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Congressional District # 06


EPA ID# WID980610190
Last Updated: April, 2015

Site Description

The 7.3-acre Ripon City Landfill (RCL) site is located northwest of the city limits of Ripon, Wisconsin. The site is in a rural area surrounded by woods, a gravel pit, a park, and cropland. Several private homes are located within one-half mile.

The RCL site was a former gravel pit that was owned by a private party who leased the land to the Speed Queen Corporation in 1967 for the purpose of landfilling. The City of Ripon began leasing the property in 1968 for the disposal of wastes, and in 1969, it was issued a license to operate the landfill. Later, the Town of Ripon joined with the City of Ripon in operating the landfill. The landfill was operated until 1983 and accepted municipal, commercial, and industrial solid wastes for disposal.

In 1984, a residential well located 500 feet south of the site was found to be contaminated with substances from the landfill. The well was abandoned. In 1985, the landfill area was capped with clay, vegetation was established, and a gas venting system was placed along the western edge of the landfill. In 1992, a group of potentially responsible parties (PRPs) signed an agreement with the Wisconsin Department of Natural Resources (WDNR) to complete a full remedial investigation (RI) and feasibility study (FS) at the site and to implement a source control remedy.

According to the 2010 census, the City of Ripon had an estimated population of about 7,733 people. Ripon obtains its drinking water from an area groundwater aquifer. One of the city's municipal wells is located 3,700 feet southeast of the landfill.

Site Responsibility

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

Threats and Contaminants

The RI determined that groundwater beneath and near the RCL site was contaminated with low levels of volatile organic compounds (VOCs), including vinyl chloride, tetrachloroethene, trichloroethene, benzene, and cis-1,2-dichloroethene. Human exposure to site-related VOCs could occur if contaminated groundwater were ingested, which could cause cancer or non-carcinogenic health effects over time.


Cleanup Progress

The PRP group completed the RI and FS at the RCL site during 1993 and 1994. A Record of Decision (ROD) was signed in March 1996 to select a final remedy. For the landfill (source control operable unit), the ROD selected construction of a new landfill cap and a passive gas venting system, along with groundwater monitoring. The No Action alternative was selected for the groundwater operable unit because of the relatively low contaminant levels in groundwater.

The PRP group completed construction of the RCL site remedy in 1996. A Preliminary Close Out Report was issued on September 25, 1996. Results of groundwater monitoring conducted since the new cap was constructed have continued to show changes in groundwater quality over time.

EPA completed a Five-Year Review (FYR) at the RCL site in May 2001 and concluded that the remedy remained protective of human health and the environment based on the available groundwater monitoring results. However, in October 2001, vinyl chloride was detected for the first time in two private wells located about 1500 ft downgradient (south-southwest) of the landfill. Because the vinyl chloride was found at significant concentrations, the two private wells were fitted with individual treatment systems until the residences were connected to the City of Ripon municipal water. Two other private residences in the same area were also connected to the new water line. During this time, the State established a "Special Well Casing Pipe Depth Area" downgradient of the landfill. In this area, any new private wells that are constructed will have to adhere to stringent standards.

Semi-annual groundwater monitoring was instituted for monitoring wells associated with the landfill and several downgradient private wells. Additional monitoring wells were installed to help determine the degree and extent of the groundwater plume. An active gas management system at the landfill to replace the passive one was investigated as an improvement in the source control area. 

EPA completed the second FYR at the RCL site in September 2006 and concluded that the remedy, with the additional measures that have been taken, was protective of human health and the environment in the short term. 

EPA completed the third FYR at the RCL site in September 2011 and again concluded that the remedy remained protective in the short term. It found no evidence that humans were being exposed to site-related contaminants either at the landfill or by drinking groundwater. Long-term protectiveness of groundwater will be achieved when the groundwater reaches cleanup levels. The 2011 FYR report recommended that to ensure long-term protectiveness, effective institutional controls (ICs) should be implemented, monitored and maintained. Other recommendations in the 2011 FYR report included considering enhancements to the gas extraction system to maintain control of landfill gas, documenting the provision of an alternative water supply and the installation of an active gas extraction system in a decision document, and reviewing options to address the groundwater contaminant plume.

EPA plans to complete the next FYR at the RCL site by September 2016.


Remedial Project Manager, U.S. EPA
mary tierney (tierney.mary@epa.gov)
(312) 886-4785

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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