The Santa Clara Valley Water District board has changed its mind
about installing a portable Calgon Corp. pump and treat plant on
Morgan Hill
’s Tennant Avenue well, taken offline in 2002 because of
perchlorate contamination.
The Santa Clara Valley Water District board has changed its mind about installing a portable Calgon Corp. pump and treat plant on Morgan Hill’s Tennant Avenue well, taken offline in 2002 because of perchlorate contamination.
Instead it will likely install equipment from another company.
“We are currently negotiating with U.S. Filter,” said Marc Lucca, senior project manager for the SCVWD’s imported water unit. Lucca said the U.S. Filter plant uses the same ion exchange process as Calgon but there was at least one difference.
“Calgon was not the least costly,” he said.
Calgon originally got the nod because, with the summer season approaching and four of Morgan Hill’s city wells offline because they tested positive for low levels of the chemical, a treatment plant had to be up and running by July 1 to meet summertime water needs. Calgon said it could do this, Lucca said.
Lucca said the water board gave conditional approval to the Calgon unit, and was waiting for an order to Olin Corp. from the Regional Water Quality Control Board – the RWQCB is the lead agency in the South Valley perchlorate problem.
“When the water board approved the $1.05 million, it included in the motion a request that the Regional board essentially order Olin Corp. to be ultimately responsible for the costs,” said Mike DiMarco, SCVWD spokesman.
On May 13 Olin was ordered by the regional board to work cooperatively with the water district and the City of Morgan Hill to coordinate purchase, installation, operation and maintenance of a well-head treatment system.
Olin may propose an alternative that will otherwise allow the city to use the Tennant Avenue well or provide an alternative water supply. Failure to comply with the request may subject Olin to civil liability.
“Shortly after the original press release (in April, that the Calgon system had been chosen), we had several other manufacturers contact us, claiming they could meet requirements of the Morgan Hill site. So we took that time (waiting for the order) to put out a “Request for Proposal,” Lucca said.
The U.S. Filter system is certified for drinking water quality by the Department of Health Services, as was the Calgon system. It’s a requirement. U.S. Filter’s portable system could also make the July 1 deadline, Lucca said.
DiMarco said there was another reason U.S. Filter plant may be the one.
“It fits better into that space at the Tennant well,” he said.
“Calgon is still a very viable alternative,” Lucca said, “but there are others. With Tennant, the issue was the timing.”
Lucca said it normally takes six months to a year to bring such a treatment plant online.
Instead of buying the $300,000 – $400,000 treatment plant outright, Lucca said, the water district may lease it.
“Or, Morgan Hill could lease it themselves,” he said.
Because the water district board has reserved $1.05 million for the treatment plant, City Manager Ed Tewes said the city has asked for two plants, one for the Tennant well and one for Nordstrom, which was closed in February and, at 1,000 gallons per minute, is a high-producing well.
That request is on the water board’s agenda for Tuesday, June 3.
Besides providing sufficient water for the summer season, the treatment plant may have another benefit.
“Pumping at the Tennant Avenue site will decrease the spread of the plume south and draw the contamination back toward the site,” DiMarco said. “This may, in fact, help the San Martin residents as well.”
DiMarco said the portable treatment plant equipment could be moved to a contaminated San Martin municipal water plant when it was not needed for the Morgan Hill water supply.
INSIDE ION EXCHANGE
The ion exchange method draws water into cells containing adsorbent material. Ion exchange resins are common but silica gels, activated carbon and molecular sieves are also used, according to the Calgon Carbon Corp. The perchlorate ions attach themselves to resin units and add chloride molecules; the altered chemical configuration renders the perchlorate harmless.
However, in the past, along with treated water, the process produced a brine solution which must be disposed of. This was dumped, in the ocean or elsewhere or burned. Dumping will become illegal in California by 2006. Ion exchange is frequently used to treat water in Southern California which has a serious perchlorate problem because of the numerous defense facilities.
MH WELL REPORT
Tewes announced at Wednesday’s City Council meeting that no Morgan Hill city well showed a detectable level of perchlorate during their recent monthly testing.
Of the 13 wells, one Dunne Avenue well and the Condit and Nordstrom wells were taken off line earlier in the year because they showed levels above the state designated “action level” of 4 parts per billion. Any level below 4 ppb is considered “nondetect.” Above 40 ppb the water cannot be delivered to users. Nondetect can include levels from 0.0 to 3.9 ppb.
“We are doing advance planning about potentially putting back on line some wells that may have had trace amounts of perchlorate,” Tewes said. At the moment, however, no well is ready to be reopened, except the Tennant well in time for the water district treatment plant.
Perchlorate leached into the underground aquifer from a former Olin Corp. site at Tennant and Railroad avenues where highway safety flares were manufactured for 40 years. The chemical has contaminated hundreds of private and public wells in Morgan Hill, San Martin and a few in north Gilroy.
Rick McClure of Olin Corp. has said the company wants to assume its responsibility to the community. It has paid for some well testing.
The city recently returned a $450,000 check from Olin, covering the cost of drilling a replacement well for the Tennant well. The city had submitted documentation that its related costs were $710,000. City Attorney Helene Leichter said it is not wise to accept payment for a partial amount since the courts might consider that sufficient payment.
“We appreciate their good faith effort,” she said, “but we feel that, to accept the check at this time would send the wrong signal. We expect them to remain accountable for what they have acknowledged as their responsibility.”
The water district is providing bottled water to residents within the original contamination boundaries of Monterey Road, Tennant, Foothill and Leavesley avenues. DiMarco said the district expects to be repaid by Olin for its expenses.
Perchlorate interferes with the uptake of iodide to the thyroid and, in sensitive systems, can cause problems. Infants and pregnant women are especially susceptible because of the developing brains of fetuses and newborns.
Results of the Morgan Hill municipal wells will be posted on the city’s website at www.morgan-hill.ca.gov and on the cable Channel 17 bulletin board.
Perchlorate information: • Santa Clara Valley Water District: www.valleywater.org • Regional Water Quality Control Board: www.swrcb.ca.gov/rwqcb3/ • San Martin Neighborhood Alliance: www.smneighbor.org• Rancho Cordova perchlorate project: www.perchlorate.org • Environmental Working Group: www.ewg.org • City of Morgan Hill: www.morgan-hill.ca.gov
