Adams County Quincy Municipal Landfills #2 and #3 Superfund Site Adams County, Illinois

FOURTH FIVE-YEAR REVIEW REPORT FOR ADAMS COUNTY QUINCY MUNICIPAL LANDFILLS #2 AND #3 SUPERFUND SITE ADAMS COUNTY, ILLINOIS

Prepared by

Illinois Environmental Protection Agency Springfield, Illinois

2/20/2018 X Robert A. Kaplan Acting Director, Superfund Division Signed by: DOUGLAS BALLOTTI

Table of Contents LIST OF ABBREVIATIONS & ACRONYMS ...... 2 I. INTRODUCTION ...... 3 II. RESPONSE ACTION SUMMARY ...... 4 Basis for Taking Action ...... 4 Response Actions ...... 6 Status of Implementation ...... 8 Institutional Controls ...... 10 Systems Operations/Operation & Maintenance ...... 12 III. PROGRESS SINCE THE LAST REVIEW ...... 14 Actions Taken Since the Last FYR ...... 15 IV. FIVE-YEAR REVIEW PROCESS ...... 16 Community Notification, Involvement & Site Interviews ...... 16 Data Review ...... 17 Site Inspection ...... 18 V. TECHNICAL ASSESSMENT ...... 19 QUESTION A: Is the remedy functioning as intended by the decision documents? ...... 19 QUESTION B: Are the exposure assumptions, toxicity data, cleanup levels, and remedial action objectives (RAOs) used at the time of the remedy selection still valid? ...... 19 QUESTION C: Has any other information come to light that could call into question the protectiveness of the remedy? ...... 20 VI. ISSUES/RECOMMENDATIONS ...... 20 OTHER FINDINGS...... 20 VII. PROTECTIVENESS STATEMENT ...... 21 VIII. NEXT REVIEW ...... 21 APPENDIX A – REFERENCE LIST...... 22 APPENDIX B – SITE BACKGROUND ...... 23 Physical Characteristics ...... 23 History of Contamination ...... 24 APPENDIX C – SITE CHRONOLOGY ...... 28 APPENDIX D – SITE INSPECTION CHECKLIST ...... 29 APPENDIX E – SITE MAP ...... 44 APPENDIX F – SITE PHOTOGRAPHS ...... 46 APPENDIX G – PUBLIC NOTICE ...... 57 APPENDIX H – LEACHATE PRE-TREATMENT PERMIT ...... 59 APPENDIX I – 2000 to 2013 GROUNDWATER MONITORING DATA AND ILLINOIS EPA MAY 13, 2013 LETTER ...... 68 APPENDIX J – ENVIRONMENTAL COVENANT...... 88

LIST OF ABBREVIATIONS & ACRONYMS

CERCLA Comprehensive Environmental Response, Compensation, and Liability Act CFR Code of Federal Regulations ELCR Excess Lifetime Cancer Risk EPA United States Environmental Protection Agency ESD Explanation of Significant Difference FS Feasibility Study IAC Illinois Administrative Code ICs Institutional Controls Illinois EPA Illinois Environmental Protection Agency GCL Geosynthetic Clay Liner HI Hazard Index MCL Maximum Contaminant Level NCP National Oil and Hazardous Substances Contingency Plan NPDES National Pollutant Discharge Elimination System NPL National Priority List O&M Operation and Maintenance OU Operable Unit PCB Polychlorinated biphenyl PCOR Preliminary Close Out Report PRPs Potentially Responsible Parties RA Remedial Action RAOs Remedial Action Objectives RD Remedial Design RD/RA Remedial Design/Remedial Action RI Remedial Investigation RI/FS Remedial Investigation/Feasibility Study ROD Record of Decision STP Sewage Treatment Plant Site Adams County Quincy Municipal Landfills #2 and #3 (Adams County Landfill) Superfund Site UECA Uniform Environmental Covenant Act UU/UE Unlimited Use and Unrestricted Exposure VOC Volatile Organic Compound WPCP Water Pollution Control Permit

I. INTRODUCTION

The purpose of a Five-Year Review (FYR) is to evaluate the implementation and performance of a remedy in order to determine if the remedy is and will continue to be protective of human health and the environment. The methods, findings, and conclusions of reviews are documented in FYR reports such as this one. In addition, FYR reports identify issues found during the review, if any, and document recommendations to address them.

The Illinois Environmental Protection Agency (Illinois EPA), in consultation with the United States Environmental Protection Agency (EPA), is preparing this FYR pursuant to the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) Section 121, consistent with the National Oil and Hazardous Substances Contingency Plan (NCP)(40 CFR Section 300.430(f)(4)(ii)), and considering EPA policy.

This is the fourth FYR for the Adams County Quincy Municipal Landfills #2 and #3 (Adams County Landfill) Superfund Site (Site). The triggering action for this statutory review is the completion date of the previous FYR, which was March 1, 2013. The FYR has been prepared due to the fact that hazardous substances, pollutants, or contaminants remain at the Site above levels that allow for unlimited use and unrestricted exposure (UU/UE).

The Site consists of one, Site-wide Operable Unit (OU), which will be addressed in this FYR.

The Adams County Landfill Superfund Site FYR was led by Brian Conrath of Illinois EPA. Participants included Karen Cibulskis of EPA. The official notification of initiation of the FYR process was issued to the potentially responsible parties (PRPs) on March 22, 2017. The FYR began on March 22, 2017.

Site Background

The Adams County Quincy Municipal Landfills 2 & 3 Site is located in a rural area on Rock Quarry Road (formerly known as Old Broadway Road) south of Illinois Route 104 approximately 5 miles east of the city of Quincy, Illinois. The Site’s northern limits are bounded by Rock Quarry Road and residences, the eastern boundary is adjacent to a dairy farm and residence, the southern limit is bounded by a wooded tract, and the western boundary is bordered by a private lane and a residence. The landfill area covers approximately 37 acres of the 56-acre property Site. Approximately 30 acres of the landfilled area are covered by a landfill cap with a leachate collection system to remediate issues associated with leachate and the resulting contaminant impacts to groundwater.

The Site was used as a pasture for livestock prior to the initiation of landfill operations in 1967. In January 1967, the Adams County Health Department approved a landfill development permit requested by Ronald Thomas. Illinois EPA issued Ronald Thomas and Marion Neill a permit to operate a landfill at the Site in March 1971. The city of Quincy leased the landfill from Ronald Thomas in September 1972. Illinois EPA issued a permit to the city of Quincy to operate the landfill in January 1973. Illinois EPA issued permits to expand the size of the landfill to the city of Quincy in 1974 and in 1975.

The city operated the Site until August 1978, then purchased the Site from Ronald and Sarah Thomas in April 1982. The Site is expected to remain a closed landfill in perpetuity. Additional background information about the Site can be found in Appendix B and in the 2013 FYR.

FOURTH FIVE-YEAR REVIEW SUMMARY FORM

SITE IDENTIFICATION

Site Name: Adams County Quincy Municipal Landfills #2 and #3 EPA ID: ILD 980607055 Region: 5 State: IL City/County: Quincy/Adams

SITE STATUS NPL Status: Final Multiple OUs? Has the site achieved construction completion? No Yes

REVIEW STATUS Lead agency: State [If “Other Federal Agency”, enter Agency name]: Author name (Federal or State Project Manager): Brian A. Conrath Author affiliation: Illinois EPA Review period: 3/22/2017 - 12/29/2017 Date of site inspection: 6/13/2017 Type of review: Statutory Review number: 4 Triggering action date: 3/1/2013 Due date (five years after triggering action date): 3/1/2018

II. RESPONSE ACTION SUMMARY

Basis for Taking Action

Drinking water wells at two homes adjacent to the Site were found to be contaminated with volatile organic contamination exceeding Maximum Contaminant Levels (MCLs) established under the federal Safe Drinking Water Act in 1985. Consequently, Illinois EPA notified the home owners of the contamination and recommended that the use of private wells be discontinued. The city of Quincy connected both homes to the local public water supply in April 4

1986. The two wells were reportedly properly closed, abandoned, and are no longer available for use.

Illinois EPA issued a notice to the city of Quincy and eight other PRPs to conduct a remedial investigation (RI) and feasibility study (FS) at the Site pursuant to Section 4(q) of the Illinois Environmental Protection Act (Act) (4(q) Notice) on June 12, 1986 and December 14, 1986 due to the apparent release of landfill contaminants into the groundwater migrating off-Site. The nine parties named in the 1986 notice formed a PRP group and proposed to undertake the RI/FS without entering into a consent order. The PRPs performed the RI to determine the nature and extent of the Site contamination in 1987-88. The PRPs submitted a final RI report to Illinois EPA in May 1989 and conducted a supplemental RI and risk assessment in 1990. EPA placed the Site on the National Priorities List (NPL) in August 1990 based on the results of the RI and risk assessment.

The risk assessment developed risk estimates for potential current and future threats to human health and the environment for the following exposure scenarios: domestic use of groundwater from hypothetical wells downgradient of the Site, including both the ingestion of drinking water and the inhalation of volatile organic compounds (VOCs) during showering; the domestic use of water from the two homes with contaminated drinking water wells at some time in the future, including both the ingestion of drinking water and the inhalation of VOCs during showering; and dermal contact with leachate by local children.

The RI and risk assessment determined that exposure to groundwater is associated with significant human health risks due to exceedances of EPA's risk management criteria for reasonable maximum exposure scenarios. The NCP establishes acceptable levels of risk for Superfund sites ranging from 1 in 10,000 (1 x 10-4) to 1 in 1,000,000 (1 x 10-6) for excess lifetime cancer risk (ELCR). ECLR refers to the number of cancer cases in addition to those that would ordinarily occur in a population of that size under natural conditions should people be exposed to site contaminants over their lifetime. For the non-cancer-causing compounds, noncarcinogens, a risk number called the hazard index (HI) is calculated. If the HI is less than or equal to 1, no adverse health effects are to be expected. If the HI is greater than 1, adverse health effects are possible.

The calculated ELCRs and HIs for this Site are listed and discussed under the Basis for Taking Action Section in Appendix B.

The risk assessment data indicated that dermal contact with leachate did not pose any unacceptable excess risks. Illinois EPA, however, took the position that if Illinois EPA were to conduct a current risk assessment at the time the agency selected a cleanup remedy for the Site, the evaluation would indicate that there were unacceptable excess risks from dermal contact with leachate. Illinois EPA also considered the on-Site leachate within the landfill to be a source of groundwater contamination, and that the landfill contents could cause additional degradation in leachate quality.

The risk assessment evaluated future land use at the Site, although a landfill is the only anticipated land use of the Site. Residential or commercial development is unlikely due to the topography and the remote location of the Site. The risk assessment also evaluated on-Site 5

dermal contact with leachate during a future hypothetical recreational use scenario. The results of this evaluation determined that recreational land use would only slightly increase the risks for the Site if a remedy was not implemented.

The RI/FS and risk assessment process did not identify any critical habitats, endangered species, or habitats of endangered species at the Site. The U.S. Department of the Interior Fish and Wildlife Service, however, identified two endangered species that were possibly present in the vicinity of the Site, the Indiana bat and the bald eagle.

Based on the data gathered during the RI and the risks identified in the risk assessment, the actual or threatened releases of hazardous substances from this Site, if not addressed by implementing the response action selected in the Record of Decision (ROD), may present an imminent and substantial endangerment to public health, welfare, or the environment.

The hazardous substances released and detected in each media at the Site are listed in Table 1.

Table 1: Hazardous Substances Released at the Adams County Landfill Site Soil Leachate Groundwater Benzene Benzene Benzene Ethylbenzene Ethylbenzene Ethylbenzene Total Xylenes Total Xylenes Total Xylenes Bis(2-ethylhexyl phthalate) Bis(2-ethylhexyl phthalate) Bis(2-ethylhexyl phthalate) Chloroethane Chloroethane Chloroethane Lead Lead Lead Mercury Mercury Mercury Arsenic Arsenic Arsenic Selenium Selenium Selenium 1,1-dichloroethane 1,1-dichloroethane 1,1-dichloroethane Trans-1,2-dichloroethene Trans-1,2-dichloroethene Trichloroethene Tetrachloroethene Tetrachloroethene Trans-1,2-dichloroethene 1,1,1-trichloroethane 1,1,1-trichloroethane Tetrachloroethene Vinyl chloride Vinyl chloride 1,1,1-trichloroethane 1,1-dichloroethene 1,1-dichloroethene Vinyl chloride Arochlor-1254 (PCB) Arochlor-1254 (PCB) 1,1-dichloroethene Di-n-butylphthalate Arochlor-1242 (PCB) Chlorobenzene

Response Actions

Illinois EPA signed a ROD to select a remedial action to address the risks at the Adams County Landfill Site on September 29, 1993. The major components of the selected remedy included:

• extending the public water supply to nearby residents; • installing a new multi-layer cap over the landfill, including a minimum of three feet of cover material over a geosynthetic clay liner (GCL) with drainage layers; • leachate collection, treatment, and monitoring; 6

• installing surface controls to reduce erosion at the Site; • installing a security fence around the Site; • groundwater monitoring, with a provision for groundwater containment and treatment if groundwater goals are not met and maintained; and • implementing deed restrictions to prohibit groundwater use and building construction on the Site.

Illinois EPA and the main PRPs, also known as the Quincy Remedial Design/Remedial Action (RD/RA) Group, entered into a Consent Order agreement to conduct the RD/RA on May 13, 1996. The Quincy RD/RA Group consisted of seven of the nine PRPs who entered into the RI/FS Consent Order with Illinois EPA. Two of the previous PRPs did not join the PRP RD/RA Group.

The selected remedy addressed the two media of concern at the Site, leachate and groundwater. The remedy included a multi-layer landfill cover system (cap) to minimize the amount of precipitation infiltrating into the landfill and contain the landfill contaminants. The landfill cap would minimize the amount of leachate that was generated, which would minimize contaminant impacts to leachate and, subsequently to groundwater.

The landfill cap would cover approximately 29 acres of the 37-acre landfill area that required capping and would be a multi-layer design including a GCL. The GCL was designed as a low permeability layer that would significantly reduce infiltration and intercept possible leachate seeps. A drainage layer would be installed to drain precipitation to the leachate collection trench and into a leachate collection storage tank.

Leachate generated on-Site would be recovered and transported off-Site for treatment and disposal. The leachate remedial action was designed to control the landfill as a source of groundwater contamination, to reduce the risks associated with the Site by reducing exposure to contaminated materials, and to prevent untreated leachate from flowing off-Site.

The landfill cap would also include a passive landfill gas venting system.

The groundwater remedy involved long-term monitoring with comparing results to 35 Illinois Administrative Code (IAC) 620.410 standards. Failure to meet those cleanup levels would trigger additional remedial action.

Illinois EPA issued an Explanation of Significant Differences (ESD) on January 7, 1998 that modified the remedy in the ROD. The ESD modified two parts of the selected remedy: rewording the warning signs on the fence and allowing leachate to be discharged to Quincy's Sewage Treatment Plant (STP) rather than to surface water through a National Pollutant Discharge Elimination System (NPDES) permit.

The ESD required an on-Site leachate treatment system to remain as a potential part of the remedy until, at a minimum, the first FYR was completed at the Site. If at any time prior to the FYR and for any reason an on-Site system was deemed necessary and warranted or if the off- Site treatment was incapable of handling the leachate generated, the on-Site leachate treatment system was to be designed, constructed, and operated within six months after notification of the need for on-Site treatment. 7

The State of Illinois and the Quincy RD/RA Group also negotiated a Consent Order, No. 96- 3072, for the reimbursement of costs incurred by the state of Illinois for response actions at the Adams County Quincy Municipal Landfills #2 & #3 facility and for the performance of studies and response work by the defendants at the Site consistent with the NCP.

Status of Implementation

The PRPs extended the public water supply to six nearby residences located northwest of the Site to eliminate the groundwater exposure pathway to those residents consuming the groundwater. Other residences located near the landfill, east and west of the Site, were later connected to the public water supply system and their drinking water wells were closed.

The PRPs filed a Notice of Access Agreement with the deed to the Site property at the County Recorder’s Office on May 28, 1996. The Notice of Access Agreement prohibited and restricted the use of groundwater, the construction of buildings, drilling, excavating and other intrusive soil activities on any portion of the Site, in accordance with and except as otherwise provided in the May 13, 1996 Consent Order (Case No. 96-3072).

The PRPs capped and closed the landfill in accordance with 35 IAC 807 and 811, Solid and Special Waste Management Regulations, specifically regarding final cover and closure requirements. The PRPs completed the solid waste cap in the fall of 1998. The cap consists of a GCL layer, a gravel drainage layer, and a protective vegetative layer. The PRPs initially constructed the cap over 29 acres of the landfill. In 2011, the PRPs expanded the cap beyond the leachate collection system in an attempt to further minimize the amount of leachate that was generated, increasing the capped area of the Site to approximately 30 acres. Landfill gas is released through a network of passive vents the PRPs installed through the cap in late 1998.

The PRPs installed over two thousand feet of leachate collection lines below the cap in a trench/French drain type construction in June 1998 before the cap was constructed. The PRPs installed the lines at depths ranging from three to ten feet along the shallow, down gradient (south and west) sides of the Site. The leachate from the Site is collected in a storage tank, then trucked to the Quincy STP for treatment and disposal.

The leachate collected from the landfill is tested for compliance sampling by the Quincy STP twice a year. The treatment plant samples the leachate for five-day biological oxygen demand, chemical oxygen demand, total suspended solids, dissolved iron, pH, grease/oil, arsenic, cadmium, chromium, copper, lead, mercury, nickel, selenium, silver, zinc, and total toxic organics in 40 CFR 403 whose individual values exceed 0.01 mg/L.

The PRPs constructed surface water controls at the Site including berms, riprap lined ditches, and gabion basket catch basins composed of riprap and heavy gauge wire mesh. The surface water controls manage surface water infiltration into the landfill and minimize landfill surface erosion. The controls direct storm water and snowmelt from the landfill cover system's surface to off-Site areas, significantly reducing infiltration into known disposal areas.

The PRPs restricted physical access to the Site by installing a six-foot high cyclone fence, with barbed wire at the top, around the entire Site to prevent trespassers from easily entering the Site. The PRPs posted warning signs on the fence at the four principal compass directions, as well as other locations where there was a potential for public access.

The PRPs implemented a groundwater monitoring program to track changes in the concentrations of Site constituents in groundwater. The monitoring program used data collected from the existing monitoring well system surrounding the Site. Contaminant concentrations exceeding levels pursuant to the Illinois Groundwater Quality Standards at 35 IAC 620 would trigger additional actions. It should be noted that a contaminated groundwater plume migrating off-Site had not been detected. However, no other source of off-Site groundwater contamination had been identified as being potentially responsible for the detected off-Site well contamination other than the landfill.

The Consent Order specified that "Monitoring will continue for a minimum of five years with further duration of monitoring dependent on the results of the statistical evaluation of the groundwater data. Monitoring may cease after the standards at 620.410 have been complied with for a minimum of one year after the minimum five-year monitoring period." In addition, monitoring may cease only after the remedy is proven effective in significantly reducing leachate, as well as reducing groundwater contamination below compliance levels per the ROD.

The Site groundwater monitoring program is consistent with IAC 620.505 and IAC 620.510. Illinois EPA established a groundwater management zone for the Site consistent with 35 IAC 620 for areas undergoing effective corrective action.

The ROD did not require the immediate implementation of an active groundwater remedy because the existing groundwater data indicated that relatively few sampling results showed groundwater contamination concentrations at levels of concern. The leachate control remedy, when appropriately implemented, has had a positive impact on groundwater quality, and is an effective source control measure combined with natural attenuation to address the low-level groundwater contamination at the Site. The ROD allows for the installation of a groundwater pump-and-treat system to be installed to minimize contaminant migration if levels are exceeded. The pump-and-treat system has not been installed based on past groundwater monitoring data showing no exceedances of compliance levels.

The Site achieved construction completion in March 1999. Illinois EPA found that the implementation of the remedial action commenced in 1998, was substantially complete and was documented in the 1999 Preliminary Close Out Report (PCOR). Minimal final Site grading, fence repairs, erosion controls, well repairs, final seeding, and minor access road repair work and construction needed to be finished. Illinois EPA issued a PCOR on March 31, 1999. EPA approved the PCOR on March 31, 1999.

The PRPs’ consultant submitted a Certification of Completion of the Remedial Action report to Illinois EPA on November 17, 2000. Illinois EPA responded on April 10, 2002, that, "After a detailed review of the documents, Illinois EPA has determined that they are, in general, acceptable for their intended purpose." The original cap design called for in the ROD was not installed at the landfill; therefore, Illinois EPA did not approve the Certification of Completion. 9

Illinois EPA has since evaluated this issue further. Illinois EPA determined that the ROD, when describing the cap required "a minimum of three feet of clay cover over the landfill surface." In accordance with the Consent Order, however, the PRPs constructed the cap as follows, from ground surface to waste materials (top to bottom):

• 6 inches of topsoil • 18 inches of compacted clay • 12 inches of pea gravel (drainage layer) • a GCL, and • 6 inches of sub-grade (existing soil cover assumed to be clay)

While the cap does not include a minimum of 3 feet of clay over the landfill surface, it does consist of three feet of cover material, and the hydraulic conductivity of those materials, according to the specifications, are equivalent to the 3 feet of clay specified in the ROD. Therefore, the only difference between what was called for in the ROD and what was constructed per the Consent Order, is the actual amount (thickness) of clay placed there.

Based upon this definition, Illinois EPA determined that the change from three feet of clay to 18 inches of compacted clay with the addition of the GCL qualifies as minor change, as it occurred during the design phase, is a modification of the functional specification, addresses performance optimization and cost minimization/value engineering process, affected the type of materials, and did not have a significant impact of the scope, performance, or cost of the remedy. Illinois EPA concurred with the Certification of Completion of the Remedial Action on August 2, 2017.

Groundwater monitoring ceased in 2007 when the PRP Group believed that the groundwater monitoring data met the conditions of the Consent Order. Illinois EPA requested one additional round of groundwater sampling. The PRPs conducted the additional groundwater sampling in February 2013.

The PRPs submitted the results of the additional groundwater sampling in the Groundwater Monitoring Report – February 2013 in May 2013. The 2013 report concluded that the concentrations of landfill-related constituents in Site groundwater have declined or remained stable since 2007. Illinois EPA concurred that subsequent groundwater monitoring could be eliminated at the Site and that the remaining groundwater monitoring wells at the Site could be abandoned in a letter dated May 13, 2013. The PRPs abandoned the groundwater monitoring wells in accordance with Illinois Department of Public Health Regulations on July 2, 2013.

A copy of the February 2013 groundwater monitoring data and Illinois EPA’s May 13, 2013 letter are in Appendix I.

Institutional Controls

Institutional Controls (ICs) are required to ensure the protectiveness of the remedy. ICs are non- engineered instruments, such as administrative and/or legal controls, that help minimize the potential for exposure to contamination and protect the integrity of the remedy. Compliance with ICs is required to assure long-term protectiveness for any areas which do not allow for unlimited use and unrestricted exposure (UU/UE). 10

The ROD requires the landfill to be capped in-place (containment) and requires deed restrictions to prohibit and restrict on-Site groundwater use, on-Site building construction, and on-Site drilling except for the purposes of remedial design, sampling, monitoring, and remedial action. The ROD also states that a public water supply shall be supplied to six nearby residences located northwest of the Site to eliminate the groundwater exposure pathway to those persons consuming groundwater. This was to supplement the 1986 extension of the Mill Creek Water District to nearby residents.

The 1999 PCOR states that the real estate deed was amended to prohibit on-Site groundwater use, on-Site building construction, and on-Site drilling except for the purposes of remedial design, sampling, monitoring, and remedial action. The title of the document referenced in the PCOR was a Notice of Access Agreement; that document was filed at the County Recorder's Office on May 28, 1996. A copy of the state Consent Decree on May 24, 1996 was also filed at the County Recorder's Office.

EPA required the Quincy RD/RA Group to complete and submit an IC Study in a letter dated October 4, 2007. The Quincy RD/RA Group and their consultant agreed to perform the study on October 26, 2007. The Quincy RD/RA Group submitted the IC Study report in December 2007. Initial IC evaluation activities indicated that a deed restriction had been implemented.

After reviewing the IC Study, EPA determined that it would be appropriate to incorporate the existing deed notice for the Adams County Landfill Site into an IC prescribed under the Illinois Uniform Environmental Covenant Act (UECA). Recording the UECA Environmental Covenant improves the permanence and enforceability of the IC. EPA, Illinois EPA and the city of Quincy completed and recorded the UECA Environmental Covenant with Adams County Recorder’s Office on April 1, 2011, Instrument 2011R-03147.

ICs known at this time to be required, implemented or recommended are listed in Table 2.

Table 2: Summary of Planned and/or Implemented ICs Media, engineered ICs Called Title of IC controls, and areas for in the Instrument ICs Impacted IC that do not support Decision Implemented Needed Parcel(s) Objective UU/UE based on Document and Date (or current conditions s planned) Restrict and prohibit on-Site building construction, and Adams County Quincy Environmental on-Site drilling, excavating Municipal Landfills #2 Entire Site Covenant or other intrusive soil and #3 Property Parcel Nos. April 1, 2011, Yes Yes activities except as consisting of capped 20-0-0031-000-00 Instrument otherwise provided in the landfill and other 20-0-0046-000-00 2011R-03147 May 13, 1996, remedy components Consent Order (Case No. 96-3072).

Media, engineered ICs Called Title of IC controls, and areas for in the Instrument ICs Impacted IC that do not support Decision Implemented Needed Parcel(s) Objective UU/UE based on Document and Date (or current conditions s planned) Groundwater - current Environmental area that exceeds Entire Site Covenant groundwater cleanup Parcel Nos. Restrict and prohibit the use April 1, 2011, standards on Adams Yes Yes 20-0-0031-000-00 of groundwater Instrument County Quincy 20-0-0046-000-00 2011R-03147 Municipal Landfills #2

& #3 property

A map showing the area in which the ICs apply is included in Appendix E. A copy of the 2011 Environmental Covenant is in Appendix J.

Status of Access Restrictions and ICs: All access restrictions and ICs are in place and properly enforced.

Current Compliance: The 2011 Environmental Covenant is implemented, and current inspections confirm that the landfill property remains vacant, that the landfill cap and other remedy components have not been disturbed, and that Site groundwater is not being used as a water supply.

IC Follow up Actions Needed: None.

Long Term Stewardship: Since compliance with ICs is necessary to assure the protectiveness of the remedy, planning for long-term stewardship is required to ensure that the ICs are maintained, monitored and enforced so that the remedy continues to function as intended. The PRP Quincy RD/RA Group is responsible for ensuring long-term stewardship (LTS) of the Site. LTS includes the maintenance of physical and nonphysical requirements, and land use restrictions; as well as working with all entities, authorities, and data management systems to insure the integrity of the remedial actions. LTS procedures for the Site are included in the Illinois EPA-approved 2013 Operation and Maintenance Plan (O&M Plan) for the Site.

Systems Operations/Operation & Maintenance

The Quincy RD/RA Group performs operation, maintenance, and monitoring (O&M) activities at the Site. The city of Quincy conducts monthly Site inspections, identifies maintenance issues and has on-Site personnel performing the majority of O&M activities. The Quincy RD/RA Group retains a consultant who inspects the Site annually and is tasked with overseeing larger maintenance issues.

Maintenance activities for the landfill cap system include mowing, earthwork activities to correct erosion and sedimentation problems, re-vegetation of disturbed or distressed areas, regrading in settlement areas, as necessary, and localized repairs due to intrusion, vandalism, etc., as needed.

Storm water management system maintenance involves activities to maintain the flow of storm water across the cap through the rip-rapped channels, drop basins, and discharge structures, etc. comprising the system, directing the water to off-Site drainage ways to an intermittent creek. O&M activities include clearing debris to allow for water flow, maintaining the vegetated channels and berms, where necessary, and any earthwork necessary to maintain channel slopes and channel berms.

The operation of the leachate management system involves the periodic removal of the leachate collected in the storage tank. The leachate is removed from the storage tank through a vacuum truck or with a portable pump to a tanker truck. The leachate is then transported to an off-Site treatment facility for disposal, currently the Quincy STP.

The leachate storage tank has a capacity of 10,000 gallons which was approximately 3 times the maximum anticipated 5-day leachate generation rate for the facility.

The 1999 Post Closure Groundwater Monitoring Work Plan discusses the cap and leachate reduction plan. Leachate was to be reduced from 10,000 gallons per day to 2,500 gallons per day. The actual frequency of leachate removal, transport, and disposal activities is dependent on the results of ongoing monitoring activities performed to gauge leachate generation and collection quantities.

Maintenance of the leachate management system requires activities necessary to ensure the system performs as designed. The system has been designed to collect leachate from known leachate seep locations and to direct the leachate through the collection and conveyance piping, via gravity flow, to the leachate storage tank for eventual removal, treatment, transport, and disposal. Maintenance activities include the cleaning of piping runs to remove blockages and solids buildup and the repair/replacement of system components (manhole covers, tank vents, access covers, valves, clean out ports, etc.) as required.

Leachate disposal rates are compiled and submitted to Illinois EPA and EPA monthly. Increases in leachate production are accounted for in seasonal fluctuations, possible cap failure/compromise, or groundwater infiltration from a ravine intersecting from under the road on the northwest side of the Site.

Passive gas vents are inspected for damage. Any damage that may limit the effectiveness of the gas venting system is repaired. The vents are inspected to ensure that they are properly labeled, that the vents are clear and not obstructed, and that the landfill does not allow surface ponding around the vents.

O&M is projected to continue for a minimum period of 30 years. O&M costs for the last five years are in Table 3.

Table 3: Operation and Maintenance Costs Year Total O&M Costs 2012 $215,260.49 2013 $455,735.53 2014 $138,032.22 13

Year Total O&M Costs 2015 $133,895.76 2016 $149,761.91

III. PROGRESS SINCE THE LAST REVIEW

This section includes the protectiveness determinations and statements from the last FYR as well as the other recommendations from the last FYR and the current status of those recommendations.

Table 4: Protectiveness Determinations/Statements from the 2013 FYR Protectiveness OU # Protectiveness Statement Determination 1/Site- Protective The remedy at the Adams County Quincy Municipal Landfills #2 wide & #3 Site is protective of human health and the environment. All engineered remedies are functioning as designed. Immediate threats to human health and the environment have been addressed. There is no known consumption of contaminated groundwater and no current exposure to the contaminants in the landfill. Institutional controls are in place and are effective.

There were no issues identified in the 2013 FYR affecting the current or future protectiveness of the remedy. There were several other issues identified to be resolved through routine O&M, which do not affect the protectiveness of the remedy. The status of these other recommendations is summarized in Table 5 and discussed below.

Table 5: Status of Other Issues and Recommendations from the 2013 FYR Current Current Implementation Completion OU # Issue Recommendations Status Status Description Date (if applicable) 01/Site- Future Illinois EPA and Completed Illinois EPA concurred with 5/13/2013 wide monitoring Quincy RD/RA PRP’s request to eliminate requirements Group to determine groundwater monitoring and future monitoring abandon wells. requirements at the Site to respond to PRP request to remove monitoring wells from the sampling list. Fill in low spots PRPs to fill in low Completed Repairs completed including 7/5/2013 on cap spots on cap addition of soil, re-grading, and seeding Voles burrowing Control infestation Completed Exterminator brought in to 7/5/2013 holes in landfill of voles at the Site eradicate voles

Current Current Implementation Completion OU # Issue Recommendations Status Status Description Date (if applicable) Trees and Remove trees and Completed Excess trees and vegetation 7/5/2013 vegetation need vegetation from has been removed to be removed drainage channels from the drainage channels Protective Secure protective Completed Bollards have been secured 7/5/2013 bollards bollards surrounding leachate cleanout were loose Erosion around Fill in and re-seed Completed Erosion has been addressed 7/5/2013 protective bollards Determine status Need to determine Completed At Illinois EPA’s request, 8/2/2017 of Certification if Certification of RD/RA Group completed a of Completion of Completion of the pre-certification Site the Remedial Remedial Action is inspection and submitted a Action complete or if new request for Remedial more information Action Completion is needed Certification. Illinois EPA concurred that the Remedial Action was complete.

Actions Taken Since the Last FYR

Additional Groundwater Sampling, Discontinuation of Groundwater Monitoring and Well Abandonment

The PRPs conducted additional groundwater sampling at the Site in February 2013. Based on the sampling results, Illinois EPA concurred that subsequent groundwater monitoring could be eliminated and that the remaining groundwater monitoring wells could be abandoned. The PRPs abandoned the groundwater monitoring wells on July 2, 2013. Additional information about the 2013 groundwater sampling and results is provided in the Status of Implementation section of this FYR.

O&M Plan Updated

The PRPs updated the O&M Plan to reflect the elimination of the groundwater monitoring program and groundwater monitoring well abandonment. The current O&M Plan is dated September 2013.

Landfill Cap Repairs

The PRPs addressed the maintenance issues identified for the landfill in the 2013 FYR in July 2013. The PRPs filled in and regraded the low spots on the cap, controlled the vole infestation causing holes in the cap, removed excess trees and vegetation from the drainage channels, and secured the protective bollards around the leachate cleanout and fixed the erosion around the bollards.

The PRPs conducted additional cap repairs at the Site from October 19, 2015 to October 23, 2015. The work included major repairs to the drainage areas which consisted of:

 Repositioning culvert pipe to allow access to an on-Site borrow area;  Removing existing rip-rap from drainage channel repair areas;  Placement, grading, and compaction of fill materials in the drainage channel;  Placement of geotextile and rip-rap in the drainage channel repair areas;  Placement of topsoil, seed, and mulch over the disturbed on-Site areas. The PRPs documented the repairs in a construction report dated May 5, 2016.

Certification of Completion of the Remedial Action

The RD/RA Group submitted a request, dated July 13, 2017, for Illinois EPA to concur with the Certification of Completion of the Remedial Action for the Adams County Quincy Municipal Landfills #2 and #3 Site. Illinois EPA re-reviewed the report and provided their formal concurrence on the report in a letter dated August 2, 2017. Additional information about the Certification is provided in the Status of Implementation section of this FYR.

IV. FIVE-YEAR REVIEW PROCESS

Community Notification, Involvement & Site Interviews

Illinois EPA notified the community about the FYR by taking out a newspaper advertisement in the Quincy Herald-Whig on March 30, 2017. The newspaper advertisement stated that Illinois EPA was conducting a FYR of the Site and invited the public to submit any comments to Illinois EPA. The results of the FYR and the report will be made available to the public at the Site information repository located at the Quincy City Hall, located at 730 Maine Street, Quincy, Illinois. A copy of the public notice is in Appendix G.

During the FYR process, Illinois EPA conducted interviews to document any perceived problems or successes with the remedy that have been implemented to date. Illinois EPA conducted interviews with:

• Carlee Scharnhorst, City of Quincy, Environmental Coordinator. Ms. Scharnhorst is responsible for maintaining the landfill as well as maintaining billing/invoice information and keeping data records for the Site. • Eric Hoglund, GHD, Senior Project Manager, the Quincy RD/RA Group’s consultant.

• Brian Koch, City of Quincy, Associate Engineer. During the interviews, the Quincy representatives and Quincy RD/RA Group informed EPA and Illinois EPA that they would like to evaluate whether discharging the leachate from the landfill to surface water, as selected in the 1993 ROD, would now be more cost-effective than disposing the leachate at the Quincy STP. The Quincy representatives and Quincy RD/RA Group’s consultant proposed to evaluate whether Site leachate would meet the conditions of current surface water discharge requirements, and, if not, what on-Site treatment might be required. Illinois EPA and EPA are agreeable to this evaluation and are waiting for the PRPs to submit the required information.

The Quincy representatives and Quincy RD/RA Group’s consultant informed EPA and Illinois EPA that they are in contact with an energy company that is interested redeveloping the Site into a photovoltaic power station. The city of Quincy is working with the energy company to determine whether this land use is feasible and economically viable at the Site.

No other issues with the functioning of the remedy, access restrictions, or other ICs were raised. No problems were noted, and no concerns were expressed. Illinois EPA did not receive any calls or comments from the public about the Site.

Data Review

The PRP Group submits monthly progress reports to Illinois EPA pursuant to Paragraph 26 of the Consent Order. Groundwater monitoring ceased in 2013, so the progress reports consist primarily of the volume of leachate collected and transported to the Quincy STP.

The leachate discharge volume is regulated under Water Pollution Control Permit (WPCP) 2004- EN-0414 which was issued on May 21, 2004. This permit allows the leachate to be hauled from the Adams County Landfill Site to the Quincy STP. The permit was issued to allow the increase in the maximum flow of leachate to be hauled to the Quincy STP from 35,000 gallons per week to 80,000 gallons per week. The design average flow of 25,000 gallons per week was not increased. The prior discharge was permitted under WPCP 2001-EN-2829 and was issued on April 6, 2001.

The permit had Standard Condition No. 8 wherein the Illinois EPA could file a complaint with the Illinois Pollution Control Board for suspension or revocation of a permit: a) upon discovery that the permit application contained misrepresentations, misinformation or false statement or that all relevant facts were not disclosed; or b) upon finding that any standard or special conditions have been violated; or c) upon any violation of the Environmental Protection Act or any Rules or Regulation effective there under as a result of the construction or development authorized by this permit.

The PRP Group previously submitted letters of "Notice of Excessive Discharge Volumes" to Illinois EPA. The letters stated, "…leachate discharge increases significantly in response to precipitation events." The letters cited spring thaw, heavy rain, snow melt, and/or heavy precipitation as the source of the discharge increases. These letters ceased being submitted in 2013 for the following reasons: 17

 The original permit was a construction permit and not an operating permit. Construction of the landfill was deemed complete by Illinois EPA in September 2000.  Illinois Regulation 309.204 states under paragraph 309.204(b)(2) that an operating permit is not required if “…authorization to discharge has been issued by a publicly owned treatment works with an approved pretreatment program…”. Since the City of Quincy has an approved pre-treatment program, no Illinois EPA operating permit is required.  The landfill leachate is discharged to the Quincy STP under a Wastewater Discharge Permit issued by the City of Quincy under its pre-treatment program. The Adams County Landfill Site also has an Industrial User Water Pretreatment permit (QWTF #01-029) from Quincy. The original permit was effective August 31, 2007 and expired on August 31, 2012. The permit contained requirements on effluent limitations; monitoring schedule; schedule of conditions; and reporting requirements summary. A review of the grab samples collected showed that the leachate met the conditions set forth in the permit. A new permit was issued on August 31, 2012 and expired on August 31, 2017. Since that time, the City has been proceeding on a month-to-month basis while awaiting a new permit to be issued. A copy of the most recent permit is included in Appendix H.

Site Inspection

The FYR Site inspection was conducted on June 13, 2017. In attendance were Brian Conrath from Illinois EPA, Karen Cibulskis from EPA, Carlee Scharnhorst and Brian Koch from the city of Quincy, and Eric Hoglund from GHD, the Quincy RD/RA Group’s consultant. The purpose of the inspection was to assess the protectiveness of the remedy.

The Site inspection team walked around the surface of the landfill cap and along the fence line around the entire Site. The team inspected the leachate collection tank, the groundwater monitoring wells and passive gas vents and the posted warning signs. The Site remains vacant, the landfill cap and other remedy components have not been disturbed, and there are no wells indicating that Site groundwater is being used as a water supply.

There were no significant issues noted during the Site inspection. However, there are a few minor items that will require attention.

There are a few low areas observed on the landfill cap. These low spots could lead to ponding during rain events which can add to the leachate volume by allowing storm water to infiltrate the cap.

In a few areas, there were signs of small burrowing animals in the landfill cap. They cause damage to the cap and will also lead to additional leachate volumes. The culprits will need to be removed and the ground repaired.

Some trees appear to be growing in the drainage channels and along the fence line. These will need to be removed.

There is a minor washout under the fence near the leachate collection tank. Some rip rap has been added, but more needs to be done to correct the problem. The opening in the fence may allow unauthorized access to the Site.

All of these issues can be addressed as part of normal O&M activities. A copy of the Site Inspection Checklist is in Appendix D.

V. TECHNICAL ASSESSMENT

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

Question A Summary:

Yes. A review of the remedial systems operations data and the Site inspection provide evidence that the selected engineered remedies are functioning as intended by the ROD and ESD. An enforceable UECA Environmental Covenant is in place at the Site. There is no evidence of Site or groundwater uses which are inconsistent with existing ICs and the objectives of the required use restrictions. No inappropriate Site or media uses have been noted during the inspection or interviews. Residences in the vicinity of the landfill are connected to municipal water.

The landfill property is fenced with chain link fence and topped with barbed wire. Warning signs were observed at the Site at the time of the inspection. There was no evidence of any trespassing.

Higher than expected volumes of leachate can be generated at the Site. The excess leachate can lead to significantly increased O&M costs. The Quincy RD/RA Group may want to consider additional cap investigation or other investigations or evaluations to determine if there are other, more cost-effective measures that could be implemented to reduce the volume of leachate and/or O&M costs. It should be noted that no wastewater exceedances have been noted discharging from the Quincy STP from the leachate discharge from the landfill.

QUESTION B: Are the exposure assumptions, toxicity data, cleanup levels, and remedial action objectives (RAOs) used at the time of the remedy selection still valid?

Question B Summary:

Yes. There have been no changes in the physical conditions of the Site that would affect the protectiveness of the selected remedy at this Site. Neither has there been any substantive change in the use of the property during the last five years. There have been no changes in land use near the Site, nor are any changes expected in the near future. There have been no newly observed species or ecologic settings. Potential exposure scenarios remain the same.

There have been no changes in either the contaminant characteristics/toxicity or the federal Safe Drinking Water Act standards for the protection of groundwater as they relate to the contaminants of concern at this Site. Standard risk assessment methods have not changed in a way that would affect the protectiveness of the remedy at this Site.

In general, contaminant concentrations in groundwater, when monitored, were stable or continued to decline at the Adams County Quincy Municipal Landfills #2 and #3 Site. Groundwater monitoring data showed that the cleanup goals had been met based on the 2007 and 2013 data. The selected remedy has been and continues to be effective in protecting human health and the environment.

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

No. No new information has come to light in the last five years that would call into question the protectiveness of the selected remedy at the Adams County Landfill Site. The landfill cap, however, could be investigated further, to determine whether the excess leachate discharge levels are caused by increased precipitation or by a deficiency in the cap. This does not affect the protectiveness of the remedy, however, since the leachate is collected and transported to the Quincy STP for disposal. There have been no newly-discovered ecological risks. There have been no significant impacts from natural disasters or climate change.

VI. ISSUES/RECOMMENDATIONS

There are no issues identified that affect the current or future protectiveness of the remedy.

OTHER FINDINGS

The following recommendations, however, were identified during the FYR. Addressing these recommendations may improve the performance of the remedy and reduce costs, but do not affect current or future protectiveness:

 There are a few low areas observed on the landfill cap which should be filled in.  There were signs of some burrowing animals on the landfill cap. The undesired animals will need to be removed and the ground repaired.  Some trees appear to be growing in the drainage channels and along the fence line. These will need to be removed.  There is a minor washout under the fence near the leachate collection tank. Some rip rap has been added, but more needs to be done to correct the problem.  The Quincy RD/RA Group may want to consider additional cap investigation or other investigations or evaluations to determine if there are other, more cost-effective measures that could be implemented to reduce the volume of leachate and/or O&M costs.

VII. PROTECTIVENESS STATEMENT

OU1 and Site-wide Protectiveness Statement Protectiveness Determination:

Protective Protectiveness Statement: The remedy at the Adams County Quincy Municipal Landfills #2 & #3 Site is protective of human health and the environment. All engineered controls are functioning as designed. Immediate threats to human health and the environment have been addressed. There is no known consumption of contaminated groundwater and no current exposure to the contaminants in the landfill. Institutional controls are in place and are effective.

VIII. NEXT REVIEW

The next FYR report for the Adams County Quincy Municipal Landfills #2 & #3 Superfund Site is due five years from the signature date of this review.

APPENDIX A – REFERENCE LIST

Documents Reviewed

Record of Decision – 1993 Consent Order – 1996 Explanation of Significant Differences – 1998 Five Year Review – 2003 Five Year Review – 2008 Uniform Environmental Covenant - 2011 Five Year Review – 2013 Operations and Maintenance Plan - 2013 Site Analytical Data – 2012 to 2017

APPENDIX B – SITE BACKGROUND

Physical Characteristics

The 56-acre Adams County Landfill Site is located in a rural area on Rock Quarry Road (formerly known as Old Broadway Road) south of Illinois Route 104, about 5 miles east of the city of Quincy in Melrose Township, Adams County, Illinois. The northern limits of the Site are bounded by Rock Quarry Road and residences, the eastern boundary is adjacent to a dairy farm and a residence, the southern limit is bounded by a wooded tract, and the western boundary is bordered by a private lane and residence.

The Site is located in a semi-rural setting where agriculture is the most common local land use. Pastureland and a small wooded tract immediately adjoin the Site. A rock quarry is located approximately one-half mile west of the landfill. Though the area is generally rural, there are a number of houses nearby. A few residences are located just across Rock Quarry Road to the north, and one each to the west and east within one hundred yards of the Site. Quincy reported that a new mobile home, equipped with a water meter, was added to the east property in 2012. A small subdivision is located approximately one mile north of the Site and the village of Burton is the closest community, located to the northeast within approximately one and one-half miles of the Site.

The landfilled areas are located upland of the Mississippi River and the topography is generally hilly, sloping from the north to the south and southwest. Surface drainage on the Site flows to the south and southwest to an unnamed stream tributary to Mill Creek. A drainage ditch on the western boundary of the Site collects surface runoff and discharges to the stream.

The landfill is typical of most co-disposal municipal landfills where general refuse was mixed with municipal and industrial wastes. Disposal occurred from 1967 to 1978. The Site is wire- fenced on all sides with a locked access gate on the northern boundary. A blacktop road crosses the middle of the Site from the entrance gate on the north to the southwestern side of the Site to the leachate collection tank. The landfilled area covers about 37 acres of the property but only approximately 30 acres of the landfill required capping.

The northern two-thirds of the landfill Site, which was the area of landfill operation, is vegetated with herbaceous plants (grasses, forbs and legumes) though some woody shrubs and small trees occur throughout the surface water drainage ways. Woody vegetation, including large deciduous trees with an herbaceous understory, occurs in the drainage along the stream and on the southern part of the Site (outside the fenced area) where no disposal activities occurred. No wetlands have been identified on or near the Site.

No leachate collection or containment system was installed at the Site during its operational period. Numerous leachate seeps occurred throughout the landfill area during its operating history and after closure. Most seeps were located on the southwestern side of the Site, although several were seen in the old roadway and a large seepage area occurred in a low-lying area in the middle of the Site. Leachate accumulated in low areas and drainageways, then ran off-Site

primarily in two locations: along the western boundary fence and on the southwest to the nearby stream.

Land and Resource Use

Prior to the initiation of landfill operations in 1967, the Site was used for the pasturage of livestock. In January 1967, the Adams County Health Department approved a landfill development permit requested by Ronald Thomas. In March 1971, Illinois EPA issued Ronald Thomas and Marion Neill a permit to operate a landfill at the Site; however, Marion Neill's association ceased later that year. A new permit was issued to Ronald and Sarah Thomas the following year. The city of Quincy leased the landfill in 1972 and received a permit to operate the landfill the following year. Permits to expand the size of the landfill were issued in 1974 and 1975. The city operated the Site until August 1978 and purchased the Site from Ronald and Sarah Thomas in April 1982.

History of Contamination

After the closure of Quincy Municipal Landfill #1 in September 1972, the Site became the only operating landfill in Adams County until August 1975. During its operational history, the Site received the majority of the solid waste generated in the county, as well as industrial waste from the Quincy area manufacturing sector. Liquid industrial wastes were allegedly disposed of at the Site.

Because no leachate collection or containment system was installed at the Site prior to the Remedial Action (RA), numerous leachate seeps occurred throughout the property. Leachate collected in low areas and could have potentially migrated off-Site on the surface. This could have occurred in two locations: along the western boundary and the southwest to the nearby intermittent stream.

Initial Response

The city of Quincy completed a CERCLA Notification of Hazardous Waste Site form for the Adams County Quincy Municipal Landfills #2 & #3 Site. The notification acknowledged the disposal of unknown quantities of inorganic chemicals, organic solvents, heavy metals, mixed municipal wastes, and other undetermined wastes at the landfill. Additional response notices were received from generators of wastes disposed at the Site.

EPA completed a preliminary assessment of the Site on July 1, 1983. The preliminary assessment estimated that approximately 3,000 people were potentially affected by groundwater contamination from spent halogenated solvents used in degreasing, wastewater treatment sludge from electroplating operations, 1,1,1-trichloroethane, and other hazardous substances that were accepted at the Site.

EPA completed a Site inspection and document review of the Site on March 7, 1984. It was estimated that among other wastes, the Site had received 343,000 gallons of sludge containing

paint and toluene, 2,800,000 gallons of oily waste, 312,000 gallons of solvents, 343,200 gallons of other organic chemicals, 180,000 gallons of inorganic chemicals, and 180,000 gallons of caustic chemical bases. These estimates were based on Illinois EPA supplemental permits for Site disposal.

Basis for Taking Action

In 1985, drinking water wells at two homes adjacent to the Site were found to be contaminated with VOC contamination exceeding MCLs under the Safe Drinking Water Act. Consequently, Illinois EPA notified the home owners of the contamination and recommended that the use of private wells be discontinued. Quincy connected both homes to the local public water supply in April 1986 and the two wells were reportedly properly closed and abandoned and are no longer available for use.

Because of the apparent release of landfill contaminants into the groundwater that migrated off Site, Illinois EPA issued notices to Quincy and eight other potentially responsible parties (PRPs) on June 12, 1986, and December 14, 1986, to conduct a remedial investigation and feasibility study (RI/FS) at the Site, pursuant to Section 4(q) of the Illinois Environmental Protection Act. The nine parties named in the 1986 notices formed a PRP group and proposed to undertake the development of an RI/FS without entering into a consent order. The PRPs performed the remedial investigation (RI) to determine the nature and extent of Site contamination in 1987-88 and submitted a final RI report in May 1989. The PRPs performed a supplemental RI and a risk assessment, in 1990. Based on the results of the remedial investigation and the risk assessment, EPA placed the Site on the NPL in August 1990.

the evaluation would indicate that there were unacceptable excess risks from dermal contact with leachate. Illinois EPA also considered the on-Site leachate within the landfill to be a source of groundwater contamination, and that the landfill contents could cause additional degradation in leachate quality.

The risk assessment evaluated future land use at the Site, although continued landfill maintenance is the only anticipated future land use at the Site. Dermal contact with leachate during a future hypothetical recreational use was considered and would only slightly increase the associated risk level if exposure were to occur on a daily basis. The carcinogenic risks were highest for exposure to contaminated groundwater from a possible future ingestion pathway. Residential or commercial development is unlikely due to the topography and the remote location of the Site.

The hazardous substances released and detected in each media at the Site are listed in Table 1. A summary of Site risks is provided in Table 2.

Table 2: Cancer Risk Level (CRL) and Hazard Index Results Impacted Media Type of Cancer Risk Hazard Index Exposure Level (ELCR) Downgradient Groundwater Reasonable 1.86 x 10-6 0.108 well Maximum Exposure (RME) Allen well Groundwater Average 2.47 x 10-5 0.176 Exposure (AE) Allen well Groundwater RME 7.34 x 10-5 0.281 Jacobs well Groundwater AE 4.11 x 10-4 0.173 Jacobs well Groundwater RME 2.34 x 10-4 0.268 Dermal contact Leachate Incremental 9.40 x 10-9 0.0000203 CRL

The CRLs exceeded the point-of-departure risk level for all groundwater scenarios. The HI was less than 1, which indicates that adverse noncancer health effects are not anticipated.

APPENDIX C – SITE CHRONOLOGY

Event Date

Discovery of contamination at Adams County Landfill Site May 1, 1981 Site proposed on the National Priorities List (NPL) June 24, 1988 Adams County Landfill listed on the NPL August 30, 1990 Remedial Investigation/Feasibility Study (RI/FS) conducted September 12, 1990 – September 30, 1993 Record of Decision (ROD) issued September 30, 1993 Remedial Design conducted March 31, 1996 – December 18, 1997 Remedial Action (RA) Start December 18, 1997 Explanation of Significant Differences (ESD) issued January 7, 1998 RA Construction Start March 10, 1998 RA Completed March 31, 1999 Site Inspection of Completed Construction March 24, 1999 Preliminary Closeout Report March 31, 1999 Operation and Maintenance (O&M) Activities Begin August 1, 1999 First Five-Year Review Report Issued March 28, 2003 Second Five Year Review Report Issued March 21, 2008 Third Five Year Review Report Issued March 1, 2013 Illinois EPA Concurrence with Certification of Completion of the August 2, 2017 Remedial Action Next Five-Year Review to be Issued March 2023

APPENDIX D – SITE INSPECTION CHECKLIST

APPENDIX E – SITE MAP

APPENDIX F – SITE PHOTOGRAPHS

Photograph 1 ‒ June 13, 2017, Looking easterly over landfills 2 and 3. Photo ID 0018150006~06132017-001.

Photograph 2 ‒ June 13, 2017, Photo of gas vent 12 and protective bollards. Photo ID 0018150006~06132017-004.

Photograph 3 ‒ June 13, 2017, Drainage channel with some vegetation growing within. Photo ID 0018150006~06132017-005.

Photograph 4 ‒ June 13, 2017, Photo of repair work to fence where soil had washed out below. Still needs additional work. Photo ID 0018150006~06132017-012.

Photograph 5 ‒ June 13, 2017, Photo looking from leachate collection area back toward landfill. Photo ID 0018150006~06132017-014.

Photograph 6 ‒ June 13, 2017, Photo of leachate collection system and tanker truck used to haul leachate off-Site. Photo ID 0018150006~06132017-016.

Photograph 7 ‒ June 13, 2017, Photo of gap below fence filled with rip rap, but requires additional work to close. Photo ID 0018150006~06132017-017.

Photograph 8 ‒ June 13, 2017, Photo of larger burrow in cap needing to be addressed. Photo ID 0018150006~06132017-019.

Photograph 9 ‒ June 13, 2017, Photo of trees and assorted vegetation in fence line. Photo ID 0018150006~06132017-021.

Photograph 10 ‒ June 13, 2017, Photo of small ponding area on cap. Photo ID 0018150006~06132017-024.

APPENDIX G – PUBLIC NOTICE

APPENDIX H – LEACHATE PRE-TREATMENT PERMIT

APPENDIX I – 2000 to 2013 GROUNDWATER MONITORING DATA AND ILLINOIS EPA MAY 13, 2013 LETTER

Wo r ldwi d e E n g i n e e r i n g , E n v i r onm e n t a l , Co n s t r u c t i o n , a n d I T S e r v i c e s GROUNDWATER MONITORING RESULTS - FEBRUARY 2013 ADAMS COUNTY/QUINCY LANDFILLS 2/3 SITE QUINCY, ILLINOIS MAY 2013 REF. NO. 013822 (23) Prepared by: Conestoga-Rovers & Associates 1801 Old Highway 8 Suite 114 St. Paul, Minnesota 55112 Office: (651) 639-0913 Fax: (651) 639-0923

APPENDIX J – ENVIRONMENTAL COVENANT

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