The county is investigating a property near Nicasio School as a potential site for 16 units of farmworker housing. Though it has determined that a septic system could be installed at the 2.2-acre site, it still needs to find out if there is an adequate water supply to support the project. The county-owned property is located across from the Department of Public Works corporation yard on Nicasio Valley Road, between the school and West Marin…