Mosley Road Sanitary Landfill Superfund Site

• Location: Oklahoma City, Oklahoma County, Oklahoma
• Township and Range: Section 21, Township 12N, Range 2W
• Latitude/Longitude: 35.50677444, -97.41434367
• Site Type: Municipal Landfill
• Area: 0.113 square miles/72 acres
• National Priorities List: Final Listing Date - Feburary 21, 1990; Deletion Date - September 26, 2013
• Current Status: Cleanup complete, deleted from National Priorities List

• Cleanup Oversight Agencies: Waste Management of Oklahoma (WMO), DEQ, and EPA
• Lead Agency: EPA
• Office: DEQ, Land Protection Division, (405) 702-5100
• DEQ Site Project Manager: Makenna Hartman, (405) 702-5159
• DEQ Press Contact: Skylar McElhaney, (405) 702-7167

The Mosley Road Sanitary Landfill was originally owned by Floyd Swen, who operated the site under the name A-I Sanitation Company from 1971 to 1975.  From 1975 through 1984, the landfill was owned and operated by Oklahoma City Disposal Inc. (OCD).  Originally permitted as a sanitary landfill, OCD was authorized to accept industrial hazardous wastes between February 20, 1976 and August 24, 1976, due to the temporary closure of the Royal Hardage Landfill in Criner, OKlahoma.  During this six month time period, OCD accepted approximately 1.7 million gallon of primarily liquid hazardous waste.  All of the hazardous waste was placed in three underground, unlined pits (referred to as the waste pits) that are now buried beneath municipal waste.  In 1984, Waste Management of Oklahoma (WMO) accepted the operation and maintenance responsibilities of the site.  The landfill reached its permitted capacity and was closed in November 1987.  In order to reduce environmental and health risks for about 900 people within a 1-mile radius of the site, a clay cover was installed over the landfill and the site was proposed to the National Priorities List (1988).  The site achieved construction completion when the Preliminary Close-out Report was signed on September 8, 2004.  The EPA and DEQ determined that all construction activities, including the implementation of institutional controls, were performed according to the remedy.  The final inspection was conducted by EPA and the State on March 29, 2005.

The June 1992 Record of Decision identified remedies for the Mosely Road Sanitary Landfill Superfund Site, which included:

• Restoration of groundwater as a potential source of drinking water through monitored natural attenuation; continued groundwater monitoring and sampling to determine changing conditions (14 wells)

• Implementation of a Landfill Gas Monitoring System (LGMS) to prevent explosion and inhalation hazards

• Repairs and improvements of the existing cap

• Addition of vegetative soil layer to reduce erosion and infiltration

• Implementation of institutional controls to prevent exposure to on-site contamination

• Installation of fencing and warning signs

• A final close-out report was signed on May 15, 2013

• A direct final notice of deletion was published in the Federal Register on August 12, 2013

The fourth Five-Year Review determined that the site remedy is protective of human health and the environment.  WMO plans to continue routine operation and maintenance at the site, including operation of the Landfill Gas Monitoring System, monitoring of the groundwater, and maintenance of the cap.

Waste Management Inc is piloting ways to convert methan gas from the East Oak and Mosley Road landfills to fuel.

Institutional Controls (ICs) are in place and are enforced by Waste Management of Oklahoma and DEQ.  These ICs are in place to limit site access and industrial reuse.

• Sources of Contamination: Oklahoma City Disposal (OCD) accepted approximately 1.7 million gallons of liquid hazardous waste, which included pesticides, industrial sludges, caustics, acid solutions, oil-based products, alkaline solutions, solvents, toxaphene, and trichloroethylene

• Contaminants of Concern:
  • North Canadian Alluvium and Well Contamination - Arsenic, barium, manganese, selenium, 1,1-Dichloroethane, 1,2-Dichloroethene, naphthalene, 1,2-Dichloropropane, pentachlorophenol, 2-chlorophenol, phenol, pyrene, benzene, tetrachloroethene, bis(2-ethylhexyl)phthalate, trichloroethene, chlorobenzene, and vinyl chloride
  • Garber-Wellington Well Contamination - 1,1-Dichloroethane, cis-1,2-Dichloroethene, arsenic, manganese, barium, trans-1,2-Dichloroethene, benzene, vanadium, chlorobenzene, and xylene

• Media Affected: Waste pit soil and sediment, surface water, and groundwater

• Surface Water Impacted: Crutcho Creek, North Canadian River, and a few on-site ponds

• Groundwater Impacted: Garber-Wellington Aquifer and North Canadian Alluvium