Five-Year Review ReportSouth Brunswick Township Landfill

South Brunswick, New Jersey

Prepared by:United States Environmental Protection Agency

Region 2New York, New York

September 2007

Executive Summary

This is the fourth five-year review for the South Brunswick Township Landfill site. The site islocated in South Brunswick, New Jersey. This site is being addressed under one operable unit. The ROD called for on-site containment of the waste material and monitoring for a period of atleast thirty (30) years. The remedy was selected on the basis of its implementability and proveneffectiveness of landfill containment given the hydrogeology of the site, size of the landfill andwaste disposal practices.

This five-year review found that the remedy is functioning as intended by the decision documentsand is protecting human health and the environment.

Five-Year Review Summary Form

SITE IDENTIFICATION

Site name (from WasteLAN): South Brunswick Landfill

EPA ID (from WasteLAN): NJD980530679

Region: 2 State: NJ City/County: South Brunswick/Middlesex

SITE STATUS

NPL status: G Final O Deleted G Other (specify)

Remediation status (choose all that apply): G Under Construction O Constructed O Operating

Multiple OUs?* G YES O NO Construction completion date: 10/1993

Has site been put into reuse? G YES O NO G N/A

REVIEW STATUS

Lead agency: O EPA G State G Tribe G Other Federal Agency

Author name: Farnaz Saghafi

Author title: Rem edial Project Manager Author affiliation: EPA

Review period:** 09/17/2002 to 06/30/2007

Date(s) of site inspection: 03/29/2007

Type of review:

O Post-SARA G Pre-SARA G NPL-Removal onlyG Non-NPL Remedial Action Site G NPL State/Tribe-leadG Policy G Regional Discretion

Review number: G 1 (first) G 2 (second) G 3 (third) O Other (specify) 4 (fourth)

Triggering action:

G Actual RA Onsite Construction at OU #____ G Actual RA Start at OU#____

G Construction Completion O Previous Five-Year Review Report

G Other (specify)

Triggering action date (from WasteLAN): 9/17/2002 (Previous Five-Year Review)

Does the report include recomm endation(s) and follow-up action(s)? G yes O no

Is the remedy protective of the environment? O yes G no

* [“OU” refers to operable unit.]** [Review period should correspond to the actual start and end dates of the Five-Year Review in WasteLAN.]

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Five-Year Review Summary Form (continued)

Issues, Recommendations, and Follow-Up Actions

There are no recommendations or followup actions stemming from this five-year review. BFIis conducting routine operation and maintenance activities.

Other Comments on Operation, Maintenance, Monitoring, and Institutional Controls

See above regarding additional maintenance and monitoring requirements.

Protectiveness Statement

The remedy at the South Brunswick Landfill is protective of human health and theenvironment. The landfill cap, slurry wall and site fence are intact and in good conditionexcept for some minor needed repairs. The remedy currently protects human health and theenvironment because exposure to contaminated materials is restricted by the slurry wall andthe landfill cap which serve to contain the contamination within the landfill. The constructionof an interceptor trench in the area of wells R-10 and R-11, near the southeastern section of thelandfill, has mitigated the flow of contaminated groundwater beyond the limits of the landfill. Groundwater contamination in all other areas of the site is contained within the slurry wall.

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I. Introduction

This five-year review was conducted by Farnaz Saghafi, U.S. Environmental Protection Agency(EPA) Remedial Project Manager (RPM). This review was conducted pursuant to Section 121(c)of the Comprehensive Environmental Response, Liability and Compensation Act (CERCLA), asamended, 42 U.S.C. Section 9601, et seq., and 40 C.F.R. 300.430(f)(4)(ii) and in accordancewith the Comprehensive Five-Year Review Guidance, OSWER Directive 9355.7-03B-P (June2001). The purpose of a five-year review is to determine whether the remedy at the site isprotective of human health and the environment and functions as intended by the decisiondocuments. This document will become part of the site file.

This is the fourth five-year review for the South Brunswick Township Landfill site. The first fiveyear review was considered complete by the Region with the issuance of the preliminary close-out report (PCOR) in 1993. The PCOR documented the construction completion of the remedyand summarized post-remedial environmental monitoring activities including groundwater, soil,surface water and sediment sampling. In September 1997, EPA conducted a second five-yearreview which included a site visit to ensure that conditions at the site remained protective ofhuman health and the environment, in addition to review of documents, data and information. The 1997 five-year review determined that the remedy continued to provide adequate protectionof public health and the environment. The 2002 five-year review documented an area ofgroundwater contamination near the southeastern section of the landfill in the immediate area ofwells R-10 and R-11, as indicated by the site monitoring data (see Attachment A, Site Map). Itcalled for an evaluation of the aquifer in the area south of the landfill to determine if there werepotential migration pathways to receptors downgradient of the site. However, the remedy wasdetermined to be protective of human health and the environment since there were nodowngradient receptors that could be potentially exposed to this newly discovered area ofcontamination.

This site is being addressed under one operable unit, however site remediation has beenperformed in three phases, consisting of the following elements:

Phase I involved a hydrogeologic investigation designed to determine the nature and extent ofcontamination related to the site.

Phase II called for the development of a Remedial Plan and construction of the EPA-selectedremedy for the landfill. The Remedial Plan consisted of a leachate collection/treatment system,slurry wall, clay cap and gas venting system.

Phase III consists of an on-going post remedial environmental monitoring program designed toprovide a continuous assessment of the long-term effectiveness of the completed on-site remedialaction.

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II. Site Chronology

Table 1, below, summarizes site-related events from discovery to present operation andmaintenance activities:

Table 1: Chronology of Site Events

Event/Activity Date

Landfill Registered with the NJDEP 1970

Site Officially Closed 1978

EPA Site Investigation 1980

Site Listed on the NPL 1982

AOC Between EPA and BFI for Performing Remediation 1982

Phase I Hydrogeologic Investigation 1982

Remedial Plan Submittal for Phase II Work 1983

Remedial Action Initiated 1983

Remedial Action Completed 1985

Record of Decision 1987

Phase III Post Remedial Monitoring Proposed by BFI 1987

Administrative Order Issued by EPA 1989

Post Remedial Environmental Monitoring Implemented 1993

First Five-Year Review (Issuance of PCOR) 1993

Final Post Remedial Environmental Monitoring Report 1996

Second Five-Year Review 1997

Draft Post Closure Operation and Maintenance Plan 1997

Site Deleted from the NPL 1998

First Post Closure Annual Report 1999

Second Post Closure Annual Report 2000

Final Post Closure Operation and Maintenance Plan 2000

Event/Activity Date

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Third Post Closure Annual Report 2001

Fourth Post Closure Annual Report 2002

Third Five-Year Review 2002

R-10 Area Groundwater Investigation Report 2002

Focused Remedial Alternatives Evaluation Report 2003

Fifth Post Closure Annual Report 2003

Focused Remedial Alternatives Evaluation Report Approval 2004

Sixth Post Closure Annual Report 2004

R-10 Area Action Start 2005

Seventh Post Closure Annual Report 2005

R-10 Area Action Completion 2006

Eighth Post Closure Annual Report 2006

Ninth Post Closure Annual Report 2007

Fourth Five-Year Review 2007

III. Background

Physical Characteristics

The South Brunswick Township Landfill, owned by BFI Waste Systems of New Jersey Inc.(BFI), is located along New Road approximately one-half mile northwest of U.S. Route 1 inSouth Brunswick, Middlesex County, New Jersey. The landfill occupies an area ofapproximately 68 acres. A significant portion of the land surrounding the site is wooded. Aprivate residence is located adjacent to the site, a school and park are located directly across NewRoad and a housing development has been constructed north of the site.

The site is in close proximity to Heathcote Brook which is a tributary to the Millstone River. TheCity of New Brunswick occasionally draws water for drinking from an intake 10 milesdownstream. Groundwater flows in a southeasterly direction and the nearest public groundwatersupply is located approximately one mile north of the site.

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Geology/Hydrogeology

The site is located in the Piedmont physiographic province and lies within an outlier or erosionalremnant of coastal plain sediment. The main outcrop of coastal plain sediment is approximately1.5 miles to the southeast. Three distinct geologic units underlie the site. These units includefrom top to bottom, the Raritan Formation, residual soil or saprolite, and diabase or basalticbedrock.

Previous investigations have shown that only the sands of the Raritan Formation and thefractured basalt in the northeastern area of the site are capable of transmitting any significantamounts of water.

Groundwater exists at relatively shallow depths in the fill and underlying the Raritan Formation. Typically, the shallow groundwater occurs under unconfined conditions, however, confined orsemi-confined conditions are locally observed as a result of the variable lithology of the RaritanFormation. Groundwater flow is reported to be generally in a southerly direction.

Groundwater flow occurs primarily in the horizontal direction and discharges to a stream ortopographic low within a short distance from the site. The water table is highly variable andsubject to seasonal fluctuations in response to differential rates of groundwater recharge. Groundwater within the fractured bedrock in the northeastern area of the site occurs underconfined conditions. The unit is confined by the low permeability residual soils above and therelatively unfractured bedrock below.

Land and Resource Use

General land use and drinking water sources in the vicinity of the site have not changed since thesigning of the Record of Decision (ROD) in September 1987. A Deed Notice filed in May 2002has restricted use of the site to landfill closure, inspection, maintenance and monitoring. Inaccordance with this document, no owner or operator shall make any alteration, improvement, ordisturbance in, to, or about the affected areas of the site which disturbs any engineering control orwhich creates an unacceptable risk of exposure to humans or the environment without firstobtaining the express written consent of the EPA and the New Jersey Department ofEnvironmental Protection (NJDEP).

History of Contamination

The site, which operated for more than twenty years as a solid waste landfill, accepted municipalrefuse, pesticides, chemical wastes and hazardous wastes. The landfill was registered with theNJDEP on August 19, 1970. Pursuant to a closure order from the NJDEP on July 24, 1978, thesite was officially closed on December 31, 1978.

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Initial Response

In June 1980, the EPA conducted an investigation of the landfill. Sampling results revealedelevated levels of volatile organic compounds in seven on-site monitoring wells and at five on-site surface water sampling locations. As a result, the site was listed on the National PrioritiesList (NPL) in December 1982.

Browning-Ferris Industries of South Jersey, Inc. (BFI), as the owner and operator of the landfillsince 1973, was identified by the EPA as a potentially responsible party with respect to the site. Accordingly, EPA entered into negotiations with the company and on April 5, 1982, EPA andBFI entered into an Administrative Order on Consent (AOC) which required BFI to investigateand remediate the site.

IV. Remedial Actions

Remedy Selection and Implementation

In accordance with an Administrative Order on Consent (RCRA-700320101) dated April 5,1982, between BFI and EPA, several environmental investigations were conducted and served todevelop a Remedial Plan for the Site. The Remedial Plan was submitted to EPA in February1983.

The Remedial Action Plan consisted of the following elements:

C Multi-Layered Cap

C Slurry Wall

C Leachate Collection System

C Gas Venting System

The Remedial Action was initiated in May 1983 and completed in September 1985. In addition,a security fence was constructed along the site perimeter to restrict access, eliminate any nuisancethreats and preserve the integrity of the remedial action.

The following describes in more detail each of the remedial components:

Multi-Layered Cap

A multi-layered cap was constructed over the entire Site. The cap consists of a 12-inch layer ofcompacted clay with a maximum permeability of 1.0 x10-7 cm/sec overlain by a 6-inch sanddrainage layer and a 6-inch vegetated soil layer. The cap functions to reduce infiltration of

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precipitation, promote surface water drainage and prevent direct contact with waste materials.

Slurry Wall

A slurry wall was constructed near the perimeter of the site with a length of over 7,000 feet and aminimum 3 foot width. The alignment was based on geologic conditions where the slurry wallcould be keyed into competent bedrock or saprolite. Approximately 63% of the slurry wall iskeyed into bedrock and the remaining length is keyed into saprolite. The slurry wall wasreported to have a maximum permeability of 1.0 x10-7 cm/sec and the slurry consists of ashale/silty sand mixture with 1% bentonite. The slurry wall functions to restrict potentialhorizontal movement of leachate from the Site.

Leachate Collection System

The leachate collection system is located on the inward (landfill) side of the slurry wall. Thecollection system was constructed in a 3-foot wide trench and consists of a 6-inch diameterperforated corrugated polyethylene pipe in a coarse stone backfill. The stone and pipe areenclosed in a filter fabric envelope. In addition to the perimeter collection system, there is aninterior collection system consisting of a collection line and a french drain which tie into theperimeter system. The collection line is located in the low lying area west of the drainage swalein the central area of the site and the french drain is located to the east of the drainage swale inthe central area of the site. A second french drain was constructed in the northern section of thesite outside the cut-off wall. The leachate collection system functions to control potential off-siteleachate migration and reduce leachate heads within the landfill.

Gas Venting System

The gas collection system consists of three interior passive vents and a passive vent on eachleachate manhole. The interior system consists of three 10-inch aluminum vent risers withshallow collection pipes radiating from the risers. A security fence is located around each ventriser. The manholes are vented by a 4-inch aluminum riser. The gas system functions to controlthe potential migration of landfill gas generated by the decomposition of waste.

Site Security Fence

A security fence circumscribes the site. A main gate is located in the southeastern corner of thesite providing access from New Road. Various locking gates are located around the site. Thepurpose of the security fence is to prevent unauthorized access to the site.

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On September 30, 1987 EPA issued a Record of Decision (ROD) that concurred with theremedial action that was implemented by BFI. The ROD states:

“EPA believes the site has been effectively remediated, thereby mitigating the threat ofcontaminants into the environment which could present an imminent and substantialendangerment to human health and the environment.”

System Operations/Operation and Maintenance (O&M)

As part of routine adjustments, BFI implemented other improvements to the remedy includingconstruction of an on-site leachate pretreatment plant and surface water drainage improvements. The treatment plant was constructed in 1992 and 1993. Prior to construction of the plant,leachate was discharged directly to the sanitary sewer line for primary treatment by the StonyBrook Regional Sewerage Authority (SBRSA). The on-site plant was constructed pursuant to anAdministrative Consent Order entered between BFI and NJDEP which required ironconcentrations in the effluent to be reduced. On June 26, 1996, BFI was notified by SBRSA of achange in classification from a Class 1 to Restricted Industrial User (RIU). Effective July 26,1996, BFI was no longer required to monitor for iron and pre-treatment was no longer necessary. The plant was decommissioned shortly thereafter. Currently, BFI discharges directly to thesanitary sewer line while still monitoring pH, Chemical Oxygen Demand (COD), and flow on amonthly schedule under a license issued by the SBRSA.

Upgrades were made to the surface water drainage system in 1991 in compliance with theFreehold Soil Conservation District. The upgrades consisted of grading in the central area of thesite, construction of five surface water drainage channels, improvements to five existing culverts,installation of energy dissipaters and a scour pad, and revegetation.

The draft Post-Closure Operation and Maintenance (O&M) Plan was submitted to EPA in 1997and finalized in 2000. The O&M Plan provides for periodic inspection, maintenance andmonitoring to evaluate and maintain the effectiveness of the existing source control measures. The O&M Plan is comprised of the following major elements:

C Inspection and Maintenance Plan;C Monitoring Plan; and,C Safety Plan.

The Inspection Plan is used for routine inspections of the following elements of the remedy inorder to identify components requiring maintenance or repair:

1. Surface water drainage system (annual inspection in the spring);2. Leachate collection system (semi-annual inspection in early spring and late fall);3. Protective cover system (annual inspection in the spring);4. Groundwater monitoring wells (semi-annual inspection);

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5. Passive gas venting system (semi-annual inspection); and6. Site security system (quarterly inspection).

The Post Closure Operations and Maintenance Plan provides for scheduled monitoring andmaintenance of the components of the remedy to ensure the continued effectiveness of theremedial systems:

1. Leachate is discharged to the sanitary sewer line for treatment by the Stony BrookRegional Sewerage Authority (SBRSA). Leachate is metered during discharge tothe SBRSA. The meter is calibrated quarterly and a copy of the calibrationcertificate is provided to the SBRSA. In accordance with a letter from the SBRSAdated March 10, 2004, no further leachate sampling is required.

2. The Landfill Gas Emissions (LFG) venting system consists of three interiorpassive vents (PV-1, PV-2, and PV-3). The LFG vents are monitored annually formethane and non-methane hydrocarbons, and are analyzed by Air Toxics LTD ofFolsom, California. In addition to sampling of the passive LFG vents, BFImonitors fourteen (14) gas monitoring probes along the perimeter of the site onthe outboard side of the slurry wall. The gas monitoring probes are monitoredmonthly for percentage of the lower explosive limit and methane.

3. Groundwater is monitored by sampling fourteen (14) monitoring wells semi-annually for Target Compound List (TCL) VOCs, annually for Target AnalyteList (TAL) metals and bi-annually for TCL SVOCs. Monitoring well R-10 issampled quarterly for VOCs and annually for SVOCs and metals. Five off-property wells in the area of monitoring well R-10 are sampled quarterly forVOCs.

4. Surface water monitoring for VOCs is performed quarterly as part of the PostClosure Plan.

5. Groundwater and leachate levels are monitored quarterly to evaluate theeffectiveness of the leachate collection system in maintaining hydraulic control.

Since 1998, annual site investigations have been conducted to evaluate the effectiveness of thecompleted Remedial Action and evaluate off-site migration of contaminants, as required by theROD.

The persistence of VOCs in groundwater outside the landfill slurry wall led to an investigation ofthe R-10 area beginning in July of 2001, during which a network of temporary borings andpiezometers were installed to characterize the extent of contamination in the shallowgroundwater in the R-10 area. An additional monitoring well, R-11, was installed at the propertyboundary downgradient of R-10. Results from groundwater sampling indicated that VOC

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contamination extends approximately 130 feet downgradient of R-10 to well R-11 and about 300feet farther west of R-10 to temporary boring GW-5. Concentrations of chlorobenzene,chloroform, TCE, benzene and methylene chloride were observed in boreholes and newlyinstalled wells in July 2001 and again in May 2002. Exceedances of chloroethane, 1,1-Dichloroethene, and 1,1,1-TCA were also observed, with a maximum concentration ofchloroethane of 14,600 parts per billion (ppb) observed in PZ-1. V. Progress Since the Last Review

The third five year review for this site, which was approved on September 25, 2002, noted thatgroundwater contamination was detected near the southeastern section of the landfill in theimmediate area of wells R-10 and R-11, and that VOC contamination had migrated downgradientand west of well R-10. Monitoring well R-10, one of the wells comprising the groundwatermonitoring system, is located outside the landfill slurry wall on the downgradient side near thesoutheastern area of the slurry wall. The third five year review recommended additional plumecharacterization to completely define the lateral extent of the plume and follow-up by appropriateremedial action to ensure long-term protectiveness.

Since then, a groundwater investigation of the area was conducted in 2002. The investigationconcluded that the downgradient extent of VOC impacts was localized as defined by off-Sitewells TB-1, TB-3, TB-4 and TB-13 and the source area was determined to be limited to anapproximately 500-foot length along the perimeter of the landfill. A remedial evaluation reportwas submitted by BFI to EPA in July 2003. In February 2004, EPA approved this report whichcalled for the construction of an interceptor trench.

Construction of the 360-foot long interceptor trench took place in the fall of 2006 and includedplacement of bedding stone, installation of perforated high density polyethylene pipe (HDPE)and placement of filter sand. A groundwater transmission system including HDPE sump, pumps,power and control systems was also installed. The leachate from this area is collected andpumped with other landfill leachate to the POTW. The monitoring system for the interceptortrench consists of piezometers, measuring inward flow of groundwater.

VI. Five-Year Review Process

Administrative Components

At the BFI site, the ROD date of September 30, 1987 is considered EPA’s acceptance of theinitiation of the remedial action. Consequently, a five-year review was due on September 30,1992. In October 1993, EPA issued a Preliminary Close-Out Report (PCOR). EPA hasdetermined that the PCOR constitutes the first Five-Year Review Report. The PCORdocumented the construction completion of the remedy and summarized post-remedialenvironmental monitoring activities including groundwater, soil, surface water and sedimentsampling.

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In September 1997, EPA conducted a second five-year review which included a site inspection toensure that conditions at the site remained protective of human health and the environment

In September 2002, EPA conducted a third five-year review which included a site inspection andevaluation of remedial components. This review documented an area of groundwatercontamination near the southeastern section of the landfill in the immediate area of wells R-10and R-11 as indicated by the site monitoring data. It called for an evaluation of the nature of theaquifer material in the area south of the landfill to determine if there are potential migrationpathways to receptors downgradient of the site. However, it was determined that the remedywould remain protective of public health and the environment until the next five-year reviewsince there were no downgradient receptors that could be potentially exposed to this newlydiscovered area of contamination.

For this five-year review, the review team consisted of Farnaz Saghafi (EPA - RPM), Ed Modica(EPA - Hydrogeologist), Marian Olsen (EPA - Risk Assessor) and Michael Clemetson (EPA -Ecologist).

Community Involvement

EPA published a notice in the Home News Tribune, a local newspaper, on April 11, 2007,notifying the community of the initiation of the five-year review process. The notice indicatedthat EPA would be conducting a five-year review of the remedy for the site to ensure that theimplemented remedy remains protective of public health and the environment and is functioningas designed. It was also indicated that once the five-year review is completed, the results will bemade available in the site repository. In addition, the notice included the RPM’s address andtelephone number for questions related to the five-year review process or the South BrunswickLandfill site. Local officials and the Township Health Officer were contacted to inquire abouthealth-related complaints. They reported no complaints or comments from the residents. TheEPA RPM was not contacted by any members of the community regarding this Five-Yearreview. The Township Health Officer and other Township representatives were invited andparticipated in the site inspection performed as part of this Five Year review.

Document Review

This five-year review consisted of a review of relevant documents including O & M records andmonitoring data (see Attachment C).

Data Review

Results of the data review are compiled in separate sections below:

Hydraulic MonitoringAs part of the Post-Closure Monitoring Program, groundwater and leachate levels have been

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measured quarterly to evaluate the effectiveness of the leachate collection system to maintainhydraulic control in the landfill (the maintenance of inward groundwater flow gradients within thelandfill). Because outward hydraulic gradients were measured along the southwestern area of thesite (manhole/well pairs MH-06/R-1 and MH-08/R-2), new piezometers were installed nearmanholes along southwestern area of the site to better evaluate leachate levels within the landfill.Water levels measured in the newly installed piezometers verified that seasonal lows ingroundwater level, especially during drier seasons, cause outward gradients to occur along thedowngradient side of the landfill when water levels decrease outside the landfill wall. It wasconcluded that the seasonal occurrence of an outward gradient near the southern section of thelandfill would not of itself compromise the effectiveness of hydraulic containment provided that1) outward gradients do not persist year round and 2) groundwater and surface water quality dataremain compliant with state and federal water-quality standards. Water quality data collected inwells R-1 and R-2 from previous post-closure monitoring indicate sporadic detections of VOCs atconcentrations below NJDEP Ground Water Quality Standards (GWQS) and Federal MaximumContaminant Levels (MCLs).

Groundwater MonitoringGroundwater data over the past five years was collected and analyzed for volatile organiccompounds, semi-volatile organic compounds and metals. The groundwater is classified byNJDEP as a potable aquifer, indicating a potential drinking water source. At the current time, thegroundwater at the site is not being used for ingestion and the exposure pathway has beeninterrupted by the slurry wall and leachate collection system. An inward hydraulic gradient hasalso been maintained along the perimeter of the slurry wall as intended by the design.

Table 2 (Attachment D) compares the concentrations of contaminants found in the groundwaterthat do not have drinking water standards or exceed the current NJDEP GWQS, NJ DrinkingWater Standards, or EPA MCLs listed. The maximum concentrations exceeding their respectivestate and federal standards are identified. However, as stated above, contaminated groundwater iscontained by the slurry wall and interceptor trench.

The hydraulic gradient data collected to date in the vicinity of the newly constructed interceptortrench indicate that the trench is operating as intended and is effective in capturing contaminatedgroundwater. Operation and Maintenance requirements for the interceptor trench have beendeveloped and are part of the O&M procedures at the site.

Surface Water MonitoringSurface water monitoring for VOCs is performed quarterly at location PCSW-1, in accordancewith the Post-Closure Plan for the site, to evaluate the quality of surface water downgradient ofthe site as a result of VOC detections reported in monitoring well R-10. No VOCs were detectedabove laboratory reporting limits during the last 4 quarters.

Site Inspection

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An inspection of the South Brunswick Landfill site was conducted on March 29, 2007. Thefollowing parties were in attendance:

Farnaz Saghafi, EPA Region II Project ManagerEd Modica, EPA Region II Hydrogeologist,Marian Olsen, EPA Region II Risk AssessorMartha Goodwin, NJDEP Case ManagerChris Leaf, Golder Associates - Project ManagerHeather Lin, Golder AssociatesSteve Papenberg, Township of South Brunswick - Health OfficerDavid Smith, BFI - Regional Environmental ManagerTom Morris, South Brunswick Recreation DepartmentBonnie Bucalern, South Brunswick Recreation Department

The site inspection consisted of a physical inspection of the landfill cap, leachate collectionsystem, slurry wall, surface water drainage system (such as culverts for collection of surfacerunoff), security fence, surrounding wetlands and other components of the landfill. The coversystem had recently been mowed, which facilitated the inspection.

The inspection commenced at the southeast corner of the property, near the site entrance. Theinspection team walked the perimeter of the site and recorded relevant observations in a fieldlogbook. The inspection proceeded along the perimeter of the site in a counterclockwise directionuntil the entire perimeter was traversed. In addition to inspecting cap features, gas monitoringprobes, monitoring wells, gas vents, and leachate manholes, pump stations and the site fence werevisually inspected. The recently constructed interceptor trench system near monitoring well R-10and surrounding wetlands were inspected. After inspection of the site perimeter, the centralportion of the site was traversed and the surface water drainage features were inspected.

The following sections present the results of the site inspection broken down by each element ofthe site remedy.

Multi-Layered Cap

Inspection of the landfill cap resulted in discovery of numerous animal burrows of various sizesand depths. Animal burrows have commonly been found and backfilled at the site as part of theregular annual inspection performed by BFI. Small slope irregularities, depressions in the cap andareas of differential settlement and distressed vegetation were also noted in the cap. Somedrainage swales did not appear to drain positively off the cap due to observation of ponded waterat these locations. A couple of surface water drainage system culverts were obstructed and inneed of clearing. No cracking, excessive erosion, seeps, slope instability, or excessive vegetativegrowth was observed on the landfill cap. All monitoring wells inspected during the site visit werelocked and in good condition. Since the inspection, these repairs have been completed.

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Slurry Wall

While inspecting the perimeter of the site, the slurry wall was assessed for signs of distress orsettlement. No obvious signs of distress or settlement were observed along the slurry wallalignment during the site inspection.

Leachate Collection System

The leachate manhole designated as Pump Station A was uncovered during the inspection. BFIpersonnel indicated that the station was open to facilitate repairs to the internal force-main piping. That work was completed shortly after the walk through, and the station was re-secured. ThisPump Station A as well as Pump Station B have relatively light “Bilko” doors. These doors arenormally secured with a lock and chain to prevent unauthorized entry. The remaining manholeshave heavy-duty, street rated sewer lids which are difficult to remove, making accidental entryimprobable.

Gas Venting System

All passive gas vents and gas monitoring probes observed during the site inspection were in goodcondition, labeled, and locked. With the exception of some animal burrows observed adjacent topassive gas vent PV-2, no deficiencies were observed at the passive gas vent locations.

Site Security Fence

The security fence was generally in good shape. BFI personnel indicated that occasionaltrespassers break through the fence in order to drive their all terrain vehicles through the property. BFI regularly inspects the fence and repairs any such areas of damage. All personnel gatesobserved during the site inspection were locked.

Record Keeping

The following documents are currently not maintained on-site in their entirety:

• Site Specific Health and Safety Plan• As-Built Drawings• Maintenance Logs• Final Post Closure Operation and Maintenance Plan

In addition, it was determined during the inspection that the site security fence, personnel gates,signs and passive gas vent numbers are not shown on the Site Plan in the Final Post-ClosureOperation and Maintenance Plan. EPA has raised these record keeping issues to BFI and BFI hasagreed to address all issues. In addition, gas monitoring probe results are not currently included in

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the annual post closure monitoring reports, but will be included in the future.

Interviews

Several interviews were conducted to supplement the inspection. Stephen J. Papenberg, SouthBrunswick Health Officer was interviewed prior to his participation in the March 2007 siteinspection and indicated that no health-related complaints were reported or filed with the SouthBrunswick Township Health Department regarding the site. David Smith, BFI’s project managerfor the site, was interviewed before, during and after the site inspection regarding site operation,maintenance, and record keeping issues.

VII. Technical Assessment

Question A: Is the remedy functioning as intended by the decision documents?

Yes, all components of the remedy are functioning as intended by the decision documents. Theremedy consists of a multilayered cap, a perimeter slurry wall/leachate collection system, and agas venting system. The cap is composed of a 6-inch sand drainage layer over topped by a 6-inchlayer of vegetated soil cover and a 12-inch layer of compacted clay. The cap is generally in goodcondition and has been functioning to reduce infiltration and promote surface water drainage. Water-quality data in monitoring wells around the landfill show that contaminated groundwater iscontained within the landfill area.

A low permeability slurry wall, constructed near the perimeter of Site, restricts horizontalmovement of leachate from the Site. A leachate collection system, also installed along the Siteperimeter, collects and conveys leachate by gravity to one of two pumps. There is also an interiorcollection system consisting of collection lines and French drains that are tied into the perimetersystem. The slurry wall and leachate collection system function to contain leachate within thelandfill. Post-closure monitoring data indicate that inward hydraulic heads are generallymaintained. Operations and maintenance records indicate that regular inspections andmaintenance to the collection and pumping systems are being performed in accordance with theapproved Post-Closure Plan.

In the fall of 2006, a 360-foot long interceptor trench was installed outside the slurry wall toaddress one area of groundwater contamination detected outside the slurry wall in the area of wellR-10. This trench connects to the leachate collection system sending leachate to the POTW.

A gas venting system, made up of three interior passive vents and a passive vent on each leachatemanhole, is operational. As indicated in the most recent annual post closure environmentalmonitoring report, only two of the three passive gas vents have had measurable flow in the lastfew years. During the Site inspection, no noticeable gas odors were observed at the site other thanadjacent to the passive gas vents. BFI personnel indicated that landfill gasses are occasionallydetected in the gas monitoring probes located around the perimeter of the landfill. However,

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borehole probes advanced small distances from the exceedance locations have displayed gasconcentrations within acceptable ranges. The security fence surrounding the Site is in good repair. Occasional trespassers have been observed to breach through the fence, but in general, securitymeasures appear to be effective in preventing unauthorized access to the Site.

A palustrine forested wetland area along the southern border of the South Brunswick Landfill sitewas impacted as a result of remedial activities associated with the construction of a groundwaterinterceptor trench in late 2006. Consequently, restoration work was initiated to mitigate thedisturbance. During the site visit, it was observed that although plantings were conducted in thewetland area, in the spring of 2007, a significant amount of them had not survived. It was evidentthat volunteer species from the surrounding canopy will thrive. Therefore, an evaluation of thearea will be conducted and consideration given to replanting the same or different species to bestsuit the conditions for the area. The survival percentage trigger criteria should be re-examinedand wetland monitoring should continue on an annual basis.

Question B: Are the exposure assumptions, toxicity data, cleanup levels, and remedial actionobjectives used at the time of the remedy still valid? There have been no changes in the physical conditions of the Site over the past five years thatwould change the protectiveness of the remedy. In general, the Site has limited access based onits location with a significant portion of the property around the landfill being wooded; a privateresidence is located adjacent to the site, a school and park are located directly across New Roadand a housing development has been constructed north of the site. The landfill cap, fencing tolimit or prevent access to the Site, and signage provide barriers to exposure. During theinspection, BFI personnel indicated that there is an ongoing issue with trespassers cutting throughfences to ride their all terrain vehicles on the site but they are performing continuing inspectionsand maintenance of the fencing to reduce these exposures. The ongoing procedures to inspect andre-establish the fencing where appropriate should continue.

The property is zoned R-1, residential. The general land use and drinking water sources in thevicinity of the site have not changed since the signing of the ROD in 1987. Groundwater use atthe Site is not expected to change. The previous 5 year review included a discussion of ascreening level assessment performed at that time to update the toxicity/exposure information,since the 1987 Record of Decision was issued before current Risk Assessment Guidance. Thisinformation was used to develop a screening level assessment that established risks above theNCP range. The chemicals of concern in the groundwater identified included: benzene,chloroform, 1,2-dichloroethane, methylene chloride, trichloroethene, and vinyl chloride,chlorobenzene, 4-methyl-2-pentanone and toluene. The assessment of the last five years of dataindicates that risks due to groundwater contamination continue to be accurately addressed. Thiscontaminated plume is contained by the remedy.

Groundwater

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The ROD established the MCLs as the cleanup criteria for contaminants of concern identifiedabove. The toxicity values for several of the chemicals of concern were updated (e.g., benzene,chlorobenzene, chloroform, vinyl chloride, chromium, lead, manganese and nickel) or are beingupdated through the Integrated Risk Information System (IRIS) EPA’s consensus toxicity system(chloroethane, trichloroethylene, methylene chloride, and beryllium). The EPA MCLs andNJGWQs, and NJ MCLs remain protective. Groundwater within the landfill is being collectedand disposed of off-site at a POTW and will continue to be contained by the remedy unless thesecleanup goals are achieved within the slurry wall.

Soil Vapor IntrusionAt the current time, there are no residences on the Site. As shown above, groundwatercontaminated with volatile organic compounds was found in one well outside the slurry wall(monitoring well R-10). Monitoring well R-10 is located over 100 feet from the nearestresidential area. Consistent with OSWER Draft Guidance for Evaluating the Vapor Intrusion toIndoor Air Pathway for Groundwater and Soil, since the well is located over 100 feet from thenearest property, further evaluation of this pathway is not appropriate. In the future, in theunlikely event that buildings are placed on this property, this pathway should be further evaluated.

Overall, based on the past remedial actions and ongoing monitoring at the site, the remedyremains protective under the current conditions.

Question C: Has any other information come to light that could call into question theprotectiveness of the remedy?

No. Presently, the landfill cap is protective of the contaminated material and the leachatecollection system and interceptor trench are effective in removing the contaminated leachate fromthe site. The site security fence further protects the site from invasive activity that maycompromise the integrity of the containment system.

Technical Assessment Summary

According to the data reviewed, the site inspection and the interviews, the remedy is functioningas intended by the decision documents. There have been no changes in the physical conditions ofthe site that would affect the protectiveness of the remedy.

VIII. Issues, Recommendations and Follow-up Actions

There are no recommendations or followup actions stemming from this five-year review. BFI isconducting routine operation and maintenance activities and adjustments are made on an on-goingbasis as needed.

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Attachment A

Site Map

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Attachment B

List of Acronyms:

EPA (United States) Environmental Protection AgencyFS Feasibility StudyMCL Maximum Contaminant LevelNJDEP New Jersey Department of Environmental ProtectionRAO Remedial Action ObjectiveRI Remedial InvestigationROD Record of DecisionTCE TrichloroetheneUSACE United States Army Corps of EngineersVOCs Volatile organic compoundsCOC Contaminant of ConcernMCL Maximum Contaminant LevelGWQS Groundwater Quality Standard

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Attachment C

Documents Reviewed:

C Wehran Engineering, Certification Report for Slurry Trench Cut-off Wall ConstructionSouth Brunswick Township Landfill Remedial Action Plan, June, 1984

C Browning-Ferris Industries, Leachate Collection Systems Construction Report, May, 1986C Record of Decision, September 1987C Hydro Group, Inc., Field Operation Procedures (FOP) for Excavation, Storage, Cap

Disruption, and Placement of Material at the Browning-Ferris of South Jersey SouthBrunswick Landfill (Closed), November 17, 1992

C First Five-Year Review Report (PCOR), 1993C Post Remedial Environmental Monitoring, Final Report, June 1996C Second Five-Year Review Report, September 1997C First Annual Post Closure Report, December 1998C Second Annual Post Closure Report, December 1999C Final Post Closure Operation and Maintenance Plan, October 2000C Third Annual Post Closure Report, January 2001C R-10 Area Groundwater Investigation Interim Data Report, November 2001C Fourth Annual Post Closure Report, January 2002C Leachate Collection System Field Investigation Report, March 2002C USACE Inspection Report, August 2002.C Third Five-Year Review Report, September 2002C R-10 Area Groundwater Investigation Report, 2002C Fifth Annual Post Closure Report, February 2003C Final Focused Remedial Alternatives Analysis Report, 2004C Sixth Annual Post Closure Report, April 2004C Seventh Annual Post Closure Report, March 2005C Eighth Annual Post Closure Report, March 2006C Ninth Annual Post Closure Report, March 2007C Construction Completion Report, Groundwater Interception Trench, April 2007

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Attachment D

Table 2 - Chemical Constituents in Groundwater

Chemical EPAMCL

(mg/l)*

NJDEPGWQS

* *(mg/l)

NJ StateDrinking

WaterStandards(mg/l)***

Max. Conc.Location

Sample ID(last 5 yearsof samples)

Result

Chloroethane NA NA NA 0.002 mg/l R-1

NoStandards

Benzene 0.005 0.001(PQL)

0.001 0.0036 mg/lR-10 (3/10/06)

ExceedsNJGWQS andDrinkingWaterStandard

Chlorobenzene 0.100 0.050 NA 0.530 mg/lR-10 (8/31/06)

ExceedsEPA andNJGWQSvalues

Chloroform 0.08 0.07 NA 0.110 mg/lR-10 (3/10/06)

ExceedsEPA andNJGWQSvalues

Methylene chloride 0.005 0.003 0.003 0.0065 mg/lR-10 (8/31/06)

ExceedsNJDWQS,EPA and NJDrinkingWaterStandards

Trichloroethylene 0.005 0.001 0.001 0.038 mg/l R-10 (3/10/06)

ExceedsEPA andNJGWQSandDrinkingWatervalues

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Vinyl chloride 0.002 0.001 0.002 0.0023 mg/lR-10 (3/10/06)

ExceedsEPA and NJDWQSandDrinkingWater values

1,2-dichloropropane 0.005 0.001 0.005 0.0019 mg/lR-10 (6/29/06)

ExceedsNJGWQS value

Aluminum (total) – 0.200 – 8.130 mg/lR-6 (11/28/05)

ExceedsNJGWQSvalue

Beryllium (total) 0.004 0.001 0.004 0.0027 mg/lR-6 (11/28/05)

ExceedsNJGWQSvalue

Chromium (total) 0.100 0.070 0.100 0.116 mg/lR-8 (11/28/05)

ExceedsEPA andNJGWQSvalues

Iron (total) 0.300(2nd

Standard)

0.300 0.300 *2ndStandard

7.280 mg/lR-6 (11/28/05)

ExceedsNJGWQSEPA andNJDEP 2ndStandardMCLS

Lead 0.015ActionLevel

0.005ActionLevel

0.015 ActionLevel

0.0053 mg/lR-7 11/28/05

ExceedsNJDGWQS

Manganese (total) 0.05 2ndStandard

0.050 0.05 2ndStandard

7.780 mg/l R-10 11/28/05

ExceedsNJGWQSandsecondarystandard

Nickel (total) -- 0.120 No MCLMonitoringRequired

0.388 mg/lR8 11/28/05

ExceedsNJGWQS

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• *EPA drinking water standards available from: http://www.epa.gov/safewater/contaminants/index.html#mcls• **Values from http://www.state.nj.us/dep/wms/bwqsa/gwqs_table1.html• ***Values from http://www.state.nj.us/dep/watersupply/standard.htm