Treatment center slated for Burlingame site: Controversial plan skirted concerns from San Mateo residents, will be located at new county-owned land

The county has long needed a local substance use continuum of care facility — due to the closure of a 14-bed sobering center in May 2025. 

Horizon Treatment Services was awarded a $25 million state grant in October 2025 to establish one in the county, and the grant was initially tied to a site identified at 101 N. El Camino Real in San Mateo. However, nearby residents made it clear they didn’t want the facility near them. 

The proposed 69-bed behavioral health treatment facility, operated by Horizon Treatment Services, was proposed to bring sobering, detox and residential care “together under one roof,” Horizon CEO Jaime Campos said in a statement Wednesday. 

“Integration of these services is a condition of the State grant that funds the project, because a connected continuum of care produces better outcomes for the people we serve,” Campos said. 

While the plan to establish this continuum of care has experienced a major bump in the road, the county quickly reconsidered the site option to ensure services could be provided to residents as soon as possible. 

The purchase of the Burlingame site was only made after the uproar by San Mateo residents who claimed the treatment center clients would trespass on school property to prey on their children, attract crime and drug dealers to their neighborhood, increase congestion and lower their property values. Horizon staff has attempted to debunk what they called misconceptions. 

The Board of Supervisors already allocated a $2 million local match for Horizon’s state application, which was ultimately awarded. The property purchase for $13 million was made with the hope that Horizon could move its proposed facility, avoid the resident conflict and potentially house other county programs as well, including the Pride Center which has been without a physical location since August 2025. 

Supervisor Noelia Corzo described the site change, and property purchase, as “unnecessary” but ultimately felt any effort to bring the treatment center’s services to the county is a win. 

“The biggest priority for me has always been that we bring the services that our county residents need to our county,” Corzo said. “I’m grateful to Horizon, I’m thankful to them for it. I would have been proud to have the treatment center located in my district, but that’s not possible anymore.” 

“Misinformation and fearmongering” were persistent throughout this process, which ultimately cost the county money, Corzo said. 

“It’s an investment I don’t think was necessary and the use of county dollars I don’t think was necessary, but if that’s what it takes to bring this center to our county, it’s still a win for our residents.” 

Changing the location was a matter of listening to hundreds of residents who were in opposition to the San Mateo site that bordered Hillsborough as well, Supervisor David Canepa said previously.

“I think it’s a win for those in the San Mateo, Hillsborough community, and a win for the county,” Canepa said. 

The matter will be considered and voted upon at the board’s meeting at 9 a.m. Thursday, July 2.