Region 8
Serving Colorado, Montana, North Dakota, South Dakota, Utah, Wyoming and 27 Tribal Nations
Superfund Program
National Information
Regional Information
Site Information
National Priorities List (NPL) History
Proposed Date
12/30/1982
Final Date
9/8/1983
Marshall Landfill
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Site Type: Completed NPL City: Boulder County: Boulder Street Address: 1600 S. 66th Street Zip Code: 80303 EPA ID#: COD980499255 Site ID#: 0800187 Site Aliases: Landfill Inc. Congressional District(s): 02 |
Site Description
The 160-acre Marshall Landfill site is located at the foothills of the Rocky Mountains, about three miles southeast of Boulder. The Marshall Reservoir is immediately west of the site.
In 1981, water that collected contaminants as it leached down through the landfill was discovered seeping into the open Community Ditch. The ditch carries drinking water from the reservoir to the City of Louisville and irrigation water to downstream ranchers.
The inactive landfill had high levels of contaminants in both surface water and groundwater. Identified contaminants were benzene, trichloroethylene (TCE), tetrachloroethylene, barium, iron, manganese and zinc. Benzene and TCE are known to cause cancer; the others are toxic to fish and other aquatic life. Because significant levels of contamination from the landfill were found in surface and groundwater on and next to the landfill, EPA added the site to its Superfund National Priorities List in 1983.
Current operation and maintenance activities include operating a groundwater treatment system, maintaining the landfill cover and groundwater monitoring. A five-year review was completed in September 2006. The review found that the remedy, as designed, constructed and operated is protective of human health and the environment.
EPA issued an Explanation of Significant Differences (ESD) in September 2003 that documents amendments made to the 1986 Record of Decision for Marshall Landfill. The ESD describes new or changed standards for groundwater and surface water at the site. At the time of the Record of Decision, groundwater standards did not exist for several volatile organic compounds. In addition, many of the State of Colorado's surface water quality standards have been updated.
The ESD determines that standards be brought up to date in order to be protective of human health and the environment and to assure that the original remedy is protective.
Site Risk
| Media Affected | Contaminants | Source of Contamination |
| Surface water, ground water, soil, liquid waste | Benzene, trichloroethylene (TCE), tetrachloroethylene, barium, iron, manganese, zinc | Landfill operations |
Cleanup Progress
These cleanup activities were completed in 1993 by the potentially responsible parties:
- Constructed a groundwater collection and treatment system.
- Regraded and revegetated the landfill soil cover.
- Drained and treated leachate from lagoons.
- Installed a pipeline to convey water from the Community Ditch through the landfill to prevent further contamination of the groundwater.
Cleanup construction was completed in August 1993.
Community Involvement
Community comment was solicited for the five-year review completed in September 2006. EPA produces an annual update (see link below) to the five-year review, which presents the current status of the cleanup.
Land Use Controls
The 2003 ESD identified that institutional controls (ICs) were necessary to ensure long-term protection of the engineered remedy and to prevent future release of contamination. The site has implemented ICs containing two components, informational and enforcement. (Click this link to see where land use controls apply) (LARGE PDF file: 8 MB).)
- Informational -- an electronic map in the Boulder County Planning Department outlines the landfill boundary and identifies the property as a Superfund Site. All applications related to development or changes in land use are submitted to the county.
- Enforcement -- A rural Preservation Planning Area land use designation prohibits the development of the Superfund Site. The land use restriction is enforceable by Boulder county and all surrounding municipalities through the Intergovernmental Agreement US 36 Interstate Corridor Comprehensive Development Plan effective June 20, 2000. Specifically, the agreement states that the municipalities "shall not grant a permit for development" for all areas within the Rural Preservation Planning Area including the Superfund Site.
Land Use Control Documents
Intergovernmental Agreement US 36 Corridor Comprehensive Development Plan, June 20, 2000 (PDF, 12 pp, 715 kb)
Site Documents
The documents below are Adobe PDF files (about PDF files)
Five-Year Review, September 29, 2006 (LARGE PDF, 30 pp, 3.5 MB)
Note: the best way to open this file is to right-click on the above link and save it to a folder
Annual Update to the Five-Year Review, December 2008 (66 K, PDF file, 2 pp)
Explanation of Significant Differences (ESD), September 2003 (527 K PDF file )
Contacts
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EPA Fran Costanzi Jennifer Chergo |
Colorado Fonda Apostolopoulos |
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View Documents at: EPA Superfund Records Center Boulder Public Library |