More benzene found in Santa Rosa water tests after Sonoma County fires

Benzene, the cancer-causing chemical that city officials believe was sucked into its water system in a heavily burned area of Fountaingrove, is continuing to be discovered outside the advisory area, including one place in Coffey Park, city officials acknowledged for the first time this week.

But officials insist the new findings are not an indication the problems in Fountaingrove are migrating to other parts of the city.

However, they have now found 20 locations outside the Fountaingrove advisory zone with elevated levels of benzene. Fourteen of the locations were identified in the last month after the city aggressively expanded its testing program.

All but one - a burned lot on Waring Court in Coffey Park - were located near the advisory zone in Fountaingrove.

City officials said the new problems have been easy to resolve, confirming their conclusion that the 184-acre advisory area in Fountaingrove has a unique and pervasive problem far different than any other area of the city.

“We have a difficult isolated issue of contamination (in Fountaingrove) and some very sporadic outliers that are dealt with in a very easy way that are not suggestive of any widespread nature,” Ben Horenstein, the director of Santa Rosa Water, said Thursday.

The relatively low number of positive samples the city has found since expanding the sampling effort last month, the locations in the water system where they’ve been identified, and the success water engineers have had in making problems disappear following simple repairs give them confidence that the significant contamination issue remains isolated to Fountaingrove .

City officials plan to present detailed information to the Board of Public Utilities and City Council at 2 p.m. Tuesday.

The samples from outside the zone that showed benzene at levels above the maximum containment level (or MLC) for benzene in drinking water, or 1 part per billion, have all been found in the service lines, not the water mains.

Service lines run from the water main in the street to the water meter on the property, and are easily replaced. With one exception that never returned, tests of the mains outside the zone have all come back clean, said Jennifer Burke, the city’s deputy director of water and engineering resources

The reason benzene and other contaminants outside the zone have never infiltrated the water mains is probably because the water pressure remained strong enough to keep the contaminants isolated near the burned properties, Horenstein said.

Unlike Fountaingrove, which experienced sharp drops in water pressure during and following the Tubbs fire, “Coffey Park is tied to the aqueduct, so you’re never going to run out of water,” he said.

Jeff Okrepkie, chairman of the Coffey Strong neighborhood group, said the city told his organization about benzene showing up in a water test in Coffey Park.

But officials assured neighbors that the chemical disappeared after the water lines were cleaned.

“They told us they flushed it and it goes away,” he said.

You can reach Staff Writer Kevin McCallum at 707-521-5207 or kevin.mccallum@pressdemocrat.com. ?On Twitter ?@SRCityBeat.