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DANE COUNTY
STOUGHTON
Congressional District # 02
HAGEN FARM
EPA ID# WID980610059Last Updated: September, 2008
Site Description
The Hagen Farm site is located at 2318 County Highway A in the town of Dunkirk, approximately one mile east of the city of Stoughton, Dane County, Wisconsin. The Hagen Farm property is about 28 acres in size. Within the property boundary is a waste disposal area of approximately 10 acres, underlain by contaminated groundwater. The site is bounded on the south by County Highway A and on the north by a gravel pit operation. 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 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, 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. Groundwater contamination from the site potentially affects 11 nearby residential drinking water wells along County Highway A and Collins Road.
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 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 the site was listed on the National Priorities List (NPL) in 1987.
In July 1987, the PRPs signed an Administrative Order on Consent (AOC) with the United States Environmental Protection Agency (U.S. EPA), whereby they agreed to conduct a Remedial Investigation and Feasibility study (RI/FS) at the site. An RI is an investigation into the nature and extent of contamination at the site. An FS is a study which evaluates cleanup alternatives for the site. The RI/FS took place between 1988 and 1992, and determined that the site cleanup would be approached by dividing the cleanup into two operable units (OU). The first OU, known as the source control operable unit (SCOU), dealt with the waste refuse and contaminated soils beneath the disposal area. The groundwater control operable unit (GCOU) addressed the groundwater contamination plume beneath the property and downgradient of the property boundary.
Site Responsibility
This site is being addressed through potentially responsible party (PRP) actions, with federal and state oversight.Threats and Contaminants
The RI/FS for the SCOU concluded that there were three disposal areas onsite, but that most of the waste was in one main area (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 major contaminants found in the waste and groundwater coming in contact with the waste were THF, benzene, ethylbenzene, toluene, xylenes, various semivolatile organic chemicals, barium, lead, and mercury.
The contaminants of greatest concern in the groundwater were volatile organic chemicals (VOCs). The most prevalent of these, THF, occurred in concentrations as high as 630,000 parts per billion. 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 the groundwater onsite and offsite. 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.
Cleanup Progress
A document memorializing the selected cleanup approach, known as the record of decision (ROD), was signed in September 1990 for the onsite waste disposal area, or SCOU. A ROD addressing the contaminated groundwater was signed in September 1992 for the GCOU. The ROD for the waste disposal area 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 contaminated groundwater called for pumping and treating the groundwater. The PRP, Waste Management of Wisconsin, Inc. (WMWI), conducted remedial design and remedial action (RD/RA) construction for the entire site under the enforcement authority of two unilateral administrative orders (UAOs). The UAO for the SCOU was issued in March 1991. The UAO for the GCOU was issued in November 1992.In general, all RA construction activities were completed by spring 1996. Waste consolidation and capping were completed in May 1992. The cap was designed to eliminate the threat of direct contact with the waste and to reduce the potential for additional contamination loading into the groundwater. The vapor extraction system was installed in January 1993 and is currently operating. The system was designed to treat contaminants in the waste disposal pit by drawing out volatile contaminants. 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 groundwater pump and treat systems are expected to operate for approximately 10 years. A preliminary close out report for the site was completed on August 27, 1997.
Groundwater monitoring data from the last three years indicate that the contaminant plume has been significantly reduced. In August 2000, the PRP 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 air sparge system, which pumps air into the groundwater, began operating. The air sparge system operated with the pump and treat system from January 2001 through August 2001. On August 23, 2001, U.S. EPA approved a temporary shutdown of the pump and treat system as a pilot test to evaluate the full scale effectiveness of the air sparge system. Temporary shutdown of the pump and treat system began on September 1, 2001.
In 2004, U.S. EPA performed a comprehensive review of the groundwater data under the pilot test and concluded that the air sparge system did not appear to be sufficient. 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. The U.S. EPA and WDNR are currently evaluating whether the rate of contaminant degradation in groundwater using the enhanced air sparge system is optimal, or whether the groundwater extraction system needs to 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 onsite and do not pose a health threat to nearby residents.
Two five-year review reports were completed for the site in 1996 and 2001. In general, the second report concluded that the remedy remains protective of human health and the environment, but recommended continued active remediation through the vapor extraction system, low-flow air sparging, groundwater extraction and treatment, or a combination of the two until it has been demonstrated to U.S. EPA that groundwater cleanup objectives have been achieved.
A third five-year review was issued in September 2006. The comprehensive data review indicated that the enhanced air sparging system is effective; VOC concentrations in groundwater are showing a declining trend. The 11 residential wells potentially affected by the site continue to be monitored on an annual basis. The sampling conducted in August 2007 and showed no site-related contamination. The analytical results have not been received yet for the sampling conducted in August 2008.
On September 27, 2007, a consent decree (CD) was finalized between U.S. EPA and WMWI. The terms of the CD include the requirement that WMWI will continue to perform studies and remedial response work at the site. An attached Scope of Work (SOW) for the RA Work Plan requires the continued implementation of the two RODs issued in September 1990 and September 1992, and the two ESDs issued in April 1991 and August 1996. In designing, implementing, and submitting deliverables for the ongoing RA work at the site, WMWI is required to adhere to the SOW, the RD/RA guidance and work plans, RODs, ESDs, all U.S. EPA-approved operation and maintenance (O&M) plans, all additional approved plans, and any additional guidance provided by U.S. EPA.
Property Reuse
The Site is inspected by WMWI's O&M consultant 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 will be increasingly necessary to reevaluate the need for off-property controls such as groundwater use restrictions. In conjunction with the 2006 five-year review, U.S. EPA is assessing the institutional controls (ICs) at the site. The PRP performed an IC study as requested by U.S. EPA. The U.S. EPA will develop an IC plan to include any corrective measures necessary after the IC study is reviewed. The effectiveness of the ICs will be reevaluated during the next five-year review in 2011. To date, no property reuse inquiries have been received.Contacts
Remedial Project Manager, U.S. EPAsheila sullivan (sullivan.sheila@epa.gov)
(312) 886-5251
Community Involvement Coordinator, U.S. EPA
susan pastor
(312) 353-1325
Aliases
NO NAME PROP AT 2318 COUNTY A.