Page 7 of the PAERAB's Spring 2011 Community Update Newsletter

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Text Box: to metals and Radionuclides in Groundwater,” July 12, 2011 from 11 am to 1:15 pm “Performance Specifications and Long-Term Stewardship for Solidification/Stabilization Projects,” September 8, 2011 from 11 am to 1:15 pm

Text Box: The courses are free. Register on-line at www.itrcweb.org/ibt.asp. The USEPA Technology Innovation Program has an internet course scheduled as follows: “Bioavailability-Based remediation of Metals Using Soil Amendment

Considerations and Evaluation Techniques,” June 22, 2011 from 2 to 4 pm

Internet courses may be archived at the respective websites for reference at the user’s convenience.

Close to ROD for Site 78?

Text Box: The USEPA commented on the Site 78 Record of Decision (ROD) dated July 2010 on January 26, 2011. Many of the comments were editorial in nature. The Army replied to those comments on February 28, 2011. Replying favorably the Army agreed to the USEPA’s suggested text changes and editorial revisions. The Army also addressed such minor suggestions as a USEPA request to either add a new figure or revise an existing one that would depict the land use control boundaries for Site 78. The Army agreed to this request. The comments from the USEPA that were more substantive in nature related to the following: the accumulation of vinyl chloride from degradation and concern that VC degradation was not favorable under current conditions (found at general comment no. 2); and possible changes in cancer risk (making the risk higher) due to increasing concentrations of vinyl chloride. In regard to General Comment 2 – the USEPA stated : “EPA has concerns with the selected remedy of MNA unless additional data/monitoring show that VC will degrade under

Text Box: current conditions (and more specifically in wells 78MW-3 and 78MW-6, where increasing trends of VC are apparent). It seems very possible that the groundwater would need to go through anaerobic conditions to allow for reductive dechlorination of TCE to VC, followed by aerobic conditions to further dechlorinate VC. The remedy of monitoring natural attenuation will only seem protective if this process of anaerobic and aerobic degradation is proven to exist at the site. It is recommended that a contingency remedy be added to the ROD to address the VC, in the case that VC is not shown to naturally degrade under the current site conditions.” The Army replied that: “Cis-1,2-DCE and VC can degrade under either aerobic or anaerobic conditions. As indicated in the attached graphs (Attachment 1), analytical results of samples collected in September and December 2010 show that concentrations of cis-1,2-DEC and VC have decreased at both 78MW-3 and 78-MW6 since 2007, further supporting that the existing environment at the site is conducive to the natural degradation of these constituents.”

Text Box: As for potential increases in risk due to accumulating VC, the Army referred back to the response to General Comment 2 and noted that “The 2007 VC concentrations are temporal and expected [to] fluctuate over time. The concentrations detected during the 2010 sampling events showed an overall decrease in VC concentrations compared to 2007.” In addition to responding to the USEPA’s written comments the Army also “included table and graphs that were discussed as part of the meeting last week that supported the MNA [monitored natural attenuation] decision for this site.” The meeting referred to was the February 22, 2011 technical project meeting. However, no specific information on Site 78 was included in the meeting minutes. The Army’s response was then approved by the USEPA on March 1, 2011. The NJDEP also submitted comments about the ROD. On April 18, 2011 the Army was notified that Mr. Ed Putnam of the NJDEP had comments regarding groundwater results at the site. The Army replied on April 28, 2011. Among its responses

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