Ohio is not the only state that is reviewing all sites that have trichloroethylene (TCE) contamination. Massachusetts Department of Environmental Protection (MassDEP) recently announced that is was going to review 1,000 closed sites with TCE contamination.  MassDEP will evaluate the sites "based on the current understanding of health risks, even if the site was previously closed properly under earlier standards."  

Unlike Ohio, MassDEP issued a public statement in April 2016 that it discussing its review of TCE Sites. Ohio EPA has not made a public announcement similar to Mass DEP.  Rather, Ohio EPA has discussed its review in meetings with environmental consultants and through issuance of letters and requests for information to sites with TCE contamination.

TCE was widely used as a degreaser for industrial metal parts and as an extraction solvent for organic oils. As a result of its use, TCE contamination related to use of solvents is very common at manufacturing sites.  

A discussed in the MassDEP announcement, the heightened scrutiny of sites with TCE contamination was based, in part, on a 2011 review to the U.S. EPA toxicity information.  The review included assessment of the potential for fetal developmental effects following even short-term exposure to TCE contamination.  As a result, the standards related to TCE have become significantly more stringent.

MassDEP provided a comparison of the levels of concern from 2011 to 2016 which shows the TCE standards:

Changes in TCE Risk-Based Levels in Massachusetts
Pathway 2011 Level of Concern 2016 Level of Concern
Indoor Air (Residential) 85 ug/m3 6 ug/m3
Groundwater (near residences)

300 ug/l pre-2006

50 ug/l post-2006

5 ug/l
Health Effect of Concern Long-term cancer risk Short-term development effect

 The primary pathway of concern in both Massachusetts and Ohio is vapor intrusion (volatilization of contaminants into the indoor air of a building).  Ohio’s current indoor air standards are relatively comparable to MassDEP.

Ohio TCE Indoor Air Standards
Pathway Standard
Residential 2.1 ug/m3
Commercial Industrial 8.8 ug/m3

Continued developments with regard to TCE are surely forthcoming.  As the new significantly more stringent standards get implemented property owners and site developers that have TCE contamination will need to proceed cautiously.  This includes sites that previously completed investigations or cleanup activities.