface water.

In February 1983, EPA sampled eleven potable water wells for pH, sulfate andmetals. All wells were off-site to the east and north of the plant boundary.All samples met primary and secondary drinking water standards for the criteriaevaluated.

The Sodyeco Site was placed on the National Priorities List in December 1982,due to the presence of potable water wells within a three mile radius and thepresence of two municipal surface water intakes on the Catawba River. EPA andSandoz signed a RI/FS Consent Agreement on February 10, 1986. The final RIreport was issued August 17, 1987 and the draft FS was released to the publicAugust 19, 1987.

The objectives of the site investigation were to determine:

* The population, environmental and welfare concerns at risk;* The routes of exposure;* The amount, concentration, hazardous properties, locations,environmental fate and transport, end the form of the substances present;

* Hydrogeological factors;* The extent to which the substances have migrated or are expected tomigrate from the area of their original location and whether futuremigration may pose a threat to public health, welfare or theenvironment;

* The contribution of the contamination to an air, land, water, and/orfood chain contamination problem.

SOD 001 0008G7

-7-

The purpose of the feasibility study was to develop and examine remedialalternatives for the site, and to screen these alternatives on the basis ofprotection of human health and the environment, cost-effectiveness andtechnical implementability. In accordance with the Comprehensive EnvironmentalResponse, Compensation and Liability Act of 1980 (CERCLA), as amended by theSuperfund Amendments and Reauthoriration Act of 1986 (SARA), alternatives inwhich treatment would permanently and significantly reduce the volume,toxicity, or nobility of the hazardous substances at the Site were preferredover those alternatives not involving such treatment.

2.0 ENFORCEMENT ANALYSIS

The Sodyeco Site was added to the NPL in December 1982 and EPA assumed leadresponsibility for the site at that time. The Sodyeco Company has operated onthe site since 1936. The current owner, Sandoz, acquired the site in 1963 andagreed to perform the RI/FS. Therefore, no potentially responsible partysearch was conducted. A notice letter was sent to Sandoz Chemicals, on August30, 1985. Negotiations for the Rl/FS Consent Agreement were concluded with thesigning of the document by both EPA and Sandoz on February 10, 1986.

The Remedial Design and Remedial Action will be conducted under an amendment tothe Resource Conservation and Recovery Act (RCRA) Part B Permit NumberNCD001810365, issued March 31, 1987. Personnel in EPA's RCRA program willoversee the work to be performed.

3.0 CURRENT SITE STATUS

3.1 Hydrogeologic Setting

The Sodyeco Site is located in the Piedmont Physiographic Province, a northeasttrending zone underlain by igneous and metamorphic rocks. The Piedmont issubdivided into other northeast trending geologic belts. One of these, whichcontains the Sodyeco Site, is termed the Charlotte Belt. This belt ischaracterized by residual soils developed from the in-place chemical weatheringof rock which was similar to the bedrock currently underlying the site.

Groundwater recharge in this area is derived almost entirely from localprecipitation. Generally, the depth to the water table depends on thetopography and rock weathering. The water table varies from the ground surfacein valleys (streams) to more than 100 feet below the ground surface in sharplyrising hills.

A groundwater divide is located approximately 50 feet north of CERCLA Area Aand approximately 900 feet north of Area C. In general, groundwater flow isnortherly, north of the divide, and south-southwesterly, south of the divide.

SOD 001 000868

-8-

Average groundwater flow rates from the CERCLA areas to Long Creek werecalculated to be approximately 180 gallons per day (gpd) from Area A,approximately 200 gpd from Area B and approximately 70-140 gpd for Area C.Estimated flow from CERCLA areas D and E to the Catawba River wereapproximately 3,000 gpd and 10,000 gpd respectively.

The primary hydrologic features influencing the Sodyeco site are the CatawbaRiver (regional drainage feature) and Long Creek (major tributary to theriver). Surface drainage from the western side of the site is directly to theriver, from the northeastern area to the river via several small streams, andfrom the eastern and southeastern areas to Long Creek, and then to the river.The five CERCLA areas are not within the 100-year flood elevation of Long Creekand the maximum recorded level in the Catawaba River since development ofdownstream Lake Wylie in 1904.

3.2 Site Contamination

The Sodyeco Site contains five CERCLA areas designated as A, B, C, E and E.Soil, groundwater, surface-water and sediment samples have been collected inand around each area and analyzed. All samples have been analyzed for thefollowing volatile organic indicator parameters that were chosen based uponprevious HSL scans at the Sodyeco Site:

* Trichloroethylene* Tetrachloroethylene* Chlorobenzene* Ethylbenzene* o-Dichlorobenzene* Toluene* Xylenes

Surface-water and sediment samples were also analyzed for three polynucleararomatic hydrocarbons:

* Anthracene* Fluorene* Phenanthrene

In addition to the above analyses, two surface water samples from the CatawbaRiver and two surface water samples from Long Creek (upstream and downstream ineach) were analyzed for the Hazardous Substance List (ESL) parameters. Sinceacetone was detected in many samples, acetone results are also reported.Acetone is believed to have been a laboratory and decontamination processcontaminant.

Areas A & B

Figure 4 shows the soil and groundwater sampling locations in and around AreasA & B includes the analyte concentrations detected.

SOD 001 000869FIGURE

ANALYTE CONCENTRATIONS (ppb)IN GROUND-WATER AND SOIL SAMPLES

FROM AREAS A AND BOctober, 1986 to January 1987

a.6-rCB - 7.1

T-t .6

23,5-25CB - 220

ODCB - SB

26.5-30'CB - 43

OOCB - 27

I - 4CE - II

ODCB - tlO

0 - CB - 48 t.5-10CB - 8.8ODCB - ft

NOTCt4CSeau

OOCITXSI

1$• lS':|:: it£iEC'l %J -IA|M £f!iAN»*ILt %|$ :1

IFSND

5Ji- -t ND

1-1-1-

wo-n^WQ-»* 0

SCALE U200

FEET

-9-

SOD 001 00087°

-10-

Boring B-2-1 lies between CERCLA Areas A and B and shows chlorobenzeneconcentrations of 220 and 43 ug/Kg and o-dichlorobenzene concentrations of 85and 26 ug/Kg at depths of 23.5 to 25 feet and 28.5 to 30 feet, respectively.Since this boring lies downgradient of Area A and at a depth within the watertable, the contamination most likely indicates organic migration in thedirection of the groundwater gradient froa Area A towards Area B.

Figure 5 shows the locations of groundwater sampling veils where no organiccontamination was detected.

Volatile organics were detected in samples from well cluster WQ-5A, which islocated about 100 feet from the southwestern edge of Area B.

These results indicate that the upper aquifer rone is not contaminated. Theintermediate aquifer rone in the vicinity of CERCLA Area B shows contaminationwith tetrachlorethylene, chlorobenzene, and o-dichlorobenzene, and the de;epaquifer zone shows much lower concentrations of two of these three indicatorparameters (chlorobenzene and ortho-dichlorobenzene).

Area C

Figure 6 depicts the soils and groundwater sampling locations in Artia C andlists all analytes detected with their respective concentrations.

The results from the samples define the maximum boundary of the cont:amir.atedsoil in Area C. In the past, this area contained three trenches cr pits, C-l,C-2, and C-3.

Based on the boring analyses and field observations, there are approximately5,800 cubic yards of contaminated soil and uncontaminated soil cover in Area C.

Four wells in the immediate vicinity of Area C were sampled: WQ-27, WQ-28,WQ-29 (well cluster), and WQ-34 (well cluster). Well WQ-6 ie considered theshallow well of well cluster WQ-29.

Area D

Analyte concentrations detected in the soil and groundwater samples from Area D•re shown in Figure 7. Boring D-l-3 was sampled twice. The volume ofcontaminated soil is about 40 cubic yards with about 75 cubic yards of coversoil.

All aquifer cones of well cluster VQ-33, which are located approximately 75feet south of D-2-2, are contaminated with volatile organics. These resultsIndicate that contaminants In Area D have migrated downward into the alluvium,gravel and upper bedrock zone to an 84 foot depth.

Groundwater flowing through Area D discharges into the Catawba River.

CO

LOCATION OFGROUND-WATER SAMPLING WELLS

WHERE ORGANIC COMPOUNDSWERE NOT DETECTED

December, 1986 to January, 1987

ooo00-v)

ft

SCALE

roi

ANALYTE CONCENTRATIONS (ppb) INSOIL AND IN GROUND-WATER

SAMPLES FROM AREA COctober, 1988 to January, 1987

«.»-»*t* - >••.•••

OOCV - «}•,*••I - !.«••.•••

n.t-w• • - TTV.M*

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OOC« - !!•.*••T - 4«,»««I - 4.1*l.«l*

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SOD 001 000873FIGURI 7

ANALYTE CONCENTRATIONS (ppb)IN GROUND-WATER AND SOIL SAMPLES

FROM AREA DOctober, 1986 to January, 1987

4.1 - rCl - 1,100OOCB - 21,000X - 2.700

2nd tempi* 2-28-872.1 -

Cl - 11,000ODCB - 8,000,000

0.8 - TCB -EB - 45ODCB - 23,000X - 340 ^.^-^wo-aa

Units •! ClftCLA A»««

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e*irMt»rlsatl«a

- Ulttrm*dlit* Aqultw Z*n«

D - 0*»d Aqulftf !•«•

1• 4CE - 86CB - 18,000EB - 2,300

ODCB - 19,000T - 7,600X - 4,800

1 - CB - 1,100EB - 710

ODCB - 12,000T - 2,100X - 1,«00

D • 4CE - 480CB - 14,000EB - 890

ODCB - 38,000T - 2,700X - 1,700

4CE - T«tr*«hl*r**thrl»n«

CB - Chlerob«ni«n«

EB -

-13-

SOD 001 000874

-14-

Area E

All borings sampled in Area E were field screened as clean (See Figure 8).These results indicate that the unsaturated rone and the shallow, saturatedrone sampled were uncontaminated. Samples from Well K and Well Cluster W^-32contained volatile organics (intermediate and deep rones).

Groundwater flow to this area is from the old manufacturing area locatedsoutheast of Area E vhere chlorobenrene and o-dichlorobenrene were formerlystored.

Boundary

Fourteen wells along the site property boundaries were sampled. These wellswere positioned to be in the most sensitive areas of concern, namelypreferential flow directions (i.e., channelized drainage features) and/or inline with potential groundwater users (although upgradient). Figure 5 showsthe well locations. Since no volatile organics were detected in any of theseboundary wells, no contaminated groundwater migration beyond the north, south,and east boundaries has been observed or is expected given the sitehydrogeology.

Surface Water

The Catawba River is the major surface water feature at the Site. Tributary Band Long Creek empty into the Catawba River and Tributaries A and C flow intoLong Creek. The analytical results of the surface water samples and samplelocations are shown in Figure 9. Two samples from Long Creek and two samplesfrom the Catawba River were analyzed for the Hazardous Substance Listparameters. No volatile indicator parameters were detected.

Groundwater from Area E and Tributary B discharge to the Catawba River.Samples collected in the Catawba River upstream from Area E and along theriver adjacent to Area E showed no signs of organic contamination.Volatilization and dilution likely reduced the organics in the dischargedgroundwater to undetectable levels.

There are three surface water features around Area B: Tributary A 0.1 thi?east, Tributary C on the vest, and Long Creek to the south.

Tributary A, as seen in Figure 9, flows south of Area C and into Long Creek.Two surface water and two sediment samples were collected in Tributary A,

During the first sampling period, Tributary A, at sampling point TR1BA-l, was stagnant and was mainly composed of groundwater recharge. The flowrate was much greater for the second sampling because a storm prior tosampling Increased surface water runoff to the tributary. Groundwaterrecharge from Area C is the suspected source of the organic compounds detectedin TRIE A-l. The difference in concentration between the firstand second samples is probably the result of dilution with surface waterrunoff during the second sampling period. The downstream surface water sampleTRIE A-2 was not contaminated. Organics detected upstream were likely tovolatilize before reaching the downstream sampling point.

SOD 001 000875FIGURE 8

ANALYTE CONCENTRATIONS (ppb)IN GROUND-WATER AND SOIL SAMPLES

FROM AREA EOctober, 1986 to January, 1987

t -ND

I-CBODCi

X

D - CiODCi

- 11.000- 1T.OOO- too

- 110- 7iO

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LEGEND

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eni

1*1 ••mpl« 18/18/888W - TCE - 330

4CE - 460CB - 110

ODCB - 18SO - TCE - 2t

4CE - 22CB - 22

F - ItP - 5.3

4/19/87BW - TCE - f

4CE - 7CB - 23

8wfM« W*t*r •*•**•

8W - NO80 - X - i.T

F - 1.4F - 1.7

80 - A - 1.1

SW - ODCB - 1.0SO - NO A - telkr»««i«

BW - NDSO - F - t.0

P - 14SW - NDSO - P - 1.1

TMBUTAMY C

60 - P - 3.«

ANALYTE CONCENTRATIONS (ppb)IN SURFACE-WATER AND

SEDIMENT SAMPLES AT THESODYECO SITEOctober, 1986

NOTE: Ph*n*nlhr»n» (1.8 ppbl »nd llourvn* (2.1 ppbl w»ft d«l*c1*d In lh« •il*fn«l Mdlownl Hank

00

ooo00-oen

SOD 001 000877

-17-

Two sediment and surface water samples were collected from Tributary B whichflows through Area E. Analysis reveals that neither the upstream surface watersample (TRIE B-l) or the downstream sample (TRIE B-2) is contaminated withvolatile organics. Both sediment samples contained relatively lowconcentrations of anthracene and fluorene.

Seven surface water samples from the Catawba River were collected and analyzedfor the indicator parameters; samples upstream and downstream from the SodyecoSite were also analyzed for the HSL parameters. Figure 9 shows the location ofeach sampling point. Volatile organics were not detected in any of thesesamples.

Air Quality

Air quality monitoring was conducted as part of this investigation. Basec onmeasurements taken during sampling activities and worst case predictedemissions, no air quality problems are icnown or expected to exist. Since AreaD contained the highest concentration of volatile organics in soils, additionalair monitoring and flux analyses were conducted in this area to determine amass emission rate. Using a dispersion model in conjunction with site specificwind rose data, worst case downgradient concentrations were estimated. Allconcentrations were well below the threshold limit value (TLV), whichestablishes acceptable 8-hour exposure concentrations for health basedstandards.

3.3 Receptors

Groundwater in the Sodyeco Site aquifer is classified as Class IIA, a currentsource of drinking water, using the USEPA Groundwater Classifications;Guidelines of December, 1986. Although the site aquifer is not currently usedfor drinking water purposes, potential (future) use was incorporated in thebaseline risk assessment. Consideration of potential groundwater use isconsistent with 40 CFR 300.68(e)(2)(v).

Groundwater has been noted to be contaminated on-site. Groundwater on-sit:emoves west to the Catawba River and south-southeast to Long Creek, dischargingto these surface water features. Groundwater contamination was notedprincipally In the area south of Highway 27 and in Area E. No drinking waterwells currently exist between these areas and groundwater discharge points,,thus, pathway completion via domestic well usage is currently Incomplete.

Fugitive dust generations (FDG) is considered an unlikely event. Areas A and Bare capped by gravel and/or concrete; Areas C and E are well vegetated. Area Dis in a low lying, grass covered area.

Contaminated soils will continue to leach Co surrounding soils.

Surface runoff from surface soils may contaminate additional soils, althoughconcentrations would not be expected to be high. Tracking of soils by on-siteworkers may occur in Areas C and D.

SOD 001 000878

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Volatilization from contaminated soils and sediments in Areas C and D mayoccur. This may affect on-site workers within the zone of influence. Volatileorganic contaminants were found in significant concentrations in Area D noils;lower levels were found in Area C. Emission levels from Area D would beexpected to be minimal and would quickly dissipate. Emissions from Area C wouldbe expected to be undetectable.

The Catawba River was found to have several potential exposure pathwaysassociated with it. The Catawba is routinely used for swimming and fishing.There are several Industrial river water intakes across the Catawba River fromthe plant. Sodyeco uses the river as a source of drinking water for the plantand for process water. Water used for drinking is treated by rapid sandfiltration, polymeric coagulation and chlorine. The City of Belmom: drinkingwater intake is located approximately 3 miles downstream of the Site. Althoughthere were several exposure points identified, pathway completion via thisroute is not expected since no surface water contamination was found in theriver. The possibility of ingestion of fish or other aquatic life, that hadbioaccumulated low (non-detectable) levels of site contaminants wasconsidered. However, BCF values are very low for the site related volatileorganics. The three polynuclear aromatic, hydrocarbons (anthracene, fluoreneand phenanthrene) have elevated BCF values. However, a review of theliterature and discussions with experts in the field of PAHs indicates thatthese compounds do not, in general, bioaccumulate in vertebrates such as fishand man.

The final potential exposure pathway presented considers local waterfowl andsmall mammals that may frequent contaminated areas. These animals may receiveexposure via ingestion or dermal contact with soils and sediments. Localresidents may then hunt and consume these animals. The probability of pathwaycompletion via this route is very low and difficult to quantify.

4.0 Cleanup Criteria

The extent of contamination was defined in Section 3.0, Current Siti; Status.This section examines the relevance and appropriateness of water qualitycriteria under the circumstances of release of contaminants at this Site,Based upon criteria found to be relevant and appropriate, the minimum goals ofremedial action at this site have been developed.

4.1 Groundwater Remediation

In determining the degree of groundwater cleanup, Section 121(d) of theSuperfund Amendments and Reauthoriration Act of 1986 (SARA) requires that: theselected remedial actions establish a level or standard of control whichcomplies with all "applicable or relevant and appropriate requirements(ARARs)".

Groundwater in the area is classified as Class II A, a current source ofdrinking water, using the USEPA Groundwater Classifications Guidelines ofDecember, 1986. A survey was made of existing off-site water supply wells

SOD 001 000879-19-

within a one-half mile radius of the Sodyeco CERCLA facilities on the east sideof the Catawba River. (The Catawba River acts as a groundwater divide.) Aconvenience store, located north of the plant, receives water from the Sodyecowater supply system. A gas station (owned by Sandoz) has a well that provideswater for a minnow tank. The potable water used by the gas station is providedby the Sodyeco plant. An upholstery shop, owned by Sandoz, has a well that isused only for sanitary facilities.

There are seven wells supplying water to twelve buildings within a one-halfmile radius of the Site (all upgradient) (Figure 10). One well is a communitywell which supplies water to seven houses; one residence has two wells; and theother wells serve single residences. The nearest domestic wells to the CERCLA•ites are about 1300 feet northeast (near Highway 27) and about 3000 feetsoutheast (along Belmeade Road), both hydrologically upgradient from the CERCLAsites.

The value to society of Class IIA groundwater resources supports restoration ofthis contaminated groundwater to levels protective of human health and theenvironment. Based upon groundwater classification, remediation of thegroundwater to reduce contaminants to levels protective of human health and theenvironment would be necessary. Groundwater cleanup goals given in Table 1meet these requirements.

Future exposure to contaminated groundwater was estimated based oc thepossibility of a well being placed on the site and producing water containingthe maximum levels of contaminants which were detected in monitoring wellsduring the remedial investigation. Lifetime cancer risks were calculated underthese assumptions for the indicator chemicals identified in the Public HealthEvaluation (PHE). EPA's draft "Guidance on Remedial Actions for ContaminatedGroundwater at Superfund Sites" (October 1986) specifies that groundwaterremediation should achieve a level,of protection in the 10 to 10excess cancer risk range, with 10 being the nominal acceptable lifetimevalue. Larger values present an unacceptable risk from exposure. BecauseSection 121 of SARA requires consideration of potential as well as currentgroundwater use, the levels of contaminants in the groundwater must be reducedto acceptable levels.

The conclusion of the above discussion is that a no-action alternative forgroundwater would be out of compliance with Section 121 of SARA, which requirescleanup of contaminated groundwater to levels which are protective of humanhealth and the environment. Classification of the groundwater and thepotential future use of the groundwater indicates that present contaminantlevels in the groundwater are not acceptable.

Indicator chemicals were used to establish cleanup goals for groundwater.Indicator chemicals were selected based on the results of previous samplingactivities and the current RI results. All indicator chemicals analyzed for inthe RI were utilized in the Public Health Evaluation.

Groundwater is not used by human receptors downgradient of the Site.Groundwater from the site discharges to Long Creek or the Catawba River, andthere are no intermediate users.

SOD 001 000880FIGURE 10

y£lv\) olJ&i&vSr >- -»SHOFFSITE WATER SUPPLY WELLS

WITHIN ONE-HALF MILE OFCERCLA AREAS

SCALE T-2000TEXPLANATION

OA APPROXIMATE WELL LOCATION

~— ONE-HALF MLE RADIUS BOUNDRYFROM THE CERCI.A AREAS

SOD 001 000881

TABLE 1

QROUNDWATER CLEANUP GOALS

COMPOUND

Tri chloroethylene

Tetrachloroethylene

Chlorobenzene

Ethylbenzene

1,2-d i chlorobenzene

Toluene

Xylene

Anthracene

Fluorene

Phenanthrene

CLEANUP GOAL ug/1

2.7

0.8

60

(2)

(2)

(1)

680 (1)

400 (5){3!

2,000 (1)

440 (1)

2.8 ng/1 (4)

2.8 ng/1 (4)

2.8 ng/1 (4)

(1) Proposed Maximum Contaminant Level Goals, 50 Federal Register 46936(November 13, 1985).

(2) The concentration value given for potential carcinogens corresponds toa cancer risk level of 10-6 .

(3) Includes all iscmers.

(4) As total polynuclear aromatic hydrocarbons, no criteria set for thesecompounds alone.

(5) USEPA, "Superfund Public Health Evaluation Manual," Ofice of Emergencyand Remedial Response, Washington, D.C., 1986. USEPA Ambient WaterQuality Criteria for Aquatic Organisms and Drinking Water.

-21-

SOD 001 000882-22-

Levels presented as groundwater cleaup goals are based on the followingcriteria: drinking water Maximum Contaminant Levels (MCLs) and MaximumContaminant Level Goals (MCLGs), Federal Ambient Water Quality Criteria,National Ambient Air Quality Standards (NAAQs), and State environmentalstandards. Indicator chemicals, maximum concentrations detected in groundwaterat the Sodyeco Site, and the cleaup goals for these chemicals are presented inTable 1.

4.2 Soil Remediation

The Public Health Assessment in the RI Report determined that risks to hurranhealth as a result of exposure to on-site contaminants via inhalation,Ingestlon, and dermal contact are low under present use conditions at theSite. For potential future use scenarios, the risk Is higher. Therefore,remediation or institutional controls will be undertaken to assure that ar.increased risk to human health is not posed in the future.

Contaminants remaining in the soil following groundwater remediation may, overtime, leach into the groundwater. Therefore, the soils and the leachate fromthe contaminated soils will be sampled and analyzed for the indicator compoundsand the soils will be treated until the leachate meets the ARARs.

4.3 Surface Water Remediation

The contaminant levels in the surface water (Tributaries A, B and Long Creek)are expected to decline, as groundwater and soil remediation continues. Thus,it was concluded that remediation of surface water Is not necessary. No surfacewater contamination was detected in the Catawba River.

5.0 Alternatives Evaluation

The purpose of remedial action at the Sodyeco Site is to mitigate and minimizecontamination in the soils and groundwater, and to reduce potential risks tohuman health and the environment. The following cleanup objectives weredetermined based on regulatory requirements and levels of contamination foundat the Site:

* To protect the human health and the environment from exposure- cocontaminated on-site soils through inhalation or direct concact.,

* To restore contaminated groundwater to levels protective of humanhealth and the environment.

An Initial screening of possible technologies was performed to identify thosewhich best meet the criteria of Section 300.68 of the National Contingency Plan(NCP) (Tables 2 & 3).

TABLE 2P R F t , t M l N » R Y SCRFFNIMf: OF TRFATHF>»T ANT) DISPOSAL TFTIIMTlI/ir;IFS

Technology Description

SOILS

Fxcsvatlon

Landfill

Irsjtoi

Physical removal of contaminatedmaterial* for treatment or dls-posal.

Dlapoaal of excavated materialsin an approved hazardous wastefacility. Materials may bedrummed or disposed of In bulk.

Surface ctoraqe of excavatedmaterial*.

00o0

ntsPossibly

ApplicableNot

Applicable

Should be considered for landfllledm a t e r i a l s In Area B and contaminatedsoils In Areas C and O.

Since the total concentration ofF-Ilsted solvents !• >t\ In nonelocations, l a n d f l l l l n q Is prohibitedat * RCRA f a c i l i t y . Land ban Unitsscheduled for July 8, 19ft7 applyto haloqenated organic compounds (HOC)In total concent ratlonfl greater than orequal to 1000 mq/Vg. However, • two-yearnationwide variance w i l l delay thecompliance date until July, 1989.

Require* monitoring and maintenance.Generally considered to be an In-terim as opposed to long-termsolution.

Oo00COcc

Incineration

In-Sltu Flushing

Solvent Flushing

Thermal contaminant destructionby conbustlon/oxldatIon at veryhigh temperatures.

Percolation of water throughcontaminated soils to solublllzradsorbed compounds and reduceresidual concentrations.

Percolation of solvent thrrmqhcontaminated no! IB which canarh I eve twn pttr p<T*ins : «»«! r-recovery for » n r f « ' > « ' t r***t **«»n*or s o l u h l l l r . a f l o n nf flf lnorh*™^compoundfi to pnhnnre i n - s l l utr* > ^fn"*nt . • pprfvf^ry of * i f i l v * * n t\ n flrrowp 1 1 f»h»'f1 t hr oii'ih a wo 1 1polnt f lyn t pm.

A proven technology for destructionof moat organic*. A possible treat-ment technique for excavated material*/contaminated soils. Disposal ofremaining ash must b* considered.

tion.Provides an alternative to excavaMay shorten the time required forground-water ptimplnq of the aquiferhy reducing the extent of sourcecontamination. Recovery would beachieved through a well system.

Given ground-w« t r«- elevations anddepths of contain! naterl soils on site,(h<- f l u s h i n g solvent r.>nM ^.|r^»^»•r, . > « t * .ttwt HA I «' i ( r i u i i t i 1 w ^ F ^ v .

TABLE 2 GOPRELIMINARY SCRFFTMNC OF TRF.ATMFKT AMD DISPOSAL TETHNClI,nr;TFS

(Tont i nued)

Technology DescriptionPossibly

Comments ApplicableHot

Appl Icable

SOILS (continued)

In-Sltu SteamStripping

GROUND MATCH

Permeable TreatmentBeds

Activated CarbonAdsorption

Resin Adsorption

Air Stripping

Steam Stripping

An innovative technology wherebladed drilling equipment andsteam are used to drive volatilesfrom contaminated soils to thesurface. Vapors are collected,treatedt and relnjected forclosed-loop operation.

A trench, installed downgradlentof a plume, is filled with atreatment media (e.g., activatedcarbon) to decontaminate groundwater aa it flows through.

Ground water removed by pumpingIs passed through • column whereorganic contaminants absorb to thecarbon due to physical/chemicalforces.

Similar to activated carbon exceptresin la used as the adsorbent.

Remove* vo l a t i l e organlcs froman aqueous stream. If necessary,dissolved gases transferred tothe air stream can be treatedby activated carbon or >her»*loxidation.

S i m i l a r to air stripping ewrrptsteam is inrri «T rhr T t r i p p i n qgas.

Steam w i l l volatilize contaminantsfaster than air. Equipment provide*soil mixing for more homogeneous treat-ment. Haxlmum removal efficiencieshave not been demonstrated.

Requirements are a shallow aquiferand underlying Impermeable bed. The.shallow aquifer condition is not met.Generally considered to be temporarydue to plugging potential,

An applicable method for removingorganic compounds from water.

A complex treatment scheme would resultsince different resins would be requiredto remove the different organic compounds.Not cost competitive with carbon adsorption.

A demonstrated technology for removingv o l a t i l e organic contaminants fromwater .

A dfmons tr at«d t pr-hnoloov for removingv,,i*:|jM ,,,i|..i.f. i-.»ir.iml»;*nt* fr,--Kwsler at r a i n s f a i t e r th.in .ilr stripping.M.iy rx- economl ra I J y co*np*» 11 11 ve w i t h airq t r l p p i n q whr>n a lourro of tnox pons I vo

ooo00oo

TABLE 2PRELIMINARY SCREENING OF THF.ATHENT AND DISPOSAL TECHNOLOGIES

(Contlnupd)

Technology Description Ton ApplicableNot

Applicable

IINJcni

BiologicalTreatment

ChemicalOxidation

UV Oxidation

Reverie Oamosl*

Liquid/Liquid(Solvent)Extraction

Biological degradation techniquewhere bacteria utilize aupplledoxygen to oxidize orqanlcs toCO,.

Contaminant destruction bychemical reaction. Variousoxidising agents exist fororganic compounds.

Ultraviolet light Is used as anoxidizing agent. A primarytreatment process for orqanlcs.

Concentrate* Inorganic salts and•OM organic* by forcing thesolvent through a semi-permeablemembrance which acts as a filter.

Process where the contaminantla removed from one liquid mediumInto another easily extractableliquid Medium that has a hlqherabsorption capacity (or thecontaminant. Extracted com-ponents are disposed of orreused.

Biological treatment (aerated lagoons)are part of the existing RCRA waste-water facility on site.

Chemical oxidation (I.e. ozonatlon)Is not economically competitivewith activated carbon for treatinglow-level organic wastes.

Generally only economical for smallquantities of water.

Primary uses have been as a pretreat-ment step In the removal of Inorganic*(Ion-exchange) or In recovery ofreusable Impurities.

Primarily used for phenolic extractionsHost economical when material recovery I*possible to offset process costs. Finalpolishing Is usually needed. It I* noteconomically competitive with biologicaloxidation or adsorption for large quantitiesof dilute waste. Steam stripping Is moreeconomical for low-moderate concentra-tions of volatile solutes.

oooGOUDCT

Deep Nell Injection

nff-site Treatment

Injection of contaminated waste-water Into a very deep substratawhich 1« not hydrnulleallyconnected fo nthPF aqulfpr rones *

Discharge to the Charloi-te-H«"i K lenburq utility r>«> pa r t m«-n t(tntlD) Publicly Owned TreatmrntWorks (P1ITV) w»Mt«-w,»tPr collert-lr»n and trp-atmnnl syitom.

Under Section 300*<M of RCRA, EPAconsideration of underground HOC Injec-tion Is not expected until result* of anaqpncy study (due August, 19RR) evalu-a t i n g protectivpness oir issued.

An application has been submitted.Rrqsil remonf •> for -J1 qlll ( I rant Industrie)iner^ are t>*» I nq enamlnprl to dptermlnp tfwithdrawn qround-water would be accppted.

TABLE 2PRELIMINARY SCRFF.NINT, OF THFATNKNT AND DISPOSAL

(Continued)

00

Technology Description CommentsPossibly

ApplicableMot

Applicable

SOILS (continued)

Soil Hashing

Btodegradatlon

IroSoil Aeration

Composting

In-SltuAir Stripping

Thermal Processtrxj

Place excavated, screened soilsand Main water In a flotationmachine with a mechanicalImpeller for mixing.

In-sltu treatment using micro-organisms to blodegrade theorganic contaminants.

Mechanical addition of air to aid•Icroblal decomposltIon. Fre-quently used In conjunction withIn-sltu treatMent Methods andland disposal technologies.

Mixing excavated soils withnutrients to achieve aerobicdegradation at an elevatedtempera tut*.

Mechanical Injection of clean airInto contaminated soils to vola-tile organic*. Air Is withdrawnand vented to the atmosphereor to an emission control system(ft.q* actlviirrfl carbon adsorption)dependlnq on volstllf concentra-tions.

An lniv>v»tlve technology whereexcavator! soil* **<r plarrr? Ina heat exchanger (thermal proceniorand heated to vnlatillre orqanlcs.Vapors are treated In an ali»*r-rmrnnr or otherwise treated asneceisary.

Withdrawn leachate would requiretreatment.

Given the contaminant types, concen-trations, depths, and soil permeabili-ties, degradation In soils has a lowprobability of success. Toxlclty pro-blems could result from some of thedegradation by-products.

Typically used In conjunction withbiological degradation.

An experimental technology for the hazar-dous soils on-slte. May be performed withan Induced draft under controlledcondltIons.

Most effective for loose, sandy soilswell above the ground-water table. Thedegree of fines, clay content, and rockformations on-slte are unfavorableconditions which are expected to severelyl i m i t contaminant removal. Ultimateeffectiveness hjis not been establishedrvtrn ur.ilrr i^e*! soil conditions.

An alternative to tn-sttu air strip-ping when- soils srr tightly p«cKed,li,»v<' high (lay content, »nd/orrock fotw.it Ions are present.

oooooooCJ5

TABLE 3PRELIMINARY SCRKFHIHG OF CONTAINMENT AMD MIGRATION CONTROL TECHNOLOGIES

00

Technology DescriptionPossibly

Comments ApplicableNot

Applicable

SOILS

Iro

Capping

Solidification/Encapsulation

fixation

GROUND HATCT

Ground-WaterRecovery

SubeurfaceCollectionOralne

ImpermeableBarrlen

Collection

An Impermeable barrier la placedover the eoll eurface to minimizethe amount of water percolationthrough contaminated materials/aolla.

Contaminated materials/soilsare incorporated In a aolldmatrix to reduce contaminantmobility and leachate generationCan alao be uaed In conjunction•1th landfllllnq.

Proceaa to mix chemical waatee•1th Inert material (e.g., limefly aahl to reduce waateaolubillty.

lumping from a mil point eya-tem and/or trenchea to withdrawcontaminated ground water.

A trench la excavated, backfilledwith Highly permeable material,and uaually lined to preventplugging.

Underground barrlera used tophysically divert ground-waterflow away from an area or tocontain a contaelnant plume.

u»<"«1 to Interrupt leachatebefore It contawtnatea fjroundwater. Consists of a aeries ofdralne which Intercept lenchateand channel It to a nump, wptwnll,or aurface dlscharqe point.

May be applicable to the landfillIn Area B and contaminated aolla inAreas C and D.

Host economical for email waate quanti-ties. The technology la developmentalfor organic contaminated aolla.

Primarily applicable to acid. Inorganic,and scrubber sludge waatea.

A demonstrated technique forground-water removal. Aquifer•characteristics must be determinedfor design.

Requires continuous monitoring. Naybe used In conjunction with ground-water pumping.

The barrier must be tied Into a rela-tively shallow Impermeahla ha«e layer.Silo corKS'.r'.or.s iri net veil «•_•» »•"<for t h i n option.

(ifiieratly asnoriated w i t h d«*tqn«<!Isipoumlments or l A n < l f l l l a arvd UK»*<4In annoclatIon with the leachatecon t r o I n •

O

Oooooo

SOD 001 000888-28-

Following the initial screening of technologies, potential remedial actionalternatives were identified and analyzed (Table A).

These alternatives were further screened and those which best satisfied thecleanup objectives, while also being cost effective and technically feasible,were developed further (Table 5).

5.1 Alternatives

Alternative 1; No Action

This alternative will eventually reduce the volume of soil contaminationthrough natural flushing. Contaminant mobility and toxicity are not reduced inthe absence of treatment. Given the contaminant concentrations at the Site,the time required to significantly reduce contaminant levels is unrealistic.No action does not provide permanent source control.

Alternative 2: Natural Soil Flushing Areas B, C, DGroundwater Recovery and Treatment Areas A - E

This alternative does not employ a soil technology and, therefore, the exposurepathways and associated risk are the same as for the baseline no-actionalternative. In the absence of source control measures, the time required topump and treat the groundvater is unrealistic.

This alternative and the others that will be described below, requires thecollection of the groundwater through a series of recovery wells to interceptthe contaminant plume in each area before it reaches Long Creek or the CatawbaRiver.

The biological degradation and aeration of the groundwater in Sodyeico'sexisting facility was chosen as the best groundwater alternative. It will beeasy to implement since all that is required is the connection of the CERCLAgroundwater collection system to the existing sewerage system. Organiccompounds in the groundwater will be biodegraded by the microorganisms presentin the aeration lagoon; a portion of the organics will be volatilized as aresult of aeration. This treatment system is more than 98 percent efficientbased on the removal of o-dichlorobenzene. Of the organic contaminants,,o-dichlorobenzene is the most difficult to remove. Removal efficiencies near99 percent are expected for the other compounds. The treated groundwater willthen be discharged to the Catawba River under the NPDES permit for thefacility. The CERCLA influent and the total effluent will be sampledperiodically to monitor the effectiveness of the treatment.

Alternative 6: Cap Area BExcavate Areas C and DIncinerate Excavated Materials On-SiteGroundwater Recovery and Treatment Areas A - E

Approximately 6,000 cubic yards of soil will be excavated for incineration.Incineration is a proven method for destruction of organic contaminants. Thismethod provides the same basic level of protection as other treatmenttechnologies considered, however, the cost is prohibitive.

TABLE 4

PRELIMINARY SCRFEWtNG OF GFNFRAL At/TFRNATIvrSBASF!) ON FFFFTTtVRMF.SS, 1MP1.FMFHTAR 11.ITT , ANP COST CRITERIA

GO

A1ternativeMo.

Description nts Retain for Petal lAssessment

Ho Action.Natural aoll fluahlnq Areas B, C, DGround-water monitoring Areas A-E

Natural aoll fluahlnq Areas B, C, DGround-water recovery and treatment

Area* A-E

Capping of Areas B, C, DGround-water recovery and treatment

Area* A-E

Bxcavata Areaa B, c, DIncinerate excavated Materials off site.Ground-water recovery and treatment

Areas A-E

Public health not predicted to beat risk. Provides baseline compari-son for other alternatives.

Partial containment with treatment option.Contaminants In the unsaturated zoneMigrate naturally to the qround waterand are withdrawn and treated.

Combined containment and treatment option.Capping In Arpas C and D Is not effectivefor lonq-term source control.

Costa for excavating and off-sitaIncineration are approximately $4R million.Findings of the baseline public healthrisk assessment do not justify thislevel of expenditure over othertreatment alternatives (S0.8-5.B mllllon).

Yes

Tes

No

No

oooCOooCO

Excavate Area* B. C, DIncinerate excavated materials on-siteGround-water recovery and treatment

Areas A-E

Cap Area BExcavate Areaa C and DIncinerate excavated materialson-slte

Ground-water recovery and treatmentAreaa A-E

Costs for excavating and on-slte Inciner-ation are approximately $31 million.Findlnqs of the baseline public riskassessment do not justify this levelof expenditure over other treatmenta l t e r n a t i v e s (SO.R-S.H mi l l i o n ) .

Adequate to protect public health and theenvironment. Fjuploys a permanent treatment

for <rmf Ami nant destruction.

No

4 (Continued)PRn.IHTNARY SrREFKINO OF CrNFRAL ALTFRNATIVrS

OH FFFBTTIVCTIF,S9, TMPI.KMFNTAFI L1TY, AND COST CRTTKKIA

AlternativeNo.

Description Comment* Detain for DetailedAaaeaament

10

Sam* •• Alternative 6 aubatttutlnqoff-*lt* Incineration for on-alteIncineration

Same •• Alternative 6 substitutingthermal stripping* of excavated•oil* for on-slte incineration

Cap Urea •Treatment of Area C Soil byi

9h In-altu (tea* stripping,*»• Thermal Processing9C In-altu Mushinq*. "r90 Maahlnq*

Kxcavate Area D and incinerateoff-lit*

Oroand-water recovery and treatmentArea* A-E

Cap Area BNatural fluah Area CEicavate Area D and Inclnerat•

off-siteGround-water recovery an<J trriitnent

Area* A-K

t* not coat co«petltlve with on-*lteIncineration for the waate quantltle* ofcnncern. Kequlrei transport of contami-nated awterlala for a alqnlflcant distance.Offer* no advantaqea over on-alteIncineration.

Innovative/developmental treatment technoloqywith hlqh aucce** probability for orqanlc aollcontamination. Adequate to protect publichealth and the environment. Potentiallymore coat-effective than on-alte Incineration.

Innovative/developmental treatment technologywith potential for the aoll* with orqanlccontamlnnnta. Potentially more coat-effective than on-alte Incineration.Tnnoqraphy In Area D precludea ln-*ltvatrlpplnq. Contaminant concentration* inArea D would make treatment by the remainingtechnoloqles more difficult.

Combined containment and treatment option.The lime to pump and treat qround waterrecovered from Area C w i l l be lonqer In theabsence of soil treatment.

No

Ye*

Tea

OOOCOCDO

Ye*

An Innovative/developmental technology

S O D 0 0 1 000691

TABLE 5

SUMMARY OF SCREENING CRITERIA FOR COMPARING AUTERNATIVES

Technical Feasibility,Reliability

ReducesMA/V Cost

Alternative 1

No ActionNatural soil flushingLong-term OW monitoring Anas A-E

Monitoring is routine Minor reductions in contariinantvolume will require antime period.

S 170,000

Alternative 2

Natural soil flushing Areas B,C,DQU" recovery t treatment Areas A-E

No engineered soiltechnology employed.Ok' purrp & treat is ademonstrated technology.

Minor reductions in volunwflushing. Significant reductionin mobility and toxicity throughGW pump and treat.

S1,01€ ,OOC

Alternative 6

Cap BExcavate Areas C 4 DIncinerate excavated materials onsiteGK recovery i treabnent Areas A-E

All technologies aredemonstrated.

Provides permanent 4 significant 56,765,000redactions in

Alternative 6

Cap BExcavate Areas C I DOnsite thermal processing of

excavated materialsGW recovery i treatment Areas A-E

Includes an innovative/developmental treatmenttechnology. Reliabilitynot proven.

Provides permanent I sign.if icarreductions in M/TA7

53,776,000

Alternative 9

Cap BTreatment of Area C soils

9A: In-situ Steam Stripping9B: Onsite Thermal Processing (CiD)9C: In-Situ Flushing9D: Soil Washing

Excavate D and incinerate offsiteGU recovery & treatment Areas A-E

Includes an innovative/developmental treatmenttechnology. Reliabiltynot proven.

Provides permanent andsignificant reductionsin

9A:9B:9C:9D:

$ 3 , 7 9 2 , O O CS3,776,000S 2 , 0 6 9 r O O C$3,865,000

Alternative 10

Cap 6Natural soil flushing Area CExcavate Area D and incinerate off siteGW recovery and treatment Areas A-E

All technologies aredemonstrated.

Provides permanent I significantreductions in M/T/V. Moreextended period to pimp and treatOK in Area C.

$1,S66,OOC

-31-

SOD 001 000892-32-

Area B in this and the other remaining alternatives will be a cap consisting of3 inches of asphalt, 2 Inches of binder-bituminous concrete and a 9 inch gravelbase.

Alternative 8: Cap Area BExcavation and Treatment of Areas C and D SoilsGroundwater Recovery and Treatment Areas A - E

This alternative recommends the excavation and treatment of contaminated soilsin Areas C & D by thermal processing. The treated soils would then bebackfilled and the area would be regraded.

Alternative 9: Cap Area BTreatment of Area C SoilsExcavate Area D and Incinerate Off-SiteGroundwater Recovery and Treatment Areas A - E

The excavation and off-site incineration from Area D (approximately 150 cjbicyards) will effectively eliminate the area that contains the highest level ofcontamination. The area will be backfilled with clean, low permeability soiland regraded. Off-site incineration is cost effective given the small volume ofmaterial from Area D.

Four different innovative technologies will be subjected to treatabilitystudies to determine the most effective treatment technology, i.e., thetechnology that is most effective in removing the contaminants within areasonable time frame. These are:

1) Flushing - In situ percolation of water through contaminated soils tosolubilize adsorbed compounds and reduce residual concentrations.Water would be introduced through a header system and recovered througha series of wells.

2) Soil Washing - Place excavated, screened soils and wash water in aflotation machine with a mechanical impeller for mixing. Treatwithdrawn leachate in the existing wastewater treatment facility withrecovered groundwater.

3) Thermal Processing - Place excavated soils in a heat exchanger(thermal processor) to volatilize organics. Vapors are treated In anafter burner or treated otherwise as necessary.

4) In-sltu Steam Stripping - In-Situ steam injection through bladeddrilling equipment to volatilize organics. Vapors are collected,treated, and reinjected for closed-loop operation.

Alternative 10; Cap Area BNatural Flushing Area CExcavate Area D and Incinerate Off-SiteGroundwater Recovery and Treatment Areas A-E

This alternative proposes no action for the contaminated soils in Area C,Therefore, the exposure pathways and associated risk would not be reduced.Since the source of groundwater contamination would still be present, a longerperiod to pump and treat the groundwater in Area C would be required.

SOD 001 OOOS9J

-33-

6.0 Recommended Alternatives

6.1 Description of Recommended Remedy

The recommended alternatives for remediation of groundwater and soilcontamination at the Sodyeco Site include extraction, treatment and dischargeof groundwater; excavation and off-site incineration; capping; and on-sitetreatment of contaminated soil. (Alternative 9)

Treatability studies will be performed for the contaminated soils in Area C todetermine the treatment system which will be used. The systems to be evaluatedare: 1) Flushing; 2) Soil Washing; 3) Thermal Processing and 4) In-SituSteam Stripping. The contaminated soils in Area D will be excavated andincinerated off-site. Area B will be capped with asphalt.

Groundwater will be extracted through recovery wells, and transported throughthe plant's sewer system to the on-site wastewater treatment facility.

These recommended alternatives meet the requirements of the National Oil andHazardous Substances Contingency Plan (NCP), 40 CFR 300.68(J), and theSuperfund Amendments and Reauthorization Act of 1986 (SARA). This recommendedremedy permanently and significantly reduces the volume of hazardous substancesin the groundwater, and reduces the volume and/or mobility of contaminants inthe soil.

6.2 Operation and Maintenance

When the remedy is completed, long-term operation and maintenance (O&M) will berequired on the asphalt cap. Long-term groundwater monitoring will be requiredto assure the effectiveness and permanence of the other soil and groundwaterremedies.

6.3. Cost of Recommended Alternatives

Capital costs for groundwater remediation is $335,000 with system operating andmaintenance cost at $80,000 per year, which includes sampling and analysis.The total present worth cost of the groundwater remediation is $1,016,000.

Capping of Area B is estimated at $378,000 including 0 & M for 20 years.Excavation and off-site incineration of contaminated soils in Area D isestimated at $173,000. The treatment of Area C soils, including thetreatability studies will range from $634,000 to $2,505,000 depending on whichtechnology is used. These costs include engineering, overhead, profit,contingency and administration fees.

The total present worth cost of this remedy, Including both soil andgroundwater remediation, will range from $2,089,000 to $3,865,000.

SOD 001 OOOS94-34-

6.4 Schedule

The planned schedule for remedial activities at the Sodyeco Site will begoverned by RCRA permitting requirements, but tentatively is as follows:

September 1987 - Approve Record of DecisionDecember 1987 - Begin Remedial Design/Treatability StudiesMarch 1988 - Install Recovery WellsAugust 1988 - Complete Treatability StudiesNovember 1988 - Complete Remedial Design and Begin Mobilization

6.5 Future Actions

Following completion of remedial activities, long-term groundwater monitoringwill be required to assure the effectiveness of the groundwater cleanup.Maintenance of the asphalt caps on Areas A & B will continue.

6.6 Consistency with Other Environmental Laws

Remedial actions performed under CERCLA must comply with all applicable Federaland State regulations. All alternatives considered for the Sodyeco Site wereevaluated on the basis of the degree to which they complied with theseregulations. The recommended alternatives were found to meet or exceed allapplicable environmental laws, as discussed below:

* Resource Conservation and Recovery Act

The recommended remedy will be incorporated into Sodyeco's ResourceConservation and Recovery Act (RCRA) Part B permit. The inciaeraclonwill be conducted off-site at a permitted facility.

* Clean Water Act

Trace amounts of contamination were detected in surface water.The soil and groundwater remediation will result in an end tothe water contamination.

* Floodplain Management Executive Order 11986

The CERCLA areas do not lie within a floodplain and thus are notsubject to the requirements of E. 0. 11988.

* Department of Transportation

Transport of hazardous substances is regulated by theDepartment of Transportation (DOT). Material transported tothe incineration facility will follow DOT regulations governingits shipment.

* Occupational Safety and Health Administration

A health and safety plan will be developed during remedialdesign and will be followed during field activities to assurethat regulations of the Occupational Safety and HealthAdministration (OSHA) are followed.

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* Safe Drinking Water Act

Maximum Contaminant Levels (MCLs) established under the Safe DrinkingWater Act were found to be relevant and appropriate to remedial action atthe Sodyeco Site. The cleanup goals for groundwater were established inSection 4.

* National Pollutant Discharge Elimination System

Discharge of treated groundwater IB part of the recommended remedialalternative. This discharge will meet effluent limit requirements of theNational Pollutant" Discharge Elimination System (NPDES). Aquatic lifechronic toxicity values, which are used in the NPDES permitting system,were used in determining the groundwater cleanup goals in Section 4.

* Endangered Species Act

The recommended remedial alternative is protective of species listed asendangered or threatened under the Endangered Species Act. Requirementsof the Interagency Section 7 Consultation Process, 50 CFR, Part 402, willbe met. The Department of the Interior, Fish and Wildlife Service, willbe consulted during remedial design to assure that any endangered orthreatened species, if identified, are not adversely impacted byimplementation of this remedy.

* Ambient Air Quality Standards

The soil and groundwater treatment systems will be designed andmonitored to assure that air emissions meet all State and Federalstandards.

* State Drinking Water Standards

Maximum contaminant levels established by the State of North Carolinaregulations are adopted from those of the Federal Safe Drinking WaterAct, and will be met.

7.0 Community Relations

Fact sheets were transmitted to interested parties, residents near the Site,•edia and state, local and federal officials before the Rl work began at theSite in August 1986.

Two Information repositories were established, one in Mt. Holly near the Siteand one in the city of Charlotte.

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A public M.tl.| w. held „„ Augu.t 19. 1987 •'

process. No other commentB in regard to .ny of the alternativesSoring the three-week public comment period which ended September 9,

The public did .how a desire for remediation of the Sltj j Jo oPPOsUio: rothe public is expected if the recommended remedial alternative v

A Responsiveness Summary has been prepared to .u«aarire co«nunity concerns andEPA's community relations activities.