FOURTH FIVE-YEAR REVIEW REPORT FOR THE HENDERSON … · Henderson Road Fourth Five-Year Review...

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FOURTH FIVE-YEAR REVIEW REPORT FOR THE HENDERSON ROAD SUPERFUND SITE

MONTGOMERY COUNTY, PENNSYLVANIA

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December 2013 .-,

Prepared by

U.S. Environmental Protection Agency ~egion III' '

Philadelphia, Pennsylvania

Kathryn A. Hodgkiss, Act g Director Date Hazardous Site Cleanup Divlsio~ p.S. EPA, Region III

Henderson Road Fourth Five-Year Review Report December 2013

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TABLES

Table 1 Table 2 Table 3 Table 4 Table 5 Table 6

FIGURES

Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 Figure 17 Figure 18 Figure 19

Chronology of Site Events ............................................................................................ 2 VOC Compounds and Associated ARARs .................................................................. 7 Annual O&M Costs ............................................................................................ , ........ 19 Concentration Comparison of ARAR Exceedances in Impacted Wells ..................... 28 Issues .... , ................. : ................................................................................ .'.................... 34 Recommendations and Follow-Up Actions ................................................................ 34 _

Site Location Map ' Approximate MW Locations Shallow Groundwater Contour Map Intermediate Groundwater Contour Map Deep Groundwater Contour Map Plan View Screen Capture of ARAR ExceedaJ:!ces in Groundwater South to North Screen Capture ofARAR Exceedances in Groundwater Vapor Intrusion Sampling Locations Groundwater Results June 2013 HorizontarDistribution of Benzene above the ARAR Horizontal Distribution of Benzene above the ARAR (2003 -2012) Horizontal Distribution of Chlorobenzene above the ARAJl Horizontal Distribution of Chlorobenzene above the ARAR (2003 - 2012) H~rizontal Distribution of 1,1-DCA above the ARAR Horizontal Distribution of 1,1-DCA above the ARAR (2003 -2012) Horizontal Distribution of Vinyl Chloride above the ARAR Horizontal Distribution of Vinyl Chloride above the ARAR (2003 - 2012) Horizontal Distribution of Xylene above the ARAR Horizontal Distribution of Xylene above the ARAR (2003 -2012)

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ATTACHMENT

Attachment 1 Photo Log Attachment 2 Public Notice

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TABLE OF CONTENTS

List of Acronyms ................................................................................................ -............................. v . s . ' ..Executlve ummary. .......... ....... .......... .. ... ..... ... .... ............ .. .. .. .... ........ .... .. . ... .. ... . ....... ... ..... .. ......... vn

Five-Year Review Summary Form................................................................................................ i_x-

I. Introduction ..................................................... : ................................................................... 1 \ II. Site Chronology ................. : ................................................................................................ 2 III. Background ......................................................................................................................... 3

Physical Characteristics ......................................................... : ...................................... 3 ' Land and Resource Use ................................................................................................ 3

History of Contamination ........................... -....... :.-................. : ....................................... 3 Basis for Taking Remedial Action ............................................................................... 4

· IV. Remedial Actions ................................................................................................................ 6 '

Remedy Selection····················································:_:··················································· 6 Remedy Components .................................................................................................... 6 Remedy Implementation .................................~ ............................................................. 8 System Operation/Operation and Maintenance ... , ..................................... -................. 15

Progress Since ~he Last-Five-Year Review ................. .'.......................................... , ......... 19 Five-Year Review Process ............................................................................................... 24

Administrative Components ....................................................................................... 24 Community Involvement ............................................................................................ 25 Document Review ......................................... , .......................................................... !. 25 Site Inspection ......................................................................................... : .................. 25 -, Int~rviews ................................................................................................................... 26

/ Data Review................................................................................................................ 26 VII. Technical Assessment .... ~ ......................................... ; ............................................. : .......... 31

Question A: Is the remedy functioning as intended by the , decision documents? ............................................................................ 31

Question B: Are the exposure assumptions, toxicity data, clean-up levels, and Remedial Action Objectives used at the time of the remedy selection still valid? ................................................................. 31

Question C: Has any other information come to light that could call into question the protectiveness of the remedy? ......................................... 33

Technical Assessment Summary·················:······························································ 33 VIII. Issues.................... : ............................................................................................................ 34 , IX. Recommendations and Follow-up Actions ....................................................................... 34

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x. Protectiveness Statement .................................................................................................. 34 XI. Next Review ..................................................................................................................... 35

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AO ARAR MC DOH CD CERCLA CFR coc CIC EI EPA ESD FS' GAC gpd GMUC GPRA IW IWOU IC LNAPL LOU MCHD MW MCL NCP NPDES NPL O&M OU PADEP PADER PCB PCE PCOR

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ppb PRPs PSWC PTC RAO RAU RI ROD· RSL

LIST OF ACRONYMS

Administrative Order Applicable or Relevant and Appropriate Requirement Montgomery County Department of Health Consent Decree Comprehensive Environmental Response, Compensation, and Liability Act Code of Federal Regulations Contaminant of Concern Community Involv~ment Coordinator Envirorimental Indicator U.S. Environmental Protection Agency Explanation of Significant Difference Feasibility Study Granular Activated Carbon gallons per day Groundwater Migration Under Control Government Performance and Results Act Injection Well _ Injection Well Operable Unit Institutional Control Light, Non-Aqueous Phase Liquid Landfill Operable Unit Montgomery County Health Department Monitoring Well Maximum Contaminant Level National Contingency Plan National Pollution Discharge Elimination System National Priorities List Operation and MaintenanceOperable Unit Pennsylvania Department of Environmental Protection Pennsylvania Department of Environmental Resources

. Polychlorinated, Biphenyl Tetrachloroethene Preliminary Close-Out Report Photoionization Detector parts per billion Potentially Responsible Parties Philadelphia Suburban Water Company Pennsylvania Turnpike Commission Remedial Action Objective Ready for Anticipated Use I'

Remedial Investigation r

Record of Decision Regional Screening Level

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. Henderson Road

RPM SEPTA SI svoc SWRAU TCE TSC UMR USGS VES VI voe µg/kg µg/L

Fourth Five-Year Review Report December 2013

Remedial Project Manager Southeastern Public Transportation Authority Site Inspection , S~mi-Volatile Organic Compound Site-Wide Ready for Anticipated Use Trichloroethene Technical Steering Committee Upper Mer~on Reservoir U.S. Geological Survey Volatile Extraction System Vapor Intrusion Volatile Organic CompQund microgram per kilogram microgram per liter

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EXECUTIVE SUMMARY

The remedy for the Henderson Road Superfund Site in Upper Merion Township, Montgomery County, Pennsylvania was selected in two separate Records of Decision ("ROD"): the 1988 Injection Well Operable Unit ("IWOU") ROD included the installation and operation of a groundwater extraction and treatment system, installation and operation of a volatile extraction system, implementation of a comprehensive groundwater monitoring program, and institutional controls. The 1989 Landfill Operable Unit ("LOU") ROD included the relocation of Site waste materials to an existing on-Site landfill, capp\ng of the landfill, and collection and treatment of leachate from the landfill. The Site achieved construction completion with the signing of the Preliminary Close-Out Report on October 28, 1992. An initial Fjve-Year Review was completed on September 28, 1998. The third Five-Year Review report was completed op. November 21, 2008. The third Five-Year Review report is the trigger for this fourth Five-Year Review.

This fourth Five-Year Review for the Henderson Road Site finds that the remedy has been implemented in accordance with the requir~ments of the Records of Decision.

The Injection Well Operable Unit is protective of human health and the environment in .the short term and is expected to be fully protective at completion. In the interim, exposure pathways that could result in unac~eptable risks are being controlled. Contaminants remain in ' groundwater at concentrations that do not allow for unlimited use and unrestricted exposure. However, contaminated groundwater is contained to within the general facility area and institutional control~ are in-place that _effectively limit exposure to groundwater. A

· determination needs to be made regarding the appropriateness and feasibility of modifying the selected groundwater remedy; a periodic reevaluation of the groundwater cleanup objectives, as required by the 1988 ROD, needs to be performed; a groundwater background study needs to ,be performed; and the risk evaluation associated with the-volatile organic compound concentrations in the on-Site garage indoor air needs to continue.

The remedial action.associated with the Landfill Operable Unit is protective. The landfill has been capped and a leachate collection system has been installed, thereby reducing infiltration and the migration of contaminants.

Government Performance and Results Act ("GPRA") Measure Review

The GPRA holds federal agencies accountable for using resources wisely and achieving program results. ·As part of this Five-Year Review, two environmental in'Clicators ("EI") and one land revitalization measure were reviewed. The status of these measures is presented below:

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P~rformance Measure Progress Category/Status

Site-Wide Human Exposure EI Current human exposure under control

' -Contaminated Groundwater Migration EI Contaminated groundwater migration under control

Site-Wide Ready for Anticipated Use Conditions for Site-Wide RAU status have been ("RAU") achieved

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Henderson Road ~ Fourth Five-Year Review Report December 2013

Five-Year Review Summary Form

SITE IDENTIFICATION

. Site' Name: Henderson Road /

EPA ID: PAD009862939

City/County: Upper Merion Township, Region: 3 s·tate: PA Montgomery County

SITE STATUS

NPL Status: Final

Multiple OUs? Has the site achieved construction completion? Yes (two) Yes

REVIEW STATUS

/ Lead agency: U.S. EPA

Author name (Federal or State Project Manager): Timothy Gallagher

Author affiliation: U.S. EPA Region 3

Review period: November 2012 - November 2013 \

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Date of site inspection: May 3, 2013

Type of review: Statutory

Review number: 4 '

Triggering action date: November 21, 2008 '

Due date (five years after triggering action date): , November 21, 2013

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Five-Year Review Summary Form (continued)

Issues/Recommendations

OU(s) without IssueslReco~mendati9ns Identified in the Five-Year Review: ,

OU-2

Is~ues and Recommendations Identified in the Five-Year Review: .. Issue 1 Issue Category: Remedy Performance _/

(OU-1) Issue: PRP is evaluating a proposal to modify the selected groundwater remedy.

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~ecommendation: Determine the appropriateness and feasibility of modifying the selected groundwater remedy.

Affect Current Affect Future Implementing Oversight Milestone Date Protectiveness , Protectiveness - Party Party

-No Yes PRP EPA 12/31/2014

Issue 2 . Issue Category: Monitoring (OU.:1)

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Issue: The 1988 ROD requires periodic reeval~ation of th~ groundwater ( remedial action objective.

Recommendation: Continued reevaluation of the· groundwater cleanup goals. .

Affect Current Affect Future Implementing Oversight Milestone Date Protectiveness Protectiveness Party Party

No " Yes PRP EPA 12/31/2014

Issue 3 Issue Category: Monitoring (OU-1) Issue: The indoor air concentrations in the on-Site garage-are higher than

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Recommendation: Perform a risk assessment of the on-Site garage workers. -·

Affect Current Affect Future Implementing Oversight Milestone Date Protectiveness Protectiveness Party Party

No Yes EPA/PRP EPA 1/31/2014'

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Issue 4 Issue Category: Monitoring (OU-U Issue: Cleanup standards for certain groundwater COCs (i.e. TCE) may 1not be

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Recommendatiop.: Perform a new groundwater background study. f I

Affect Current Affect Future Implementing Oversight , Milestone Date Protectiveness Protectiveness Party Party

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No Yes PRP EPA 12/3112015

Five-Year Review Summary Form (continued)

Protectiveness Statements

Operable Unit: Protectiyeness Determination: Addendum Due Date: OU-1 Protective Not applicable

Protectiveness Statement: ' (

The Injection Well Operable Uqit is protective of human health and the environment in the short term and is expected to be fully protective at completion. In, the interim, exposure

. pathways that could result in unacceptable risks are being c<mtrolled. dmtaminants remain'in groundwater at concentrations that do not allow for unlimited use and unrestricted exposure. However, contaminated groundwater is contained to within the general facility area and institutional controls are in-place that effectively' limit ~posure to groundwater. A determination needs to be made regarding the appropriateness and feasibility of modifying the selected ground~ater remedy; a periodic reevaluation of the groundwater cleanup objective, as required by the· 1988 ROD, needs to be performed; a groundwater background study needs to be performed; and risk evaluation associated with the volatile orgamc compound concentrations in the on-~Fte garage indoor air needs to continue.

Operable Unit: Protectiveness Determination: Addendum Due Date: -

OU-2 Protective Not applicable

Protectiveness Statement: The remedial action associated with the Landfill Operable Unit is- protective. The

landfill has been capped and a leachate collection system has been installed, thereby reducing infiltration and the migration of contaminants.

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Henderson Road Fourth Five-Year Revfow Report December 2013 )

I. Introduction

The purpose of the 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 id~ntify issues fm~nd during the review, if any, and identify recommendations to add~ess thegi.

The United States Environmental Protection ,Agency ("the Agency" or '-'EPA") is preparing this Fiye-Year Review Report pursuant to .Section 121(c) of the Comprehensive Environmental Response, Compensation and Liability Act ("CERCLA") 'and the National Contingency Plan ("NCP"). CERCLA §121(c) provides:

"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 judgment of the Presidenf that action is appropriate at such site in accordance with section [104] or [106], the P;esident shall take or require such action. The President shall report to the_ Congress a list offacilities for which such review is required, the results of all such reviews, and any actions

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taken as a result ofsuch reviews. "

EPA interpreted this requirement further in the NCP, in the Code of Fede~al Regulations ("<?FR") at 40,CFR §300.430(f)(4)(ii) which provides:

"If a remedial action is selected that results in hazardous substances, pollutants, or c;ontaminanfs remaining at the site above levels that allow for unlimited use and unrestricted exposure, the lead agency shall review such action no less often thari every five years after th~ initiation ofthe selected remedial action. "

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This is the fourth Five-Year Review for the Site. The· action triggering this statutory review was the completion of the third Five-:.Year Review, which is documented as November 21, 2008. This-review was conducted from November 2012 through October_2013 by the assigned Remedial Project Manager ("RPM"). This report documents the results of the review.

This Five-Year Review is statutorily required because the implemented remedy resulted in hazardous substances being left on the Site. Specifically, hazardous substances remain: in the soils on the Henderson Road property at concentrations which do not allow for unlimited use and unrestricted exposure. In addition, until the long-term groundwater recovery and treatment remedy achieves Site groundwater cleanup standards, contaminants also remain in the groundwater at concentrations which do not allow for unrestricted exposure. '

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II. Site Chronology

Table 1. Chronology of Site Events

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Initial discgvery of Site contamination November 1, 1979

EPA places the Site on the National Priorities List September 211, 1984

EPA issues the Administrative Order on Consent for performance of a November 15, 1985 remedial investigation/feasibility study ("RI/FS") for the Injection Well

Operable Unit ("IWOU") and the Landfill Operable Unit ("LOU") ~

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RI/FS complete for the IWOU June 29, 1988

Record of Decision for the IWOU - June 30, 1988 I

Consent Decree ("CD") for Remedial Desigri and Remedial Action for the February 24, 1989

IWOU is entered

Remedial Design complete for the IWOU September 12, 1992

Remedial Action start for the IWOU - August 28, 1989 Construction complete for the IWOU October 30, 1992

-RI/FS complete for the LOU - September 29, 1989

( Record of Decisioll'for the LOU ,

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September29. 1989 -

Administrative Order for Remedial Design and Remedial Action for the LOU August 10, 1990 ' -

Remedial Design complete for the LOU/ Remedial Action Start for the LOU March 15, 1991

Construction complete for the LOU September 4, 1992 -Preliminary Close-Out Report is signed October 28, 1992

EPA issues the first Five-Year Review September 28, 1998

EPA issues the second Five-Year Review ' September 23, 2003

Start of the long term Shutdown/Rebound test for the groundwater pump and July 17, 2006 treat operations Start of th~ Shutdown/Rebound test for the volatile extraction system ("YES") August 23, 2007 '

' EPA issues the third Five-Year Review November 21, 2008

Installation of six additional monitoring ~ells north of the Pennsylvania - '

April 2010 :o.._ May 2011Turnpike

Repair and restart of the YES November 21, 2012

Addendum to the-2008 Five-Year Review is signed January 30, 2013 ' -

Biopopulation assessment, bromide tracer test study, and geophysical April.- July 2013

investigations

Achievement of SWRAU status September 2013

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III. Background ,

Physical Characteristics

\ The Henderson Road Superfund Site (The "Site") is located at 362 '- 372 South Henderson Road in Upper Merion Township, Montgomery County, Pennsylvania (Figure 1). The Site is 7.64 acres in area bound to the north by the Pennsylvania Turnpike, to the south by the Norfolk Southern Railway (formerly Conrail) rail line, to the east by the Southeaste,m Pennsylvania Transportation Authority ("SEPTA") Norristown High-Speed Line and an intermittent stream-named Frog Run, to the northwest-by 'the Chester Valley Railroad tracks (owned,by Norfolk Southern), and to the west by Henderson Road. A 36-inch pressurized water main, operated and maintained by a subsidiary of Aqua America, Inc; Aqua Pennsylv~ia, Inc. (formerly the Philadelphia Suburban Water Company ("P~WC")), crosses through the eastern portion of the Site landfill. A flooded former .quarry, the Upper Merion Reservoir ("UMR"), located approximately 2~000 feet north of, and downgradlent of, the Site is operated by Aqua Pennsylvania, Inc. as a drinking water supply reservoi~ serving over 250,000 customers. Groundwater pumping at'the UMR draws down groundwater from an approximate area of 2.4 square miles', which includes the Site area. The UMR pumping has depressed the groundwater table at the Site to approximately 120 to 160 feet below the surface.

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The Site is currently owned by the O'Hara family. The property was initially used by the O'Hara Sanitation Company, Inc ("O'Hara") for waste transfer, waste recycling, and vehicle maintenance.,, A portion of the Site property is currently operated by Republic Services, a solid waste management company.

Land and Resource Use

" The current and projected land use for the property surrounding the Site is commercial

and industrial. The population surrounding the Site uses public water as. its primary source of water supply. One groundwater well, located at a nearby commercial facility, that was once used by the employees .of a former lumber yard (and addressed in the IWOU Record of Decision ("ROD")) has since been closed and the facility is now serviced by the public water supply. There are no known private wells on or around the Site property that are currently in-use or that could potentially be impacted by the Site.

History of Contamination

The Site was brought to the attention of state authorities in 1977 by an anonymous telephone _call. On March 22, 1977, a truck that was observed while being filled at a local manufactutjng facility, entered' the O'Hara Sanitation property and, a short time later, leaving the property empty of its contents. A former water supply well, referred to henceforth as the injection well ("IW"), located inside the maintenance garage on the property was being used as a liquid waste depository. According to the Pennsylvania Department of Environmental Resources ("PAD ER"), now the Pennsylvania Department of Environmental Protection ("PADEP"), 6,000 gallons of liquid waste were disposed into the well the following day. PADEP sampled and characterized the waste as including a wide range of organic compounds. This disposal was not

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an isolated incident. It was later determined that the well was used for waste disposal between 1974 and. 1977. The total amount and exact composition of waste injected into the well is unknown.

A landfill that contains a waste volume of approximately 125,000 cubic yards is situated, to the yast of the former O'Hara offices and occupies an area of approximately 5.2 acres. O'Hara collected and transported residential and commercial trash. The property was also used . for truck maintenance and storage, container storage, recycling operation~ and office facilities. From October 1975 through 1979, and allegedly through ·1984, landfill operations took place at the Site. The waste material which consisted primarily of construction and demolition debris and. some residential trash and hazardous waste, was placed randomly on existing cinder materials from a cinder block manufacturing company formerly located at the Site. A portion of the fill area extended onto neighboring properties owned by Norfolk Southern to the south and the P~nnsylvania Turnpike Commission ("PTC") t<? the north.·

Basis for Taking Remedial Action , I

From September 1978 to,June 1983, multiple rounds of groundwater, surface water, and sediment sampling were conducted by the EPA and PADER. Based on the sample results, the Site was proposed for the National Priorities List ("NPL") on September 8, 1983. In November 1985, seven firms: (O'Hara Sanitation Company, Inc., Smithkline Beecham Corporation, Alumax Inc., Childers Products C9mpany, Sandvik Inc., Scott Paper Company, and Dould Inc.) and two individuals (William J. O'Hara and Betty O'Hara), considered the potentially responsible parties ("PRPs") entered into a Consent Order with the EPA to conduct a Remedial Investigation and Feasibility Study ("RI/FS") for the Site. The initial RI Report was submitted to the EPA in October 1986. Based on subsequent meetings between the EPA and the PRPs in 1987, the Henderson Road Site was separated into two operable units; the Injection Well

·Operable UQit ("IWOU") an,d the Landfill Operable Unit ("LOU"). Additional investigations of the Site commenced. EPA approved the final RI/FS for the IWOU in June 1988.

The following compounds are ·Considered to be chemicals· of cop.cern detected in groundwater samples collected from the injection well and/or Site monitoring wells (Figure 2 includes the approximate monitoring well locations): '

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Benzene, chlorobenzene, chloroethane, chloroform, 1,4-dichlorobenzene, 1,1dichloroethane, 1,1-dichloroethene, 1,2-dichloroethane, trans-1,2-dichloroethylene, 1,2dichloropropane, 2,4-dimethylphenol, ethylbenzene, phenol, · methylene chloride, 2, methylphenol, 4-methylphenol, toluene, tetrachloroethene ("PCE"), bis (2-ethylhexyl) phthalate, butyl benzyl -phthalate, benzoic aciq, vinyl chloride, 1,1,1-trichloroethane, trichloroethene ("TCE"), xylenes, dichlorobenzene isomers, naphthalene, 2-methylphenol; 4-methylphenol, benzyl alcohol, di-n-butyl phthalate, n-nitrosodiphenyl~ine, 4-chloroaniline, carbon tetrachloride, dibromochloromethane, dichlorobromomethane, cadmium, copper, and zinc.

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. During the LOU RI, samples taken of surface soil, surface sediment, surface water, leachate, and soil beneath fill material contained twelve volatile compounds ("VOCs"), 25 semivolatile compounds ("SVOCs"), five pesticides, and two types of polychlorinated biphenyls

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("PCBs"). The following organic compounds w~re identified in soil, sediment, and/or cinders at the Site in concentrations greater than 1 mg/kg: bis (2-chloroethyl) ether, benzidine, 1,2dichloroethane, tetrachloroethene, polycyclic aromatic hydrocarbons, bis (2-ethylhexyl) phthalate, hexachlorobutadiene, PCBs, ethylbenzene, dichlorobenzene, toluene, 2,6dinitrotoluene, hexachlorobenzene, hexachloroethane, and trichloroethene. ·Low concentrations of barium, lead, and chromium were also detected at the Site, as well as two pesticides.

Based upon the potential for release of contaminants to the groundwater beneath the landfill, the following contaminants were identified as contaminants of concern for the LOU: aldrin, benzene, bis (2-chloroethyl) ether, chloroform, ethylbenzene, hexachlorobenzene, lead, toluene, trichlorofluoromethane, polychlorinated aromatic hydrocarbons, 4,4dichlorodiphenyltrichloroethane, benzidine, barium, chromium, 1,3-dichloropropane, hexachlorobutadiene, polychlorinated biphenyls, trichloroethene, and tetrachloroethene.

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The primary groundwater flow direction is northern, across the Site iri the direction of the Upper Merion Reservoir which is located approximately 2,000 feet north of, and hydraulically downgradient of, the Site. Figures 3, 4, and 5 represent the shallow, intermediate and deep groundwater contour maps, respectively. The most significant threat posed by the Site is increased risk of cancer due to ingestion of contaminated groundwater. Included in this risk is the potential grovndwater ingestion by several hundred thousand customers of Aqua Pennsylvania, Inc. who are served by the Upper Merion Reservqir. Figure 6 depicts a plan view' of a ,cut section, which runs south to north, through the Site property (A) to the Upper Merion Reservoir (A'). Figure, 7 depicts the cut section showing the Site monitoring wells and the projected groundwater contamination plume based on sample results.

' The soils and/or leachate within the LOU were also determined to contribute to the

groundwater risk via downward infiltration of contaminants. Ingestion of contaminated soil and inhalation of wind-borne soil also contributed to the calculated risk posed by the Site.

. The IWOU and LOU Records of Decision selected Site cleanup levels intended to reduce the risk posed by ingestion of groundwater contaminated by the Site to an acceptable level by reducing groundwater contaminant concentrations for each contaminant to the most conservative value derived from the following: Maximum Contaminant Level ("MCL"), Maximum Contaminant Level Goal, Aquatic Water Quality Criteria,· Drinking Water Equivalent Level, Suggested No Adverse· Response Level, model outputs developed during risk assessment, processes described, in the Superfund Public Health Evaluation Manual, and specific values accepted by EPA (where no other ARAR exists). If such levels are achieved for each contaminant (or background levels for certain contaminants), the calculated cancer risk posed by the IWOU would be reduced· to an acceptable risk level. The groundwater risk posed by the , LOU would be reduced from 8.4 x 10-3 to 4.2 x 10-6 by reducing infiltration through the LOU (cap), thus preventing leaching of contaminants into the groundwater.

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IV. Remedial Actions

Remedy Selection ·.

Remedial Action Objectives - The remedial action objectives which were developed for both the IWOU and the LOU and specified in the RODs are listed below:

• Reduce the risk for groundwater, soil, fill materials, leachate, and air to an accep~able level for_carcinogens and noncarcinogens;

• Restore the aquifer beneath the Site to Class IIA classification; • Prevent significant transport/migration of the contaminants m soil, fill, and

leachate to groundwater; • Prevent the generation of leachate and thereby prevent the release of contaminants

to groundwater; and • Significantly reduce the potential for release of Site contaminants to the

, environment through fugitive particulate or vapor emissions.

Remedy Components J

IWOU

The IWOU ROD, issued by EPA Region III on June 30, 1988, included the following , major components to address groundwater contamination:

• Installation of clusters of groundwater recovery wells on-Site and, if necessary, ' downgradient; • Air stripping of groundwater and probable disc,harge-to the intermitte,nt stream

adjacent to the Site; a portion of the ground~ater may be re-injected to the aquifer in the vicinity of the ipjection well as part of unsaturated zone treatment;

- • Closure of the injection well, including excavation of contaminated oil pit sediments, in accordance with federal Underground Injection Well Program requirements and removal of significant waste, if feasible, directly out of the injection well;

• Placement of deed restrictions limiting or prohibiting µse of groundwater on the '-affected properties;

• Installation of a treatment system on the one off-Site active potable well (the _Mcilvain Well) considered to be affected by the Site-related contamination;,

• Periodic on-Site and off-Site_ groundwater monitoring throughout the Operation and Maintenance ("O&M") period;

• Further data collection and evaluation of the unsaturated and saturated zones during Remedial Design and periodically during Remedial Action, to determine the feasibility of in-situ volatilization of volatile organics or other treatment in the ·

_ unsaturated zone; and • Periodic re-evaluation of cleanup goals throughout O&M.

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The sediments within th,e well pit were cleaned out but it was determined that it would be beneficial to use the ~njection well as either a monitoring well or a recovery well and a point of vapor extraction. As

1a result of the additional data collection and evaluation activities required

by the ROD, it was concluded that a significant amount of contamination could be removed by pumping and treating groundwater and by extracting and treating vapors from the,injection-well. The periodic on and off-Site monitoring_ of groundwater was initiated and is being performed pursuant to the O&M Pl~n. The air stripping treatment system was replaced and enhanced during Remedial Design with biological treatment and carbon filtration of the groundwater as allowed in the ROD. During the first year of operation of the groundwater treatment plant, the groundwater regime was reinvestigated via· groundwater sampling and pumping tests (Phase II investigation).

As a result of this Phase II investigation, two additional recovery wells were connected to the gro1:ffidwater treatment ,Plant to enhance groundwater recovery. ,The treatment plant originally discharged to the sanitary sewer system.

· Under a National Pollution Discharge Elimination System ("NPDES") permit issued by PADEP, the treated water discharge point was modified to the adjacent iµtermittent stream via underground piping that surfaces at an installed lieadwall.

- . Table 2 lists the groundwater A~Rs taken from the 1988 IWOU ROD, Exhibit 16.

Thi 2 - voe c 'a e ompounds andAssoc1ated ARARs Compound . ARAR (U!!/I)

Acetone I ** Benzene 5.52~ (5.0 MCL) Bromodichloromethane 100

J 2-Butanone ** Carbon Disulfide ** Chlorobenzene 60 Chloro,ethane 19,000 Chloroform 100 Chloromethane ** -1, 1-Dichloroethane 5.06* 1,2-Dichloroethane -6.02* 1,1-Dichloroethene 7 \

cis-1,2-Dichloroethene 70 1,2-Dichloroethene 7o_ 1,2-Dichloropropane 6.28* Ethyl benzene 680 ,_

2-Hexanone -

** 4-Methyl-2-Pentanone ** Methylene Chloride 47 ' -

Styrene ** ,r

Tetrachloroethylene 6.9* (5.0 MCL) Toluene 2,000 Total Xylenes 175

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1, 1, I-Trichloroethane 200 Trichloroethylene 25.8* (5.0 MCL) /,

Vinyl Chloride 2 ,_Carbon Tetrachloride 5 Trichloroflouromethane . 12,000 Dibromochloromethane 100 *ROD alternative concentration limit based on background contamination. **No ARAR specified in the ROD.

The LOU ROD, issued by EPA Region III on September 29, 1989, included the following maj9r components to address soil, surface water, air, and groundwater contamination:

• Run-on, run-off, and erosion controls; • Short and long-term leachate collection; • Capping of the landfill, and relocation of-the on-Site water main unless a means

- of maintaining the water line on-Site while still achieving remedial objectives and State ARARs can be implemented;

• Groundwater recovery and treatment if, after two years of pumping groundwater beneath the Site for the IWOU; Site-related groundwater contamination· is detected at or near the property line and groundwater is still leaving the Site;

' • r Relocating trash, ~hallow soils, and shallow cinder fill from the Pennsylvania Turnpike property adjacent to the Site to the Henderson Road Site (LOU), additional characterization of the Turnpike property, and appropriate remediation to address wastes, contaminated soil, leachate, and bedrock left in place;

• Monitoring in coordination with the IWOU reme,dial action; • Institutional controls on-Site and on adjacent properties to restrict activities that

~ould interfere with remediation _at the Site; •. Further sample collection and data evaluation in the western portion of the Site, in

co.ordination with the IWOU remedial action, to determine the feasibility of insitu volatilization or other treatment, and/or capping 'in that area; and

• 'Periodic reevaluation of clean-up goals throughout operation and maintenance in coordination with the IWOU remedial ac;tion.

Rather than relocation, the water main was isolated from the LOU pursuant ·to an agreement with the PSWC (now Aqua Pennsylvania, Inc.) and as prov~ded in the ROD. Ongoing groundwater monitoring (in conjunction with the IWOU monitoring plan) .and re-evaluation of

· the remedial action is planne'd throughout the O&M Phase. The LOU cleanup standards are itemized in Exhibit 15 of the ROD.

Remedy Implementation

The IWOU remedial activities being implemented pursuant to a partial Consent Decree entered by and between EPA, seven firms (William J. O'Hara, Inc.; Smithkline Beecham Corp.oration; Alumax, Inc.; Congole'Um Corporation; Sandvik, Inc.; Scott Paper Company; and

8


(Childers Products Company), and two indiviciuals (William J. O'Hara and Betty E. O'Hara). The LOU remedial - activities are being implemented pursuant to a unilaterally issued Administrative ·otder by EPA to eight firms (O'Hara Sanitation Company, Inc.:; William J. ~ O'Hara, Inc.; Smithkline Beecham Corporation; Alumax Inc.; Congoleum Corporation; Sandvik, Inc.; Scott Paper Company; and Gould, Inc.) and two individuals (William J. O'Hara and Betty .E. O'Hara). '°'

IWOU

Implementation. of the remedial action activities for the IWOU commenced in July 1989 with the clean-out of the injection well pit to a depth of 174 feet using compressed. air from a drill rig. The work was completed in August 1989. '

On September 19, 1989, a point source treatment system was instalJed for the Mcilvain potable water well. This well was used for drinking water by employees of a lumber yard l~cated locally and downgradient to the Site. Well water analytical results revealed that low levels of organic contaminants, including 1, 1 -dichloroethane, chloroethane,. and chlorobenzene , were present within the well water. Based oh these results, the ROD required that a potable ·

, water treatment system be installed to remove contaminants from the water prior to human consumption.. The chosen treatment system consisted of activated carbon tanks. The treatment

. system became fully'operational and functional on March 15, 1990. The well was used until 1995 when the owner closed· it and the point source treatment system was removed. The property was then connected to the public water supply.

On April 2, -1991, excavation for the foundation of the groundwater treatment plant began. The excavated m~terial was hauled onto and consolidated within the LOU. Approximately 300 truckloads of mater,ial were excavated in preparation for the treatment plant construction. To provide a stable base for the plant construction, two lifts of granular crushed stone were placed and, compacted. A more ,uniformly graded crushed stone was subsequently placed up to within six inches of the base of the foundation. A layer of gedtextile fabric was then placed, followed by six inches of g~anular ·crushed stone to bring the backfill up to the proper

· elevatiop.. '

In May 1991, installation of the groundwater treatment plant commenced. Initial construction acti~ities involved placement of the concrete foundation, groundwater piping and electrical connections for the extraction wells, and the installation of additional monitoring wells .

. Qn June 5, 1991 the concrete floor of the treatment plant was placed. The groundwater treatment plant tanks and process equipment were· installed during the week of June 17, 1991. The treatlllent plant includes an equalization tank, two biological treatment towers with associated chemical feeds, and two activated carbon polishing units. The structural steel for the walls arid roof of the plant was brought on Site on July 8,' 1991. Erection of the walls and placement of the/ mezzanine floor followed. 'Installation of additional equipment and the a~sociated electrical and piping work continued thereafter until construction was complete.

The treatment plant began operation during the week of August 28, 1991. Initially, only purge water from the monitoring well drilling operations was pumped through the plant. Du~·to

9

Henderson Road Fourth Five-Year Review Report December 2013,

the initial low flows through the plant, the official first day of operation was not until September 4, 1991, the first day that flow from the injection well was pumped through the plant. The initial pumping rate was 50 - 60 gallons per minute. The plant utilized an aerobic bioremediation process to reduce organic contaminant levels followed by carbon adsorption to remove residual contaminants. The treatment plant was also expected to enable future treatment of landfill leachate. The treatment plant was. constructed with the capability to discharge treated water to either the local Publically Owned Treatment Works or to the intermittent stream that runs along the eastern boundary of the) Site. When operating, the treatment system is capable of processing ·approximately 1.6 million gallons of contaminated groundwater per month. Treated water is

~ - . discharged to an adjacent swale ultimately entering the nearby Frog Run in accordance with a NPDES permit issued by PADEP.

On February 20, 1992, after extensive pilot testing, EPA approved a volatile extraction system ("VES") design, which maximized the extent of subsurface-vacuum in order to maximize the amount of organic. contamination recovered from the unsaturated zone. The VES system was installed to extract contaminant vapors from the head space in some monitoring wells. It was tied ipto the treatment plant during the week of March 30, 1992. Originally, the VES was pulling extracted air through a series of vapor-phase carbon drums. After the groundwater treatment plant became fully operational, the vacuum induced within the plant could accomplish the same task and the bugs within the biological towers would benefit from the additional contaminant volume, thus enhancing the aerobic bioremediation process. In 1999 the VES was expanded and began operating as a stand-alone system. Extracted vapors are directed through a series of vapor-phase granular carbon tanks located on the north side of the treatment plant. building. The VES system is still in operation.

In April 1992, the PRPs installed five additional monitoring wells, (Phase II wells). The decision to drill these wells was based upon the reco~endations of a Saturated Zone Report prepared by the PRP. The location and depth of the five wells 'were selected with the intent of gaining additional information about the direction of contamination flow from the injection well (Figure,2): Two of the five wells (HR-24 and HR-26) were eventually chosen to be used as extraction wells. Pump tests were run on the two new extraction wells to determine the maximum possible pumping rate, and the extent ofdraw-down in adjacent monitoring wells. On Sept. 12, 1992, EPA approved the connection of the two wells to the treatment plant.

Institutional controls ("I Cs") are also a reqll;ired part of the IWOU remedy.

Implementation of IWOU Institutional Controls

By deed, r~cord.ed on December 15, 1989, the site owners acknowledge disposal of hazardous substances on or under the property from a former water supply well known as the injection welt and the disposal of, hazardous substances at the. landfill, citing to the Rls for the IWOU and the LOU.

In the deed, the owners (urther covenanted, among 'other things, that the grantee shall not interfere with or disturb the work (as defined in the CD} or any future response activities (including O&M) that may be performed. Grantee further covenants that· the property shall not

10


be used in a manner inconsistent with the IWOU RD/RA and shall insure that the restrictions ~~~~~ (

Montgomery County Health Department regulations restrict the use of groundwater. The regulations require the issuance of a permit before any well is installed and further requires that the well be sampled for VOCs prior to any use as a potable water supply. It is believed that all potentially (IWOU) affected properties are currently served by the public water system(s).

'

In 1989/1990 letters were sent by the PRP group to Potentially Affected Property Owners /

which requested owners of the potentially affected properties to restrict access to their groundwater until cleanup goals are achieved. The restrictions requested were to: 1) restrict drilling or pumping of wells; 2) prohibit development of wells; and 3) prohibit interfere11ce with the groundwater cleanup. ·

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On September 19, 1989, a treatment system for the Mcilvain potable. water well was installed. This well was used for drinking water by employees of a lumber yard located near the Site. Well water analytical results revealed that low levels of organic contaminants were present within the.well water. Based on these·results, the ROD required that a potable water treatment'

I

system be installed to remove contaminants from the water prior to human consumption. The chosen treatment system consisted of activated carbon tanks. The treatment system became fully operational an.d functional on March 15, 1990. In 1995 the OWI)er closed the well, removed the treatment system and connected to the public water supply. ' · ·

In January 1990, the PRP group counsel indicated that institutional controls under the Consent Decree for the Site property were achieved by deed dated April 28, 1989 which states the property may not be used in a mruµier inconsistent with the RD/RA for the IWOU. In addition, the PRP group counsel confirmed that the owner (Mrs. O'Bara) will not, and will not permit others, to drill or develop any groundwater wells other than those required by the RD/RA.

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, The above-listed efforts demonstrate that ICs under the IWOU ROD have been fully

implemented.

r Pursuant to an August 10, 1990 Administrative Order for Remedial Design m1d Remedial Action for the LOU, remedial action activities commenced in February 1991 with the removal of debris, soil, and cinder fill from the Pennsylvania Turnpike property along the northern boundary of the LOU. The excavated material was incorporated into the main waste fill area of the LOU. The remedial design plans were reviewed by the PTC and several modifications were made to conform to standard PTC d~sign requirements and to accommodate future expansion of the Pennsylvania Turnpike. Included as part of the remedial action was the installation of a leachate collection system within the LOU perimeter! The portion of the collection system along the northern boundary of the Site was installed while the Pennsylvania Turnpike property excavation was still open. The leachate collection system trenching was installed along the eastern, southern, and (partial) west~rn boundaries of the landfill during July and August 19~1. The system consists of perforated plastic pipe installed within a stone-filled perimeter trench. The pipes are

11


sloped to drain by gravity fo a collection sump at the eastern end of the Site .. Collected leachate can then be p~mped to the treatment plant. The main elements of the storm water control system were installed concurrent with the leachate collection system in July and August of 1991. ,

Initial grading of the landfill material b_e'gan in August 1991 in preparation for placement of the solid waste ·cap. Debris within 25 feet of the Conrail tracks along the southern .boundary of the Site was consolidated and· pulled back ·into the LOU. The landfill material was graded to a minimum slope of 3% and a maximum slope of 25% (4 horizontal to 1 vertical) for adequate drainage and slope stability.

LOU construction activities were temporarily postponed in November 1991 because the amount of time remaining before the arrival of prohibitively cold weather was insufficient to complete the LOU cap system installation. The water main' isolation system, which consisted of, essentially, a trench box for the water ~ain pipeline, was constructed after the initial· grading performed during the following spring. The PSWC'~ 36-inch potable water distribution main crosses the eastern edge of the LOU. The water main was isolated from the LOU for the

. following reasons: (1) to prevent potential water leaks from the pipeline from generating leachate· production within the LOU; (2) to eliminate the possibility of water main failure from carrying LOU material into the adjacent seasonal stream; (3) to allow repairs on the main without disturbing the cap; and (4) to prevent contaminating water within the main from contact with landfill ma~erial. PSWC and EPA agree.d that isolating the water main from the LOU was a reasonable and protective measure which would meet Applicable or Relevant and Appropriate Requirements ("ARARs").

The water main was isolated from the landfill material by placing a PVC liner under the pipe and covering the liner with a six-inch thick layer of concrete. Reinforced concrete was then placed on the west wall (landfill side) and bottom of the isolation trench. The base of the isolation trench was then fitted with a drainage system that consisted 'of a one-foot thick layer of crushed stone placed around an installed per~orated, corrugated pipe. At four locations, thi~ pipe system drains to the adjacent seasonal ·stream. Vertical riser pipes were installed along· each of the four drain pipes to monitor for the presence of st~ding water within the isolation trench which could indicate a water main le~ or a blocked drainage line. The design plans were reviewed by PSWC. Several modifications to the design and construction were made to, accommodate the water company's concerns. PSWC provided an inspector to witness the construction.

After completion ~f the water main isolation work,, placement of the ~olid waste cap began. Installation of the solid waste cap was the primary component LOU remedial action. The cap was installed over areas of the Site which contained construction debris and municipal waste. The construction debris consisted primarily of wood, metal, plastic, concrete, and asphalt mixed with soil. An asphalt paving cap was placed over the western portion of the Site and is part of the current parking area used at the Site.

The infiltration barrier originally chosen for the solid waste cap system consisted of a one- foot layer of compacted clay. EPA determined that the clay which was_ stockpiled for the project could not meet the required performance criteria for permeability. The PRPs then

12


proposed to use a geo-composite bentonite mat as the infiltration ~arrier.

The cap system installation consisted of the placement ·of a one-foot layer of protective cover soil directly on the surface of the landfill area. The cover soil was intended to act as a protective buffer between the waste material and the additional components of the cap system should any of the waste materials shift upward towards the cap system. A one-foot layer of low permeability clay was placed directly above the protective cover soil. This one-foot layer of clay was placed on areas of the landfill where infiltration prevention was most critical, such as around the main storm water inlet on the landfill surface where water was likely to pond, and on the southern edge of the Site, within 25 feet of the Conrail tracks where the clay was used to provide an edge seal with the bentonite mat. On areas of the landfill- where the layer of clay was not placed, the protective soil cover was placed to a depth of two feet. These layers of soil were compacted in six-inch thicknesses to 95% of the standard proctor maximum soil density.

< The bentonite mat was placed directly on the previously installed soil over the entire

landfill area. The mat consists of a thin layer pf bentonite clay sandwiched between one woven and one non-woven layer of geotextile.- Permeability tests ·were conducted on the 'bentonite mat and the required performance criteria for the cap were satisfactorily met. Powdered bentonite

' was placed inside/atop overlapping mat seams for additional protection against leakage. Directly ' I

above the bentonite mat a-geo11et drainag~ layer was placed. On top of the geonet an additional non-woven geotextile, that is designed to stop fine particles of soil from entering the geonet, was placed. Above the various geotextiles, a one and one half foot layer of cover soil was installedand compacted to 95% of the standard proctor maximum soil density. The final six inches of soil was then placed and compacted to 92% of the standard proctor maximum· soil density. To complete the cap system, a six-inch layer of topsoil was placed and vegetated with a lowmaintenance grass seed variety. )

On July 31, 1992, leachate within the leachate collection system began to be pfunped, initially to a ·clarifier for metals. treatment, and then into the grotindwater treatment plant. Leachate prodliction declined steadily since the start-up of the collection system and 4as not been seen within the collection manholes since 1998; (Several··leachate collection manholes were inspected during the May 3, 2013 Site inspectiqn; the manholes were, essentially, dry).

As with the IWOU, ICs are also a required part of the LOU remedy.

Implementation of LOU Institutional Controls

' t Restrictions were necessary for the Conrail property because the PRPs had excavated

waste and extended the landfill cap onto the property, then owned by Conrail (now owned by Norfolk Southern Railway Company). To implement these restrictions, on August 30, 2012, EPA issued a Notice of ICs for that Property to Norfolk Southen:i. As part of this notice, (an informational IC device), EPA notified Norfolk Southern ·of the ICs for the Property as required · ' for the IWOU and LOU RODs. Within the letter, EPA listed the specific restrictions that must b~ adhered to at the Property for the LOU:

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Prohibit any activities that would interfere with or jeopardize the integrity of the remedy, including,-but not limited to:

a) Any activity that would jeopardize the cap, the leachate collection system, fence and/or signage; ·

b) Any earth movement/excavation of any kind on the Property without prior approval of EPA;

c) No vehicle movement within the fenced area on the Property without prior approval ofEPA;

d) Any activity that would interfere with Site drainage.

The PRP group entered into a perpetual Access, Release and Indemnification Agreement with Philadelphia Suburban Water Company ("PSWC") which sets out restrictions protective of

- the remedy. It provides, among other things, that cover/material would be present above the waterline such that any excavation for maintenance by PSWC would not expose waste material; the PSWC must coordinate with the PRPs on any work which would disturb the· cap; and the PRPs would restore the cap afte~ any disturbance. This Agreement was recorded on May 12, 1992. /

In April 1991, the PRP group also entered into an agreement with the Pennsylvania Turnpike Commission ("PTC"), entitled "Institutional Controls Agreement (Easements, Covenants, Restrictions)" ("the Agreement"),_ to allow expansion of the Turnpike to be completed without impacting the remedy. The agreement also provided, among other things: c'ontrols to prevent disturbance of the cap; reporting obligations to the PRPs in the event that Turnpike operation impacts the integrity of the cap; notice to the PRPs of any_ work which would disturb the cap; documentati9n of activities which the PTC may undertake so long as there is no disturbance of the cap or wells. All covenants, agreements, restrictions and easements set forth in the agreement shall run with' the PTC property. This Agreement is perpetual and remains in

' effect. (While the Agreement calls for recording of the instrument, such recording was apparently never accomplished, according to the Wor~ Group's counsel. However, this Agreement is effective as an IC as a contract between the parties, which is enforceable by law between the parties. Moreover, it is not expected that this property, operated as a six-lane turnpike, will be sold in the foreseeable future; if that were to occur, the Agreement is, by its terms, binding upon the successors-in-interest to the Commission Property.)

, I

On January 22, 1996, Betty O'Hara, grantor, executed a trustees' warranty deed, recorded on February 23, 1996, which acknowledged that hazardous substances had been disposed in the landfill area as described in the RI report for the LOU. The warranty deed further recited the restrictions contained in the 1989 deed for the IWOU, whereby the restrictions run wi~h the land. Moreover, the 1989 deed covenanted that the grantees shall not interfere with the work as defined by the CD or any future response activities thereby covering the LOU activities. In addition, the UAO required the owners to record a deed notice for the purpose of giving notice of the existence of the UAO to prospective purchasers. A deed notice was filed on November 29, i 990 citing to and noting that the property is subject to the UAO.

The above-listed efforts demonstrate that ICs under the LOU ROD· have been fully

14


implemented.

System Qperations/Operation and Maintenance

IWOU

Operation and Maintenance requirements for the IWOU include general equipment ·and well maintenance, quarterly or annual sampling of the groundwater extraction and monitoring wells (in accordance with the approved groundwater monitoring program), periodic indoor air sampling of the occupied garage, break room and injection well areas, and periodic inspection of the treatment plant building and process equipment. ·

As part _of the groundwater monitoring program, twenty-one monitoring wells are sampled on a quarterly basis and an additional twelve wells are sampled on an annual basis. Groundwater is analyzed for VOCs, 1,4-dioxane, dissolved gases, metals, anions, geochemical parameters, and field parameters.

,, O&M monitoring reports had been prepared and submitted_ by the contractor for the PRP

(also referred to as the Technical Steering Committee ("TSC")), RT Environmental, on- a quarterly basis. Currently, the reports are being submitted by Golder Associates ("Golder") on a monthly basis. The reports contain des°'criptions of significant events that occurred during the reporting period, volatile' extraction system monitoring results, operations summaries, groundwater analytical results, and trend charts for the following prevalent groundwater contaminants: 1, 1-dichloroethane, benzene, chlorobenzene, total xylenes, vinyl chloride, and trichloroethene.

Periodically, from 1991 to the present, shutdown/rebound tests have been approved and conducted to evaluate contaminant rebound under static (non-pumping) conditions. Three short

-- term tests were conducted between 1995 and 1999. The first two tests were for two-week durations and the third test lasted three weeks. During these tests the extraction and treatment system was shut doWfi and a select group of monitoring wells were sampled weekly to determine to what degree that Site-related contaminants would recover or increase. During the 1999 test the concentrations of contaminants showed a slight increase from the,· previous sampling events, indicating that contaminant equilibrium had not been reached within that time period.

Gro'undwater Treatment Plant Operations Chronology

GWTP- Full Operation: GWTP GWTP Reduced 1991 - June Shutdown June Pumping Rate

2003 2003- DecemberC) C)December 2003 - July 3 Minor

2003 2006shutdowns; 6/1995-4/1999

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_ On May 9, 2003 EPA approved a proposal submitted by RT Environmental for a "long terffi" shutdown/rebound test that extended from June 2003 to December 2003. The approved proposal called for the measuring of water levels and the sampling of monitoring wells every two weeks. The test was expected to determine at what concentration level and within what time frame the contaminants would stabilize at each well location. As a result of the test, a-modified pumping sequence was implemented. _

EPA approved the PRP's request for the implementation of a second long-term shutdown/rebound test in June 2006. The test commenced on July 17, 2006. During the shutdown period, monitoring well sampling and water level monitoring were conducted on a quarterly basis with results provided to EPA., Contaminant levels remained relatively consistent for the initial five years (and because of this, extensions to the shutdown test were granted). However, in March 2012, relatively large contaminant level increases were noticed in several _monitoring wells, including the injection well. EPA responded to these observed increases by letter on June 14, 2012 requiring an increased monitoring frequency _in ten of the .Site wells; from quarterly to monthly and performance of an additional vapor intrusion evaluatic;m. EPA also indicated that continuance of the shutdown of the extraction and treatment system was being reevaluated. The PRP responded to EPA's letter by commencing monthly groundwater sampling in ten Site monitoring wells and starting a re-evaluation for vapor intrusion. The PRP also requested that a meeting be held to discuss groundwater remediation options. On the eve of the scheduled October 25, 2012 meeting, EPA was ihfor_med that RT Environmental was no longer the prime consulting contractor and that th~y had been replaced by Golder and Project Coordinator, Dr. James Hagan.

During the October 25th meeting, Golder presented their understanding of the groundwater, and groundwater contamination, conditions at the Site. Golder requested that EPA allow for the performance of new groundwater studies intended to result'in a modification to the groundwater remediation technology. EPA responded to the request by letter of November 8, 2012 wherein EPA requires 1) submissioQ-- of the Work Planj'or Data Collection no later than December 31, 2012 and,2) resumption of the VES operations, as proposed.

The VES was shutdown on August 23, 2007 after a request received from the PRP. EPA agreed to the shutdown because the results of the quarterly air sampling at five locations (injection well, injection well vault, garage area, break room and,outdoor air) in and around the injection well pit indicated consistent values below risk levels. After shutdown, quarterly sampling continued with results, demonstrating consistent compliance, provided to EPA.

One of the activities performed by Golder after replacing RT Environmental was to evaluate the condition of the VES. Golder and the property owner rehabilitated the motors and fans, replaced the activated carbon- in the four tanks, performed an inspection of the system piping, and restarted the system on November 21, 2012. Golder's inspections of the system piping revealed several defects that all contributed to infiltration of "clean" outside air into the VES piping. Repairs to the system piping were performed by the property owner and resulted in an increase in vacuum from between 1.0 to 1.3 inches of water column to 5.5 and 5.7 inches of water column. Photoionization , de~ector ("PID") measurements also increased dramatically; from 100 to _1,700 ppb ("parts per billion") bet_ween December 3, 201,2 and December 18, 2012

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to over 40,000 ppb on December 19, 2012.

Monitoring of the system is currently performed on a monthly basis for the following parameters: pressure with a magnehelic gauge, volatile organic compounds with a ppbRAE 3000 (P,ID), and air velocity, flow, and temperature with a VelociCALC 9565 ventilation meter. The following locations are monitored: · '

• Each of the three extraction wells; HR-3-255, IW, and B-1 • The header ~m the exterior wall of the GWTP, upstream of carbon treatment • Between carbon vesse~s 1 and 2, and between carbon vessels 3 and 4 to detect break

through of each lead vessel (pressure and voes only) • At the exhaust stack, post-treatment (pressure and VOCs only)

In December 2012,.Golder submitted their Technical Memorandum and Work Plan that described a remediation strategy that involves in-situ groundwater treatment with the main emphasis placed on enhanced bioremediation using aerobic or anaerobic oxidation. In order to evaluate the applicability of in-situ groul)dwater treatment at the Site, the following elements '

- need to be determined:

• Effectiveness of the reactant in treating Site-specific contaminants; • Reactant mass (i.e. dosage) needed for treatment; • Method of delivering the reactant into the subsurface; and • Potential for mixing/contact with the contaminants.

A schedule was provided by Golder to perform the following design data collection activities. The information collected will ultimately be used to design a pilot test for the selected reagent.

Baseline Sampling Groundwater concentrations of Site Contaminants of Concern ("COCs") have been monitored regularly at the Site. However, parameters typically analyzed to characterize the biogeochemical setting of the bedrock aquifer, such as pH, and electron donor concentration have not been monitored. Golder sampled .all of the Site wells except the IW, for a total of 46 wells, during the baseline sampling event that took place between February 18, 2013 and March 6, 2013. The IW was not sampled as part of the baseline sampling event due to the fact that a light, non-aqueous-phase, liquid ("LNAPL") was observed within the well at a thickness of approximately 1 to 5 inches. The collected groundwater was analyzed for VOCs, 1,4-dioxane, metals, dissolved gases, anions, and other general chemistry parameters such as total organic ,carbon and carbonate alkalinity.

I

Biopopulation Assessment - On March 1, 2013 Golder deployed Bio-Trap® Samples in monitoring well~ HR-3-255 and HR-3-280. -Each sampler was comprised of four individual units that acted as separate microcosms; three amended with an electron acceptor (oxygen, nitrate, or sulfate) -·and one contained no ame,ndment and was considered to be representative of existing Site conditiop.s. The units were installed

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17

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, within the mon!torif1:g wells at depths that correlated with ·suspected fracture zones to maximize the likelihood of intercepti_ng laterally flowing groundwater. The samplers were deployed for 48 days. After collection, on April 18, 2013, the samplers were shipped to Microbial Insights Laboratory in Rockford, Tennessee for quantitative polymerase chain reaction analysis: '

As reported by Golder Associates, September 2013: The results of the biopopulation assessment indicate that intrinsic· biodegradation of BTEX compounds, cVOCs, and chlorobenzene is occurring at the Site under current geochemical conditions (predominantly methanogenic). The intrinsic microbial community is limited by electron acceptors and the results ofthe biopopulation assessmenf'indicate oxygen stimulated the most growth ofaerobic bacteria and would be t~e most effective additive.

Bromide Tracer Testing - The data collected dur_ing tracer tests is useful because it can be usea to assess the radius of groundwater influence from the tracer injection point. In May 2013, bromide, a non-toxic chemical, was injected into monitoring well RE-205 (the original plan identified the IW for the introduction of the bromide. This was changed, however, when the LN.APL was discovered in the IW.). Tr_acer dispersion was monitored with an in-situ ion-specific electrode in bedrock groundwater wells located, within a 100foot radius of the bromide injection point. The wells included in that radius are: IW, HR3-255, HR-3-280, HR-3-295, HR-2-175, HR-2-195, HR-2-295, HR-6-377, HR-7-383,

. HR-26-475, and HR-25-325 .

. The pertinent conclusions, as reported by Golder Associates, September 2013:

• Groundwater flow rates !fS indicated by tracer test 'responses in observation wells range from 6 to 19 ft/day and average 13 ft/day.

• The fastest tracer response time was observed in wells HR-2-195 and HR-25325 (1~9 ft/day and 16 ft/day, respectively). HR-2-195 is located approximately 120 feet east-northeast of the IW; HR-25-325 is located approximately 140 feet west-northwest of the IW.

'

~ Geophysical Investigations - . Geophysical mapping, used to validate the groundwater . · flow migration pathways that control contaminant movement beneath the Site,' was

) ·performed during the summer of 2013. Electrical Resistivity Imaging was performed on several transects at the Site to assess the complex geology. and migration pathways beneath the Site. As a result of the investigation, it was concluded that there appear to be at least two areas of lower resistivity (in the direction of the groundwater flow, north of the Site) that may correspond 'to zones ofmore fractured and weathered bedrock.

The results of the baseline groundwater sampling, biopopulation assessment, bromide , tracer test, and geophysical investigations described above will be used to design a pilot test for the chosen reagent. ·

18

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r

Henderson Road Fourth Five-Yea~ Review Report December 2013

LOU 0 & M includes grass maintenance, observation of the leachate 'monitoring manholes, and observation of the cap area for settlement, ~rosion, damage, etc. Leachate was collected and treated during the initial years of the remedial action. However,, no leachate has b~en collected in over 15 years, apparently due to the effectiveness of the landfill cap. Landfill gas vent sampling was discontinued over ten years ago after a number of consecutive years of "non-detect" sample results. '

The annual O&M costs for the past five years, as reported by the Hend~rson Road Tec_hnical Steering Committee consultant, James Hagan, Ph. D., for each of the operable units, are presented.belQw in Table 3.

· Table 3 - O&M Costs YEAR 'IWOUCOSTS LOU COSTS TOTAL 2008 $122,980 $10,588 . $133,568

-2009 $186,731 ,$15,026 $201,757' 2010 $417,367 $19,842 $437,209 ' 2011 $479,534 $10,534 $490,068 2012 $267,491 $7,836 $275,327 '

V. Progress Since the Last Five-Year Review

The previous (2008) Five-Year Review contai_ned the following protecti\;eness statement:

The remedial action associated with OU-1 (Injection Well Operable Unit), is expect~d to achieve protectiveness in the long term, but a protectiveness determination is being' deferred at this time. A groundwater extraction and treatment system has been installed that has been successful in reducing the contaminants, but final standards have yet to be achieved. There hqve been a number of changes to MCLs and factors used in assessing risk since the original ROD was issued. In addition, sampling forl,4-dioxane has not been conducted, nor have current background concentrations been ivaluated. As provided in the 1988 ROD,. a formal reevaluation of the groundWater cleanup goals should be performed. Also, a vapor intrusion evaluation needs to be performed. It is expected that these actions will take approximately two ye/irs to implement, at whicli time a protectiveness determin'ation will be made.

The. remedial action at OU-2 (Landfill Operable Unit) is protective. The landfill has been capped and a leachate collection and treatment system has been installed, (hereby reducing infiltration and the migration ofcontaminants. As a result ofthe Site inspection, the landfill gas, vent risers need to be inspected and repaired, as necessary. ·

The Issues and Recommendations and Follow-Up Actio~s identified in the 2008 Fivey ear Review follow:

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November 2008 Five-Year Review Issues

Issue Currently Affects Affects Future Protectiveness Protectiveness

(YIN) (YIN)

1. Groundwater cleanup values N y

2. Vapor intrusion y y

3. Damaged landfill vent risers N N

4. 1,4-Dioxane - y y

/November ecommend f C IOnS2008 R a rnns and F oIIow-up At' 1Issue Follow-up Party Oversight Milestone Protectiveness

- Actions Responsible _Agency Date _ Affected? (YIN) - , Current Future

1. Groundwater Perform PRP EPA 9/30/2010 N y

cleanup values J

reevaluation of groundwater cleanup levels

/

per 1988 ROD 2. Vapor Perform a PRP EPA 9/30/2010 y , ,

y

intrusion vapor intrusion -evaluation

3. Damaged Repair/replace PRP EPA 3/31/2009 N ~ N landfill vents damaged risers 4. 1,4-Dioxane Sample PRP EPA 9/30/2009 y y

groundwater for 1,4-dioxane

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Actions taken to resolve the issues identified above: c

Issue # l, "Groundwater cleanup 'values": Page 24 of the IWOU ROD requires "Periodic e;valuation of the progress of the treatmentsystem jn -achieving ARARs and, if appropriate, reevaluation of the aquifer restoration objective and ARARs, considering feasibility and costeffectiveness."

)

Also stated in the IWOU ROD: "EPA has selected aquifer restoration as the clean-up , goal for the_ Site because data uncertainties and complexities related to the movement ofwastes to the aquifer make predictions difficult regarding potential off-site release which would pose a risk to human health and the environment":

Since the issuance of the 2008 Five-Year Review, EPA has identified~ and informed the P_RP Group of, data gaps that exist at the Site. For example, EPA had informed the PRP Group that the existing monitoring well network was not considered satisfactory to adequately delineate either the depth or the lateral extent of the contamina~ed groundwater plume.

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In an effort to address the identified data gaps: the PRP Group, from 2010 to 2011, installed two monitoring well- ("MW") clusters; HR-31 and HR-32, that each contain three wells for the purpose of monitoring the shallow, intermediate and deep groundwater zones immediately north of the Pennsylvania Turnpike. In addition to the new well installations, geophysical testing was also performed on MW 24-476 in an attempt to identify the actual depth wh~re the contaminated groundwater enters the well. .

/

The PRP Group is compiling recent monitoring well data and has been meeting with EPA and the United States Geologic Survey to discuss their understanding of the current groundwater situation and to collaborate on the development of a groundw_ater conceptual site model.

Although a milestone date of September 30, 2010 was listed for completion of this issue in the 2008 Five-Year Review report, the actual RAO reevaluation is (and h8:,S been) an on-going process with a timeline that is in part dependent on the groundwater conceptual site model and the near-term monitoring well analytical results.

Issue# 2, "Vapor Intrusion": Vapor Intrusion ("VI") was identified as an- issue in the November 2008 Five-Year Review. Since the previous (2003) Five-Year Review, EPA has identified vapor intrusion as a new pathway to be evaluated for sites with voes. When voes exist, in groundwater, a vapor intrusion evaluation is warranted for those buildings located aboye or adjacent to the contaminated groundwater plume.

At the Henderson Road Site, several structures are located atop the known contaminated plume. Since 2007, in an effort to evaluate air quality, the PRP Group has been conducting interior and exterior air sampling on a quarterly basis at five separate locations:

1) Injection well; 2) Injection well pit; 3) Garage area; 4) Breakroom; and 5) Outdoors

These sample locations are shown on the attached Figure 8. ' '

The quarterly sample results indicate that although there are Site-related constituents at levels above their respective Regional Screening Levels ("RSLs") within the injection well and the injection well pit area, the indoor air sampled within the occupied areas (the garage and the break room), remains below the RSL for all constituents except xylenes. It was determined that the xylene exceedances are not attributable to vapor intrusion, however, for the following reasons: 1) the total xylenes concentrations in the injection well and the injection well pit are at levels that are below those levels within the garage area and 2) oils are commonly utilized, bufn.ed, spilled (on occasion), etc: within the garage area as part of routine truck maintenance.

On- September 16, 2011, a meeting was held at EPA Region III to determine whether or not VI constituted a current protectiveness issue at the S~te. To summarize, it was determi~ed that VI does not currently seem to be an issue at the Site but that the qu~erly air sampling at the

. ~.

21


five locations in and around the injection well area should continue. The conclusion was reached by all in attendance: Patricia Flores (Air Protection Division), Joe McDowell (Senior RPM), Mindi Snoparsky (Site hydrologist), Jeff Tuttle (Site toxicologist) and Tim Gallagher (Site RPM). This determination was documented in a September 2011 memo to the Site file.

Subsequent to the September 16, 2011 meeting, revised assessments for TCE and PCE were posted to the Integrated Risk Information System (September 28, 2011 and February 10,

' " .2012, respectively). Because of this, an additional comparison was performed utilizing the most ·recent Henderson Road air sampling results and the April 2012 RSL Summary Tables. "The result of the comparison again revealed that vapor intrusion was not a concern within the occupied areas at the Site.

Because of the discovery of LNAPL within the injection well during the February-March ·2013 baseline sampling event, EPA again requested that the PRP reevaluate the possibility of vapor intrusion within the on-Site maintenance garage. The PRP performed vapor intrusionsampling in June 2013 at a n~mber of locations within, and exterior to, the garage and subsequently submitted their findings to EPA.

The August 2013 PRP-submitted Vapor Intrusion Pathway Evaluation Report, which contained the results of the June 2013 VI sampling report, indicated that the presence of background sources of contaminants, likely from products used at the facility, are responsible for any unacceptable indoor air levels. The report concluded that VI should not be considered a concern at the facility.

EPA's Air Protection Division conducted a review of the report and had the following observations (excerpted): "' '

The report attributes most of the voes detected in the garage -to background sources of contaminants, likely from products used at the facility. However, the voes detected in the garage were found to be in lower concentrations than in the Injection Well Vault which would imply that the voes in the garage are due to vapor b:ztrusion. While the facility may use products that contain some of these contaminants, there' is no definitive evidence that vapor intrusion is not occurring. OSHA permissible exposure limits will apply only if the site-related contaminants are currently being used or created in operatio!'s at the site.

(EPA) disagree(s) with the report that vapor intrusion is not a concern at the facility. The indoor _atr voe concentrations in the garage are higher than the RSLs, and they may be due to the LNAPL recently discovered in the Injection Well. The report implies that the groundwater ' ,voe concentrations in the Injection Well influent samples are not high enough to support vapor intrusion, howeyer, the vapor samples from the Injection Well Vault demonstrate that the LNAPL can be a source ofthe voe vapors. c

I

EPA recommended the following:

• The Site toxicologist should calculate the associated risk to a garage worker. If the risk is unacceptable, the bay doors in the garage area should be left open while the employees

22

Henderson Road Fourth Five-Year Review Report Dece~ber 2013

are working to ensure sufficient ventilation. Routine indoor air sampling should be ·continued. ,

• A survey of the chemicals currently used or created in the garage should be made. If even one of the Site-related chemicals is not used or"'created during current operations, some form of mitigation might be needed to lower the voe concentrations to acceptable levels. ·

• The sampling that was performed did not include at least one duplicate sample, and the data adequacy and usage was reviewed by Golder Associates instead.of undergoing third party validation. The next round of sampling should_ include duplicates and third party validation.

)

Indoor air monitoring continues on a quarterly basis.

Issue # 3: "Damaged Landfill Vents": During the 2008 Five-Year Rev.iew walk through inspection of the landfill cap, several upright landfill gas vents were observed in poor condition, potentially affecting the passive venting operations. These vents were repaired and/or replaced by the milestone date ofMarch 31, 2009. ·

Issue # 4, "l,4-Dioxane": EPA has become aware t~at sites with voes in groundw~ter sometimes contain 1,4-dioxane, a solvent stabilizer, as a contaminant as well. The concern with 1,4-dioxane is. that it cannot be removed by conventional groundwater treatment technologies (such as air stripping and carbon filtration), is water soluble, and can move ahead of a voe groundwater plume. Analysis of this compound was not included in either the rem~dial investigation sampling or the groundwater monitoring program. Sampling for 1,4-dioxane was recommended in the 2008 Five-Year Review.

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I 1 '\

In response, the PRP Group began analyzing 1,4-dioxane, as part of their quarterly groundwater monitoring program, in February :2009. This analysis continues to date and the data reveals results that have ranged from non-detect to 63.8 parts per billion (ppb).

Although it is not currently sampled on a routine basis at the UMR, EPA has informed the operators of the reservoir of the presence of·I,4-dioxane in some of the Site monitoring wells .

. Aqua Pennsylvania ;responded to EP('\'s notification by sampling for 1,4-dioxane in June 2009 followed by several sampling efforts since then. All analyses 'results have been below their

', reporting limit. ·

EPA prepared an adde~dpm to the 2008 Five-Year Review to address the IWOU protectiveness determination deferment that was signed in January 201'3. The addendum included the following protectiveness statement:

A determination regarding the protectiveness ofthe Operable Unit_:_] remedy was deferred in the November 2008 Five-Year Review pending a vapor intrusion evaluation and the initiation of1,4dioxane sampling. Based on the results of a 2011 vapor intrusion evaluation- and the 1,4dioxane sampling results (coupled with the fact that institutional co,ntrols are in place which / prohibit exposure to contaminated groundwater), it can now be determined that the remedy for Operable Unit-I is protective ofhuman health and the

/ environment. ,

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VI. · Five-Year Review Process

Administrative Components

On December 20, 2012, Upper Merion TownshiP,. supervisor; David Kraynik, tne PRP's Site Project Manager; Dr. James Hagan, and Dennis Kutz, PADEP, we're informed by letter that the Five-Year Review process had been initiated.

The Five-Year Review team was led by Tim Gallagher, EPA Remedial Project Manager and included Mindi Snoparsky, EPA Hydrogeologist, Jeff Tuttle, EPA Toxicologist, Mary Rugala, EPA Office of Regional Counsel, and Dave Polish, EPA Community Involvement Coordinator ("CIC").

A Site-specific approach was developed for the Five-Year Review, which included:

• Community Involvement - Notifying the community that EPA is conducting a Five-Year Review at the Site and providing information on whom to contact and how to get more information about the process, and notifying the community of how to obtain a copy of the Five-Year Review Report upon completion;

• · .Interviews - Con~ucting interviews with responsible parties and local officials to determine whether these parties have any concerns regarding the Site;

• . Document and Data Review - Reviewing all pertinent Site documents and_ environmental monitoring ,data. Researching ARARs cited in the ROD and subsequent modifications to the ROD, for revisions as well as identifying potentially new ARARs which may be significant to the Site circumstances, and checking available published toxicity references for Site-related contaminants to determine if there ·have been" changes since the Site-specific risk assessment which may be relevan~ to the review team's evaluation of remedy protectiveness;

• Site Inspection - Visiting and inspecting the actual Site property to visually confirm and document the conditions of the remedy, the Site, and the surrounding area; and

• Preparing the Five-Year Review Report and coordinating the review by team members and management.

EPA will continue to perform reviews of the Site remedy every five years because the selected remedy relies on the combination of containment and institutional controls to prevent exposure to contaminated soils and groundwater that remain on the Site that have contaminant concentrations which do not permit unrestricted use.

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Community Involvement

On November 17, 2013, a notice wa_s published in the King ofPrus,sia Courier notifying the community that EPA was conducting a Five-Year Review at the Site. The notice included a brief overview of the response actions taken at the Site, and.the reason that a review is necessary. The notice listed who to contact and how to get additional information related to the Site. In aqdition, the notice identified when the review was scheduled to be completed and stated that once completed, a copy of the review report would be available at the Upper Merion Library, the EPA Public Reading Room at 1650 Arch Street in Philadelphia, or over the internet at http://loggerhead. epagov/5yr/search.

Document Review

This .Five-Year Review process included tht! review of a number of relevant documents including, among others, the 1998 IWOU and 1999 LOU Records of Decision, the 1985 Admin_istrative Order on Consent, the 1989 Consent Decree (IWOU), the 1990 Administrative Order (LOU), quarterly (RT Environmental) and monthly (Golder) O&M reports, and numerous technical reports and memorandums.

Site Inspection \

On May 3, 20'13, an inspection of the remedy was conducted (See Photographic log). Those present at the Site inspection included: Dennis Kutz, PADEP project manager, Kyle Schmeck, Montgomery County Health Department ("MCHE:>''), Rachel DeMarzio, MCHD, Mike O'Hara, Site property owner, Dr. Jarries Hagan, Technical Steering Committee consultant, Kevin McCullen, Golder, Mindi Snoparsky, EPA hydrogeologist, Jeff Tuttle, EPA toxicologist, and Tim Gallagher, EPA RPM. Prior to the commencement of the Site walk, Tim Gallagher delivered a brief history of the Site cleanup and the reason that the Five-Year Review was necessary and discussed the status of the issues raised during the 2008 Five-Year Review process. The inspection _attendees also discussed what remedial activities and progress has occurred at the Site since the last Five-Year Review.

An inspection was then conducted of the injection well area within the active maintenance garage, the landfill cap surface, the perimeter fence, the landfill gas· vents, the leachate collection manholes; the HR-32 monitoring well area, the volatile extraction system carbon tanks and piping, and the interior of the rwou groundwater extraction and treatmei).t system building.

· The components of the groundwater treatment system had previously been drained and "winterized" but appeared to be in good condition and well maintained (although this could not be verified due to the fact that the system was shut down at the time of the walk through). The volatile extraction treatment system was operating and appeared to be in good working condition. The landfill grass had been cut the day prior to the Site visit, allowing for a closer inspection for 'erosion damage, subsidence, damage to the cap system, etc. Leachate manhole covers were opened and landfill gas vents were observed. Nb issu_s::s were noted during the walkthrough regarding the injection well, the landfill area, the volatile extraction system, or the

25


groundwater extraction system.

In addition to visiting the various Site areas, the EPA RPM toured the adjacent residential neighborhood and the Upper Merion Reservoir (outside the fence). Other than road-widening construction by the Pennsylvania Department of Transportation on Henderson Road, no major

> changes in land use were observed at the time of the inspection.

Interviews

On April 29, 2013, Mr. David Kraynik, the Upper Merion Township Supervisor, was interviewed for this Five-Year Review. Tirri Gallagher described the current status of the Site and the reason for the Five-Year Review. Mr. Kraynik stated that the Site, generally surrounded by industry, generates little to no interest in the community and that the Township does not have any issue with the Site at this time. Mr. Kraynik offered the Township's assistance with the Site whenever needed.

During the May 3, 2013 Site inspection, Tim Gallagher interviewed the Site owner, Mike O'Hara, about the-operations at the property and the landfill area. Mr. O'Hara stated that the garage and office areas of the Site are currently being leased to Republic Services, a solid waste management company. Mr. O'Hara.also indicated that he is evaluating the possibility of paving a portion of the landfill cap for the purpose of reuse as a parking area and may formally submit a proposal to EPA in the future. Mr. Gallagher asked the PADEP and the MCHD representatives if they had any questions or concerns related to the Site or if the Site had generated any interest from the public that EPA should know about. Neither PADEP nor MCHD had any issues or concerns to report. Dr. Hagan and Kevin McCullen discussed the current Site schedule, the status of current project activity, and described ~he recent groundwater sampling event when LNAPL was discovered within the injection well.

Tim Gallagher also interviewed a representative of Aqua Pennsylvania, the operators of the Upper Merion Reservoir, regarding the sampling results of the UMR water. According to the sampling results provided by Aqua Pennsylvania, no Site-related contaminants exist within the · UMR that exceed the Site cleanup levels. It is notable, however, that 1,4-dioxane levels have been seen at levels above its regional screening level of 0.67 ppb in January 2013 (1.5 ppb) and April 2013 (1'.51 ppb).

Data Review

Subsequent to the completion of construction pertaining to the IWOU and LOU remedial action components in 1991, an extensive groundwater monitoring program had been implemented to evaluate the progress of the remedial action. In order to facilitate this, the following groups of groundwater monitoring wells have been installed at the Site:

• Wells HRl (series) to HRS (series) and HR-RE-205 were ins.talled as part of the Remedial Inve~tigation stage (January to March 1986);

• Wells HR6 (series) to HR 13 ( se'ries) were installed during the investigation of the Site saturated zone (March 1990-August 1991);

. 26

Henderson Road Fourth Five-Ye,ar Review Report December 2013

• Wells HR14 (series) through the HR20 (series) were installed per recompiendations contained .in the interim saturated zone report (April 1991 June 1991); and

• Wells HR22 • and higher are either investigation or recovery wells installed at the direction of the EPA (from April 1992 - April 2011). The niost recent well installations-were the HR-31 and HR-32 series wells, which were installed north of the Pennsylvania Turnpike in 2010 - 2011 at the request of EPA, to address a noted data gap.

*Although there appears to be a gap in the sequencing, monitoring well HR-21 was planned for but never installed.

Well locations have been chosen, mafoly along fractures, for either delineation or recovery purposes. The two major fractures that influence groundwater movement under tlie Site have been d~signated as the "northea~t fracture'', which in.eludes wells (moving southwest to northeast) HR-1-280; the Injection Well; RE-205; HR-26; HR-13-147; HR-14-178; HR-22-300;

/

~d HR-17-170 ahd the "northwest fractµre", which includes wells (moving southeast to northwest) HR-15-255; the Injection Well; the HR-3 series; HR-24;,the HR-6 series; and HR-23350.

The extent of the current gro~p.dwater monitoring program is the result of several modifications made prior to and during the groundwater treatment plant shutdown/rebound tests and after the installation of the additional monitoring wells in 2010 - 2.o 11.

From 2008 until early 2012, the quarterly groundwater monitoring results have indicated that voe contaminant concentrations in the monitoring wells on and near the Site property have, for the most part, remained in a relatively close range. However, in March 2012, quarterly sampling results revealed a noted spike in several voe concentration levels in the source area wells (immediately downgradient of the injection well). These increased levels were mostly maintained throughout the remajnder of 2012 and into 2013. Although there have ·been dramatic decreases in voe concentrations since the initiation of the groundwater monitoring program in 1991 (and the subsequent extraction and treatment of groundwater), the levels for several voes remain much higher than their· associa~ed ARAR. Figure 9 shows the groundwater sampling results at select locations.

, Table 4 is' a comparison, over time, of concentration levels in the most impacted Site wells for the most prevalent contaminants"with ARAR exceedances (shown in bold).

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27

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Table 4 - Concentration Comparison of ARAR Exceedances in Impacted Site Wells Parameter Benzene Chlorobenzene 1,1-DCA Vinyl ·Total Xylenes 1,4-Dioxane (ARAR) (5.52 ppb) (60 ppb) (5.06 ppb) Chloride (17~ ppb) (0.67 ppb(S»

(2 ooh)" IW Baseline<1l 1,500<5> 530 4,200 00 5,500 5.7 July 2006(2) 10.2 35.8 2.3 0.36 19 6 March 201i3l 199 164 12.9 27.4 769 00 Februarv 2013(4

) NS NS NS ) NS NS NS RE-205 Baseline<1> 110 0.0 2000 73· 0.0 0.0 July 2006<2> 16.1 54 2 2.5 0.0 27.9 March 2012<3> 148 111 6.9 13.8 370 0.0 February 2013<4> 2.5 40 1 3 1.4 1. I. <4.0 HR-2-195 Baseline(!) 500 310 1,600 00 56,000 0.0 July 2006(2) 31 18.9 0.46 0.34 44 8 March 201i3> 72.9 23.3 0.0 0.0 0 47 0.0 February 2013<4> 169 20.9 0.75 <O 5 90 <0.4 HR-3-255 Baseline(!) . 1,800 0.0 1,100 - 0.0 5,500 13 July 2006(2) 349 99.5

I

2.5 1.0 3,140' March 2012(3> 66.5 5.0 \ 0.0 0.36 ' 38 7 17 4 February 2013<4> 333 77.0 <2.5 <2.5 566 <20 HR-3-280 Baseline<1> 1,600" ' 0.0 2,700 0.0 8,400 40 . July 2006(2) 257 78.8 4.9 1.3 278 March 2012(3>: 215 62.4 0.0 0.0 0 66 0.0 ,

' -Februarv 2013(4) 167 '84.7 <2.5 <2.5 <7 5 <20

HR-3-295 Baseline<1l 1,700 280 1,120 36.4 18,000 13.7 July 2006<2l 8.1 19.2 . . 2.0 0.33 67 March 201 i 3l 36 19 6 155 34.1 147 00 February 2013(4

) 14.3 30.2 11.4 2.7 26.3 <4 -

HR-6-377 J Baseline<1> 760 180 0.0 0.0 2,800 .12.1

July 2006<2> 128 32.9 00 0.0 0.55 March 201 i 3l 121 54.1 o:o 0.0 05 13.8 Februarv 2013<4> 141 57.1 <O 5 <O 5 1.8 12 8 HR-7-383 \

Baseline(!) ' 430 160 0.0 . 0.0 420 9.0 July 2006<2> 18.7 12.8 0 58 00 0.0 March 201i3> 63.9 148 00 00 0.0 0.0-February 2013(4> 62.5 96.8 \ <2.5 <2.5 <7,5 <20 HR-14-376 Baseline(!> 170 28 9.0 -~o.o 150 21 July 2006(2) 16 27.5 2.2 0.0 0.0 March 201i3> 48 46 6~8 0.0 0.0 30.2 February 2013(4

) 2.4 36 4.4 0 34 . <1.5 - 11.2 HR-26-457 Basehne<1l 6,000 410 82 0.0 4,200 22 July 2006<2> 23.3 70.9 2.4 00 32 3 March 201 i 3> 54.5 59.1 2.0 0.64 11.1 0.0 Februarv 2013<4> 114 44.6 <2 5 <2.5 11.1 <20 ..\IJ Basehne, or 1mtml, groundwater samplmg event under the groundwater momtormg program. Specific dates vary, depending on the well, between the years 1991 and-1992. Sampling was initiated for 1,4-dioxane in February 2009. <2l Baseline sampling event at the start of the current shutdown p_eriod (July 2006 - prese11.t). <3l Sampling event with dramatic VOC increases that prompted the change in sampling frequency.

28 /

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' <4l Golder comprehensive baseline sampling event. IW not sampled ("NS") du~ to the presence of LNAPL. <5

) 0.67 is the EPA Region.al Screening Level ·

A summary of the A~R exceedances of the five most prevalent contaminants of concern, and 1,4-dioxane, since the 2008 Five-Year Review:

)

Benzene (ARAR - 5.52 ppb). Since 2008 the most prevalent COC in the Site groundwater has been benzene. Benzene has been discovered above its ARAR in over a dozen monitoring wells at levels ranging up to 1,070 ppb in the injection well (January 2013) and 513 ppb in HR-3-255 (February 2008). Other notable exceedances: 509 ppb (October 2012), 384 ppb (January 2013),

' )

359 ppb (December 2012), and 333 ppb (February 2013) in HR-3-255. 238 ppb (October 2012) in th('. injection well, 231 ppb (September 2012) and 229 ppb (October 2012) in HR-3-280, 195 ppb in HR-6-377 (March 2010), 169 ppb in HR-2'..195 (February 2013), 167 ppb in HR-3-280 · (February 2013), and 148 ppb in RE-205 (March 2012). Benzene levels have not exceeded ARARs in any of the wells north of the 'Pennsylvania Turnpike.

Chlorobenzene (ARAR - 60 ppb). Another prevalent Site contaminant, chlorobenzene has been seen at levels above its ARAR in numerous monitoring wells. Most notably: 750 ppb (January 2013) and-348 ppb in the injection well (August 2012), 326 ppb in HR-24-476 (December 2009),

_, 288 ppb' (March 2010), 226 ppb (September 2010) and 189 ppb (September 201 l)·all -in HR-6141, 174 ppb (September 2011) and 178 ppb (December 2012) in HR-6-241, 157 ppb in HR-7383 (August 2012), and 155 ppb ih RE-205- (August 2012). Chlorobenzene levels have not exceeded ARARs in any of the wells north ofth~ Pennsylvania Turnpike.

1,1-DCA (ARAR - 5:06 ppb). Since the '2008 five year review, 1,1-DCA is the only COC discovered within' a MW located north o( the Pennsylvania Turnpike; 8.5 ppb in HR-32-545 (September 2011). At least 10 monitoring wells have indicated the presence of 1,1-DCA at levels above its ARAR. The most notable ARAR exceedances include: 155 ppb (March 2012) and 36.6 ppb (January 2013) in HR-3-295, 1 lJ ppb (August 2012) and 28.3 ppb (January 2013) in the injection well, 75.7 ppb in RE-205 (August 2012); 29.J ppb (D~cember 2011), 26.8 ppb (September ~011) and 22 ppb (February 2013) all in HR-12-150. '

Vinyl Chloride (ARAR - 2 ppb). 09ly 3 monitoring wells have shown noted ARAR exceedances of vinyl chloride since the previous five-year r:_evie~, all within the general vicinity of the injection well: 34.1 ppb

1

(March 2012) all in HR-3-295, 103 ppb (August 2012) all in RE- _ 205, the injection well contained vinyl chloride at levels up to 190 ppb (August 2012), 23 ppb (January 2013).

Total Xylenes (ARAR - 175 ppb). Xyl~ne ARAR exceedances have bt:;en limited -to fi;nir monitoring wells since the previous five year review, all within the immediate vicinity of the injection well; 2,930 ppb (March 2011), 1,010 ppb (December 2012), 773 ppb (January 2013), and 566 ppb (February 2013) all in HR-3-255, 248 ppb in HR-3-295 (October 2012), 523 ppb

- (August 2012) and 448 ppb (July 2012) in RE-205, and 3,065 (January 2013), 1,140 ppb (August 2012), 769 ppb (March 2012) and 634 ppb (September 2012) all in the injection well.

1,4-Dioxane (RSL range: 0.67 - 67 ppb) .. The presence of 1,4-dioxane is widespread at the Site,

29


although the levels appear to exist within the acceptable risk range. The re&ional screening level of 0.67 ppb represents the 1 o-6 value with 67 ppb representing the 10 value. The largest exceedance has been seen in HR-9-191; 63.8 ppb in February 2013. It has been discovered in wells immediately downgradient of the IW at levels up to 24.3 ppb in HR-6-377 (August 2012), 18.2 ppb in HR-3-295 (March 2011) and 17.4 in HR-3-255 (March 2012), and north of the Pennsylvania Turnpike at levels up to 19.6 ppb in HR-32-545 (December 2012) and 6.1 ppb (HR-31-485 in December 2012). ,

)' Other notable COCs with ARAR or MCL exceedances since the 2008 Five-Year Review:

• 1,2-dichloropropane (ARAR:. 6.28 ppb): 137 ppb (August 2012) and 15.5 ppb panuary 2013) in the injection well and 97.3 ppb in RE-205 (August 2012).

• cis-1,2-dichloroethene (70 ppb): 487 ppb in the injection well (August 2012) and 236 ppb in RE-205 (August 2012).

• 1,2-dichloroethane (6.02 ppb): 23.3 ppb (August 2012) in the injection welJ._

• Toluene (2,000 ppb): 6,200 ppb (January 2013) in the injection welL_

• Ethylbenzene' (680 ppb): 693 ppb (January 2013) in the injection well.

• TCE (ARAR - 25.8 ppb): Although_ there have been no ARAR exceedances of TCE in any of the monitoring wells since the previous Five-Year Review, there has been one <MCL (5.0 ppb) exceedance in HR-15-255; 10.5 ppb in February 2013 and numerous·/ MCL exceedances in HR-18-190: September 2010 (14.6 ppb), December 2010 (10.3 ppb), ·March 2011 (16.3 ppb), June 2011 (11.6 ppb), September 2011 (12.4 ppb), December 2011 (12.8 ppb), March 2012 (10.7 ppb), June 20f2 (11.8 ppb), September 2012 (11 ppb), December 2012 (9.3 ppb), and February 2013 (6.5 ppb).

Figures 10 through 19 represent the horizontal distribution of select contaminants at four different points in time since 2003.

Aqua Pennsylvania continues to monitor water quality in the Upper Merion Reservoir and these analytical results are periodically provided to EPA. The results indicate the continuous

\,

presence of TCE in the reservoir, however, the levels (mostly in the 1 ..::... 2.5 ppb range) have remained under both the ARAR and the MCL over the past five years. TCE concentrations in the UMR have not ~xceeded the MCL since July 2001 (5.6 ppb).

The landfill area is inspected and maintained on a regular basis. Leachate observation wells are checked for the presence of leachate, and the landfill cap area is mowed two times per year and inspected for any signs of erosion or settling. Leachate has not been observed in the observation wells in over 10 years, landfill gas sampling was discontinued over 5 years ago and no significant settlement or erosion of the landfill area has been observed. Landfill security fencing is routinely checked for any signs of damage and ~aming signage is posted at adequate

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I


intervals.

VII. Technical Assessment

Qu~stion A: Is the remedy functioning as intended by the decision document? - )

The review of documents, ARARs, and the results of the -Site inspection indicates that the remedies for both the IWOU and LOU are functioning as intended by the RQDs. The primary components of the IWOU include the installation of recovery wells, a volatile extraction system, a groundwater treatment system, and a vapor treatment system; implementation of a comprehensive groundwater monit~ring program; and implementing institutional controls to restrict activities that could interfere with the remedy.

Even though all groundwater cleanup standards have not yet been met, significant progress has been achieved since the IWOU remedy was first implemented. This is evident by the general overall reduction in Site-related contaminant concentrations in groundwater on and near the Site. A long term shutdown/rebound test is currently on-going and the PRP has proposed (and is currently implementing) a pilot test that may result in a proposed change to the selected remedy.

The primary components of the LOU include the relocation and consolidation of waste; installation of a landfill cover system; installation of erosion control measures; installation of a leachate collection system; and implementing institutional controls to restrict activities that could interfere with the remedy. The success of this portion of the remedy is evident not only from the results of the groundwater monitoring program but also from t4_e lack of leachate generation. No leachate has been generated from the LOU since 1998.

Section IV, above, lists the efforts taken by both EPA and the PRP to demonstrate that the institutional controls required for both the IWOU and the LOU RODs have been fully implemented.

Question B: Are the exposure assumptions, toxicity data, cleanup levels, and RAOs used at the time of the remedy selection still valid?

Changes in Standards and Standards To Be Considered CTBC)

Have standards identified in the ROD been revised, and does this call into question the

protectiveness ofthe remedy? Do newly promulgated standards call into question the

protectiveness ofthe remedy? H_ave TBCs used in selecting cleanup levels at the Site changed, and could this affect the protectiveness ofthe remedy?

Changes in certain MCLs have occurred since the issuance of the ROD and TBCs, including the Risk Screening Levels, are updated twice a year. Also; reassessments for certain COCs including TCE and PCE have been completed. Once the ROD cleanup standards are achieved it is rec~mmended that risk estimates using curr~nt risk assessment methodology and

31


-assumptions and toxicity values be calculated. For those COCs where an ARAR was not available, or where background cone'entrations were chosen as cleanup values, it is highly recommended that an updated background study be conducted for groundwater to determine

/whether the ROD values are still appropriate. ·

Changes in Exposure Pathways

Has land use or expected land use on or near the site changed?

No change to the land use on or near the Site has been noted. The surrounding land use continues to be commercial and industrial.

Have human health or ecological routes of exposure or receptors been newly identified or changed in a way that could affect the protectiveness ofthe remedy? Are there newly identified contaminants or contaminant sources? Are there unanticipated toxic byproducts of the remedy not previously addressed by the decision documents? Have physical site conditions or the understanding of these conditions changed in a u:ay that could affect the p~otectiveness of the remedy?

A VI study has been con,ducted since the last Five-Year Review. A discussion regarding the source of the sampled VOCs and the results/conclusion of the study is currently underway between EPA and the PRP. It appears that both Site-related CERCLA releases and releases as part of the facility's daily operations are occurring. It is recommended that VI sampling be continued especially with the discovery' of Site-related -LNAPL in groundwater and that additional ventilation measures be implemented in the garage building to provide add.itional air flow to increase worker protection.

Changes in Toxicity and Other Contaminant Characteristics

Have toxicity factors for contaminants ofcqncefn auhe Site changed in a way that could affect the protectiveness ofthe remedy? Have other contaminant characteristics changed in a way that could affect the protectiveness ofthe remedy?

The presence of 1,4-dioxane in the UMR warrants continued inclusion of the analyte in the groundwater monitoring program. Based on concentrations being found in the UMR that are up to nearly two orders of magnitude greater than its RSL (0.67 ug/l), continued sampling for it by the operators of the UMR is recommended.

Changes in Risk Assessment Methods Have standardized risk assessment methodologies changed in a way that_ could, affect the protectiveness ofthe remedy?

Toxicity criteria have changed for TCE an~ PCE, and the methodology of calculat.ing risk for TCE has changed. These changes do not significantly impact the remedy at this time, and will be evaluated after all cleanup levels have been reached. There are no current exposures to

32


Site contaminants above the groundwater cleanup standards, and ICs prevent future exposure to human receptors.

)

, There have also been changes in reference doses, cancer slope factors, 'and inhalation toxicity values- since the issuance of the ROD. These will need to be evaluated more closely as the Site groundwater concentrations approach the groundwater cleanup standards; however, with the continued large exceedences of MCLs by a number of Site COCs, any changes are not likely to impact the protectiveness of the selected remedy. ~

'

Question C: Has ·any other information come to light that calls into question the protectiveness of the remedy?

J ' There is no other information that calls into question the protectiveness of the .remedy.

Technical Assessment Summary

As the. groundwater concentrations of CO Cs still exceed the performance standards for a number of Site-related COCs, a 'final determination as to whether the performance standards are protective may be pre~ature. Toxicity factors and parameters (MCLs, toxicity values, exposure factors,: etc.) may change in the future and protectiveness is best assessed at the time when it is, believed tpat remediation (for groundwater) has been achieved. It is therefore recommended that groundwater risks be calculated and evaluated whep the remedy has achieved it goals based on the ROD. In order to ensure that the remediation goals listed in the ROD (ARARs) are currently protective, the groundwater background values utilized during the time of the ROD preparation should be reevaluated and modified·, if appropriate. Currently, contaminated groundwater is not being used by local residents or workers at the Site. Monitoring of the Upper Merion Reservoir and the ·Site monitoring wells for Site-related COCs (including 1,4.:.dioxane) should continue although it is recommended that the method detection limits and the reporting limits being utilized by the UMR operators are appropriate (at or below RSLs for the COCs).

Per the 1988 ROD, periodic reevaluation of the groundwater RAO is required. This evaluation is an on..:-going activity. EPA utilizes\ relevant Site data such as the groundwater monitoring results and the Upper Merion Reservoir sample results to continually evaluate the appropriateness of the groundwater RAO. EPA is also considering a PRP proposal to treat contaminated groundwater in situ rather than by extraction and treatment followed by discharge. EPA is awaiting the result~ of several PRP-imposed tests that will provide information on both the aquifer 'and the underlying Site geology. EPA will then make a determination of the feasibility of m'odifying the selected groundwater r~medy.

r

The vapor intrusion study that was conducted in June 2013 appears to show that Siterelated vapors may be entering the garage; however, vapors from the same chemical entities (e.g., benzene and ethylbenzene) found as a result of daily operations make a final determination difficult. VI monitoring of the Site buildings should continue, preferably sometime during the winter months to determine if vapor concentrations increase during the heating season (whiJe the

, overhead doors and_ other openings are closed).

33

He~derson Road Fourth Five-Year Review Report December 2013

VIII. Issues

Table 5 - Issues Affects Affects Current Future

Protectiveness Protectiveness Issue

~

(YIN) (YIN) PRP is evaluating a proposal to modify the selectedI. yNgroundwater remedy.

2. The 1988 ROD requires periodic reevaluation of the ygroundwater remedial action objective.

N

3. The indoor air concentrations, for several VOCs, ,in the on-' yNSite garage are higher than the RSLs(

4. Cleanup standards for certain groundwater COCs (i.e. TCE) yN may nofbe appr~priate.

IX. Recommendations and Follow-Up Actions

Table 6 Recommen a ions and F 0 IIow-Up- d f ACf IOnS Affects

Protectiveness-(YIN)Party. -Oversight Milestone

Recommendation and F'ollow-Up Action Responsible Aeencv Date Current Future

I. Determine the fea.sibility of modifying PRP EPA 12/31/14 N y

the selected groundwater remedy.

2. Continued reevaluation of the "'-'

yPRP EPA 12/31/2014 Ngroundwater cleanup goals. -

3. Perform a risk assessment of the on-Site yEPAIPRP EPA 1/31/14 Ngarage workers,

-4. Perform a new backgrqund study- of yPRP · EPA 12/31/15 N"groundwater.

X. Protectiveness Statements

The Injection Wep Operable Unit is protective of human health, and the eJ)vironment in the short term and is expected to be fully protective at completion. In the interim, exposure pathways that could result in unacceptable risks are being controlled. Contaminants remain in groundwater at concentrations that do not allow for unlimited use and unrestricted exposure._ However, contaminated groundwater is contained to within the general facility area and institutional controls are in-place that effectively limit exposure to groundwater. A determination needs to be made regarding the appropriateness and feasibility of modifying the selected groundwater remedy; a periodic reevaluation of the groundwater: tleanup objective, as required by the 1988 ROD, needs to be perf?rmed; a groundwater background st~dy needs to be

34

I

Henderson Road Fourth Five-Year Review Report_ December 2013

performed; and the risk evaluation associated with the volatile organic compound concentrations/ in the on-Site garage indoor air needs to contipue.

' I

The remedial action associated with the Landfill Operable Unit is protective. The landfill has be~n capped and a leachate collection system has been installed, thereby reducing infiltration and the migration of contaminants.

XI. Next Review

The fifth Five-Year Review for the Henderson Road Site is required no later than five years from the signature date of this Five-Year Review.

' '

I '

. \

35


-1

[This page left intentionally blank.]

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36

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~~ ~ Feet

~' t-------~~~----------------~~~----------T"----------------------------------------------------.....1! <11 SCALE AS SHOWN

"' Gold DATE 09/09/13 N ~ er SITE LOCATION MAP ~ Associates AMDESIGN

13 Mt. Laurel , N ew Jersey GIS AM [ t:-:".'.""".~~~~~~~~~~~~~..J..,......,,.,~~~~~---1 ; tF~~~~. ~ 7~_0_1_6--l~ HEC~ FIGUREIL E No~~~~~~~~1-23_8_60~3B C~~ K~~B_A_R~~_,.--------------------------------------....,,....------------.J ,l; PROJECT No. 123-86073 REV. O REVIEW EVVD HENDERSON ROAD SUPERFUND SITE 1 ~ .______________1...-__.........________.1.-______________________....1.._____:____J

LEGEND

• APPROXIMATE WELL LOCATIONS

.REFERENCES 1) APPROXIMATE WELL LOCATIONS EXTRACTED FROM "FIGURE 1: GROUNDWATER MONITORING WELL NETWORK" PROVIDED BY RT ENVIRONMENTAL SERVICES, INC .

2) BASE AERIAL ORTHOIMAGERY OBTAINED FROM : U.S. GEOLOGICAL SURVEY HIGH RESOLUTION ORTHOIMAGERY FOR DELAWARE COUNTY, PENNSYLVANIA.

HENDERSON ROAD SUPERFUND SITE UPPER MERION TOWNSHIP, PENNSYLVANIA

APPROXIMATE WELL LOCATIONS

JSGolder\ZP"'Associates FIGURE 2

Mt.L• ur•I, N• wJ• r••

I

l

LEGEND • APPROXIMATE WELL LOCATIONS

SHALLOW GROUNDWATER CONTOUR • - (DASHED WHERE INFERRED)

21. 28 g~~~~D~~E:o~~~A~~~~L~A:~:NE~

REFERENCES 1) APPROXIMATEWELL LOCATIONS EXTRACTED FROM "FIGURE 1: GROUNDWATER MONITORING WELL NETWORK" PROVIDED BY RT ENVIRONMENTAL SERVICES, INC.

2) BASE AERIAL ORTHOIMAGERY OBTAINED FROM : U.S . GEOLOGICAL SURVEY HIGH RESOLUTION ORTHOIMAGERY FOR DELAWARE COUNTY, PENNSYLVANIA.


SHALLOW GROUNDWATER CONTOUR MAP

JUNE 201 3

~Golder\Z7Aisoa.ates FIGURE 3 M1. L..1ur.I, New J• t1 •

LEGEND 9 APPROXJMATE WEU LOCATIONS

INTERMEDIATE GROUNDWATER CONTOUR " - (DASHED WHERE INFERRED)

22.11 ;~~~~D~~E:o~~~0'~~~:L~~RNE~

REFERENCES 1) APPROXJMATE WELL LOCATIONS EXTRACTED FROM "FIGURE 1: GROUNDWATER MONITORING WELL NETWORK" PROVIDED BY RT ENVlRONMENTAL SERVlCES, INC.

2) BASEAERIALORTHOIMAGERY OBTAINED FROM : U.S. GEOLOGICAL SURVEY HIGH RESOLUTION ORTHOIMAGERY FOR DELAWARE COUNTY, PENNSYLVANIA.


INTERMEDIATE GROUNDWATER CONTOUR MAP

JUNE 2013

~~older'Z:'A....odates "" FIGURE 4 ...,Mt . L•ulel. New Jera•

LEGEND 9 APPROXIMATE WELL LOCATIONS

DEEP GROUNDWATER CONTOUR • - (DASHED WHERE INFERRED)

U .?4 g~~~~D~~E:o~~Zi"~~~~~L~A:~E~E~

REFERENCES 1)APPROXIMATEWELL LOCATIONS EXTRACTED FROM "FIGURE 1: GROUNDWATER MONITORING WELL NETWORK" PROVIDED BY RT ENVIRONMENTAL SERVICES, INC.

2) BASE AERIAL ORTHOIMAGERY OBTAINED FROM: U.S. ' ..! '~.r~1..1;:..:.;i GEOLOGICAL SURVEY HIGH RESOLUTION ORTHOIMAGERY FOR

DELAWARE COUNTY, PENNSYLVANIA.


DEEP GROUNDWATER CONTOUR MAP

JUNE 2013

l!ICALE. NS SHOWN REV D

FIGURE 5

LEGEND APPROXIMATE WELL LOCATIONS

r:_, .., PROPERRTY BOUNDARY (APPROXIMATE)

CROSS SECTION DESIGNATION FIGURE NO. WHERE CROSS SECTION IS PRESENTED

NOTE 1.) FEBRUARY-MARCH 2013 ARAR EXCEEDANCES IN GROUNDWATER (TOTAL FOR BENZENE, CHLOROBENZENE. 1,HllCHLOROETHANE, VINYL CHLORIDE, AND TOTAL XYLENES) REPRESENTED BY PURPLE PLUME.

REFERENCES 1) APPROXIMATE WELL LOCATIONS EXTRACTED FROM "FIGURE 1: GROUNDWATER MONITORING 'NELL NETWORK• PROVIDED BY RT ENVIRONMENTAL SERVICES, INC.

2) BASE AERIALORTHOIMAGERY OBTAINED FROM : U.S. GEOLOGICAL SURVEY HIGH RESOLUTION ORTHOIMAGERY FOR DELAWARE COUNTY, PENNSYLVANIA.

3.) HORIZONTAL DATUM REFERENCES THE PENNSYLVANIA SOUTH STATE PLANE COORDINATE SYSTEM, NORTH AMERICAN DATUM OF 1983 (NAO 83) .

I ~

~ ~ • e t' • ~

~ • & ~ •'a,

~.•! I t' :i

I HENDERSON ROAD SUPERFUND SITE UPPER MERION TOWNSHIP, PENNSYLVANIA

~ PLAN VIEW SCREEN CAPTURE OF

" ARAR EXCEEDANCES IN GROUNDWATER §

t £ l.

SCALE NJ SHOWN REV. 0

Figure 6

A A' s N

UPPER MERION RESERVOIR

SITE

2S3500 Ill 28~000.00 284500.00 2851lll 00 205500 00 t 28500).00


NOTES nTlE

SOUTH TO NORTH SCREEN CAPTURE OF 1.) FEBRUARY-MARCH 201 J ARAR EXCEEDANCES IN GROUNDWATER (TOTAL FOR BENZENE, ARAR EXCEEDANCES IN GROUNDWATER CHLOROBENZENE, 1,1-0ICHLOROETHANE, VINYL CHLORIDE . AND TOTALXYLENES) REPRESENTED BY PURPLE PLUME.

&CALE "5 SHOWN REV, o2.) APPROXIMATE WELL SCREEN INTERVALS SHOWN IN BLUE.

________j

LEGEND REFERENCES • APPROXIMATE WELL LOCATIONS

1.) IYl-VAULT-06092013 2.) GARAGE-06092013

1) APPROXIMATE WELL LOCATIONS EXTRACTEO FROM "FIGURE 1: GROUNDWATER MONITORING WELL NETWORK" PROVIDED BY RT ENVIRONMENTAL SERVICES, INC . HENDERSON ROAD SUPERFUND SITE

UPPER MERION TOWNSHIP, PENNSYLVANIA 3.) BREAK ROOM-06092013 4.) PL-AA--06092013

2) BASE AERIAL ORTHOIMAGERY OBTAINED FROM ARCGIS ESRI ONLINE

VAPOR INTRUSION SAMPLE LOCATIONS 40 20 0 40

f'!l""""'ll~1i-iiij-~~-1iiliilii~~~~~~i Fe111

Figure 8

LEGEND e APPROXIMATE \l\ €U LOCATIONS

-, SHALLOW ZONE WEU

.___! INTERMEOtATE ZONE WEll.

L-- j DEEP ZONE WEU.

NOTE 1) BOLO AND SHADED INOfCATE EXCEEOAHCES OF AAARS. BOLO INDICATE EXGEEO.AHCES OF MCLS

REFERENCES 1) APPROXIMATE WELL LOCAnCMS EXTRACTED FROM "RGURE 1: GR(Mlff)ViPr.TER MONITORING WEU NETWORK" PRCMOEO BY RT EN\1ROMIENTAL SEINtCES. ~

2J BASE AERIAL ORTHOMAGERY 08TAHE.O FROM:: U.S. GEOLcx;iw::.tiL SURVEY HIGH RESOt.VTION C>RTHOIMAGERY FOR OEi..AIMliRE CCMMTY. PENNSVLYNIMA


GROUNDWATER RESULTS JUNE 2013

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PHOTO LOG

Henderson Road Superfund Site Five-Year Review Site Inspection

Henderson Road Superfund Site Injection Well

Henderson Road Superfund Site View, from the Mezzanine, of the GWTP Process Equipment

Henderson Road Superfund Site Volatile Extraction System Vapor-Phase Carbon Tanks

Henderson Road Superfund Site Tracer Testing at Monitoring Well RE-205

Henderson Road Superfund Site Bio-Trap Removal at Monitoring Well RE-205

Henderson Road Superfund Site NE Corner of the Landfill

EPA PUBLIC NOTICE U.S. Environmental Protection Agency Reviews

Cleanup at Henderson Road Superfund Site The U.S. Environmental Protection Agency (EPA) is conducting its fourth Five-Year Review of the Henderson Road Superfund Site located in Upper Merion Township, Montgomery County. This review seeks to confirm that the cleanup of the landfill portion of the site, which included installing a multi-layer

. cap over contamination; installing a leachate collection system, and placing restrictions on future use, continues to be protective of public health and the environment. EPA's last formal review of the site identified several issues that potentially affected the protectiveness of the remedy. Since then, these issues have been closely evaluated and successfully addressed. A summary of cleanup activities and evaluation of the long-term protectiveness of the landfill cleanup remedy will be included in the Five-Year Review report.

What is an EPA Five-Year Review? EPA inspects Superfund sites every five years to ensure that cleanups conducted remain fully protective ofhuman health and the environment. These regular reviews, which are required by federal law when contaminants remain at a site, include:

• Inspection ofthe site and cleanup technologies; • Review ofmonitoring data, operating data, and maintenance records, and • Determination if any new regulatory requirements have been established since EPA's

original cleanup decision was finalized.

When will EPA's Five-Year Review Report be available? The Five-Year Review report will be available at http://epa.gov/Syr by December 2013.

For more information You may also contact

There are several ways to review site information. The Ifyou have any questions, concerns or information Administrative Record, which includes EPA decision about a change in current site conditions, contact: documents used for selecting the cleanup remedy, is available at www.epa.gov/arweb. You may also review

Larry C. Johnsonsite information at: EPA Community Involvement Coordinator Upper Merion Library Phone: (215) 814-3239 or (800) 553-2509 175 West Valley Forge Road

King of Prussia, PA 19406 Email: [email protected]

OR OR EPA Region 3 Public Reading Room Tim Gallagher Attn: Paul Van Reed (3HS42) EPA Remedial Project Manager 1650 Arch Street, 6th floor Phone: (215) 814-3196 Philadelphia, PA 19103 Email: [email protected] Phone: (215) 814-3157 (Please call for appointment)

For more Information visit: http:l/go.usa.gov/DPzF

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