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Congressional District # 03


EPA ID# OH6890008984
Last Updated: May, 2015

Site Description

The U.S. Department of Energy's (DOE) Mound Plant (Mound) is located in Miamisburg, Ohio, in Montgomery County, about ten miles southwest of Dayton, Ohio.  It is a 306-acre site located approximately 2,000 feet east of the Great Miami River and partially overlying the Buried Valley Aquifer (BVA), a designated sole source aquifer.  The site is in the middle of Miamisburg, surrounded by several private residences, a city park, and a golf course.  Since 1948, Mound has operated as a research, development, and production facility in support of DOE's weapons and energy programs.  Mound's current mission is to support DOE's efforts in environmental management and to transition the site, in cooperation with the City of Miamisburg, into a commercial or industrial park.

Site Responsibility

This site is being addressed by the US Department of Energy, with US EPA and Ohio EPA support.

Threats and Contaminants

Contamination at Mound consisted of radionuclide contamination in soil, primarily plutonium-238, thorium-232, and tritium, and volatile organic compound (VOC) contamination in the Buried Valley Aquifer, a sole source drinking water aquifer.

Cleanup Progress

A Federal Facilities Agreement (FFA) was signed by DOE and the United States Environmental Protection Agency (U.S. EPA) in October, 1990.  The Ohio Environmental Protection Agency (OEPA) signed the FFA in July, 1993.  DOE, as the lead agency, is conducting the cleanup of the Mound, with oversight being provided by the U.S. EPA and the OEPA.

A Record of Decision (ROD) was signed on June 12, 1995 for Operable Unit 1 (OU1), to remove VOC contamination from the aquifer underlying a landfill at the facility by pumping and treating the groundwater with an air stripper.  Construction of the treatment system began in the fall of 1996.  The system was started in February 1997, and to date has treated over 400 million gallons of groundwater.  After the pump and treat system was in place, a soil vapor extraction (SVE) system was installed to augment the exisitng system.   As of December 2001, the air stripper had removed about 25 pounds of VOCs from the aquifer while the SVE system had removed almost 4,000 pounds.

In May 2005, in response to concerns raised by the Miamisburg Mound Community Improvement Corporation (MMCIC) regarding the OU1 landfill's impact on their ability to reuse and market the Mound site, the Core Team of DOE, Ohio EPA and US EPA reviewed the remedy selected for OU1 in 1995 based upon new information and data obtained in the ten years since the original remedy selection.  Based upon this new information, the Core Team concluded that the 1995 remedy selection was still appropriate for OU1 and that excavation and offsite disposal of landfill materials was not practical.  However, the Miamisburg Mound Community Improvement Corporation (MMCIC) was not satisfied with this remedy and petitioned Congress for funding to remove the landfill materials from the Mound site.  

In November 2005, Congress passed legislation providing $30 million to the Department of Energy (DOE) to implement a new remedy at OU-1 that was mutually agreeable to DOE and to the MMCIC.  This legislation led to the awarding of a DOE contract to excavate and dispose of landfill wastes offsite to facilitate future reuse of the property.  It was agreed by DOE, MMCIC, US EPA and OEPA that DOE would use their authority under CERCLA to address the contamination and implement this “voluntary removal action” at OU-1.  A removal plan was developed in 2006 and reviewed by US EPA and OEPA, in a consultation role.  US EPA’s and OEPA’s role in reviewing this plan was to evaluate short-term effects associated with the removal and to insure that the appropriate data was generated to allow for a change in institutional controls at the end of the removal, if requested.  The removal plan was then provided to the public for a 30-day comment period.  The removal of landfill materials began in January 2007 and the first phase was completed in January 2008.  The $30 million was not enough to completely remove the OU1 landfill wastes in 2008, and some landfill materials were expected to remain onsite with an appropriate landfill cover.  Subsequently, DOE obtained another $20 million in economic stimulus funding to complete the excavation of the OU-1 landfill wastes in 2010.  After completion of backfill and restoration activities, DOE submitted a proposed ROD Amendment for OU-1 to reflect the new end-state for the property requiring ongoing groundwater treatment and specific institutional controls for the OU1 area, including a prohibition of future residential use of the OU-1 property and a prohibition on the installation of drinking water wells.  DOE released the Proposed ROD Amendment in July 2011, and a public meeting was held that same month to solicit comments on the proposal.  No comments were received, and the ROD Amendment became effective in September 2011.  An Ohio Uniform Environmental Covenant encompassing deed restrictions was established for the OU-1 area (now known as Parcel 9), and it was recorded in February 2012.

Sediments in the Miami-Erie Canal, which runs along the western boundary of the Mound plant, were contaminated with plutonium-238.  This was caused by a plutonium waste line break in 1969, and a subsequent rain event which washed the contamination down a hillside into the canal.  In October 1996, DOE began removing about 38,000 cubic yards of contaminated sediment for disposal at an offsite facility.  The entire removal action was completed in May 1998, with all cleanup objectives being met.  A ROD was subsequently signed for the canal area, known as Operable Unit 4 (OU4), in 2004.  This ROD stated that the canal cleanup had been protective for residential use and the ROD required "no further action" for OU4.

A ROD was signed on March 15, 1999, for Release Block D, a 12-acre parcel at Mound.  This parcel has since been transferred to the Miamisburg Mound Community Improvement Corporation (MMCIC) for economic development.  In addition, a ROD was signed for Release Block H, a 14-acre parcel, on June 18, 1999.  This parcel was also transferred to the MMCIC for economic reuse.  Both RODs called for institutional controls to be placed on these parcels to restrict future use to industrial/commercial use.  On April 16, 2001, these Release Blocks were deleted from the National Priorites List (NPL) through partial deletion.

In 2001, RODs for parcels 3 and 4 were completed at Mound.  The ROD for Parcel 4 was signed on March 12, 2001, and the property was subsequently transferred to the MMCIC for economic development. T he ROD for Parcel 3 was signed on August 28, 2001. These two RODs contained the same required institutional controls as those described in the RODs for Release Blocks D and H.  Parcel 4 was deleted from the NPL on December 2, 2002.

On July 31, 2003, a ROD was signed for the 87-acre Phase I parcel of property at Mound. This ROD calls for industrial use institutional controls and for monitored natural attenuation of groundwater contaminants underlying Phase I.  The Phase I property was transferred to MMCIC in February 2009.

The last removal action to remove contaminated soil from the rail spur area at Mound was completed in 2009.  The final ROD for the Mound site, the Parcel 6, 7 and 8 ROD, selected institutional controls for parcels 6, 7 and 8 and also addressed the offsite areas and seeps.  This ROD was completed on November 19, 2009. 

The initial five-year review for the Mound Plant was completed in September 2001.  DOE recently completed the third five-year review for the site in September 2011.  The review determined that the site is protective of human health and the environment since the site has been successfully cleaned to industrial/commercial risk-based cleanup standards, migration of contaminated groundwater is being controlled and appropriate institutional controls are in place to prevent residential use of the property. 

Congressional Interest


Property Reuse

The planned reuse of the Mound Plant is industrial/commercial.  Deed restrictions are placed on the Mound property at the time of transfer to the Mound Development Corporation (MDC), formerly the Miamisburg Mound Community Improvement Corporation (MMCIC), to restrict the future use of the property to industrial use.  182 of the original 306 acres of property (60%) have been transferred to the MMCIC for economic reuse as an industrial and commercial research park.  The remaining parcels, Parcels 6, 7, 8 and 9, are being leased by MDC and will be transferred as MDC identifies parties interested in reusing the land.


Remedial Project Manager, U.S. EPA
david seely (seely.david@epa.gov)
(312) 886-7058

Community Involvement Coordinator, U.S. EPA
susan pastor
(312) 353-1325




Site Profile Information

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


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