Following nearly a year of study during a temporary moratorium on commercial non-medical marijuana activity, San Mateo County is doing public outreach on a proposed Commercial Cannabis Cultivation Ordinance for the unincorporated area of the County.  
Upcoming meetings:

Nov 9, 7pm, Ted Adcock Community Center
           535 Kelly Ave, HMB
Nov 13, 7pm, Agricultural Advisory Committee (staff report)
           Old Train Depot, Higgins Canyon Rd, HMB
Nov 14, 7pm, Pescadero Municipal Advisory Council
           Pescadero Community Church, 363 Stage Rd, Pescadero

The draft ordinance provides for commercial cultivation within greenhouses with a Business License with extensive operational requirements, oversight and enforcement.

The City of Half Moon Bay is working on their own cannabis cultivation ordinance. The boundary between unincorporated Midcoast communities and HMB is at Mirada and Alto Roads.  

Environmental review & draft ordinance
Oct 2017 presentation at MCC / news article
July 2017 presentation at MCC / BoS study session / news article
Dec 2016 BoS study session / urgency moratorium / news article