The Sonoma County Board of Supervisors on Tuesday adopted new benchmarks to measure and guide county firefighting coverage in unincorporated areas.

The policy adopts national response time standards that six of the county's 15 volunteer fire departments are currently not meeting.

Supervisors voiced an interest in resolving those service gaps, but the board postponed action on recommendations by fire officials, including a boost in manpower and money for the volunteer departments.

"We recognize there is absolutely a challenge when it comes to funding," said Supervisor Efren Carrillo, who vowed a "healthy and robust discussion" about the budget for county fire services in the future.

Six of the 15 volunteer departments are centered in Carrillo's west county district, with five in Supervisor David Rabbitt's south county district and two each in Mike McGuire's and Valerie Brown's districts.

The network is responsible for covering 680 square miles of the unincorporated area and is overseen by a central county fire division, which was formed in 1994 and is separate from city and independent fire districts in the county.

Measures since 2009 have backed increased centralization of the service through the county command, but the Board of Supervisors has at the same time wrestled with how to fund a broader county fire service. Another competing vision would break apart the division and consolidate volunteer departments with other fire agencies. Board members Tuesday only touched on that debate in their deliberation about funding.

"All options lead to a discussion about dollars, and of course that's the issue we are going to be tested with in the months to come," said McGuire.

In the formal action, the board focused on adopting the new performance benchmarks for county fire service. They call for a response time of 15 minutes or less on 80 percent of incidents. Nine departments have met that national standard for rural agencies over the past four years and six are falling short, a report from the county's Fire and Emergency Services Department found.

Longer travel times in remote terrain are main factors, fire officials said. A shortage of able hands in rural communities is another, they said.

To boost volunteer numbers and training and address other operational needs, Sonoma County Fire Chief Mark Aston recommended supervisors consider additional funding for the division. Its annual $3.9 million operations budget is drawn from the county's general property tax levy but gets no help from the general fund, the main pot of discretionary dollars supporting mostly public safety programs.

Prompted by Supervisor Shirlee Zane, Aston on Tuesday made his funding request public: An additional $1.2 million a year, to cover the cost of fuel, station utilities, vehicle maintenance and replacement. A separate infusion would be needed for capital improvements, including replacement of stations in San Antonio and Two Rock, Aston said.

An advocate for increased centralization, Aston said the county was on "a precipice where we have to decide where to go" with the fire division.

The funding recommendation ran into an immediate challenge from Zane, who has no county fire service stationed in her district and who repeatedly voiced concerns about committing to a larger county fire department. She pressed for more study of "cost efficiencies" and consolidation with existing fire protection districts.

But such partnerships are difficult to achieve and have been voted down in the past, Carrillo told Zane. "If I could have just used my gavel to consolidate, that would have been done a long time ago," he said.

The board members present ultimately agreed to accept the report from Aston's office but directed him to return with a fuller set of options on the money and manpower recommendations.

Supervisor Valerie Brown was on vacation and Supervisor David Rabbitt left the meeting early because he wasn't feeling well.

(You can reach Staff Writer Brett Wilkison at 521-5295 or brett.wilkison@pressdemocrat.com.)