Page 7 of the PAERAB's Spring 2008 TAPP Contractor Newsletter

Text Box: in assessing exposure scenarios for industrial research workers, construction excavation workers, and youth visitors. EPA rescinded its approval of this approach in a letter addressed to Ted Gabel dated February 7, 2008. “EPA expects to return usable ground waters to their beneficial uses wherever practicable, within a timeframe that is reasonable given the particular circumstances of the site.” (40CFR300.430(a)(1)(iii)(F)). Since the most beneficial use of Picatinny ground water is drinking water, ground water must be returned to that use wherever practicable within a reasonable timeframe regardless of calculated risks.’

Text Box: The use of the risk assessment for groundwater in the Site 78 Feasibility Study (FS) by Arcadis received sharp criticism from the USEPA (comments dated March 6, 2008), almost identical to the comments relating to the Mid-Valley FS. The comments on the Mid-Valley FS are part of what precipitated the February 19, 2008 meeting with regulators and which may ultimately lead a path to dispute resolution. The USEPA’s rationale for rejecting the risk assessment approach is documented in a February 7, 2008 letter from the USEPA to Picatinny Arsenal (a copy of which can be viewed in its entirety on the RAB website). This letter also included a copy of a March 14, 1995 internal USEPA memorandum regarding the USEPA’s stance on the necessity of groundwater cleanups being dependent on the groundwater classification. In the comments on Site 78 the USEPA stated the following: ‘The risk assessment approach for Site 78 ground water follows the Phase III-1A Human Health Risk Assessment Approach

Text Box: As we have observed with Area D, the USEPA does not appear to consider 100 plus years to be a reasonable time frame and therefore this is presumably why the USEPA rejected the application of MNA to groundwater at Area D. It appears that a reasonable

Image of effluent draining from city Storm / Sewer Drain Pipe into body of water

from becoming a reality. In addition, the Arsenal is actually very large and it occupies a significant portion of Morris County.

Picatinny Arsenal resides on top of vast groundwater sources which may someday need to be accessed by the communities of Morris County and elsewhere. Fortunately, most if not all of the RAB members reside in communities surrounding Picatinny Arsenal and this tends to make us keenly aware of the need to safeguard our potential drinking water sources.”

timeframe will be based on a consideration of site-specific conditions.

In response, Mr. Tim Llewellyn of Arcadis explains Arcadis’ perspective regarding Area D, by stating that “… we ( referring to the Army and Arcadis ) have observed with Area D that the USEPA considered 100 plus years to be a reasonable timeframe for the protection of Green Pond Brook with the construction of the Area D PRB. As a point of clarification, the signed Area D ROD does specify MNA as the remedy for groundwater, with a time-frame estimated to be up to 170 years. The permeable reactive barrier is designed to protect surface water, not treat the entire TCE groundwater plume”.

Mr. Glaab, the RAB Community Co-chairman comments that : “...since the groundwater in the aquifers beneath Picatinny could eventually migrate out beyond the boundaries of the Arsenal it is both advisable and prudent to use remediation time frames which are of sufficiently short duration to prevent this long standing concern of the PAERAB