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Congressional District # 06


EPA ID# WID052906088
Last Updated: November, 2014

Site Description

The Hechimovich Sanitary Landfill site (AKA Land and Gas Reclamation Landfill) is situated on 24 acres and is located in Williamstown, Wisconsin, a rural area, located approximately two miles south of Mayville. The site is a former municipal and industrial waste landfill that operated under different ownerships from about 1959 to 1986. For a period of time the site was licensed to accept hazardous waste and the site did receive liquid industrial wastes that were placed in unlined pits. Some of the types of wastes disposed in these pits included paint sludges, cutting oils, and spent organic solvents. The Wisconsin Department of Natural Resources (WDNR) required the pits to be closed in 1980.

The U.S. Environmental Protection Agency (EPA) detected volatile organic compounds (VOCs) in two wells downgradient of the site in 1984. During operations, the owner of the site violated the terms of the landfill's operating license by depositing solid waste in areas beyond those previously approved by WDNR. This violation was the subject of a state enforcement action in July 1987.

EPA proposed the site for inclusion on the National Priorities List (NPL) in June 1988 and finalized the site on the NPL in March 1989. 

The towns nearest to the site are Mayville with 4,330 residents and Horicon with 3,585 residents. Approximately 5,000 people obtain their drinking water from private wells located within three miles of the site.

Site Responsibility

This site is being addressed through federal, state, and potentially responsible party (PRP) actions. 

Threats and Contaminants

Groundwater monitoring has been conducted at the site since the early 1980s. However, groundwater quality data collected since the early 1990s are primarily used to make decisions about the condition of the site. The shallow groundwater VOC contamination plume is stable in both the concentration of detectable contaminants and in the plume boundaries. Groundwater monitoring conducted in 2009, including the sampling of more than 20 private wells, discovered contamination northeast of the landfill in the bedrock units underlying the site. Two of the private drinking water wells that capture water from the dolomitic aquifers beneath the dolomite and shale layers of the Maquoketa Formation were found to have contamination of chlorinated VOCs above the state and federal drinking water standards and detections of other chlorinated VOCs. On-site soil is also contaminated with VOCs. Direct contact with or ingestion of contaminated groundwater or soil may pose health threats. Local surface waters could be used by residents for recreational activities. If site-related contaminants should migrate into the surface water, residents could be exposed to them when coming into direct contact with these bodies of water. Directly north of the Hechimovich Landfill site is a wetland which could be at risk from site runoff.

Cleanup Progress

Following completion of the Remedial Investigation and Feasibility Study (RI/FS), WDNR signed a Source Control Interim Record of Decision (ROD) on January 13, 1994. The 1994 Interim ROD documented the installation of a new clay cap and an active landfill gas extraction system. EPA concurred with the ROD.

The final remedy for the site, documented in a ROD signed by WDNR on September 6, 1995, included the existing clay cap and gas extraction system, operational changes to the gas system to emphasize gas removal from those areas of the waste fill believed to be major contributors of contaminants to the groundwater, and long-term groundwater monitoring. EPA concurred with the ROD. The Hechimovich site consists of two operable units (OUs). OU1 is the source control remedy and OU2 is groundwater.

Long-term and recent groundwater monitoring downgradient of the site has shown some improvement in the shallow groundwater quality in impacted monitoring wells. Operation of the remedial action selected in the 1995 ROD appears to be improving the groundwater quality in the shallow unconsolidated aquifer directly north of the landfill. However, in the spring of 2009, the information concerning site conditions changed. As a result of contamination exceeding state and federal drinking water standards found in two private drinking water wells located 1,800 – 4,000 feet northeast of the waste boundary, it was determined that a deeper, previously unknown, groundwater contaminant plume may be leaving the landfill moving to the northeast through various bedrock units and possibly impacting private wells cased 180-190 feet below the ground surface. Since 2009, sampling has been conducted at various private wells in the area and investigations are currently being conducted by the potentially responsible parties (PRPs). These investigations are being conducted to determine the source(s) of the new contaminant groundwater plume, including the landfill; to define the degree and extent of the plume; to assess potential human and environmental risks; to identify remedial options; and to implement any necessary remedial actions.

As an interim public health protection measure, bottled drinking water is being provided to one home with contaminant levels exceeding drinking water standards. A filtration system was also installed at this home and the sampling indicates that it is working properly. The only other well that exceeded drinking water standards was converted to a monitoring well and is no longer useable as a drinking water supply well.

As a part of the expansion of the nearby Glacier Ridge Landfill, the Hechimovich Landfill is being dismantled and the waste relocated into Glacier Ridge. Upon completion of the waste relocation, the Glacier Ridge Landfill will then be expanded over the footprint of Hechimovich. The project includes a diversion of the piping for the gas extraction system. Best management practices will be utilized to minimize the time waste is exposed.

Five-year reviews were completed in February 1999, June 2004, and June 2009. The Fourth Five-Year Review Report for the site was signed by EPA on June 13, 2014. The five-year review found that the site remedy is protective in the short term, since human health and ecological exposures are currently under control. The five-year review also identified some issues that need to be addressed in order for the remedy to be protective in the long term.


Remedial Project Manager, U.S. EPA
sheila desai (desai.sheila@epa.gov)
(312) 353-4150

Community Involvement Coordinator, U.S. EPA
susan pastor
(312) 353-1325




Site Profile Information

This profile provides you with information on EPA's cleanup progress at this Superfund site.


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