Olin Corp. has presented its 22nd report to the state water
board that oversees its attempt to clean perchlorate from South
Valley soil and groundwater.
Olin Corp. has presented its 22nd report to the state water board that oversees its attempt to clean perchlorate from South Valley soil and groundwater.
While the chemical remains at varying levels in many private and city wells and in soil on Olin’s site at 425 Tennant Ave., the report summed up what the company did in May to get a handle on the situation.
Results and analysis will be released in the quarterly report that Olin will file with the Central Coast Regional Water Quality Control Board based in San Luis Obispo on July 30.
Basically Olin’s consultants sampled 20 on-site and offsite wells plus 26 nested BarCad wells at eight locations on the site of the former safety flare manufacturing plant where the soil is contaminated.
A BarCad well is several wells in one. A single hole is drilled and several pipes are introduced with testing areas available at different levels. On the Olin site, according to Tom Mohr, an engineering geologist with the Santa Clara Valley Water District, the first one was at a depth of 400 feet with several others testing between 200 and 400 feet.
“With this arrangement they can find what the pressure and perchlorate levels are,” Mohr said. “They can tell if the perchlorate tends to move up or down.”
Perchlorate was used as an oxidizer to make the flares burn more efficiently, the same reason the chemical is used in rocket fuel. Perchlorate from rocket fuel has appeared in Southern California wells and elsewhere around the state and nation.
Treatment systems in operation at several sites cleansed 4,564,159 gallons over the course of the month.
David Athey, water resource control engineer for the regional board said in an e-mail to concerned parties that the board was accepting Olin’s report but has not taken an official position on details it contained.
This and other reports about the South Valley contamination can be found on the regional board’s website and, in hard copy, at the Morgan Hill Library, 17575 Peak Ave. 779-3196.
CCRWQCB will meet Thursday and Friday, July 8-9, in Watsonville City Council Chambers, 250 Main Street, Watsonville. The public is welcome to attend.
Details: www.swrcb.ca.gov/rwqcb3/ More details on perchlorate: www.valleywater.org/
