MARTINEZ -- County supervisors are allowing the Contra Costa County Fire Protection District to continue exploring a joint fire station in Lafayette with the Moraga-Orinda Fire District, despite growing concerns from some residents about equity, response times and the suitability of the proposed site.

The Board of Supervisors voted 4-1 on Tuesday to allow ConFire Chief Daryl Louder to continue "serious" negotiations with Moraga-Orinda Chief Randy Bradley to jointly build, operate and staff a new fire station on the Orinda-Lafayette border. Supervisor Karen Mitchoff opposed the talks, and John Gioia -- who had previously expressed reservations about the discussion -- asked for more financial analysis.

The approval came a day after a majority of Moraga-Orinda directors voted to proceed with informal negotiations despite an outcry from residents living near the project site.

Neighbors cautioned officials that the area of Lorinda Lane and El Nido Ranch Road is prone to flooding and slides.

"If you go into this process now having not thought about those things, it could end up costing you much more," warned Sharon Dixon McLaughlin. Officials said there will be a full environmental review.

The fire districts estimate it will cost between $5 million and $6 million to buy the land, complete site and utility work and construct the new fire station. They also estimate it will cost about $2 million annually to staff the station and about $186,000 to operate it each year.

Other residents voiced concerns about costs and a lack of public engagement.

"You want to move to cover some losses that some other entity has (that's) caused them to close a fire station," said Orinda resident Jerry Dimsdale. "You say we're going to save $1 million a year (but) you haven't asked me if I'm willing to foot any of that bill."

A handful of the more than 40 attendees voiced support for continued talks.

The negotiations have been under way since January, when ConFire approached the district about operating a joint facility following the closure of a station in west Lafayette due to budget cuts.

Moraga-Orinda would close its station on Via Las Cruces as part of the consolidation -- a move some Orinda residents oppose.

The district's board president, Frank Sperling, on Monday once again voted against the joint proposal, arguing that Moraga-Orinda was bailing out ConFire. Director Steve Anderson, who supported the measure, argued the $1 million annual savings was an opportunity to ensure Moraga-Orinda's long-term sustainability.

The approvals will allow the district to continue negotiating the purchase of a Lafayette property where the new station would be built. MOFD bid on the property earlier this month and has until March 28 to submit a $15,000 nonrefundable deposit, which it says it will split with the county. The chiefs are planning to bring a final contract back to their boards for approval in May.

The Lafayette Planning Commission will hold a special study session Monday to discuss the station. The Board of Supervisors will discuss the station merger again March 19 and the Moraga-Orinda district will hold a public workshop on the consolidation March 20 in Orinda.