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Middletown Air Field
EPA Region 3 (Mid-Atlantic)
EPA ID# PAD980538763
17th Congressional District
Last Update: January 2015
Current Site Status
The remedy at the Middletown Air Field consisted of removal of contaminated materials, implementation of institutional controls, closure of the fire-training pit, and treatment of contaminated water supply wells.
Treated groundwater is currently utilized as a water supply by the Harrisburg International Airport (HIA) and surrounding residents.
The site was deleted from the EPA's National Priorities List in 1997 and oversight of the continued implementation of institutional controls was turned over to the Pennsylvania Department of Environmental Protection (PADEP).
EPA conducted Five Year Reviews at the site in September 1996, September 2002, September 2007, and July 2012. The most recent Five Year Review, issued on July 24, 2012, indicated that the Site was protective of human health and the environment in both the short and long term.
In June 2014, Perfluorinated Chemicals (PFCs), were detected in multiple water supply wells at HIA. The impacted water supply wells were taken out of service and long-term treatment options are currently being evaluated.
From 1868 through 1966, the United States Federal Government owned and operated the Middletown Air Field as the Olmstead Air Force Base. The site encompasses approximately 200 acres located between Middletown and Highspire in Dauphin County, Pennsylvania. Now privately and Commonwealth-owned, the property houses Harrisburg International Airport, a Pennsylvania State University Campus, several industrial properties, and storage for the Middletown School District. Historically, the site was utilized for the maintenance, overhauling, and testing of aircraft as well as housing United States Air Force (USAF) personnel. The HIA portion of the site was operated by the Pennsylvania Department of Transportation (PennDOT) from 1966 until 1997 when it was sold to SARAA.
In 1983, discovery of chlorinated solvent contamination in six of ten HIA water supply wells resulted in the temporary shutdown of the supply system. A water treatment system was installed by the major PRPs at the site, PennDOT and USAF, under an agreement with EPA. This action returned all of the supply wells to potable use. The water supply on the site provides water to about 3,500 full-time area residents, as well as to airline travelers and industrial users. Located in a mixed residential and industrial area, approximately 19,500 people obtain drinking water from wells within 3 miles of the site.
- Site Responsibility
- This site is being addressed through a combination of Federal, State, and PRP actions.
- NPL Listing History
- Our country's most serious uncontrolled or abandoned hazardous waste sites can be cleaned using federal money. To be eligible for cleanup money, a site must be put on the National Priorities List (NPL). This site was proposed to the NPL on October 14, 1984 and was formally added on June 10, 1986 making it eligible for federal cleanup funds. The site was deleted from the NPL on July 10, 1997.
Threats and ContaminantsWells, groundwater, and soils are contaminated with VOCs including trichloroethylene (TCE) and heavy metals such as lead. The primary risk at the site was identified as the ingestion of contaminated groundwater from the onsite water supply system. Accidental ingestion of or direct contact with contaminated soil was also identified as a potential health risk.
Contaminant descriptions and risk factors are available from the Agency for Toxic Substances and Disease Registry, an arm of the CDC.
In March 1983, chlorinated solvent contamination was discovered in six of the ten groundwater supply wells operated at the HIA facility, then owned by PennDOT. In 1984, the State removed all sludge and liquids in the waste collection building, began closure of the fire training pits, and removed all contaminated materials from the location. The same year, the USAF removed some waste drums from the Mead Heights area.
In 1987, the EPA issued a Record of Decision documenting the selection of an interim remedy for the HIA water supply system consisting of the construction of a central treatment plant in conjunction with continued groundwater monitoring. These cleanup activities were implemented by the PRPs and were considered an interim response pending supplemental investigation of the remainder of the site. Construction of the groundwater treatment system was completed in 1987 and is currently operational.
Five disposal areas were identified as potential sources of groundwater contamination at the site and were investigated during the Remedial Investigation and Feasibility Study (RI/FS) from 1988 through 1990. In December 1990, EPA issued a second Record of Decision documenting the selection of the permanent remedy consisting of continued operation of the groundwater treatment system, land-use restrictions, and groundwater monitoring. In April 1992, EPA issued an Explanation of Significant Differences (ESD) in response to PADEP's concerns regarding the relationship between soil and groundwater contamination at the site. The ESD redesignated the 1990 ROD as an interim ROD and required additional characterization of soil and groundwater to determine the final remedy, and the modification of the existing institutional controls. In September 1993, EPA signed an Administrative Order on Consent with the USAF for the implementation of a Supplemental Studies Investigation and Focused Feasibility Study and completion of the work outlined in the 1990 ROD and 1992 ESD.
Following the completion of the additional investigation, in September 1996, EPA issued a final ROD documenting the determination that no further action was necessary at the site and the currently implemented remedies and institutional controls were sufficient to protect human health and the environment. The site was deleted from the NPL in July 1997.
As a result of the September 2007 Five Year Review, the protectiveness of the remedies and institutional controls were more closely evaluated. The evaluation indicated that that the remedy currently in place at the North Base Landfill portion of the site is protective and no additional investigation is necessary. Additionally, EPA and PADEP requested that SARAA conduct groundwater sampling at the HIA portion of the site to determine if a vapor intrusion investigation will be necessary. The additional data indicated that vapor intrusion was not a concern at the Site. The fourth FIve Year Review was issued on July 24, 2012 documenting the findings of these investigations.
EPA conducted Five Year Reviews at the site in September 1996, September 2002, and September 2007. The September 2007 Five Year Review concluded that the groundwater remedy implemented by the SARAA (Susquehanna Area Regional Airport Authority) at HIA, which involved treatment of solvent contaminated groundwater supply wells, is operating as required by the 1990 Record of Decision (ROD) and 1992 Explanation of Significant Differences (ESD). However, the review also determined that the vapor intrusion pathway has not been evaluated at the HIA facility and deferred the protectiveness statement until the vapor intrusion pathway has been evaluated. Additionally, the review concluded that insufficient data was available to make a determination of protectiveness at the North Base Landfill portion of the site and recommended additional sampling.
EPA recently located additional data that was not available at the time the 2007 Five Year Review was conducted. The evaluation of this new information indicated that that the remedy currently in place at the North Base Landfill portion of the site is protective and no additional investigation is necessary. Additionally, EPA and PADEP requested that SARAA conduct additional groundwater sampling at the HIA portion of the site to determine if a vapor intrusion investigation will be necessary. The data indicated that vapor intrusion is not a concern at the Site.
The fourth Middletown Airfield Five Year Review was issued on July 24, 2012. The following Protectiveness Statement was presented in the Five Year Review.