FIFTH FIVE-YEAR REVIEW REPORT FOR LAUREL PARK LANDFILL SUPERFUND SITE BOROUGH OF NAUGATUCK NEW HAVEN COUNTY, CONNECTICUT Prepared by U.S. Environmental Protection Agency Region 1 Boston, Massachusetts Bryan Olso , D · tor Date Office of Site Remedia tion and Restoration Table of Contents LIST OF COMMON ABBREV IATIONS & ACRONYMS ...................................................................... 3 I. INTRODUCTION ........................................ ........................................................................................... 4 FIVE-YEAR REVIEW SUMMARY FORM ......... ....... .................................................. ...................... 5 11. RESPONSE ACTION SUMMARY .................... ....... .. ........................................................................ 5 Basis for Taking Action .......................... .. .......................... ..... ............................................................... 5 Response Actions ................................................................. .. .............................................................. .. 6 Status of ln1plementation ................ ..... ................................................................................................... 8 IC Sun1n1ary Tables ................................................................................................................................ 9 Operation & Maintenance and Long-term Monitoring ........................................................................ I I III. PROGRESS SINCE Tl-I E LAST REVIEW .......... .. .. .. ....................................................................... 11 IV. FIVE-YEAR REV IEW PROCESS ......................... .. .. ...................... ............................................. .... 12 Community Notification, Involvement & Site Interviews .................................................................... 12 Data Review ...................................................... ..................... .. ............................................................. 14 Site Inspection ....................................................................................................................................... 19 V. TECJ-INlCAL ASSESSMENT ............................................................................................................ 20 QUESTION A: ls the remedy functioning as intended by the decision documents? .......................... 20 QUESTION B: Are the exposure assumptions, toxicity data, cleanup levels, and remedial action objectives (RA Os) used at the time of the remedy selection still valid? .............................................. 22 QUESTION C: I-las any other info m1ation come to light that could call into question the protectiveness of the rernedy? ............................................................................................... ................ 27 YI. ISSUES/RECOMMENDATIONS ..................................................................................................... 27 OTI-IER FIN DINGS ....................................................................................................... ....................... 28 VI I. PROTECTIVENESS STATEMENT ........................................................................................ ........ 28 VIII . NEX'r REVIEW ......................................................................................................................... 29 APPEN DIX A - REFERENCE LIST .... .. ........................................................................................ ......... 30 APPEN DIX B - ADDITIONAL DA TA TABLES AN D FIGURES 2 LIST OF COMMON ABBREVIATIONS & ACRONYMS ARAR Applicable or Relevant and Appropriate Requirement CERCLA Comprehensive Environmental Response, Compensation, and Liability Act CFR Code of Federal Regulations coc Contaminant of Concern CT DEEP Connecticut Department of Energy and Environmental Protection CTDPH Connecticut Department of Public Health EPA United States Environmental Protection Agency FYR Five-Year Review GES Groundwater Extraction System GWPC Groundwater Protection Criteria GWPS Groundwater Protection Standards gpm gallons per minute ICs Institutional Controls LC/GES Leachate Collection/Groundwater Extraction System LPC Laurel Park Coalition LTMP Long-Term Monitoring Plan MCL Maximum Contaminant Level mg/Kg milligrams per kilogram mg/L milligrams per liter NPL National Priorities List NWPCF Naugatuck Water Pollution Control Facility OSWER Office of Solid Waste and Emergency Response OU Operable Unit O&M Operation and Maintenance PFAS Per- and Polyfluoroalkyl Substances POTW Publicly-Owned Treatment Works POC Point of Compliance RAO Remedial Action Objective RCRA Resource Conservation and Recovery Act RI/FS Remedial Investigation/Feasibility Study ROD Record of Decision RSR Remediation Standard Regulation SWPC Surface Water Protection Criteria TPY tons per year µg/L micrograms per liter voe Volatile Organic Compound 3 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 reports such as this one. In addition, FYR reports identify issues found during the review, if any, and document recommendations to address them. The U.S. Environmental Protection Agency (EPA) is preparing this five-year review pursuant to the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) Section 121 , consistent with the National Contingency Plan (NCP)(40 CFR Section 300.430(f)(4)(ii)), and considering EPA policy. This is the fifth FYR for the Laurel Park, Inc. Superfund Site (the "Site"), more commonly referred to as the Laurel Park Landfill Superfund Site. The triggering action for this statutory review is the completion date of the last FYR in September 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 Operable Unit (OU) that will be addressed in this FYR. The Laurel Park Landfill Superfund Site FYR was led by Karen Lumino, Remedial Project Manager for EPA Region 1. Other participants from EPA Region 1 include Joy Sun (Senior Enforcement Counsel); Courtney Carroll (Human-Health Risk Assessor); Bart Hoskins (Ecological Risk Assessor); and ZaNetta Purnell (Community Involvement Coordinator). Sheila Gleason (Environmental Analyst) with the Connecticut-Department of Energy and Environmental Protection (CT DEEP) also participated in this review. The Settling Defendants were notified of the initiation of the five-year review which began on November 20, 2017. Site Background The Laurel Park Landfill Superfund Site is located in the Borough of Naugatuck, Connecticut, approximately 1 mile west of the Naugatuck River and Connecticut Route 8, and encompasses 35 acres on Huntington Hill (a.k.a. Hunter's Mountain) (Figure 1). The capped landfill occupies 19 acres, and sits in glacial till on the eastern slope and on weathered bedrock on the western flank. A chain-link fence extends around the perimeter of the Site. Beyond the fenceline, most of the area is forested. Adjacent land use is dominated by residential development. Surface water from the landfill flows into Spruce Brook and Long Meadow Pond Brook which are tributaries to the Naugatuck River, located 1 mile west of the Site. Long Meadow Pond Brook is fed by an unnamed stream that begins at the base of the landfill. Groundwater in the vicinity of the Site flows predominately within the shallow bedrock in a north-northwesterly direction. In the shallow and deep overburden, the flow has a more northerly component. 4 Both sanitary and industrial waste were accepted at the landfill from the late 1930s until it closed in 1987. Operational problems at the landfill were first reported in the early 1960s. Complaints included chemical spills on roads leading up to the landfill, large quantities of black acrid smoke, unpleasant odors and blowing litter. Leachate from the landfill was found to be running into surface water. The Site was listed on the National Priorities List (NPL) in 1983. Also in 1983, as a condition of their operating permit, the State of Connecticut ordered Laurel Park, Inc., to provide residents with bottled water, until construction of a public water line was completed. FIVE-YEAR REVIEW SUMMARY FORM SITE IDENTIFICATION Site Name: Laurel Park, Inc. Superfund Site EPA ID: CTD98052 I I 65 City/County: Borough ofNaugatuck/New Haven NPL Status: Final Multiple OUs? Has the site achieved construction completion? No Yes REVIEW STA TUS Lead agency: EPA Author name: Karen Lumino, Remedial Project Manager Author affiliation: MENT/CT Superfund Section, OSRR, EPA Region I Review period: 11/20/2017 - 9/4/2018 Date of site inspection: 4/12/2018 Type of review: Statutory Review number: 5 Triggering action date: 9/25/2013 Due date (five years after triggering action date): 9/25/2018 II. RESPONSE ACTION SUMMARY Basis for Taking Action The Remedial Investigation/Feasibility Study (RVFS) was conducted from 1985 to 1987. The RVFS concluded that the existing leachate collection system was only partially effective in capturing leachate. Leachate continued to contaminate soil, surface water, and groundwater in the vicinity of the