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Congressional District # 01


EPA ID# MID980794408
Last Updated: May, 2015

Site Description

The Hedblum Industries (Hedblum) Superfund site is situated on 10 acres within a mixed-use, industrial and residential area in AuSable Township, Iosco County, Michigan. About 13,700 people live in the greater site area. The closest residence is about 350 feet from the site. An industrial park is located less than one mile north. Most of the Oscoda and AuSable Township populations (about 9,500) live within a three-mile radius of the site.

From 1958 through 1985, the site was leased to a series of industrial firms that manufactured automobile parts. The Hedblum site first came to the attention of the Michigan Department of Environmental Quality (MDEQ) Water Quality Division during a routine inspection of the facility in 1972. At that time, Thompson Industries was on the site and was engaged in the assembly of anti-rattling devices for the automotive industry. Cooling and rinse waters were discharged from the plant directly onto the ground. During another site inspection, MDEQ was informed that every two weeks from 1968 to 1972, Thompson had dumped approximately 40 gallons of trichloroethylene (TCE) from a degreasing tank onto the ground. The state estimated that 4,000 gallons of TCE were dumped over this four-year period.

Samples from several residential wells indicated that two of them were contaminated with TCE. As a result, the state recommended that local residents not use their wells. The affected residents replaced their contaminated wells with deeper ones in an attempt to tap an uncontaminated water supply. Two more wells found to be contaminated in the AuSable Heights area in 1975 were also replaced with deeper wells.

In 1977, the local health department received a complaint about a strong odor from one of the replacement wells. Sampling indicated that the well had also become contaminated with TCE. By 1978, the city of Oscoda had extended water mains into the AuSable Heights subdivision and began providing an alternate water supply to the subdivision. Some property owners in the subdivision elected not to be connected to the Oscoda water system. The Oscoda County Health Department continued to assess conditions at the site and sampled liquids contained in an underground storage tank near the northeastern side of the site in 1980. Upon finding TCE and other solvents, the tank was removed.

In 1981, the state installed seven monitoring wells, determined that the groundwater flow beneath the site was to the northeast, and confirmed the presence of solvent contamination. In 1985, the Hedblum Industries property was purchased by Aircraft Tool Supply, which currently produces aircraft parts at the site.

EPA proposed to place the Hedblum site on the National Priorities List (NPL) in December 1982 and the site was listed on the NPL in September 1983. 

Site Responsibility

The Hedblum Industries site is being addressed through potentially responsible party (PRP) actions under state and federal oversight. 

Threats and Contaminants

Groundwater and soil at the Hedblum site are contaminated with volatile organic compounds (VOCs), including TCE.  Low levels of VOCs, including TCE and vinyl chloride, have been detected in the surface waters of a bayou located northeast of the AuSable Heights subdivision.  

A sampling of residential wells in 1990 found no VOC contaminants above detection limits. On-site groundwater flows northeast toward the bayou.

Cleanup Progress

EPA issued a Record of Decision (ROD) selecting the site cleanup approach in September 1989.  The selected remedial action (RA) included: extraction, treatment, and monitoring of contaminated groundwater in the AuSable Heights subdivision; abandonment of six older groundwater monitoring wells; and collection and analysis of on-site soil samples.  A PRP, under a federal enforcement agreement, completed the groundwater treatment system design and installation in 1992.  EPA and MDEQ have been working with the PRPs to ensure compliance with the enforcement agreement and that the groundwater contaminant plume is being effectively captured.

EPA completed the first five-year review (FYR) at the Hedblum site in September 1999.  The FYR report determined that although the site remedy was protective, the RA was not being performed effectively, thus it likely would require more than the projected five years to restore the groundwater quality.

In September 2004, EPA completed the second FYR at the site. As part of this process, EPA and MDEQ reviewed all groundwater monitoring data collected under the operation and maintenance (O&M) program in order to evaluate the site cleanup status. The second FYR report concluded that further investigation, such as vertical aquifer sampling (VAS), was needed to better define the groundwater contaminant plume and to evaluate the need for expanding the groundwater extraction system. EPA deferred its determination of whether the remedy was protective of human health and the environment to a later date.

The VAS investigation and studies to optimize the groundwater extraction system were performed by MDEQ during summer 2005. In coordination with EPA, an investigation report was released in November 2005 indicating that the existing RA was not capturing the plume effectively, and that the groundwater extraction and treatment system must be expanded and operated more effectively. In 2005 and 2006, MDEQ and the PRPs each sampled groundwater, including the private wells of those residents still using area groundwater for drinking water or other purposes. To date, only one resident voluntarily uses a private well for drinking and other household needs. Recent information indicates that the occupants of this residence are not exposed to groundwater contamination since the residence lies outside of the contaminant plume. A few residents use a private well solely for outdoor activities. All residents were notified and advised to discontinue use of these wells. 

In order to accelerate the groundwater cleanup, the PRPs submitted a proposal to EPA to expand the groundwater cleanup and to improve the O&M of the existing extraction and treatment system. EPA, in consultation with MDEQ, concurred with the proposal and issued an Explanation of Significant Differences (ESD) in April 2009 to memorialize expansion of the groundwater cleanup remedy. Institutional controls (ICs) to restrict groundwater use and well installation were not a component of the 1989 ROD as they were not deemed necessary at the time. However, ICs were included in the 2009 ESD because groundwater had not been cleaned up within the time period originally anticipated in the ROD. 

EPA issued an administrative order in June 2009 to the PRPs that amended the scope of work to include the proposed expansion of the groundwater cleanup remedy, also referred to as the Remedial Enhancement Measure (REM). Under the expansion, the PRPs would install and operate 24 groundwater recirculation wells and three soil vapor extraction (SVE) wells. The proposed technology combines in-well air stripping, air sparge, and SVE within each of the 24 wells to remove the VOCs. As successfully demonstrated at similar sites, EPA anticipated that this technology will greatly reduce the time to clean up the aquifer as well as long-term dependency on the extraction and treatment system.

EPA completed the third FYR at the Hedblum site in August 2009.  The FYR report found the remedy to be protective of human health and the environment over the short term. However, in order for the remedy to be protective over the long term, the groundwater remedy must achieve the groundwater cleanup goals. In the interim, the ICs afford protection of human health and the environment by restricting human exposure to groundwater.

In April 2011, EPA approved the remedial design for the REM. Separately, a local ordinance was passed by the AuSable Township Board in April 2012 to prohibit the use or installation of private wells. The three existing private wells potentially in use for non-potable consumption were plugged and abandoned.

Construction and installation of the REM began in July 2012, and the system began operating in November 2012.  Data collected to date indicate that the system is removing both groundwater and soil vapor contaminants. EPA completed the fourth FYR report on August 8, 2014 and found that the remedy is protective of human health and the environment in the short term because the REM is removing contaminants from the groundwater and is intercepting and removing soil vapor contaminants. Effective ICs have been implemented and are being monitored to prevent all contact with contaminated groundwater. In order for the remedy to be protective in the long term, soil gas monitoring needs to be conducted to assess the potential risks from SVL The groundwater monitoring network should also be expanded in order to confirm that cleanup goals have been met along the southern margin of the plume.

EPA, in consultation with MDEQ, approved the Remedial Action Completion Report on September 17, 2014, certifying that the installation of the REM system has been completed. EPA now considers the Hedblum Site to be in the operation and maintenance (O&M) phase. EPA determined that the ICs identified as part of the UAO and ESD had been put in place such that the remedy was protective for reasonable future land use scenarios at the site. This finding is memorialized in the Site-wide Ready for Anticipated Use (SWRAU) document of September 29, 2014. 

EPA is currently working with the PRP to develop a soil gas sampling work plan. The plan will outline a study to assess the potential for soil vapor intrusion to occur at homes in the Au Sable Heights subdivision. EPA anticipates that this work will be conducted in fall 2015. 

Community Involvement

The AuSable Township utilities superintendant has been working with EPA and MDEQ to identify residences with service connections to the municipal supply and to track the use of private wells in the AuSable Heights subdivision. In March 2012, a public meeting was held to present a draft local ordinance to prohibit the use of private wells and the installation of groundwater wells. The ordinance was passed by the AuSable Township Board in April 2012. Community feedback on the cleanup has been positive.

Property Reuse

The 1989 ROD did not require ICs prohibiting groundwater use beneath the site property or other areas where the contaminated groundwater has migrated.  EPA issued an ESD in April 2009 that adopted ICs as part of the remedy to ensure protectiveness until groundwater cleanup goals are met. Because enforceable ICs are a necessary component of the remedy, a local ordinance was passed by the AuSable Township Board in April 2012 to prohibit groundwater use. There are no property reuse issues at this time.


Remedial Project Manager, U.S. EPA
sheila sullivan (sullivan.sheila@epa.gov)
(312) 886-5251

Community Involvement Coordinator, U.S. EPA
cheryl allen
(312) 353-6196

Site Profile Information

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


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