Congressional District # 07
NORTH BRONSON INDUSTRIAL AREAEPA ID# MID005480900
Last Updated: October, 2010
The North Bronson Industrial Area (NBIA) site, located in Branch County, Bronson, Michigan, consists of two lagoon areas and a county drain which runs adjacent to the lagoons. Several industries in the area discharged plating and other industrial wastes to seepage lagoons between 1939 and 1981. An industrial sewer system was used to transport plating wastes to both sets of lagoons, which were owned and maintained by the city of Bronson. The seepage lagoons are no longer used for waste disposal; however, they contain an estimated 130,000 cubic yards of heavy metal sludges.
The majority of the city of Bronson is within a one-mile radius of the old lagoons at the NBIA site. The area surrounding the site is mixed industrial and residential; north of the site is primarily rural. The majority of the residents in the area of the site are connected to the municipal water supply system, although an estimated 3,000 people living within three miles of the site use wells as a source of drinking water. The primary supply wells are located approximately 5,000 feet west of the site and are screened in the upper aquifer.
The U.S. Environmental Protection Agency (EPA) proposed the NBIA site for the National Priorities List (NPL) in October 1984 and finalized the site on the NPL in June 1986.
Site ResponsibilityThis site is being addressed through federal, state and potentially responsible parties' (PRPs') actions.
Threats and ContaminantsHigh levels of trichloroethylene, dichloroethylene, and vinyl chloride (also known as volatile organic compounds or VOCs) as well as elevated levels of heavy metals and cyanide have been detected in private and groundwater monitoring wells in the area. Polychlorinated biphenyls (PCBs) and metals such as cadmium have been found in sediment samples downstream of the old lagoons. Lagoon sludge contains heavy metals, including cadmium, chromium, and lead. Municipal wells are located upgradient of the site with only a remote chance of site contaminants reaching these wells. Accidental ingestion of or direct contact with the contaminated groundwater, sediment, and sludge could pose a health threat to people.
In 1988, action was taken to eliminate immediate threats by removing from service private wells found to be contaminated with metals and VOCs. Alternate water supplies were provided to the affected residences. In 1993 and 1994, EPA Technical Assessment Teams were dispatched to the site. During the 1993 visit, the site was evaluated for immediate threats to human health. In several of the remaining buildings, waste piles, vats and drums were identified, characterized and secured. In 1994, the vats were pumped clean, and the drums were overpacked and removed from the site. The vats were covered and the buildings were secured to prevent trespassing.
The Remedial Investigation and Feasibility Study (RI/FS) was conducted by the State with federal funding (i.e., State lead, Fund-financed). Cleanup options to address the lagoons and the drain (Operable Unit 1 (OU1)) were evaluated and a decision on the final cleanup remedy was made in a June 1998 Record of Decision (ROD) signed by the Michigan Department of Environmental Quality (MDEQ, now known as the Michigan Department of Natural Resources and Environment or MDNRE) and EPA. The selected remedy for OU1 is to consolidate contaminated soils into one area of the western lagoons, dredge sediments from the County Drain #30 and consolidate them in that area as well, and to construct a wetland to treat groundwater from the lagoon area.
Remedial Design and Remedial Action (RD/RA) negotiations with the potentially responsible parties began a week after the ROD was signed. A Consent Decree (CD) was signed by EPA and the five PRPs. RD began in February 2000, with the first task being Pre-Design Studies (PDS). Field Work for PDS took place between February 2001 and March 2001, including the installation of new monitoring wells, abandonment of wells, sampling sediment and development of new wells.
The Draft PDS Report was submitted in July 2001 for EPA and MDEQ review and comment. The revised report was submitted on November 5, 2001, and did not meet the requirements of the Statement of Work and CD. Per a request from EPA, the Draft Phase II PDS Work Plan was submitted on May 20, 2002, which included additional field studies north and south of the County Drain #30. The final Phase II PDS Work Plan was submitted in July 2002.
Pre-Design Studies field work took place in August 2002. EPA received the Draft Phase II PDS Technical Memorandum in December 2002. Work conducted as part of the PDS showed possible problems with the implementation of the constructed wetland approach for groundwater treatment. Pending resolution of implementation issues with the ROD-selected groundwater treatment approach, the PRPs proposed to enhance the source control portion of the lagoon closure remedy by adding solidification and stabilization additives. This will give the lagoon sludges the strength necessary to support a cover and should reduce leaching of contaminants to groundwater. In 2006, the PRPs evaluated solidification and stabilization mixes and conducted a pilot scale field test of mixtures. EPA issued an Explanation of Significant Differences (ESD) document in September 2008 that clarifies the cleanup requirements and documents that the use of stabilization and solidification is acceptable in conjunction with lagoon closure activities. Any modification to the original groundwater remedy selected in the ROD will be addressed though a future ROD amendment.
Additional sampling and analysis was completed for soils and sediments associated with County Drain #30 and the groundwater near the western end of the contaminant plume during April/May 2010. A final report will be completed after the results are evaluated, and further potential remedial activities are under consideration.
Operable Unit 2 (OU2) consists of the Industrial Sewer that was used by the industries to transport their liquid wastes to the waste lagoons. MDEQ began investigations of the sewer in September 1996 and subsequently sampled again in May 1998. Results of these two sampling activities are reported in Technical Memorandums for the Industrial Sewer. EPA began negotiations with the PRPs in September 2000 for the FS. As a result of these negotiations, EPA and the PRPs agreed to evaluate upstream source area "abandoned facilities" prior to completing work on the Industrial Sewer.
North Bronson Former Facilities - The upstream sources that were identified as part of the discussions for OU2 were evaluated by EPA and PRPs. Work on these sources is proceeding. These facilities collectively are known as the North Bronson Former Facilities and include the former Bronson Reel facility, the former L.A. Darling facility, and the former Scott Fetzer facility.
* Former Bronson Reel Facility - EPA issued a Record of Decision for the former Bronson Reel facility on September 26, 2006. The ROD requires: (1) the implementation of a warranty deed restriction on the property to require follow-up sampling under the site buildings if the foundations are ever removed, and (2) the implementation of groundwater use restrictions because of concerns about site-wide groundwater contamination that impacts the northern industrial area of Bronson. No other risks from this source area were identified.
* Former L.A. Darling Facility - - The former L.A. Darling facility contains metal and solvent contamination in its soil and groundwater. The site PRP completed the RI Report in 2006 and submitted a draft FS for EPA review in the Fall of 2006. The PRP revised the FS based on EPA and MDEQ comments. In the fall of 2007, L.A. Darling commenced a partial removal of contaminated soil from the property to allow for the construction of a road though part of the property. In a Record of Decision issued in September 2008, EPA selected a cleanup approach for the facility. The cleanup plan requires excavation of contaminated soils above the water table and institutional controls to ensure continued commercial/industrial use of the property. The ROD selected an interim action for groundwater, with the selection of Air Sparging and Soil Vapor Extraction (SVE) to remove volatile organic contaminants. When the efficiency of the Air Sparge / SVE system slows and is no longer removing sufficient levels of VOCs from the groundwater and saturated soils, the system will be converted to a groundwater extraction and treatment system. This two-pronged approach, with Air Sparge / SVE and then “pump and treat,” should dramatically reduce VOC concentrations at the facility. This groundwater approach is an interim remedy because it is not meant to address the entire contaminant plume from the former L.A. Darling facility. Groundwater contamination from L.A. Darling overlaps with contamination from other sources. A cleanup plan to address combined plume areas will be issued as a separate decision document. Remedial work for the L.A. Darling facility is expected to be conducted during 2011.
* Former Scott Fetzer Facility - - The former Scott Fetzer facility also contains metal and solvent contamination in its soil and groundwater. The site PRP completed the RI report in February 2008 and submitted the final FS report in June 2009. In a Record of Decision issued in September 2009, EPA selected a cleanup approach for the facility. The cleanup plan requires partial excavation of contaminated soils above the water table, soil vapor extraction of volatile chemicals in soils, and institutional controls to ensure continued commercial/industrial use of the property. The ROD also selected an interim action for groundwater, with the selection of Air Sparging and Soil Vapor Extraction to remove volatile organic contaminants. When the efficiency of the Air Sparge / SVE system slows and is no longer removing sufficient levels of VOCs from the groundwater and saturated soils, the system will be converted to a groundwater extraction and treatment system. This two-pronged approach, with Air Sparge / SVE and then “pump and treat,” should dramatically reduce VOC concentrations at the facility. This groundwater approach is an interim remedy because it is not meant to address the entire contaminant plume from the former Fetzer facility. Groundwater contamination from Fetzer overlaps with contamination from other sources. A cleanup plan to address combined plume areas will be issued as a separate decision document. Remedial work is expected to be conducted for the Former Fetzer facility during 2011.
* Former L.A. Darling and Former Scott Fetzer Facility - - Groundwater contamination from the former L.A. Darling facility and the former Scott Fetzer facility extends under a residential area in the north of Bronson. Because EPA was concerned that the high VOC levels in the shallow groundwater could pose a threat to the indoor air of nearby residents, the site PRPs implemented a soil gas monitoring program. Soil gas samples were collected from yards near the facilities and public right-of-ways, and from nearby homes that were potentially impacted. To date, three homes near the facilities have been found to contain VOC vapors above indoor air action levels. The PRPs, working with EPA and homeowners, installed venting systems to reduce or eliminate potential impacts to indoor air. Additional monitoring indicates that further actions may be needed. After additional monitoring, additional control measures will be implemented if necessary.
ContactsRemedial Project Manager, U.S. EPA
james hahnenberg (firstname.lastname@example.org)
Community Involvement Coordinator, U.S. EPA
AliasesNORTH BRONSON IND AREA
BRONSON RESIDENTS WELL
BRONSON PLATING MFG CO
BRONSON PLATING CO