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HIGHLIGHTS

National Risk Management Research Laboratory
Ground Water and Ecosystems Restoration Division
Robert S. Kerr Environmental Research Center
Status Report for the week of June 30, 2014

TECHNICAL ASSISTANCE

Technical Assistance Region VIII: On June 4, 2014, Dr. Brace Pivetz (Dynamac Corporation), under the direction
of Dr. David Burden (GWERD), provided technical review comments to RPM Joe Vranka on the Additional Site
Characterization Report-DR4FT, BNSF Former Tie Treatment Plant, Somers, Montana, October 4, 2013 (the Report).
The Report was very well-written and comprehensive. It contained clearly stated and concise descriptions of the
characterization activities and the rationale for those activities. The report also included a detailed discussion of non-
aqueous phase liquid NAPL transport relative to the Site. In general, all the necessary information for evaluating the
discussions and conclusions in the Report were included within the Report and Appendices; although, some supporting
information was not found. In general, the characterization methods appeared suitable for their intended purpose and
appeared to be conducted properly and with careful planning. The conceptual site model (CSM) was comprehensive,
well-reasoned, and technically sound, especially in regard to the discussion about NAPL fate and transport. If site
conditions change significantly, or the area of interest expands beyond the current boundary, the CSM would then
need to be updated again.

(14-R08-001)	(D. Burden (GWERD) 580-436-8606)

Technical Assistance Region IX: On June 9,2014, Mr. Steven Acree (GWERD) and Dr. Robert Ford (LRPCD) provided
technical review comments to RPM David Seter on the "Site-Wide Groundwater Operable Unit (OU-1) Remedial
Investigation WorkPlan, Revision 1," YeringtonMine Site, Yerington, Nevada. In general, the revisions to the document
adequately address previous comments. Although the body of this work plan is a framework document outlining the
remaining data gaps in the remedial investigation and the proposed path toward completion of the investigation, it
also includes several detailed work plans and reports as attachments. In response to previous comments, the document
provides approximate submittal dates and time frames for the remaining products defining the remedial investigation
(e.g.. Background Work Plan, Bedrock Characterization Plan, and Geochemical Characterization Work Plan). It is
recommended that these approximate submittal dates/time frames be reviewed and revised, as necessary, to reflect the
most current estimates.

(14-R09-004)	(S. Acree (GWERD) 580-436-8609) (R. Ford (LRPCD) 513-569-7501)

Technical Assistance Region IX: On June 17,2014, Dr. Eva Davis (GWERD) provided technical review comments to
RPM Carolyn D 'Almeida on the "Draft Addendum # 1 Remedial Design and Remedial Action Work Plan (RAWP) for
Operable Unit 2, Revised Groundwater Remedy, Site ST012, Former Williams Air Force Base, Mesa, Arizona." This
addendum outlines the steam injection/extraction startup strategy to be used for the Steam Enhanced Extraction system
based on the observed presence of light nonaqueous phase liquids (LNAPL) in borings advanced for construction of
the system of steam injection and extraction wells. The purpose of this addendum is to ensure that LNAPL does not
migrate away from the thermal treatment zone due to steam injection, or minimize the potential for such undesirable
migration. There are some concerns with the scoring system employed to categorize the boring intervals for potential
LNAPL presence. There is also a concern about large areas with significant LNAPL contamination that, with the
injection/extraction strategy outlined here, will not receive significant steam. It is strongly recommended that the use
of cyclic steam injection (as described in the Final Remedial Design and Remedial Action Work Plan) be considered
for particular areas in order to treat them with steam while minimizing the risk of spreading LNAPL outside of the
treatment area.

(14-R09-002)	(E. Davis (GWERD) 580-436-8548)

David Burden. Ph.D., Director
Ground Water Technical Support Center
580-436-8606 burden, davidt@epa.gov

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