Rotten eggs? Sewage spill causes foul-smelling water, but no harm
By Kymberli W. Brady
Staff Writer

Last week, residents of Almaden may have noticed a foul smell and possibly even an unpleasant taste in their water. But according to Mike Demarco with the Santa Clara Valley Water District, it was nothing to be alarmed about.

"Wednesday night about 8:30, we got a report of a sewage spill at Holiday Lake Estates near the Anderson Reservoir," he said. "Because it was dark and in a semi-rural area, we couldn't determine whether any had ended up in the reservoir. Until we could get out there at daybreak, we decided to discontinue taking water out of it and instead pull from the Calero Reservoir in south San Jose."

Demarco explained that the situation is not unusual for this time of year. Calero is much smaller than Anderson and with a combination of hot weather and typically low levels at Calero, bacterial decomposition of algae and organisms at the bottom of the reservoir robs the water of oxygen, giving it a rotten egg smell. The district's treatment process re-oxygenates the water and removes the odor.

Upon examination at first light the following morning, it was determined that the sewage spill had stopped 50 to100 feet from the reservoir and the water district then switched back to Anderson without any further incident. "We knew that we really had no choice and had to keep serving customers," Demarco added. "So we notified people the quickest way we could through radio and television. We can treat it, but some of the smell and taste can remain in the water. It's no harm, just an inconvenience."

The Santa Clara Valley Water District manages Santa Clara County's wholesale drinking water resources, coordinates flood protection for its 1.7 million residents and provides stewardship for the county's 10 reservoirs and more than 700 miles of streams. For more information on water and treatment, visit www.valleywater.org.