City: Fountaingrove water system needs $43 million replacement due to contamination after Sonoma County fires

The entire water-delivery system in a 184-acre section of the devastated Fountaingrove neighborhood will likely need replacement after becoming contaminated with benzene, and it appears the city will initially be on the hook for a project whose estimated costs have soared to $43 million.

The intensive investigation into the exact cause of the contamination continues, but officials say they now understand how the cancer-causing hydrocarbon found in gasoline and plastics made it into the water mains in the area.

The city’s team of water engineers, consultants and regulators is “converging on the recommended approach” that would require the “full replacement of the distribution system, from the water mains to the meters on the properties” and related equipment like fire hydrants within the advisory area, Ben Horenstein, director of Santa Rosa Water, said Thursday.

The cost of that solution, which Horenstein had previously estimated at up to ?$20 million, has now more than doubled, and completion may take significantly longer than the year he initially hoped.

The development raises a host of questions about how quickly the devastated ?Fountaingrove neighborhood, which lost 1,420 homes in the Tubbs fire, may be able to recover, how the city can fund the needed repairs, and what it means for residents who still live there.

Before the fire, there were 350 homes in the advisory area, centered on the north and south sides of Fountaingrove Parkway near Fir Ridge Drive. Restrictions on water use for the 13 homes that remain standing have been in place since November. While lots are being cleared, few former residents of the advisory area have applied for city permits to rebuild.

Contamination of the water system has become one of the most pressing and confounding challenges facing the city as it seeks to recover from the October wildfires, the most destructive in U.S. history, with 5,100 homes lost in Sonoma County alone. Melted plastic storm drains that caused sinkholes and confusion over the acceptable level of arsenic in soil before cleared lots could be rebuilt have also been curveballs, but nothing like the contamination problem.

City officials say it has become increasingly clear over recent weeks that the benzene and other hydrocarbons detected in the water system in the advisory area originated when plastic components of the system melted during the fires and were somehow sucked into the water mains though a severe drop in water pressure.

Normally, positive water pressure pushes contaminants outward, acting as a protective barrier against broader contamination of the system, Horenstein said.

In this case, however, the sharp drop in water pressure that the Fountaingrove area suffered during the fires - something firefighters complained about as they battled the blaze - likely created a vacuum effect on the system.

Water pressure in the hillside neighborhood is provided by a combination of pumps that send the water uphill and pressure from the millions of gallons capable of being stored in seven holding tanks in the area.

But at the time of the fire, one of those tanks was empty because it was down for seismic retrofitting, said Jennifer Burke, the city’s deputy director of water and engineering resources.

It’s not clear how much having that tank offline contributed to the low water pressure, but it likely had some impact, Horenstein said. It also wasn’t immediately clear how full the other tanks were at the time of the fire.

The combination of firefighters trying to save structures, residents turning on hoses in efforts to save their own homes, and water being released as homes were destroyed all created intense demands on the system, Burke said.

Complicating the issue is that the city lost the ability to monitor the pressure in the system. The equipment that monitors pressure and communicates data to decision makers went down in the fire, leaving water managers “blind” on the night of the fire, Horenstein said.

Officials believe the sharp drop in pressure created the conditions that allowed a combination of benzene, superheated air, ash and debris to enter the main water delivery pipes at some point during and after the fire. There, it sat for more than a month, adhering to and becoming absorbed by the plastic components in the system, and then leaching out over time, Horenstein said. Valves were closed to isolate the contamination to the advisory area.

“It’s difficult, if not likely impossible, to get rid of it in any reasonable time frame other than by replacement,” he said.

Water officials have been gradually coming to the conclusion that full replacement of the system in the advisory area might be necessary. Horenstein first raised that possibility with the City Council in December, when he first gave the $20 million estimate.

Since then, however, the increasing number of test results showing benzene persisting in the mains in the advisory area have made the replacement need clearer. The complexity of the project has sent the projected costs skyward.

The latest $43 million estimate is based on the deepening understanding of just how massive a project the replacement would be, especially if it were fast-tracked, Horenstein said.

The higher costs reflect the complexity of installing the new water lines in and around other utilities, and the need to phase the project to ensure no cross-contamination. The project would also need to take into account home rebuilding efforts while the line replacements are underway, and existing homeowners would need to have water service continued in some fashion, Horenstein said.

Doing all that in an expedited fashion - something the city would like to see given the time constraints on homeowners, whose insurance policies stop covering living expenses at two years - would likely require significant incentives for contractors, Horenstein said.

But the city’s plan to pay for such a project took a hit recently when it learned the Federal Emergency Management Agency was unlikely to provide advance funding for it, Horenstein told the Board of Public Utilities last week.

Such advance payments are typically for emergency response measures, not long-term infrastructure repair. The city received some contradictory information on this point, initially believing it was entitled to 40 percent of the project’s cost, or ?$17.2 million. The surprise has caused the city to scramble to figure out how to pay for the project in the short term. It currently plans to draw down reserves and hope for reimbursement on the backside. Water officials referred to the surprise as a “glitch,” something Board of Public Utilities Chairman Bill Arnone found an odd descriptor under the circumstances.

“Calling an unanticipated $17.2 million loss of early funding a ‘glitch’ is a colossal understatement,” Arnone said.

Veteran BPU member Dick Dowd said he felt city water staff were doing a “marvelous job” addressing the issue, and he noted that conservative fiscal policies of recent years have paid off.

“We have some reserves to absorb the shock of this fire disaster that our community experienced in October,” Dowd said. “But if the FEMA money does not come forth to us, there probably will be the need for some significant rate increases.”

To help the City Council and the public better understand the investigation status, repair plans and options, the city plans a rare joint meeting of the Board of Public Utilities and the City Council at ?2 p.m. Tuesday.

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