EPA/AMD/R04-97/187 1997 EPA Superfund Record of Decision Amendment: MUNISPORT LANDFILL EPA ID: FLD084535442 OU 01 NORTH MIAMI, FL 09/05/1997 <IMG SRC 971870> 5 9 0001 RECORD OF DECISION AMENDMENT MUNISPORT LANDFILL SUPERFUND SITE North Miami, Florida <IMG SRC 97187A> Prepared by: United States Environmental Protection Agency Region IV, Atlanta, GA 5 9 0002 DECLARATION RECORD OF DECISION AMENDMENT SITE NAME AND LOCATION Munisport Landfill Site North Miami, Dade County, Florida STATEMENT OF BASIS AND PURPOSE This decision document represents an amendment to the Record of Decision (ROD) formerly issued by the United States Environmental Protection Agency on July 26, 1990. This amendment was made in accordance with the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), as amended by the Superfund Amendments and Reauthorization Act of 1986 (SARA) and the National Contingency Plan (NCP). This decision is based on the administrative record for this site. The State of Florida, as represented by the Florida Department of Environmental Protection (FDEP), has been the support agency throughout this project. In accordance with 40 CFR 300.430, FDEP, as the support agency, has provided input during the project. Based upon comments received from FDEP, it is expected that concurrence will be forthcoming; however, a formal letter of concurrence has not yet been received. Upon receipt, the State's concurrence letter will be placed in the Administrative Record for this site. The Metropolitan Dade County Department of Environmental Resources Management (DERM), as the local regulatory agency, has been consulted throughout this process as well. Based on DERM's comments, it does not object to EPA's determination to amend the ROD. A copy of DERM's comments regarding the amendment will be placed in the Administrative Record for this site. The National Oceanic and Atmospheric Administration (NOAA) was also consulted in the development of the amendment. NOAA concurs with EPA's determination and a copy of their comments regarding this amendment will be placed in the Administrative Record for this site. DESCRIPTION OF THE AMENDMENT This amendment provides for no further remedial action under CERCLA. DECLARATION STATEMENT This amendment is protective of human health and the environment according to the requirements set forth in CERCLA, and requires no further response by EPA pursuant to said requirements. Actions to date have mitigated the significant threat to the environment posed by elevated ammonia levels and toxic conditions in the Mangrove Preserve as established in the ROD, such that further response by EPA is not necessary. Since this amendment relies on no engineering or institutional controls to prevent unacceptable risks, a five-year review of the protectiveness of the remedy is not needed. Finally, amendment of this ROD to no further remedial action constitutes completion of construction of all Superfund-related activities. Therefore, this site now qualifies for the inclusion on the Construction Completion List. This amendment is separate from, and does not preclude, any actions the State of Florida and/or Metropolitan Dade County may deem appropriate for the site. <IMG SRC 97187B> RECORD OF DECISION AMENDMENT DECISION SUMMARY MUNISPORT LANDFILL SITE NORTH MIAMI, DADE COUNTY, FLORIDA Prepared by: United States Environmental Protection Agency Region IV, Atlanta, GA Table of Contents Section Page No. 1.0 Introduction 1 2.0 Site Background 1 3.0 Community Participation 6 4.0 Scope and Role of Response Action 7 5.0 Site Characteristics 8 5.1 Causeway Breach 8 5.2 Service Road 11 5.3 Hydraulic Barrier System 11 6.0 Summary of Site Risks 13 6.1 Study Approach 15 6.1.1 Sample Locations 15 6.1.2 Tidal Assessment 18 6.1.3 Water Quality Assessment 18 6.1.4 Toxicity Assessment 22 6.2 Study Approach 22 6.2.1 Tidal Assessment 22 6.2.2 Water Quality Assessment 23 6.2.3 Toxicity Assessment 27 6.3 Conclusions 27 7.0 Description of No Action Alternative 29 8.0 Explanation of Significant Changes 30 Figures Figure No. Description Page No. 2-1 Site Location Map 2 2-2 Evolution of Information and Key Decisions 5 5-1 Remedial Action- Phase I Causeway Breach 9 5-2 Surface Water Quality Sampling Locations 10 5-3 Toxicity and Ammonia Correlation 12 5-4 Hydraulic Barrier Layout and Location of Verification Test 14 6-1 Study Area Location Map 16 6-2 1996 Mangrove Sample Locations 17 6-3 Dania Canal reference Site 19 6-4 Biscayne Creek reference Site 20 6-5 Black Point reference Site 21 Tables Table No. Description Page No. 6-1 Initial Field Screening 24 6-2 Comparison of Total Ammonia Concentrations to Ambient Water Quality 25 6-3 Comparison of Organic and Inorganic Concentrations in August 1996 to Ambient Water Quality Criteria 26 6-4 Summary of the Results of Toxicity Tests Performed on Munisport Water Quality Samples, August 1996 28 Appendices Description Appendix No. Responsiveness Summary 1 1.0 INTRODUCTION The United States Environmental Protection Agency (EPA) issued a Record of Decision (ROD) for the Munisport Landfill Superfund Site on July 26, 1990, to address the significant threat posed to the environment. This threat was documented by EPA in 1989, after the investigation of the water quality and toxic conditions of a wetland adjacent to the landfill. This wetland is comprised of a mangrove swamp that is part of the State of Florida Biscayne Bay Aquatic Preserve, consequently known as the Mangrove Preserve ("Preserve"). The ROD provided for the interception of the flow of leachate-contaminated groundwater from the landfill to the Mangrove Preserve to reduce the risks posed to aquatic organisms in the Preserve due to elevated levels of ammonia. Through this remedy EPA intended to achieve the necessary degree of environmental protection set forth in CERCLA. Results from the Remedial Investigation and Baseline Risk Assessment conducted by EPA in 1988 documented no significant risks to human health. Therefore, protection of human health was not a component of the ROD. Closure of the landfill and management of storm water runoff was not part of this ROD and was to be addressed independently via State Landfill Closure established in Section 62-701 of the Florida Administrative Code. Although this amendment supersedes the remedy originally established for this site, it will not provide a detailed discussion of historical and technical information formerly presented in the ROD. The ROD and other documents included in the Administrative Record for this site will still be the proper source regarding such information. 2.0 SITE BACKGROUND The Munsiport Landfill is a former municipal landfill, 170 acres in size, located within the City of North Miami, Dade County, Florida. As shown in Figure 2-1, the landfill is bordered to the west by a United States Post Office and a large multi-department retail store along Biscayne Boulevard; to the north by 151st Street; to the east by hydraulically altered wetlands and the Mangrove Preserve; and to the south by Highland Village, a residential community. The landfill is part of a 291-acre parcel of land that was formerly planned as part of a trade and cultural, and later, a recreational center. The tract of land can be divided into the four following areas: 170-acre landfill; 15-acre upland; 93-acre hydrologically altered wetland; and 13-acre wetland adjacent to Biscayne Bay. In addition to the 291-acre parcel, the State Mangrove Preserve is comprised of an approximately 130-acre mangrove forest located east of the landfill and altered wetlands. Filling of low-lying areas with clean fill and construction debris began in 1974. As described in a detailed history of the site in the ROD and Remedial Investigation Report (1988), Munisport Inc., the City of North Miami, and ABC Demolition were involved in various enforcement activities regarding the permitting of the landfill. A temporary operating permit was eventually issued by the Florida Department of Pollution Control (now know as the Florida Department of Environmental Protection) in 1976. The U.S. Army Corps of Engineers also issued earlier in 1976 a dredge and fill permit pursuant to Section 404 of the Clean Water Act (CWA) to allow the filling of "waters of the U.S." with clean fill. <IMG SRC 97187C> EPA became involved with the site in 1980 in opposition to a request by Munisport, Inc., to the Corps of Engineers to modify the dredge and fill permit to allow the use of garbage in the filling of the wetlands. EPA formally issued a veto pursuant to Section 404(c) of the CWA to prevent the use of garbage to fill the wetlands. Landfill activities subsequently ceased in 1981. To date, however, the landfill has not been properly closed in accordance with FAC 17-101. In 1982, EPA evaluated the landfill for inclusion on the National Priorities List (NPL). The site was added to the NPL in 1983, primarily due to the potential threat to nearby municipal wells. These wells were subsequently taken out of service due to saltwater intrusion. As a result, the City of North Miami petitioned EPA to remove the site from the NPL. Consistent with EPA's policy of not rescoring sites that had been finalized on the NPL, EPA did not delete the site and decided to conduct an RI to evaluate potential risks to human health and the environment. EPA completed an RI of the site in 1988 that documented no threat to human health; however, the threat to the environment was inconclusive. Because of the threat to the environment appeared marginal, EPA proposed an action in July 1988 that included closure of the landfill in accordance with State law.