Drilling technician ‘sick’ about rupturing Forestville-area water line

A drilling technician who found himself on the wrong side of a vineyard fence was reportedly responsible for a waterline rupture that resulted in the loss Monday of an estimated 610,000 gallons of water, Sonoma County planning director Tennis Wick said Tuesday

Les Petersen Drilling & Wells, “a reputable firm,” went through “the right process” to drill a well for a new vineyard off Vine Hill Road, Wick said.

But the technician moved his rig to a different location thinking it might prove more favorable, his boss said.

The technician was just breaking into the surface to have the drill ready to go while waiting for Petersen Drilling owner Matt Petersen to call back and approve the change but struck the pipeline so quickly it was already too late, Petersen said.

“He’s beside himself,” Petersen said of the longtime employee. “I feel just sick, and he feels sick. We’ve been at this a long time. The last thing we want to do right now, in this period of time with the shortage of water, is spill water.”

The technician was about 20 feet away from the approved location and was unaware of the 48-inch Cotati Aqueduct, which runs though the Vine Hill Ranch south of River Road along a strip of water agency-owned land, Petersen said.

The top of the pipeline is only about four feet below ground, and the drill quickly tore a gash in it, releasing water onto a pasture, the Sonoma County Water Agency said.

The water agency had to drain additional water from the pipe before it could make any repairs, using trenches to direct it into a dry tributary of Green Valley Creek, water agency spokesman Brad Sherwood said.

Dechlorination tablets were used to ensure the water would not harm wildlife once it reached Green Valley Creek, and monitoring was ongoing to ensure there were no environmental impacts, Sherwood said.

The aqueduct - a steel and concrete pipe carrying water from the Russian River to Forestville, Cotati, Rohnert Park, Petaluma and northern Marin County - was patched early Tuesday morning, with a permanent repair being postponed until more planning can be done, Sherwood said.

The water loss was equal to about 1.4 percent of the county’s average daily consumption of about 43.5 million gallons, water agency personnel said.

But with water at such a premium after three years of drought, it was a painful waste, agency personnel said.

Initial questions about whether Petersen had fulfilled its obligation to alert the water agency that it was drilling near underground infrastructure appeared to be answered by the discovery that it had intended to drill elsewhere, Wick said.

But he said the company was going to refile its permit applications at a slightly more distant location to ensure there could be no interference with water

You can reach Staff Writer Mary Callahan at 521-5249 or mary.callahan@pressdemocrat.com.