In July, The South River Science Team sent out for review to its more than 100 members a draft proposal with the title “Remediation of Mercury in the South River and a Segment of the South Fork of the Shenandoah River.” Following review, the document will be submitted to NRDC and the Sierra Club to fulfill a consent agreement. This agreement also required an extensive study, recently completed, of the consequences that mercury brought about for biota in the South River region.
NRDC and the SC would not enforce the remediation measures discussed in the proposal. However, the proposal is significant for two reasons: it serves as a blueprint for an actual remediation program under RCRA regulations to be administered by DEQ and it also signals a major change in emphasis by the SRST. Since 2001, SRST has focused its efforts to find out where, how much, and in what forms mercury exists in the South River environs. Now “how to” has been added as a prime function and so engineers are playing increasingly more prominent roles.
The site conceptual model has quantitatively identified stream banks and floodplain sediments as the main sources of mercury to the South River. The primary remediation tools are to be bank stabilization and carbon (biochar) adsorption. Pilot studies have been undertaken to refine how and where these will be implemented. Remediation will be conducted in stages. The first will be the two-mile reach starting at the DuPont (now Invista) plant site in Waynesboro.
Short- and long-term monitoring will be key in assessing results and guiding future actions. Adaptive management tools will govern the evolution of the remediation; risk analysis using Boolean mathematics will play a part as well. Meanwhile, geochemical and biochemical studies will continue to see if they can supplement the primary tools.
The following task teams within the SRST have been formed this past year for the purpose of refining the remediation program:
• remedial options
• human exposure
• program integration of regulatory and legal drivers
Remediation design is scheduled for 2014; implementation commencement is scheduled for 2015.
The Friends of the Shenandoah River has been the citizens group most involved with the SRST since its inception in February 2001. Meryl Christiansen began this association at the earliest meetings. So FOSR members especially should celebrate the above developments to make our river healthier. We have an additional benefit—the mountain of excellent research that is concentrated on the South River pretty much applies to the Shenandoah River as well! Look at the website: http//southriverscienceteam.org/. A password is no longer required.
Download Bob Luce’s presentation ( ROPS Update 7-17-13) to the FOSR board. All the slides (except the first) originated from talks by other South River Science Team members on July 16 and 17 in VADEQ Valley headquarters in Harrisonburg; permission to reproduce these for FOSR members.
~by Bob Luce