Region 5 Superfund (SF)

U.S. EPA REGION 5
OAKLAND COUNTY
HIGHLAND

Congressional District # 11

HI-MILL MANUFACTURING CO.

EPA ID# MID005341714
Last Updated: October, 2008

Site Description

The Hi-Mill Manufacturing Company (Hi-Mill) Superfund site, 4.5 acres in size, is an active industrial site, located in Highland Township, Oakland County, Michigan. Hi-Mill Manufacturing, the potentially responsible party (PRP), began manufacturing tubular aluminum, brass, copper tubing, and other parts in 1946. From 1946 until the mid-1980s, process wastewater, containing residues of acids and heavy metals, was periodically emptied into lagoons on the site. Prompted by complaints from Hi-Mill employees, the Michigan Department of Natural Resources (MDNR), now the Michigan Department of Environmental Quality (MDEQ), sampled the two onsite production wells and an adjacent pond (Target Pond) in 1972. One well was contaminated with a volatile organic compound (VOC), and Target Pond was found to be contaminated with metals.

Although the shallow groundwater beneath the Hi-Mill property and nearby areas is contaminated, it cannot be used as a drinking water source now or in the future due to its low water yield. The last time the intermediate aquifer, which is a drinking water source, showed a trace amount of trichloroethylene (TCE) was in a groundwater sample collected in April 1998.  Since then, however, TCE has not been detected in any of the intermediate well samples.  The nearest homes are about 2,000 feet southeast of the site.

Site Responsibility

This site is being addressed through potentially responsible party actions under a federal enforcement agreement.

Threats and Contaminants

Groundwater in the shallow groundwater below the Hi-Mill property and Highland Road (northwest of the site) is contaminated with VOCs, including TCE, 1,2-dichloroethylene (1,2-DCE), and vinyl chloride. Surface and subsurface onsite soils are contaminated with organic and inorganic compounds. Sediment and surface water in Waterbury Lake (south of the site) and Target Pond contain elevated concentrations of heavy metals but do not appear to be adversely impacted.

There is no health risk to current workers or future residents from exposure to site soils. Groundwater from the shallow groundwater unit is not used; therefore, there is no health risk to current workers or future residents from exposure to contaminated groundwater. 

Cleanup Progress

In November 1983, under MDNR supervision, Hi-Mill cleaned up the onsite lagoons by removing 142 cubic yards of contaminated soil; 34,400 gallons of contaminated sludge; and 63,300 gallons of contaminated water. The lagoons were backfilled with clean sand. However, the results from the 1988 resampling of two onsite production wells revealed high levels of TCE and 1,2-DCE. In 1989, a new well was installed to provide Hi-Mill employees with safe drinking water. 

On February 21, 1990, the site was placed on the United States Environmental Protection Agency's (U.S. EPA's) National Priorities List. Between 1989 and 1992, Hi-Mill conducted a remedial investigation (RI), which is a study to determine the nature and extent of site contamination, and a feasibility study (FS), which is an analysis of site cleanup alternatives, under an Administrative Order on Consent signed in October 1988. It was found that shallow groundwater beneath the Hi-Mill property and nearby areas was contaminated with TCE, 1,2-DCE, and vinyl chloride. The primary sources of the organic contamination were believed to be the accidental release of solvents from solvent delivery lines and leaks from several former and current solvent storage tanks. However, the intermediate aquifer showed no sign of contamination. Sampling results from the surface and subsurface soil, sediment, and surface water from the nearby pond and lake revealed elevated concentrations of heavy metals at some locations, but the water bodies did not appear to be significantly impacted by the contamination. The source of the heavy metals was believed to be the former onsite lagoon area.

Based on the results of the RI/FS, on September 28, 1993, U.S. EPA issued a Record of Decision (ROD), which is a public document identifying the site cleanup plan. The ROD requires 30 years of groundwater monitoring and institutional controls to prevent use of the shallow groundwater beneath the Hi-Mill property. A Consent Decree, whereby the PRP agreed to implement the remedy, was entered on December 7, 1994.

Institutional controls that restricted use of groundwater on the Hi-Mill property were put in place on December 22, 1994. Installation of six shallow monitoring wells and two intermediate monitoring wells was completed in September 1995, and quarterly monitoring of groundwater began in October 1995. Between October 1995 and July 2000, groundwater samples from between 19 and 23 monitoring wells were collected four times per year. (Note: Number of samples has varied from due to freezing in some wells during winter months, lack of groundwater in some wells during dry summer months, and installation of several new wells during the five-year period.) 

According to a provision in the ROD, the PRP had the option of petitioning U.S. EPA for a reduction in groundwater monitoring requirements after three years of monitoring.  In July 2000, U.S. EPA approved the PRP's request for a reduction.  Since October 2000, two wells are sampled quarterly, three wells will be sampled biannually, and an additional 18 wells are sampled annually.

In September 2005, U.S. EPA evaluated site conditions and reviewed the 1993 cleanup decision to make sure the decision continued to be effective.  The conclusions of this review were that the cleanup decision continues to be protective of human health and the environment in the short-term. To be protective in the long term, use restrictions to prohibit the use of contaminated groundwater that has migrated beyond the Hi-Mill property boundaries will need to be implemented. In addition, it was recommended that additional monitoring wells be installed in the intermediate aquifer to ensure that groundwater is being adequately monitored.  Based on this recommendation, three new intermediate monitoring wells, along with a replacement well for shallow well SW-27, were installed in June 2008.  These new wells were sampled in July 2008.  A report summarizing the sampling results is expected by December 2008.

Property Reuse

Hi-Mill Manufacturing is still currently operating at the site.

Contacts

Remedial Project Manager, U.S. EPA
linda kern (kern.linda@epa.gov)
(312) 886-7341

Community Involvement Coordinator, U.S. EPA
bob paulson
(312) 886-0272

Aliases

HI-MILL MFG CO

 

Site Profile Information

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