Olin Corp. has an extra week to present its plan to determine if
perchlorate found in wells north of its Tennant Avenue site is
related to the chemical
’s release from Olin’s former road flare plant. The Central
Coast Regional Water Quality Control Board extended the Oct. 3
deadline to Friday.
Olin Corp. has an extra week to present its plan to determine if perchlorate found in wells north of its Tennant Avenue site is related to the chemical’s release from Olin’s former road flare plant. The Central Coast Regional Water Quality Control Board extended the Oct. 3 deadline to Friday.
The Regional Board is the state agency in charge of the Olin-caused contamination of more than 400 wells from Morgan Hill, through San Martin to north Gilroy, discovered in January to have spread widely throughout the area.
Olin is to identify all wells within one-fourth mile of either side of a line between the Tennant Avenue site and the city’s Nordstrom well at East Dunne and Murphy avenues. Further, Olin is to provide data from those wells within the line that have been tested for perchlorate and propose a monitoring and sampling program that will define the extent of the perchlorate plume in the northern area.
The original boundaries, in a Sept. 19 letter from the board to Olin, missed one important site – the Condit well, said Jim Ashcraft, city public works director. Aside from that, he said he was just about satisfied with the Regional Board’s action.
“I think we were all pleased,” Ashcraft said. “The order was almost sufficient. It just missed the Condit well by 200 feet.”
The Regional Board’s revised letter, signed by Roger W. Briggs, the board’s executive officer, was amended to include the Condit well. The letter provided evidence that the Olin site may be responsible for the northeastern contamination:
“Olin’s property on Tennant Avenue is the only site in the area that we are aware of with confirmed releases of perchlorate to the environment,” the Briggs letter said.
“Although groundwater appears to flow naturally in a southeast direction, there are conditions that could cause perchlorate-degraded water to migrate from Olin’s property to the north east. Pumping-induced gradient changes is one such condition.
“Water-level data, both current and historic, show that the gradient is relatively shallow in this area and could be influenced by the right set of pumping conditions. Successive pumping, irrigation and infiltration could also have caused migration of degraded water over many years.”
In a second letter, also dated Sept. 30, the Regional Board extended two other deadlines: the due date for the soil cleanup feasibility study for the Tennant Avenue site was moved from Oct. 31 to Nov. 21 and adding language to the Dec. 31 requirement to excuse delays due to circumstances beyond the control of Olin and Standard Fusee.
Standard Fusee Corp. is involved because it also produced safety flares and other products for which perchlorate is a byproduct, on the Olin site at times during the 40 years the manufacturing plant was in operation, from 1955 to 1996.
The complete letters can be read on-line at http://www.swrcb.ca.gov/rwqcb3/Facilities/Olin%20Perchlorate/index.html
