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The Pines Groundwater Plume site is located about four miles west of Michigan City and about one mile south of Lake Michigan in Porter County, Indiana.

EPA tested residential drinking water wells in the town of Pines in May 2002, based on high levels of the metals boron and molybdenum found in drinking water wells by the Indiana Department of Environmental Management. The metals appeared to come from coal combustion by-products, or CCBs, composed primarily of fly ash that was disposed of in a nearby landfill called Yard 520. Other areas in the town were also identified as having CCB materials, including residential yards where fly ash was used as fill material and roads where bottom ash was used as bedding and surface material. CCBs are the result of burning coal to make electricity.

Northern Indiana Public Service Co., Brown, Inc., Ddalt Corp., and Bulk Transport are the companies determined to be responsible for the contamination.

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What Is the Current Site Status?

EPA is revising the soil portion of the cleanup detailed in the 2016 decision document (PDF)(115 pp, 16.96mb, About PDF) for the Pines Groundwater Contamination Superfund site.

The changes are outlined in a new report called an “explanation of significant differences,”(PDF) (4pp, 281.04 K, About PDF) or ESD They include:

  • adding new institutional controls (deed restrictions or an ordinance)
  • removing hexavalent chromium as a contaminant of concern
  • clarifying the scope of the original soil cleanup

Originally, the cleanup called for legal restrictions to prevent exposure to contaminated soil left in place (e.g. at depth).  Landowners, however, may be unwilling to enter into a restrictive covenant or may refuse to allow EPA to clean up their properties.  The ESD allows EPA, in these situations, to use different legal options to prevent exposures, such as informational deed notices or ordinances.

The 2016 decision document noted that total chromium concentrations in some soil samples were above levels considered safe for hexavalent chromium (a subset of total chromium). After reviewing the results of hundreds of samples further analyzing for the hexavalent portion of total chromium, EPA has determined that the hexavalent chromium found in site soil is consistently below the levels considered unsafe. So, EPA is removing hexavalent chromium as a contaminant of concern for soil.

EPA is also clarifying that soil cleanups done under the 2016 decision document will be done the same way as other cleanups described in a March 17, 2016 legal agreement (42 pp, 1.87 MB) (webmaster, add AOC link here).  This includes:

Restoring cleaned-up properties to their original conditions, including repairing or replacing damaged structures.

Leaving contaminated soil in place 3 feet deep or less if required by property-specific design details, such as the location of a septic system or presence of groundwater less than 3 feet from the surface and does not present a risk to people or the environment.

Removing contaminated soil left in place in the future under a property-specific plan.

The ESD report, along with other site-related documents, is available for review at the Michigan City Public Library, 100 E. Fourth St., and on this web page under Site Documents & Data.




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Emergency Response and Removal

EPA expects that most, if not all, properties with soil contamination resulting from coal ash used as landscaping fill in the 1970s will be addressed by a second EPA action under an April 2016 legal agreement with NIPSCO. The company is required to do this work separately from the cleanup plan for the groundwater plume.

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