South County residents have opportunity to speak out on the
perchlorate contamination
The Central Coast Regional Water Quality Control Board is meeting at 8:30 a.m., March 21, at the Salinas City Council Rotunda Chambers, 200 Lincoln Ave., to discuss, among other issues, the region’s ongoing perchlorate contamination saga.
The public will have the chance to, once again, address the board with their concerns related to Tenn.-based Olin Corp.’s handling of the perchlorate contamination issue.
In December, the CCRWQC board issued its latest cleanup order for Olin. The mandate was so controversial and seemed so inadequate, in the eyes of city leaders, that Mayor Steve Tate bluntly described it as a “slap in the face” to the city of Morgan Hill. He was frustrated that residents were continuing to pay a water surcharge to clean up the more than 4,000 pounds of perchlorate from the Llagas Subbasin – the underground aquifer from which the affected well water is pumped.
Perchlorate has been detected at levels higher than the public health goal in the underground water system south of the former site of the plant on Tennant Avenue traveling southeast of U.S. 101 all the way past Masten Avenue.
Perchlorate was first detected at the former Olin site in southern Morgan Hill in August 2000 during a screening of the land by a potential buyer. The findings were reported to the CCRWQC board staff in February 2001. The contamination may have occurred due to unlined evaporation ponds that received waste from cleaning ignition mixing bowls, on-site burning of cardboard flare coatings, and accidental spills.
According to San Martin resident Sylvia Hamilton, chair of the Perchlorate Community Advisory Group, the so-called contingency clean-up plan was that Olin, after immediately cleaning the hot spots most affected by perchlorate, would simply monitor the areas once they no longer showed high enough levels of perchlorate concentration.
The maximum containment level (MCL) for perchlorate in California is 6 micrograms per liter. There is currently no federal drinking water MCL for perchlorate.
Perchlorate has been known to interfere with the natural function of the thyroid gland by inhibiting its ability to take in iodine, which decreases the production of thyroid hormones. These hormones are needed for prenatal and postnatal growth and development, along with normal functioning of the metabolism.
The size of the plume, or the contamination that has worked its way into the underground water system, is more than 10 miles long, according to Hamilton.
Since the detection, Olin has done a number of things to cleanup the contamination. Beginning Feb. 23, 2004, Olin started on-site groundwater treatment, extracting water and filtering it, removing perchlorate with a specific ion-exchange process. The treated groundwater is then re-injected into the ground. The process has continued without interruption. Olin has also installed these ion-exchange systems on 15 other domestic supply wells that tested above the desired perchlorate concentration levels, starting with the ones exceeding 10 micrograms per liter and working their way down to ones with a level situated at 7.9 micrograms per liter.
The effectiveness of their contingency plan, including the monitored attenuation, remains to be determined. About 90 percent of the area contaminated falls under the category of monitored attenuation.
“It’s an opportunity (for the public) to address the (Central Coast Water) board, and for the board to ask any questions of (our) staff,” said Roger Briggs, executive director of the CCRWQC board.
Hamilton hopes that during the meeting issues concerning this contingency plan will be discussed such as how Olin will manage the monitoring, and how it will know if it is even working. The effectiveness of this approach is a main concern.
The Perchlorate Community Advisory Group meets monthly in San Martin and is a forum for discussion concerning the perchlorate problem and potential solutions. The next meeting will be at 2 p.m. Friday, April 4 at the San Martin Lions Club.
For additional information go to www.smneighbor.org to keep updated on the issue, or check the event calendar for any upcoming meetings.
