Munisport Landfill

• Site Profile
• Administrative Record Index (PDF): OU1 (107 pp., 3.8M), ESD (2 pp., 77K),
  Amend (15 pp., 638K), Deletion (2 pp., 47K)
• Reuse Success Fact Sheet (PDF, 1 pp., 159K)
• Additional Site Documents including Five Year Reviews, Records of Decisions (ROD) and Explanation of Significant Differences (ESD).
• For documents not available on the website, please contact the Region 4 Freedom of Information Office (http://www.epa.gov/region4/foiapgs/submit.htm).

Site Background:
The Munisport Landfill Superfund Site is an inactive municipal landfill located on a 291-acre parcel of land within the city limits of North Miami, Florida, along Biscayne Bay Boulevard between NE 135th and NE 151st Streets. The landfill is bordered to the east by Biscayne Bay, and wetlands; to the south by a mobile home community, to the west by commercial developments, and to the north by a State University. Operations began in the mid-1960's as part of the construction of a trade and cultural center. Operations in the 1970's initially included the placement of construction debris to raise the elevation of wetland areas to provide a subgrade for the construction. Due to financial constraints and opportunities for increase revenues in landfill tipping fees, the developers began accepting solid waste for fill material. The owner of the property, the City of North Miami, pursued a modification of the dredge and fill permit to allow for the use of solid waste as fill material. However, the modification was denied by the United States Environmental Protection Agency (EPA) through a veto of the United States Army Corps of Engineers dredge and fill permit. However, before the use of solid waste could be halted through veto of the dredge and fill permit, an estimated six million cubic yards of solid waste had been placed in the landfill. Because the solid waste was disposed of without the use of a liner nor leachate control mechanisms, rainfall percolating through the solid waste has caused the release of elevated levels of ammonia into the underlying groundwater and discharge into adjacent surface water.

A Remedial Investigation completed by EPA in 1988 and a water quality and toxicity assessment completed in 1989 found that the landfill posed no threat to human health, but that it did pose a significant threat to aquatic organisms in the adjacent wetlands. Based on these findings, EPA issued a ROD in 1990 that included the implementation of a hydraulic barrier to intercept the discharge of contaminated groundwater from the landfill to the Mangrove Preserve. EPA and the City of North Miami entered into a Consent Decree for the cleanup in 1992. Contaminated groundwater collected as part of the implementation was to be treated through air stripping with the water discharged to the underlying aquifer. Associated actions included the tidal restoration of a State of Florida mangrove preserve and a hydraulically altered wetland area.

Cleanup Progress: Construction Completed
Due to the varying degrees of complexity in scope of the different components of the remedy, EPA decided to segment the design and construction process into the four following phases: Tidal Restoration of a wetland area included in the Biscayne Bay Aquatic Preserve, and Access and Service Road, Hydraulic Barrier Recovery Wells, and Treatment and Disposal System. Tidal restoration of the wetlands was completed in September 1995. Construction of the service road and recovery wells for the hydraulic barrier were substantively completed in 1996. A draft design for the groundwater treatment and disposal system was submitted to EPA in December 1996.

However, based on results from the monitoring of the changes in water quality and toxicity conditions in the Mangrove Preserve in 1996, as a result of the breach of tidal restoration of the Preserve, EPA concluded that the increased tidal circulation was adequate to mitigate the threat to the environment and that further response pursuant to CERCLA was not warranted. As a result, the ROD was amended to "No Further Action" in 1997. The site was removed from EPA's National Priorities List in September 1999. The state and county are expected to oversee the closure of the landfill. No Five-Year Reviews are required for the Site. No further updates are warranted at this time.