The Pines Groundwater Site is located about 5 miles west of Michigan City and about 1 mile south of Lake Michigan in Porter County, Indiana. In May, 2002, the U.S. Environmental Protection Agency (EPA) began testing residential drinking water wells in the Town of Pines based on elevated levels of the metals boron and molybdenum discovered in water wells by the Indiana Department of Environmental Management (IDEM). The metals appeared to be leached from coal combustion by-products (CCBs) composed of fly ash and bottom ash that were disposed of in a landfill near the Town of Pines called Yard 520. Other areas in the town were also identified as having been disposal sites for CCB deposits, including residential yards, road surfaces, and road subsurfaces. CCBs are produced as a result of burning coal to make electricity.
In January 2003, Northern Indiana Public Service Company (NIPSCO), Brown, Inc., Ddalt Corp., and Bulk Transport, the potentially responsible parties (PRPs) for the Site, signed an Administrative Order on Consent with EPA to provide municipal water to approximately 130 homes in and near the Town of Pines. Further testing by Pines residents and EPA revealed more contaminated wells. On April 5, 2004, the PRPs signed an amendment to the original order to provide an additional 140 homes with municipal water. About 70 additional homes would receive bottled water pending the results of an investigation into the nature and extent of the contamination and the potential long-term risks to local residents and the environment. The investigation and related work was outlined in a second Administrative Order on Consent between EPA and the PRPs signed on April 5, 2004. The investigation was conducted from 2004 to 2007. Twenty two new monitoring wells were installed along with 12 piezometers. Over 150 groundwater samples were collected, 92 surface water samples, 84 soil samples, and 27 sediment samples. Samples were analyzed predominantly for CCB-related metals, but some were also collected for radionuclides, polnuclear aromatic hydrocarbons (PAHs), and dioxins. A Remedial Investigation Report was generated by the PRPs and approved, with some modification, by EPA on May 28, 2010.
Human health and ecological risk assessments have been completed. The risk assessments identified contaminants above acceptable levels for potential future exposures and exceeding drinking water standards called Maximum Contaminant Levels (MCLs) making a feasibility study necessary. The draft feasibility study under review by EPA and IDEM includes alternatives to remediate the contaminants and proposes additional sampling to reduce the level of uncertainty in the risk assessments. After the feasibility study is approved EPA will select its preferred alternative and present that preferred alternative to IDEM and the public for their review and comment. After EPA considers comments a final determination called a Record of Decision would be generated by EPA that outlines the steps needed to reduce risks to acceptable levels. EPA would then provide the PRPs with the opportunity to perform the remedy outlined in the Record of Decision.