San Mateo supervisors approve framework to negotiate Mahler site lease with Horizon for 69‑bed recovery center

San Mateo County supervisors voted 4‑1 on July 7 to direct county staff to negotiate a ground lease with Horizon Services for the county‑owned property on Mahler Road in Burlingame and to include an option for Horizon to purchase the parcel for use as a 69‑bed behavioral health recovery center.

The motion, made by Supervisor Ray Mueller and approved after public comment, authorizes staff to negotiate transaction documents and asked county counsel to prepare indemnification language for the city of Burlingame should litigation arise. President Noelia Corso cast the sole dissenting vote.

County Executive Caligi told the board the county purchased the 26 Mahler property in April for $13,000,000 and that staff sought flexibility to negotiate a 30‑year lease with an option to purchase, plus a deed restriction limiting the property to substance‑use treatment. "What I'm looking for from the board today is to grant staff the ability and some flexibility to enter into a long term lease with Horizon, with an option to purchase," Caligi said.

Jamie Campos, Horizon's chief executive, described the project as a state‑funded, integrated 69‑bed facility that would include a sobering center, detox and residential care. Campos said the state has indicated it will consider a site transfer but that moving the project to Burlingame could add "about four to six months" to the construction timeline. He also warned the state may not accept prior costs from the originally awarded El Camino site, which could require Horizon to contribute roughly $500,000 more to satisfy match requirements.

"If this is the case, we would ask that the county consider increasing the opioid settlement matching funds to $2,500,000 from $2,000,000 in order to offset these additional cost risks," Campos told the board.

Horizon chief program officer Daria Mesores framed the proposal as county‑wide behavioral health infrastructure rather than a city‑specific project, and cited outcome research in support of residential care. "There is national data … and data released by Stanford Health that claims significant improvement in client outcomes when individuals are receiving treatment in residential communities," Daria said.

Board members and the public pressed Horizon and county staff about community outreach, transportation and safety. John Ebner, a public commenter, said he was concerned about siting a critical health facility in an area exposed to sea‑level rise and urged that evacuation planning and shoreline protection be confirmed. Carol Eldridge asked whether the county had threatened to withhold a previously committed $2,000,000 in opioid settlement funds or referrals if Horizon had been sited in San Mateo; County Executive Caligi said he had not heard of any proposal to withhold the commitment and said contracting decisions are ultimately for the board.

Supervisors and Horizon officials said the proposed agreement would include an MOU with a transportation plan and discharge arrangements for clients. Caligi and Campos described sobering centers as voluntary, unlocked facilities in which informed‑consent protocols are used and law enforcement is engaged in rare cases if a client leaves prematurely.

Supporters of the Mahler option argued it preserves the grant and avoids litigation tied to the originally proposed site. Opponents and some public commenters reiterated a preference for the San Mateo/El Camino site for transit access and raised concerns about safety and community notice.

The board's action gives staff direction to negotiate transaction documents and return to the board for approval of the final agreement; it does not finalize a sale or binding contract and remains subject to Department of Health Care Services review of the proposed site transfer and to any future board approval of negotiated documents. The meeting adjourned to closed session at 10:48 a.m. with no report anticipated following closed session.