Congressional District # 02
HAGEN FARMEPA ID# WID980610059
Last Updated: March, 2015
The Hagen Farm Superfund site is located at 2318 County Highway A in the town of Dunkirk, approximately one mile east of Stoughton in Dane County, Wisconsin. The Hagen Farm property is about 28 acres in size. The site is bounded on the south by County Highway A and on the north by a gravel pit operation. Within the property boundaries is a waste disposal area of nearly 10 acres that has contaminated the groundwater below. The Yahara River is located about 1.5 miles to the west of the site and flows in a southerly direction. Regional groundwater generally flows toward the river in a southwesterly direction from the site.
The Hagen Farm site was operated as a sand and gravel pit prior to the late 1950s. The gravel pit was then used for the disposal of waste materials from the late 1950s to the mid-1960s. Waste solvents and various organic materials, in addition to municipal wastes, were disposed of at the site including, acetone, butyl acetate, 1,2-dichloroethylene (DCE), tetrahydrofuran (THF), solid vinyl, and sludge material containing methyl ethyl ketone, xylenes, and toluene. The site stopped accepting waste in 1966. Groundwater has been impacted by acetone, THF, vinyl chloride, xylene, DCE, and trichloroethylene (TCE).
Prior to disposal activities, the land comprising the waste disposal area was excavated for sand and gravel; thus, the natural habitat that existed at the site prior to these operations was destroyed. Land in the immediate vicinity of the site has been developed for agricultural, mining, and commercial uses. The unincorporated town of Dunkirk is primarily a farming community. Approximately 350 people reside within one mile of the site.
The U.S. Environmental Protection Agency (EPA) placed the Hagen Farm site on the National Priorities List (NPL) in 1987.
Site ResponsibilityThe Hagen Farm site is being addressed through potentially responsible party (PRP) actions under state and federal oversight.
Threats and Contaminants
There were three waste disposal areas on the Hagen Farm site, with the largest occurring in one main area (called "Area A"). Area A contained about 68,000 cubic yards of waste, including municipal refuse, paint sludges, grease, rubber, plastic sheeting, and several industrial chemicals. The contaminants of concern found in the waste and in groundwater in contact with the refuse were tetrahydrofuran (THF), benzene, ethylbenzene, toluene, xylenes, various semi-volatile organic chemicals, and the heavy metals barium, lead, and mercury.
The contaminants of concern in the groundwater plume were volatile organic chemicals (VOCs). The most prevalent of these, THF, occurred in concentrations as high as 630,000 parts per billion (ppb). Though VOCs were not found in any private wells during the investigation, it was determined that contaminants in the waste and groundwater posed an unacceptable risk to human health. These exposures could occur primarily through direct contact, inhalation, and ingestion of contaminated groundwater. The highest concentrations of VOCs in groundwater were found near the former disposal areas. Soils and wastes on the property were also contaminated with VOCs. Ingestion and direct contact with contaminated soils and wastes also posed a potential health threat.
In 1983, the state of Wisconsin brought an enforcement action against Waste Management of Wisconsin, Inc. (WMWI) and Uniroyal Plastics, Inc., two potentially responsible parties (PRPs) at the Hagen Farm site, for the abatement of a public nuisance. At the same time, residents near the site filed a civil action against WMWI and Uniroyal for potential health hazards and the devaluation of their properties. In 1986, the parties to the civil litigation reached a settlement that required in part, that WMWI purchase the Hagen property and adjacent properties. The state dismissed its enforcement action against the PRPs after EPA listed the site on the NPL in 1987.
The PRPs signed an Administrative Order on Consent with EPA in July 1987, whereby they agreed to conduct a Remedial Investigation and Feasibility study (RI/FS) at the site. The PRPs conducted the RI/FS between 1988 and 1992, during which time EPA determined that the site cleanup would be best approached by dividing it into two operable units (OU). The first operable unit, called the source control operable unit (SCOU), comprised the waste refuse and contaminated soils beneath the disposal area. The second, known as the groundwater control operable unit (GCOU), addressed the groundwater contaminant plume beneath the site and downgradient of the property boundary.
EPA signed a Record of Decision (ROD) in September 1990 to select the cleanup approach for the SCOU and later signed a ROD that addressed the GCOU in September 1992. The ROD for the waste disposal area (SCOU) called for consolidating three waste disposal areas into Area A, capping the consolidated waste, and installing and operating an in-situ vapor extraction (ISVE) system. The ROD for the GCOU called for pumping and treating the groundwater contaminant plume.
WMWI conducted the remedial design and remedial action (RD/RA) at the site after EPA issued it two unilateral administrative orders (UAOs) to perform the work. The UAO for the SCOU was issued in March 1991 and the UAO for the GCOU was issued in November 1992. The RA construction activities were substantially completed by spring 1996.
WMWI completed the waste consolidation and capping phase in May 1992. The low-permeability cap was designed to eliminate the threat of direct contact with the waste and to reduce the potential for additional contaminant loading into the groundwater. The vapor extraction system was installed in January 1993 and is currently operating. The system was designed to draw out volatile organic compounds (VOCs) from the waste disposal pit. Construction of the groundwater pump and treat system was completed in April 1996. The groundwater pump and treat system was designed to keep contaminated groundwater from impacting nearby residential groundwater drinking wells and to restore the groundwater aquifer to usable conditions. The vapor extraction system and the groundwater pump and treat systems were expected to operate for approximately 10 years. EPA completed a preliminary close out report for the site on August 27, 1997.
Groundwater monitoring data submitted between 1997 and 2000 indicated that the contaminant plume had been significantly reduced. In August 2000, WMWI submitted a proposal to augment the pump and treat system with air sparging in order to accelerate the cleanup of the remaining groundwater contamination. In January 2001, the low-flow air sparge system (LFAS), which pumps air into the groundwater, began operating. The air sparge system operated in conjunction with the pump and treat system from January 2001 through August 2001. On August 23, 2001, EPA approved a temporary shutdown of the pump and treat system as a pilot test to evaluate the full-scale effectiveness of the LFAS. Temporary shutdown of the pump and treat system began on September 1, 2001.
In 2004, EPA performed a comprehensive review of the groundwater data under the pilot test and concluded that the LFAS was insufficient to remove the groundwater contaminants in a timely manner. Several of the VOC levels, particularly THF and vinyl chloride, did not appear to be declining. To address these concerns, the PRP installed four additional deeper air sparge wells and additional groundwater monitoring wells, which began operating in April 2005. EPA and WDNR then evaluated the rate of contaminant degradation in groundwater from using the enhanced air sparge system in order to determine if the groundwater extraction system should be restarted. Monitoring of the groundwater will continue until the cleanup goals have been met. According to the latest monitoring data, there are still exceedances of THF and vinyl chloride, although these have primarily occurred in the source areas on site and do not pose a health threat to nearby residents.
EPA completed two five-year review (FYR) reports for the site in 1996 and 2001. The 2001 FYR report concluded that the remedy was protective of human health and the environment, but EPA recommended continued active remediation using the ISVE system, LFAS, or by groundwater extraction and treatment, or a combination of the three, until it has been demonstrated that the groundwater cleanup objectives have been achieved.
EPA issued the third FYR review report in September 2006. The data review indicated that the enhanced LFAS was effective and that VOC concentrations in groundwater were generally showing a declining trend. The report concluded that the remedy was protective of human health and the environment in the short term, and that long-term protectiveness was dependent on instituting effective institutional controls (ICs) at the site.
On September 27, 2007, a consent decree (CD) was finalized between EPA and WMWI. The terms of the CD include the requirement that WMWI continue to perform studies and remedial response work at the site. Also in 2007, WMWI installed an oxygen generator to increase the air flow rate at the ten air sparging points. An off-gas drier unit was also installed.
In July 2011, EPA issued the fourth FYR report, which included an analysis of groundwater contaminant data. Although the trends showed that the contaminant levels had decreased in some of the monitoring wells, the overall contaminant levels in the groundwater had not significantly declined. Overall, the FYR report found that the remedy was protective in the short term and that the remedy will be protective in the long term once groundwater cleanup goals are achieved.
WMWI's plans for improving the groundwater remedy involved expanding the LFAS by converting one former monitoring well and two extraction wells into air sparge points. After EPA approved the plan, the construction work began in July 2014 and was completed in November 2014. WMWI will continue to evaluate the effectiveness of the LFAS system and make adjustments to the operation of the sparge points as needed. The first complete set of groundwater data since the LFAS expansion was collected in February 2015. Three additional quarters of data will be collected to fully assess the effectiveness of the system. To date, EPA and WDNR believe that the LFAS, which initially began in 2001 and was expanded in 2005, 2007 and 2014, has demonstrated sufficient effectiveness to justify changing the remedy of record for the GCOU from groundwater pump-and-treat to LFAS.
The residential wells closest to the site, those with the greatest potential to be affected by site contaminants, continue to be monitored on an annual basis. The sampling round conducted in August 2014 showed no site-related contamination in these wells.
EPA plans to complete the fifth FYR at the Hagen Farm site by July 2016.
WMWI inspects the Hagen Farm site on a monthly basis to conduct maintenance on the SCOU and GCOU treatment systems. As land development pressures in this area increase in the future, it may be increasingly necessary to reevaluate the need for off-property ICs such as groundwater-use restrictions.
In conjunction with the 2006 FYR, an IC study and title commitment was performed by WMWI at the request of EPA. The study confirmed that deed restrictions had been placed on portions of all three property parcels owned by WMWI. The entire restricted contiguous area lies within the WMWI site property boundary. The restricted area is fenced and the restrictions run with the land. The restrictions prohibit any residential or commercial use of the property without the approval of EPA or WDNR. Restrictions also prohibit the use of groundwater or the installation of public wells in a known contaminated aquifer or within 1,200 feet of a landfill without the approval of WDNR. No new wells have been installed except for a replacement drinking water supply well on the downgradient commercial property. The aquifer for that well is not contaminated. The IC study information was recently reviewed by WMWI and was confirmed accurate as of 2010.
A site-wide ready for anticipated use (SWRAU) determination was made in September 2010 because the site cleanup met the following conditions: 1) all cleanup goals in the ROD, ESDs and other decision documents have been achieved for any media that may affect current or reasonable anticipated land uses so that there are no unacceptable risks; and, 2) all ICs or other controls required by the ROD or identified as part of the response action to help ensure long-term protectiveness have been put in place. To date, no property reuse is anticipated.
ContactsRemedial Project Manager, U.S. EPA
sheila sullivan (firstname.lastname@example.org)
Community Involvement Coordinator, U.S. EPA
AliasesNO NAME PROP AT 2318 COUNTY A.