Investigation and Clean-up Efforts Focused on Reducing Exposures to PCE
Dane County is one of many areas around Wisconsin facing an on-going environmental challenge related to the historic use of PCE. Tetrachloroethylene (PCE), also known as perchloroethylene or PERC, is a volatile chemical solvent used in dry cleaning, metal cleaning, and degreasing operations. While the use of the solvent today is closely regulated, this was not the case in the past when PCE was widely used. To date, several dozen cases of PCE contamination have been identified by the Wisconsin Department of Natural Resources (DNR) and several of these sites have already been investigated and cleaned up. The DNR is currently investigating about thirty sites but there are probably other sites contaminated with PCE that have not yet been identified or reported. Although the DNR is the lead agency responsible for addressing this issue, Public Health-Madison and Dane County (PHMDC) will continue to assist the DNR by providing relevant public education and outreach to the community. "We are actively engaged in areas where we know that contamination has occurred, taking great care to identify sites where vapors may have the potential to affect people in buildings," said Mark Giesfeldt, director of the DNR's Remediation and Redevelopment Program. "By working with owners and developers as properties change hands or are redeveloped we can identify vapor issues before construction begins. This process helps in the discovery of previously unidentified solvent-contaminated sites." PCE can persist in the environment for decades in groundwater and soil. PCE vapors can move through the soil from contamination sites and enter into neighboring homes, schools, and businesses through cracks or other openings in the foundation. This process, known as "vapor intrusion", can lower the quality of indoor air and could expose people to unacceptable and possibly harmful levels of PCE. "In most homes where PCE has been found, it has been at low levels not expected to cause health problems to the residents of those homes," stated Henry-Nehls-Lowe, epidemiologist for the DHS. "However, long-term exposure to PCE can increase the lifetime risk of some cancers." It is important, therefore, for residents to understand PCE-related health risks and take appropriate action if necessary. Testing for PCE can include sampling of outdoor air, groundwater, soil, indoor air, and for vapor in the soil below the slab of the building. If test results exceed current air, water, or soil quality standards, there are steps that can be taken to reduce the levels of PCE. These can include the removal of the soil contaminated with PCE, testing of neighboring properties, and installing a vapor mitigation system. Vapor mitigation systems are not particularly expensive and are very effective at removing PCE vapors from the soil and safely venting them away from your home or business. These are the same systems used to reduce radon levels in the home. For additional information regarding PCE and to learn more about mitigation systems please visit: http://www.dhs.wisconsin.gov/eh/chemFS/fs/Tetchlor.htm http://dnr.wi.gov/topic/Brownfields/Vapor.html http://www.epa.gov/oswer/vaporintrusion/ To find out more about spills in Dane County, the DNR provides an online tool to search for active or closed spill sites. This database can be searched by county, the type of spill, and specific chemicals and can be found at the following link: http://dnr.wi.gov/botw/SetUpAdvSearchForm.do. If you have questions or want to learn more about PCE and vapor intrusion, please call the Public Health Madison and Dane County at (608) 266-4821. A more detailed technical report is available at: http://www.publichealthmdc.com/documents/PCEVaporIntrusionReport.pdf. If you have site-specific questions or questions concerning remediation please call the Wisconsin Department of Natural Resources at (608) 267-7562. -END- NEWS RELEASE Public Health - Madison & Dane County
