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Congressional District # 06


EPA ID# MI0001119106
Last Updated: May, 2015

Site Description

The Aircraft Components, Inc. ("ACI") site is located on the outskirts of Benton Harbor at 671 North Shore Drive in Benton Township, Berrien County, Michigan. The site is a 17-acre parcel of land bounded on the south and southeast by the Paw Paw River, to the east by a wooded area, to the west by North Shore Drive, and to the north by Ridgeway Drive. The site is primarily flat, although Ridgeway Drive, which marks the northern boundary of the site, is located atop a steep 50-foot bluff. Prior to cleanup, the bluff was littered with discarded household appliances, tires, and other items that indicated unrestricted dumping. A narrow grassy bank drops down about 10 feet to the Paw Paw River along the south and southeastern boundary of the site.  The eastern part of the ACI site is wooded and includes several wetlands. A culvert that drains a spring from the Ridgeway Road area at the top of the bluff discharges into the wetlands.

Originally, the western portion of the ACI site had five interconnected buildings on it. Four of the buildings were partially-dilapidated, single-story brick structures with concrete basements. One building was a two-story glass sided structure with a concrete basement. The site also had two Quonset huts and other miscellaneous structures on it.  Constructed in the 1910s, the main buildings were used by various manufacturing concerns, including a plating facility, until the mid-1950s. Aircraft Components, Inc., a mail-order airplane parts resale business, then occupied the property until the site was sold to D&L Sales, Inc., in the early 1990s.

Aircraft Components bought and sold World War II-era military aircraft gauges and other components and used the ACI site as a warehousing, storage, and shipping center. Some of the aircraft gauges are marked with luminescent paint containing radium-226, a naturally-occurring radionuclide. Natural decay of radium-226 causes radio-emissions of alpha particles, beta particles, and gamma radiation and the formation of radon-222, all of which are health hazards. Site investigations showed that some of the luminescent paint was beginning to deteriorate into a powder. This meant that the radium-226 could leak out of the aircraft gauges into the environment and could create an inhalation risk to anyone who handled them.

The United States Environmental Protection Agency (EPA) divided the site into two discrete phases, or "operable units," for the purpose of more easily managing the site-wide cleanup. The two phases at the ACI site are referred to as the "radiation operable unit (OU1)" and the "chemical operable unit (OU2)." OU1 addressed the cleanup of radium-226, and OU2 addressed the cleanup of non-radioactive contaminants.

Site Responsibility

The site is being addressed primarily as a federal, Fund-lead EPA action with state of Michigan consultation.  Potentially Responsible Parties (PRPs) are conducting limited remedial actions under federal enforcement oversight.  EPA and the PRPs have negotiated a Consent Decree to address the remaining remedial measures required at the site. EPA is conducting the remainder of the remedial action work at the site using funds from the Consent Decree settlement with the PRPs.

Threats and Contaminants

The radiation operable unit (OU1) addressed the clean up of radium-226, a naturally-occurring radionuclide that can be found in the environment at low concentrations. Radium-226 can enter the body by ingestion or inhalation. Exposure to radium-226 at elevated levels can cause anemia, cataracts, fractured teeth, cancer, and death. Once ingested, most radium-226 exits the body in urine and feces over a period of several months. Approximately 20 percent of the radium-226 intake amount enters the bloodstream and is carried to all parts of the body, where a portion will come to reside in bone tissue and potentially cause long-term damage. Dust particles containing radium-226 can be inhaled into and become lodged in the lungs, where alpha-particle radiation can cause great damage to sensitive lung tissue and cause lung cancer.

Ionizing radiation from radium-226 poses a health risk, since it affects humans on a cellular level. Such radiation deposits energy in body tissue which can cause cell damage or cell death. In some cases, there may be no effect on a cell; in others, the cell may survive but become abnormal, either temporarily or permanently. Abnormal cells may become malignant. In addition, harmful genetic mutations can be passed on to future generations. In large doses, radiation can cause extensive cellular damage and result in death. Smaller doses may not cause death, but the surviving person or organ may have cellular damage, leading to an increased risk of cancer. The overall extent of damage depends upon the total amount of energy absorbed, the time period and dosage rate of exposure, and the particular organ(s) exposed.

The chemical operable unit (OU2) addressed the cleanup of non-radiologic contamination such as heavy metals and volatile organic compounds (VOCs) which may exceed human health or ecological risk-based cleanup levels in the soil and groundwater at the site.

The non-radioactive chemicals of concern in site soil included the heavy metals, mercury and selenium, and to a lesser extent, lead. These heavy metals were found in small areas of the site above cleanup levels. Lead, mercury, and selenium can be ingested into the body, where they can cause toxicological problems. Lead and mercury, for example, could cause neurological problems and kidney failure. Selenium targets the eyes, liver, spleen and kidneys and, at high doses, could cause these organs to fail.

Other chemicals of concern in site soil included benzo(a)pyrene, a semi-volatile organic compound (SVOC) associated with coal tar, and alpha- and gamma-chlordane and Endrin, which are pesticides. Both benzo(a)pyrene and alpha-chlordane are potential cancer-causing agents.

The chemicals of concern in groundwater include the VOCs trichloroethene (TCE) and tetrachloroethene (PCE) and their breakdown products: 1,1-dichloroethene (1,1-DCE), vinyl chloride, and cis-1,2-dichloroethene (cis-1,2-DCE). Ingestion of groundwater containing these chemicals could cause cancer over the long-term.

Lead was found in one surface water sample and one sediment sample from the Paw Paw River. Although a single sample does not necessarily indicate widespread surface water or sediment contamination, part of the cleanup for the chemical operable unit included excavation of some river sediment.

Cleanup Progress

EPA conducted a limited, time-critical emergency removal action in July 1995 to stabilize and secure portions of the ACI site.  A gate was installed at the entrance of the access road onto North Shore Drive on the west side of the site, and broken windows and doors were boarded up on several site buildings. Radiation warning signs were posted on the buildings, and a radioactive ash pile was covered and enclosed within a fence. Lastly, small amounts of waste material, pending later disposal, were containerized and staged in a secure area.

EPA performed a detailed site inspection in February 1996. Removal and off-site disposal of radioactive airplane gauges and associated debris began in July 1997. The last phase of the removal action was completed in March 2000. Many hundreds of radioactive parts were disposed of off-site, and decontamination was initiated in some of the site buildings to reduce the risk of a large-scale release of radiation into the environment. The removal action was suspended in March 2000 when it became apparent that it would not be cost-effective to decontaminate the remaining site buildings and that another radiation cleanup plan was needed.

In August 2000, EPA released a feasibility study (FS) that evaluated several site cleanup alternatives.  Subsequently, EPA published a proposed plan, identifying EPA's preferred cleanup alternative for the residual radium-226 at the site. EPA signed a Record of Decision (ROD) on September 28, 2000, selecting the demolition of contaminated buildings and the cleanup of radiologically affected soil as the remedy for the radiation operable unit (OU1) at the ACI site. EPA selected a cleanup level for radium-226 that would allow the site to be returned to the owner for unrestricted use from a radiation standpoint.  The radium-226 cleanup was completed in early April 2003, thereby ending the last of the radiation cleanup work at the site.

EPA also investigated the site for non-radioactive chemical contaminants and, in May 2002, completed a Remedial Investigation (RI), a study of the nature and extent of remaining site contamination. In July 2002, the results of the RI/FS and a proposed cleanup plan for the chemical contaminants were presented to the community. A Record of Decision (ROD) documenting EPA's selected remedial action for the chemical operable unit (OU2) was signed in September 2002. The selected remedy included excavation and off-site disposal of metals and/or pesticide-contaminated soil and river sediment.  The plan for groundwater cleanup involved injecting a chemical compound into the contaminated area and allowing it to help decompose the contaminants. Cleanup levels will allow for the anticipated recreational or commercial/industrial use of the site in the future.

The injection of a substrate into the subsurface for the chemical operable unit remedial action was completed in August 2004. Currently, groundwater quality is being monitored to ascertain whether the treatment has been successful and whether any other actions need to be to taken. The results thus far show that two of the VOCs, TCE and PCE, have been degraded significantly in a number of the groundwater monitoring wells. The areal extent of one of the breakdown products of TCE and PCE, vinyl chloride, has increased slightly and is still above cleanup criteria in a number of site monitoring wells. To address this and the other remaining groundwater contamination, a PRP completed another round of subsurface injections in December 2007 and February 2008. EPA will continue to collect monitoring data to ensure that cleanup levels for all VOCs are met.

A PRP is interested in developing about 2 acres of the northwest corner of the ACI site into a residential area.  The site is not currently cleaned up to residential standards, so, in order to accommodate this potential future land use, EPA issued an Explanation of Significant Differences (ESD) on September 30, 2010.  The ESD served to document the following changes to the 2002 ROD for OU 2: 1) two areas of contaminated soil in the northwestern corner of the site will be excavated and backfilled; 2) a 12-inch soil cover will be placed over the areas proposed for residential use; 3) ICs prohibiting disturbance of the top 18-inch of soil will be implemented; and 4) residences will be built on slab foundations with appropriate vapor barriers.  In addition, an appropriate methane monitoring network is required; and methane venting systems may also be required .

The chemical operable unit (OU2) remedial action is the final cleanup action that EPA will be undertaking at the ACI site. 

From April 2012 to April 2013, a Five Year Review (FYR) of the remedy at the ACI site was conducted to assess the progress of the remedial action and to ensure that the remedy is functioning as intended.  EPA and MDEQ conducted the FYR inspection on July 10, 2012.  The FYR was finalized on April 10, 2013. The OU1 remedy was determined to be protective in both the short- and long-term. The OU2 remedy was determined to be protective in the short-term. Long-term protectivness will be achieved once the full extent of the contamination from the site is delineated and effective groundwater treatment measures and appropriate institutional controls are implemented.

In January 2014, an in-situ chemical oxidation (ISCO) treatment injection was conducted to remediate the remainder of the chlorinated solvent plume. The injection was performed using an activated persulfate product called PersulfOx. Quarterly groundwater monitoring events were temporarily suspended during and after the injection to allow for sufficient time for the persulfate to chemically react in the aquifer. EPA performed its first of four quarterly groundwater monitoring events in March 2015.

Community Involvement

The community involvement plan for the site was finalized and published in March 2014. Two community availability sessions were held in late 2012 and early 2013 to discuss the upcoming Five Year Review and also the planned in-situ chemical oxidation treatment at the site.

Congressional Interest

Congressman Fred Upton (R-MI, 6th District) has been a great supporter of the cleanup at the ACI site.

Property Reuse

The site property has been redeveloped as part of a golf course. The redevelopment is part of a community-wide, 530-acre redevelopment project that will include a marina, a golf course, residential homes, and condominium complexes. There is also interest in constructing a residential condominium complex on part of the ACI site. EPA is working closely with the developer to ensure that all applicable state and federal regulations are followed and that reuse of the site is compatible with cleanup levels.


Remedial Project Manager, U.S. EPA
jennifer elkins (elkins.jennifer@epa.gov)
(312) 353-4627

Community Involvement Coordinator, U.S. EPA
janet pope
(312) 353-0628




Site Profile Information

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


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