Acting on “an abundance of caution,” SCV Water officials shut down one of their wells last week, after routine testing detected the presence of perchlorate, a suspected carcinogen and long-standing concern in the Santa Clarita Valley.
Water distributed by the agency, meanwhile, remains safe to drink and in compliance with all state water quality standards.
On Tuesday night, Mike Alvord, the agency’s director of operations and maintenance, briefed members of the agency’s board about the perchlorate detection and the actions taken in response to it.
On May 8, SCV Water staffers took water samples from a well named Well Q2 as part of their regular perchlorate monitoring of specific wells, he told the board.
Six days later, they were notified that one of the samples revealed a positive detection of perchlorate in well Q2.
Within 24 hours, staffers took a “confirmation sample” from the same well and had the sample tested by Eurofins, an independent lab.
On May 15, they were notified about the results of the follow-up “confirmation sample,” which revealed an “average result” level of 0.006 milligrams of perchlorate per liter of water, or 6 micrograms per liter.
The tiny amount detected reached the maximum level allowed by the state.
“We contacted our regulators, even though we are not out of compliance, and out of an abundance of caution as soon as we received notification we shut the well off,” Alvord said. “And, it will continue to be off and we’re going to sample it monthly.”
The contaminated well sits near the Saugus Perchlorate Treatment Facility in the Santa Clara River wash behind the Lowe’s Home Improvement store on Bouquet Canyon Road, tucked inside the elbow of the Bouquet Creek bike trail that bends around the back of the hardware store.
The Q2 well has a history of perchlorate contamination.
In the winter of 2004-05, about 52 inches of rain fell on the SCV. Alvord called it “an abundant amount of rainfall.”
In April 2005, perchlorate was detected in the well’s water at a level over the maximum amount allowed by the state for that chemical.
Following the same protocol as they did last week, staffers collected a “confirmation sample,” which, in April 2005, came back over the state-allowed limit.
“We ended up putting treatment on that well within six months,” Alvord said, sharing some of the well’s history with members of the agency’s board.
Staffers who sampled the well’s water in August 2005 found results at a level so small that it did not require the agency to report it. That state-defined level is referred to as a DLR, or detection limit for purposes of reporting.
But since treatment was up and running, agency staffers continued to operate the Q2 well under treatment, stepping up sampling of its water once every week.
Over the course of two years, all the Q2 samples contained trace amounts of perchlorate below the DLR.
With state approval, weekly sampling of the well became monthly sampling and after two years of that, became quarterly sampling of the well.
“So, since those positive detections in April 2005, we’ve had 129 consecutive (results revealing the presence of perchlorate at) less than the DLR — until last week,” Alvord said
After learning of the perchlorate detection in the Q2 well, agency board member Lynne Plambeck said: “I’ve always been concerned about the well when it rains.”
The SCV saw an abundance of rain this past winter, agency directors noted Tuesday.
“I would like to suggest, again, that when we get a lot of rain like this that we don’t wait for the quarter to test and that we begin testing monthly right away,” Plambeck said.
For more than 40 years, perchlorate was used as a solid fuel component in the manufacture of munitions, fireworks, flares and other explosives at the Whittaker-Bermite site located south of Soledad Canyon Parkway, and east of San Fernando Road.
As a result of all those operations, a known perchlorate contaminant plume was identified in the SCV and several wells have tested positive for perchlorate. Improperly disposed-of waste leaked into the groundwater and contaminated the wells.
In addition to groundwater remediation efforts, there has been an ongoing cleanup effort underway on the Whittaker-Bermite property under the jurisdiction of the state’s Division of Toxic Substances Control.
Once used as a medication to treat overactive thyroid glands, perchlorate can impair the function of normal and underactive thyroids.
It has also been linked to problems with fetal development in pregnant woman.
In October 2007, state officials set a maximum contaminant threshold level for perchlorate at no more than 6 micrograms of perchlorate for every liter of water.
With regards to cleaning perchlorate-contaminated groundwater, the recently completed Saugus Aquifer Treatment Plant near the Metrolink station on Soledad Canyon Road began pumping and treating water a year ago, extracting water from 14 wells at a rate of 500 gallons a minute beginning next month.
The cleaned water, according to the plan, is discharged into the Santa Clara River watershed to recharge SCV’s groundwater.
Over the last seven years, agency staffers have regularly monitored two perchlorate-plagued wells once owned by Valencia Water Co. Early last year, they found perchlorate levels exceeding the threshold of 6 micrograms of the chemical per liter.
In April 2012, a well identified as Well V-205 was voluntarily shut down after low concentrations of perchlorate were found. It’s been out of service ever since. A well near it, named V-201, was also shut down.
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