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U.S. EPA TO HOLD MEETING ON PLAN FOR CASMALIA STORMWATER

Release Date: 10/17/1995
Contact Information: Lois Grunwald, U.S. EPA, (415) 744-1588

 (San Francisco) -- The U.S. EPA will hold a public meeting on Wednesday, October 18, in Santa Maria to discuss U.S. EPA's plans to discharge stormwater from stormwater storage ponds at the Casmalia Hazardous Waste facility and to listen to the community's comments on the plan.

     U.S. EPA is seeking comment on an action memorandum describing the planned release of the stormwater. The memorandum has been distributed and also will be available at the meeting.  

     The U.S. EPA will discuss the sampling results from the March and October 1995 testing of the stormwater ponds. The October results are preliminary and subject to further analysis by U.S. EPA.  

     The meeting will be held from 6 to 9 p.m. at the Betteravia County Government Center, Board of Supervisors Hearing Room, 511 Lakeside Parkway.

     In advance of winter rains, U.S. EPA is proposing to discharge stormwater from three stormwater ponds on the site to Casmalia Creek to prevent possible overtopping and/or breaching of the impoundments and the resulting surge of water into the creek, which have been concerns of the California Division of Safety and Dams.

     U.S. EPA believes it is necessary to release the water because the environmental and safety impacts of an uncontrolled  surge of water into the creek would be far greater than a controlled release of the water, a view shared by the California Department of Toxic Substances Control and the California Regional Water Quality Control Board. Also, if the water is not discharged, heavy winter rains may increase the amount of pollutants in the ponds.  

     The ponds contain stormwater runoff that has accumulated on the site since 1989. Samples from the March and October tests found that some contaminants, notably certain heavy metals and solvents, were detected in trace amounts.

     The levels of many of the pollutants observed in the Casmalia ponds are comparable to those typically observed in stormwater runoff from industrial and other urban areas that commonly flows to rivers, streams, and oceans. It's not uncommon for some stormwater to contain these contaminants, and others, at levels in excess of the Casmalia pond water, depending on the surface it flows over and local land uses.
 
     With the possible exception of nickel, U.S. EPA does not believe that any water quality standard established for toxic pollutants will be violated by the discharge. However, other water quality standards, such as total dissolved solids and sulfates, may be exceeded. Water quality standards are established to protect the designated beneficial uses of a waterway, such as the maintenance of habitat for fish and other wildlife.

     U.S. EPA believes discharging the pond water will not result in levels of toxic pollutants exceeding water quality standards in the creek because mixing of pond contents prior to and during the discharge should lower overall concentrations. Also, pollutants did not appear in every sample taken from the ponds, an indication that levels of pollutants in the ponds are low overall.

     The pond water slightly exceeded some drinking water standards, but because the creek is not a source of drinking water, water quality standards provide a more appropriate comparison.

     The trace metals found in the tests were barium, thallium, chromium, nickel and zinc. Barium and zinc were detected in two ponds but at levels below water quality standards. Nickel was detected in two ponds at levels close to or slightly higher than water quality standards.

     In the March test, thallium was detected in only one sample in one pond at levels exceeding water quality standards. However, the creek level of thallium was even higher. Also in March, chromium was detected in three samples in one pond, and these exceeded water quality standards. Thallium and chromium were not detected at all in the October test. The creek level for chromium was also comparable to the levels in the ponds.

     Eight toxic organic compounds were detected in the ponds. All but one were below water quality standards. Trichloroethylene (TCE), a solvent, exceeded the standards in only one sample in one pond in the March test. It was detected again in one pond sample in October, and it was below water quality standards. Other water quality standards that were exceeded included pH (March only), nitrate, fluoride, chloride, dissolved solids, turbidity, and sulfate.

     U.S. EPA also performed a test in September 1995, which measured the survival rate of stickleback fish after a controlled immersion in pond water. All of the fish survived, which shows that the pond water is not acutely toxic to aquatic life.   Additional chemical sampling is ongoing.  

     The U.S. EPA is working with the U.S. Fish and Wildlife Service and Vandenberg Air Force Base to minimize impacts to sensitive habitats downstream by slowly releasing the water and monitoring the discharge. An extensive Storm Water Pollution Prevention Plan that specifies how the discharge will be conducted has been developed with input from the Regional Water Quality Control Board, U.S. Fish and Wildlife Service.

     Written comments on the action memorandum must be made by
noon on Thursday, October 19, and should be mailed or faxed to:

                Wendy Shafir (H-3)
                U.S. Environmental Protection Agency
                75 Hawthorne St.
                San Francisco, Calif. 94108
                Fax: (415) 744-1044

     A table summarizing the data will be available at the meeting. It is also available upon request.



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