/; ^ Z ORIGINAL 

SDMS DocID 2101249 

THIRD FIVE-YEAR REVIEW REPORT 

for 

COKER'S SUPERFUND SITE 

CHESWOLD, KENT COUNTY, DELAWARE 

MAY 2009 

Prepared by: 

U.S. Environmental Protection Agency 

Region III 

Philadelphia, Pennsylvania 

ia^fi^J. Burke, Director S^52^ ^^^^ 

Hazardous Site Cleanup Division / / 
TABLE OF CONTENTS 

List of Acronyms. ii 

Executive Summary • iii 

Five-Year Review Summary Form iv 

L INTRODUCTION 1 

II. SITE CHRONOLOGY .......2 

Table 1 - Chronology of Site Events 2 

III. BACKGROUND..... 3 

Physical characteristics ...3 

Land and Resource Use.. 3 

History of Contamination 4 

Initial Response Activities 4 

1 Basis for Taking Action ....4 

IV. REMEDIAL ACTION IMPLEMENTATION 5 

V. PROGRESS SINCE THE LAST FIVE-YEAR REVIEW 8 

VI. FIVE-YEAR REVIEW PROCESS.. 8 

Administrative Components : 8 

Community Involvement ; 9 

Document Review : 9 

Data Review 9 

Site Inspection 10 

VII. TECHNICAL ASSESSMENT 10 

Question A: Is the Remedy Functioning as Intended by the Decision Document? 10 

Question B: Are the Exposure Assumptions Data, Cleanup Levels, and Remedial Action 

Objectives (RAOs) Used at the Time of the Remedy Selection Still Valid? 10 

Question C: Has Any Other Information Come to Light That Could Call into Question 

the Protectiveness of the Remedy? 11 

Technical Assessment Summary 11 

VHL ISSUES ......12 

Table 2 - Issues 12 

IX. RECOMMENDATIONS AND FOLLOW-UP ACTION 12 

Table 3 - Recommendations and Follow-Up Actions 12 

X. PROTECTIVENESS STATEMENT 13 

XI. NEXT REVIEW 13 

Figure 1 
List of Acronyms 

ARAR Applicable or Relevant and Appropriate Requirement 

CERCLA Comprehensive Environmental Response, Compensation, and Liability Act 

CFR Code of Federal Regulations 

. ( \ 

DNREC Department of Natural Resources and Environmental Control 

Easement Environmental Protection Easement and Declaration of Restrictive 

Covenants 

EPA U.S. Environmental Protection Agency 

GPRA Government Performance Results Act 

GMUC Groundwater Migration Under Control 

HHPA Long-Term Human Health Protection Achieved 

NCP National Contingency Plan 

NPL National Priorities List 

PRP Potentially Responsible Party 

RPM Remedial Project Manager 

RAO Remedial Action Objective 

RD/RA Remedial Design/Remedial Action 

RI/FS Remedial Investigation/Feasibility Study 

ROD Record of Decision 

SWRAU Sitewide Ready for Anticipated Use 

TBC To Be Considered 
Executive Summary 

The remedy for the Coker's Sanitation Service Landfills Site (Site) in Cheswold, Delaware 

included: 

• Placing deed restrictions (institutional controls) on both landfill properties. 

• Enclosing the entire waste disposal areas of both landfills with a chain-link security 

fence with a locked gate and placing warning signs along the fence. 

• ' Placing cover material along the northern slope of Landfill No.l to eliminate 

exposure to leachate seeps. 

• Backfilling to grade and seeding areas of Landfill No. 2 which had subsided due to 

uneven settling of waste. 

• Sealing leachate collection wells at Landfill No. 2 with grout to reduce the potential 

for direct contact with leachate. 

• Conducting ground water sampling semi-annually at both landfills. 

• Inspecting'the landfills semi-annually during ground water sampling events. 

• Conducfing surface water and sediment monitoring at the Willis Branch adjacent to 

Landfill No. 1 at the same time as ground water monitoring for a period of no less 

than five years. 

The assessment of this five-year review found that the remedy was implemented in 

accordance with the requirements of the Record of Decision (ROD). EPA finds that the remedy is 

protective of human health and the environment. All threats at the Site associated with exposure to 

contaminated soil, leachate or on-site groundwater have been addressed. 

The Site achieved construction completion status with the signing of the Preliminary Close 

Out Report on September 29, 1993. This is the third five-year review for the Site. The first review 

was triggered by the date that onsite construction began. The trigger for this five-year review was 

the date of the completion date of the second review, May 25, 2004. 

GPRA Measure Review 

As part of this Five Year Review the GPRA Measures have also been reviewed. The GPRA 

Measures and their status are provided as follows: 

Environmental Indicators 

Human Health: Long-Term Human Health Protection Achieved (HHPA) 

Groundwater Migration: Groundwater Migration Under Control (GMUC) 

Sitewide RAU 

The Site is not Site-Wide Ready for Anticipated Use (SWRAU) but is expected to achieve 

SWRAU on December 30, 2010. " 

111 
Five-Year Review Summary Form 

SITE IDENTIFICATION 

Site name: : Coker' 5 Sanitation Service Landfills Superfund Site 

EPA ID: DED980704860 

Region: 3 State: DE City/County: Cheswold/Kent County 

SITE STATUS 

NPL status: X Final • Deleted • Other (specify). 

Remediation Status (choose all that apply): Under Construction • Operating 

^ Complete 

Multiple OUs? QYES J^t NO Coristruction completion date: 9/29/1993 

Has site been put into reuse? G YES K NO 

REVIEW STATUS 

Lead agency: H EPA • State • Tribe • Other Federal Agency_ 

Author(s) name: Ronnie M. Davis 

Author(s) title: Remedial Project Manager Author(s) Affiliation: U.S. EPA - Region 3 

Review period: 11/2008 - 5/2009 

Date(s) of site inspection: 4/6/2009 

Type of review: K Post-SARA QPre-SARA 

• Non-NPL Remedial Action Site 

• Regional Discretion 

• NPL-Removal only 

• NPL State/Tribe-lead 

Review number: • 1 (first) • 2 (second) * 3 (third) • 

Other(specify)_ ' • 

Triggering action: 

• Actual RA Onsite Construction at Site 

• Construction Completion 

• Other (specify) 

• Actual RA Start at 0U# 

X Previous Five-Year Review Report 

Triggering action date: 5/25/2004 

Due date (five years after triggering action date): 5/25/2009 
Five-Year Review Summary Form, cont'd. 

Issues: 

The chain link security fence has been cut in several places. Additionally, a tree has fallen 

on a section of the fence. EPA is preparing to delete the Site from the NPL. Therefore, as a 

precautionary measure, groundwater, surface water and sediments should be analyzed for the 

presence of volatile organic compounds, semiviolatile organic compounds, and metals. 

Recommendations and Follow-up Actions: 

Repair the chain link security fence. Monitor groundwater, surface water and sediments for 

volatile organic compounds, semivolatile organic compounds and metals. 

Protectiveness Statement: 

The remedy at the Site currently protects human health and the environment. The chain 

link security fences around the waste disposal areas of both landfills restrict access to the Site and 

reduce the potential for exposure to Site contaminants. The soil cover on the landfills prevents 

direct contact with the waste, minimizes migration of contaminants to the groundwater, and 

reduces the generation of leachate. There is no evidence of erosion or a breach of the soil cover on 

either landfill. The closure of the leachate collection wells at Landfill No. 2 has reduced the 

potential for direct contact with leachate. Thus, there is no known evidence of current exposure to 

the waste or Site contamiriants and the remedy is considered protective in the short-term. In the 

long term, the remedy is protective because the deed restrictions (institutional controls) required by 

the ROD, which restrict the use of the land, have been implemented by the use of Environmental 

Easements. The institutional controls ensure long-term protectiveness by prohibiting any type of 

activity that could disturb the landfill surfaces or the underlying waste at each landfill, or in any 

way increase the risk of exposure to Site contaminants, including, but not limited to, any soildisturbing activities at the Site. 

Other Comments: None 
Coker's Sanitation Service Landfills 

Cheswold, Delaware 

Third Five-Year Review Report 

EPA ID No. DED980704860 

I. INTRODUCTION 

The purpose of a five-year review is to determine whether the remedy at a site is protective 

of human health and the environment. The methods, findings, and conclusions of reviews are 

documented in Five-Year Review reports. In addition, Five-Year Review reports identify issues 

found during the review, if any, and identify recommendafions to address them. 

The U.S. Envirormiental Protection Agency (EPA) is preparing this Third Five-Year 

Review report pursuant to the Comprehensive Environmental Response, Compensation, and 

Liability Act (CERCLA) § 121 and the National Contingency Plan (NCP). CERCLA §121 states: 

If the President selects a remedial action that results in any hazardous 

substances, pollutants, or contaminants remaining at the site, the President 

shall review such remedial action no less often than each five years after the 

initiation of such remedial action to assure that human health and the 

environment are being protected by the remedial action being implemented. 

In addition, if upon such review it is the judgement of the President that 

action is appropriate at such site in accordance with section [104] or [106] 

title, the President shall take or require such action. The President shall 

report to the Congress a list of facilities for which such review is required, 

the results of all such reviews, and any actions taken as a result of such 

reviews. 

EPA interpreted this requirement further in the NCP; 40 CFR § 300.430(f)(4)(ii) states: 

If a remedial action is selected that results in hazardous substances, pollutants, or 

contaminants remaining at the site above levels that allow for unlimited use and 

unrestricted exposure, the lead agency shall review such action no less often than 

every five years after initiation of the selected remedial action. 

EPA Region 3 conducted this five-year review of the remedy implemented at the Coker's 

Sanitation Service Landfills Site (Site) in Kent County, Delaware. This review was conducted by 

the EPA Remedial Project Manager (RPM) of the Site, with assistance from the Delaware 

Department of Natural Resources and Environmental Control (DNREC), from November 2008 

through May 2009. This report documents the results of the review. 

This is the third five-year review for the Site. The triggering action for this review was the 

• . 1 
completion of the second five-year review on May 25, 2009. This third five-year review is 

required because hazardous substances, pollutants, or contaminants remain at the Site above levels 

that allow for unlimited use and unrestricted exposure. 

II. SITE CHRONOLOGY 

Table 1 - Chronology of Site Events 

DATE 

1969-1977 

1976-1980 

July 22, 1987 

December 30, 1987 

September 28, 1990 

April 8, 1992. 

July 1993 

September 9, 1993 

September 29, 1993 

1993 

ACTIVITY 

Landfill No. 1 operated at the Site. 

Landfill No. 2 operated at the Site. 

EPA placed the Site on the National Priority List (NPL). 

Three PRPs signed an Administrative Order on Consent to 

conduct the Remedial Investigation/Feasibility Study (RI/FS). 

EPA issued a ROD. 

EPA and six PRPs entered into a Consent Decree for 

implementation of the Remedial Design/Remedial Action 

(RD/RA). ' 

PRPs initiated construction activity. 

EPA and the Delaware Department of Natural Resources and 

Environmental Control (DNREC) conducted the final 

inspection at the Site. 

EPA issued Preliminary Site Closeout Report. 

First groundwater sampling event. 
DATE 

1993-present 

July 17, 1998 

January 6, 1999 

May 25, 2004 

December 18, 2008 

February 19, 2009 

April 6, 2009 

ACTIVITY 

On-going groundwater monitoring. 

Site inspection for the First Five-Year Review. 

First Five-year Review. 

2"" Five-Year Review. 

Work Completion Report 

Final Close Out Report 

Site Inspection 

III. BACKGROUND 

Physical characteristics 

The Site is located near Cheswold in Kent County, Delaware, approximately six miles 

northwest of the City of Dover. The Site consists of two landfills located approximately one-half 

mile apart ori opposite sides of County Route 152. Landfill No. 1, which is on the north side of 

Route 152, and Landfill No. 2, which is on the south side of Route 152, are both part of larger, 

heavily wooded tracts of land (Figure 1). Properties adjacent to both landfills are primarily used 

for agricultural or residential development. Landfill No. 1 is bordered on the north by a forested 

wetland that includes a shallow meandering stream, the Willis Branch of the Leipsic River. 

Agricultural lands border the tree lines east and west of Landfill No. 2. Deer and other wildlife 

populate this area of Kent County. Groundwater in the vicinity of the Site is used for domestic 

purposes, including drinking water. 

Land and Resource Use 

The Site has been fenced off and is covered with grass, weeds, and trees. There have been 

no changes in physical features at the Site since the last five-year review. Several houses are 

located between the two landfills on Route 152. 
V. 

History of Contamination 

Both landfills were used for the disposal of process sludge generated during the 

manufacture of latex rubber. Landfill No. 1 was a permitted landfill which began operating in 

1969 and subsequently closed under the then-current state regulations in 1977. Approximately 

45,000 cubic yards of solid waste were disposed of in six to eight feet deep, unlined trenches. 

Landfill No. 2, which was also permitted, operated from 1976 to 1980 and also received 

approximately 45,000 cubic yards of waste. Sludge was disposed of in six feet deep, lined trenches 

that included a leachate collection system. The permit also required leachate collection and 

treatment, installation of groundwater monitoring wells, regularly scheduled site inspections, and 

periodic groundwater and leachate monitoring. The trenches were capped with soil when the 

landfill was closed in 1980. As the waste in the trenches settled and stopped producing collectable 

quantities of leachate, leachate collection was phased out in the early 80's. Landfill No. 1 is 

approximately ten acres in size, and Landfill No. 2 is approximately fifteen acres in size. 

Initial Response Activities 

The EPA conducted an initial Site Investigation in 1980, and a second one in 1983. 

Elevated levels of acrolein were found in one well and in one leachate collection pipe on Landfill 

No. 2. Ethylbenzene was detected in the same well and leachate collection pipe. Bis(2-

chloroethyl) ether was detected in two Landfill No. 1 leachate seeps. 

Basis fo r Taking Action 

Contaminants 

Hazardous substances that have been detected in leachate, groundwater and waste at both 

landfills include: 

Benzene 

Chloroform 

Ethylbenzene 

Styrene 

Cresol 

Dibutyl Pthalate 

Phenol 

Cadmium 

Manganese 

EPA placed the Site on the National Priorities List in July 1987. In April 1986, EPA issued 

letters to several Potentially Responsible Parties (PRPs) notifying them of their potential liability 

for Site response actions and inviting them to conduct the Remedial Investigation/Feasibility Study 

4 ' 
(RI/FS). On December 30, 1987, three PRPs signed an agreement with EPA in the form of an 

Administrative Order on Consent to conduct the RI/FS. The parties agreed,,under a separate order, 

to remove drums containing varying quantities of latex waste found on-site during the RI. 

Media investigation during the RI/FS included waste, leachate, groundwater, surface water 

and sediment, soil, and air. The waste at both landfills contained the highest number of 

contaminants and highest levels of contamination, primarily styrene, ethylbenzene, and phenolic 

compounds. Leachate from Landfill No; 2 (taken from leachate collection trenches within the 

lined cells) contained the same contaminants, but at lower levels. The waste and leachate were 

determined to pose a threat to human health and the environment. Groundwater at both landfills 

contained similar compounds but at significantly lower levels, and it was determined that they did 

not pose a threat to human health or the environment. 

IV. REMEDIAL ACTION IMPLEMENTATION 

Remedy Selection ^ -

EPA issued a ROD for the Site on September 28, 1990. The major'components of the 

selected remedy include deed restrictions to limit access, increasing the cover material to eliminate 

exposure and grouting the leachate collection system to reduce the potential for direct contact. The 

waste materials found in the landfills at the site is neither liquid nor highly mobile, and can be 

reliably controlled in place. EPA and the State determined that onsite containment of the waste is 

an appropriate remedial action. 

The goal of the remedial action objective is to limit exposure to Site contaminants by 

covering the landfills and limiting access to the material in the landfills. The goal of the remedial 

action for the Site is to reduce the potential for future contact with the waste or with Site 

contaminants, thereby reducing risks to within EPA guidelines. The cancer risks associated with 

no action at both landfills is at or above EPA's guideline of 1 x 10"^; after implementation of the 

selected remedy, cancer risks are below 1 x 10"^. 

The Hazard Index score for children at Landfill No.l was 3.26, which exceeds EPA's 

preferred guide line of 1.0. The Hazard Index scores for adults and children at Landfill No. 2 were 

48 and 156, respecfively. Following the implementation of the remedy, the Hazard Index score has 

been reduced to below 1.0 at both landfills. - , 

Because there are no users of ground water hydraulically downgradient of Landfill No.l, 

monitoring of Landfill No.l was conducted primarily for the protection of aquatic life in the Willis 

Branch. The trigger levels developed for each of the site related contaminants of concern for 

ground water are as follows: styrene (2900 ug/L), and ethylbenzen (3,200 ug/L). The trigger levels 

for surface water for surface water monitoring are as follows: styrene (1,400 ug/L), ethylbenzene 

(1,600 ug/L), and xylenes (900 ug/L. Sediment sampling coincided with surface water sampling and 

used to aid in the evaluation of surface water data and site conditions. 
Because a few residential wells are located hydraulically downgradient of Landfill No 2, 

monitoring at Landfill No. 2 has been conducted primarily for the protection of human health. The 

trigger levels developed for each of the site-related contaminants of concern for ground water at 

Landfill No. 2 are as follows: styrene (100 ug/L), ethylbenze (5 ug/L), 1,2,3-trichloropane (5 ug/L), 

phenolics (22,999 ug/L), and antimony (6 ug/L). 

Remedy Implementation 

On April 8, 1992, the State, EPA, and the PRPs entered into a Consent Decree for 

implementation of the Remedial Design/Remedial Action for both landfills. 

The following is a summary of the remedial action (set forth below in italics) required by 

the ROD, followed by the activities (set forth below in regular type) that have been conducted at 

the Site pursuant to the ROD, and which are described in more detail in the Preliminary Site Close 

Out Report. 

• Deed restrictions (institutional controls) will be placed on both landfill properties 

• An Environmental Protection Easement and Declaration of Restrictive 

Covenants between Alberta Schmidt, as Grantor, and DNREC, on behalf of 

the State of Delaware, as Grantee, relating to Landfill No.2 was signed on 

February 24, 2005. The document was recorded with the Office of the 

Recorder of Deeds for Kent County, Delaware on April 18, 2005 to 

implement the institutional controls for Landfill No.l. 

• An Environmental Protection Easement and Declaration of Restrictive 

Covenants between Kowinsky Farms, Inc, as Grantor, and DNREC, on 

behalf of the State of Delaware, as Grantee, relating to Landfill No.2 was 

signed on September 24, 2008. The document was recorded with the Office 

of the Recorder of Deeds for Kent County, Delaware on November 26, 2008 

to implement the institutional controls for Landfill No.2. 

• The entire waste disposal areas of both landfills will be enclosed by a chain-link -

security fence with a locked gate to restrict the access of unauthorized persons and 

equipment onto the landfills. Appropriate warning signs will be placed along the 

fence. Six foot chain-link security fences were placed around both landfills and 

warning signs were placed around the fences. . 

• Cover material will be placed along the northern slope of Landfill No. 1 to 

eliminate exposure to leachate seeps. Mulch was placed along the northern slope of 

Landfill No. 1 to cover exposed leachate seeps. The cover was graded to conform 

with the existing drainage patterns. 

• Areas of Landfill No. 2 which have subsided due to uneven settling of waste will be 

backfilled to grade and seeded. The subsided areas, as well as other portions of the 
• 

landfill surface, were covered with soil and graded as needed to promote surface 

drainage. Following re-grading, the landfill surface and other disturbed areas were 

seeded and mulched to prevent erosion. 

Leachate collection wells at Landfill No. 2 will be sealed with grout to reduce the 

potential for direct contact with leachate. The vertical sections of the leachate 

collection wells were plugged with bentonite and filled to the existing ground 

surface with grout. Following sealing, the portions of the pipes that were above the 

ground surface were removed, and the landfill surface re-graded. 

Groundwater will be sampled semi-annually at both landfills. Three wells were 

sampled at Landfill No. I and four at Landfill No. 2. The sampling parameters were 

ethylbenzene, styrene, 1,2,3-trichloropropane, antimony, and phenolics, as well as 

field parameters. Groundwater was sampled semi-annually in 1993 and 1994, and 

annually thereafter until 1999. No contamination was found in the groundwater at 

Landfill No. 1. Phenolics were found in several wells at Landfill No. 2, but at 

concentrations three orders of magnitude below the action level. Groundwater 

monitoring was discontinued based on the recommendation to do so in the First 

Five-Year review. During the preparation and completion of the Final Close Out 

Report in February 2009, EPA decided monitoring should resume at a minimum of 

every five years because waste has been left in place at the Site, 

The landfills will be inspected semi-annually during groundwater sampling events. 

The Site has been inspected regularly as required in the ROD and routine 

maintenance activities have been performed as needed. The routine maintenance 

activities have generally consisted of minor fence repairs, replacement of warning 

signs, and mowing the surface of Landfill No. 2. 

Surface water monitoring will be conducted at the Willis Branch adjacent to 

Landfill No. I at the same time as groundwater monitoring for a period of no less 

than five years. Three sampling locations were selected in the Willis Branch (one 

upstream, one adjacent to, and one downstream of Landfill No. 1). The selected 

parameters were ethylbenzene, styrene, and total xylene, as well as field parameters. 

No contaminants were detected in the surface water during any sampling event. 

During the first sampling event, xylene was detected in the upstream sediment 

sampling location. The concentration was low, and this compound was not detected 

in any subsequent sampling event. Surface waiter and sediment monitoring was 

discontinued based on the recomrnendation to do so in the First Five-Year review. 

During the preparation and completion of the Final Close Out Report in February 

2009, EPA decided monitoring should resume at a minimum of every five years 

because waste has been left in place at the Site, 
On September 9, 1993, EPA and DNREC conducted the final construction inspection. On 

September 29, 1993, EPA signed the Preliminary Site Close Out Report, which documented that 

the PRPs had completed construction activities at the Site. 

V. PROGRESS SINCE THE LAST FIVE-YEAR REVIEW 

An Environmental Protection Easement and Declaration of Restrictive Covenants between 

Alberta Schmidt, as Grantor, and DNREC, on behalf of the State of Delaware, as Grantee, relating 

to Landfill No.2 was signed on February 24, 2005. The document was recorded with the Office of 

the Recorder of Deeds for Kent County, Delaware on April 18, 2005 to implement the institutional 

controls for Landfill No. 1. 

An Environmental Protection Easement and Declaration of Restrictive Covenants between 

Kowinsky Farms, Inc, as Grantor, and DNREC, on behalf of the State of Delaware, as Grantee, 

relating to Landfill No.2 was signed on September 24, 2008. The document was recorded with the 

Office of the Recorder of Deeds for Kent County, Delaware on November 26, 2008 to implement 

the institutional controls for Landfill No.2. 

The PRPs' submitted the Work Completion Report on December 18, 2008, which 

summarizes all of the work completed at the Site. The Final Closeout Report was signed on 

February 19, 2009, and EPA will prepare the Notice of Intent to Delete, pending the results of the 

planned sampling event. 

The PRPs' mow the grass once a year at landfill No. 2. Also, they submitted a five year 

monitoring report in April 2009. This monitoring report includes groundwater, surface water, and 

sediment monitoring results from monitoring events conducted on March 21 and March 22, 2009. 

These were the first sampling events following the completion of the Final Close Out Report. 

VL FIVE-YEAR REVIEW PROCESS 

Administrative Components 

EPA notified DNREC in December 2008 of the initiation of the five-year review. The fiveyear review team was led by Ronnie M. Davis, the EPA Remedial Project Manager (RPM) for the 

Site. Steve Johnson of DNREC assisted in the review as the representative for the support agency. 

The five-year review schedule included the following components: 

• Community Involvement; 

• Document Review; 

8 
• Data review; 

" • Site Inspection; and 

• Five-Year Review Report Development and Review. 

Community Involvement 

Carrie Deitzel, EPA's Community Involvement Coordinator, informed local officials that 

EPA was conducting the Five-Year Review. EPA will place a public notice in the Delaware State 

News, after the 3^'' Five-Year Review is signed, to inform the public that the Five-Year Review has 

been conducted and that the findings are available. 

Document Review 

The following documents were reviewed for this Five-Year Review: 

• Consent Decree (entered by the Court on April 8, 1992) 

• Second Five-Year Review Report (May 25, 2004) 

• Final Closeout Report (February 19, 2009) 

• Coker Sanitation Services Landfills O & M Progress Report ( 2009) 

• Work Completion Report (2008) 

Data Review 

Sampling for ethylbenzene and styrene were approved in the sampling and analysis plan 

and monitored during the 2009 sampling event at landfill No.l. Neither parameter was detected in 

the ground water. 

Sampling for ethylbenzene, styrene, 1,2,3-tricloropropane, antimony, and total phenolics 

were approved in the sampling plan and monitored during the 2009 sampling event at landfill No. 

2. Ehylbenzene, styrene, and phenolics were not detected in the ground water, and antimony was 

below the trigger levelof 6 ug/1. 

Three parameters were analyzed in surface water and sediments: ethylbenzene, styrene, and 

xylenes (total). None of the parameters were detected in surface water or sediments. 

f 
Site Inspection 

On April 6, 2009, Ronnie M. Davis, EPA's RPM for the Site, Stephen Johnson, DNREC's 

Project Manager for the Site, and Scott R. Miller of Clean Sites Environmental Services, Inc., the 

representative for the PRPs, conducted a Site inspection as part of the five-year review process. 

The objective of the inspection was to assess the protectiveness of the remedy. The fence 

surrounding Landfill No. 2 has been cut in several places, and it looks as if a tree fell on the fence 

at one location. Scott Miller will have the fence repaired by November 2009. 

VIL TECHNICAL ASSESSMENT 

Question A: Is the Remedy Functioning as Intended by the Decision Document? 

Yes. • 

The review of the site-related documents, risk assumptions, and the result of the Site 

inspection indicates that the remedy is functioning as intended by the ROD. 

Question B: Are the Exposure Assumptions Data, Cleanup Levels, an d Remedial 

Action Objectives (RAOs) Used at the Time of the Remedy Selection Still Valid? 

Yes. 

Remedial Action Objectives 

The goal of the remedial action was to reduce the potential for future contact with the waste 

or with Site contaminants, thereby reducing risks to within EPA guidelines. The cancer risks 

associated with no action at both landfills was at or above EPA's guideline of 1 x lO"*; after 

implementation of the selected remedy, cancer risks are below 1 x 10" . The Hazard Index score was 

above 1.0 at both landfills; after implementation of the remedy, the Hazard Index score was reduced 

below 1.0. The security fence, cover material placed on the landfills, and closure of the leachate 

collection wells at Landfill No. 2 have reduced the potential for contact with the landfill waste and 

leachate. Institutional controls have been implemented and all remedial action objectives have been 

met. 

Because there are no users of ground water hydraulically downgradient of Landfill No.l, 

monitoring of Landfill No. 1 was conducted primarily for the protection of aquatic life in the Willis 

Branch. The trigger levels developed for each of the site related contaminant of concern for 

groundwater are as follows: styrene (2900 ug/L), and ethylbenzene (3,200 ug/L). The trigger levels 

for surface water for surface water monitoring are as follows: styrene (1,400 ug/L), ethylbenzene 

(1,600 ug/L), and.xylenes (900 ug/L). 

Because a few residential wells are located hydraulically downgradient of Landfill No 2, 

monitoring at Landfill No. 2 has been conducted primarily for the protection of human health. The 

10 
trigger levels developed for each of the site-related contaminants of concern for ground water at 

Landfill No. 2 are as follows: styrene (100 ug/L), ethylbenzene (5 ug/L), 1,2,3-trichloropane (5 

ug/L), phenolics (22,999 ug/L), and antimony (6 ug/L). 

Changes in Standards and To Be Considered (TBCs) 

There have been no changes in ARARs or TBCs that affect the protectiveness of the 

remedy. All ARARs were construction related. 

Changes in Exposure Pathways, Toxicity, and Contaminant Characteristics 

Because the State regulations under which the landfills were closed did not require deed 

restrictions on the property, EPA evaluated onsite risk under a hypothetical residential use 

scenario. Risks to offsite residents resulting from exposure to contaminants released from landfill 

No. 2 waste cells into the shallow groundwater following liner failure were also evaluated. The 

overall risks quantified in the risk assessment were primarily based upon exposure to the following 

compounds: benzene, cadmium, chloroform, dibutyl phthalate, manganese, phenol, cresol, 

ethylbenzene, and styrene. These assumptions are considered conservative and reasonable in 

evaluating and developing risk-based cleanup levels. No changes to these assumptions; or the 

cleanup levels developed from them are warranted. 

Question C: Has Any Other Information Come to Light That Could Call into 

Question the Protectiveness of the Remedy? 

N o . . • . • . . . _ 

Technical Assessment Summary 

The review of the site-related documents, risk assumptions, and the results of the Site 

inspection indicates that the remedy is functioning as intended by the ROD. Currently, the land is 

not being used; however, during the Site inspection, one of the owners of Landfill No.2 expressed 

an interest in rernoving the fence from around the landfill and allowing deer to graze on the grass. 

Groundwater monitoring was discontinued based on the recommendation to do so in the 

First Five-Year. During the preparation and completion of the Final Close Out Report in February 

2009. EPA determined monitoring should resume at a minimum of every five years because waste 

has been left in place at the Site. A monitoring report was completed in April 2009 and EPA is 

preparing to delete the Site from the NPL. Therefore, it is recommended that an additional round 

of groundwater, surface water and sediment samples should be analyzed for the presence of 

volatile organic compounds, semiviolatile organic compounds, and metals. 
VIII. ISSUES 

Table 2 - Issues 

Issue 

The chain link security fence has been cut in 

several places. Additionally, a tree has fallen on 

a secfion of the fence. 

EPA is preparing to delete the Site from the 

NPL. Groundwater, surface water and 

sediments should be analyzed for the presence 

of volatile organic compounds, semiviolatile 

organic compounds, and metals. 

Currently Affects 

Protectiveness 

(Y/N) 

N 

N 

Affects Future 

Protectiveness 

(Y/N), 

N 

N 

IX. RECOMMENDATIONS AND FOLLOW-UP ACTION 

Table 3 - Recommendations and Follow-Up Actions 

Issue 

The chain link 

security fence has 

been cut in several 

places. 

Additionally, a tree 

has fallen on a 

section of the fence. 

Groundwater, 

surface water and 

sediments should be 

analyzed for the 

presence of volatile 

organic compounds, 

semiviolatile organic 

compounds, and 

metals. 

Recommendations 

Repair the fence. 

Monitor for 

volatile organic 

compounds, 

semivolatile 

organic 

compounds and 

metals. 

Party 

Responsible 

PRP 

PRP 

Oversight 

Agency 

EPA 

EPA 

Milestone 

Date 

November 

2009 

November 

2009 

Affects 

Protecfiveness? 

(Y/N) 

Current Future 

N 

N 

N 

N 

12 
X. PROTECTIVENESS STATEMENT 

The remedy at the Site currently protects human health and the environment. The chain link 

security fences around the waste disposal areas of both landfills restrict access to the Site and 

reduce the potential for exposure to Site contaminants. The soil cover on the landfills prevents 

direct contact with the waste, minimizes migration of contaminants to the groundwater, and 

reduces the generation of leachate. There is no evidence of erosion or a breach of the soil cover on 

either landfill. The closure of the leachate collection wells at Landfill No. 2 has reduced the 

potential for direct contact with leachate. Thus, there is no known evidence of current exposure to 

the waste or Site contaminants and the remedy is considered protective in the short-term. In the 

long term, the remedy is protective because the deed restrictions (institutional controls) required by 

the ROD, which restrict the use of the land, have been implemented by the use of Environmental 

Easements. The institutional controls ensure long-term protectiveness by prohibiting any type of 

acfivity that could disturb the landfill surfaces or the underlying waste at each landfill, or in any 

way increase the risk of exposure to Site contaminants, including, but not limited to, any soildisturbing activifies at the Site 

XI. NEXT REVIEW 

The next five-year review for the Coker's Sanitation Service Landfills Site is required in 

May 2014, five years from the date of this review. 

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