natural attentuation -- the reality

[Arc Ecology <arc@igc.apc.org>]

Dear CPEO:

I just received (July 16, 1999) a response from the Navy to a set of
comments that I made on a petroleum corrective action work plan for Hunters
Point Shipyard.  I thought the list might find the Navy's response
"interesting."  The Navy seems to believe indeed that "dilution is the
solution to pollution.  

I am deeply concerned about these responses.  First the Navy has stretched
the concept of "natural attentuation" to absurdity.  Second, their
statements do not comply with EPA's policy on natural attentuation. Third,
these statements represent an enormous breach of trust.  DoD has reassured
the public many times (at forums sponsored by CPEO!) that they will not
abuse the concept of natural attentuation.  Well they have -- or at least
they plan to at Hunters Point Shipyard unless we stop them. 

The Navy point of contact for this project is Ms. Glenna Clark, Code 6223,
Department of the Navy, Engineering Field Activity, West; Naval Facilities
Engineering Command, 900 Commodore Drive, San Bruno, CA 94066-5006, phone:
(650) 244-2659      

###

Excerpted from "Response to Arc Ecology's Comments on draft final work plan
for additional data for Petroleum Hydrocarbon Corrective Action Plan for
Hunters Point Shipyard, San Francisco, California:"

Comment:  "Natural attentuation must not be considered for floating product.
Spreading floating         product is not natural attenuation."

Response:  "The Navy believes that the natural spreading of floating product
can lead to declining         total petroleum hydrocarbon (TPH)
concentrations by dilution in groundwater, sorption on soils, and intrinsic
biodegradation, which would be considered a natural attenuation process."  

Comment:  "I do not consider groundwater mixing and dilution caused by tidal
fluxes along the shoreline to be remediation of TPH-affected areas."

Response: "The Navy considers natural processes that cause a decrease in the
concentration of TPH in groundwater to be natural attenuation processes.
Thus, groundwater mixing and dilution caused by tidal fluxes along the
shoreline is a natural process and may be a factor to consider in the
potential remedy for TPH-affected groundwater along the shoreline.  In
addition, the RWQCB (the San Francisco area Regional Water Quality Control
Board) has agreed to consider tidal mixing along the shoreline as a factor
in a potential remedy, depending on whether or not the Navy can demonstrate
its effectiveness at HPS (Hunters Point Shipyard).