County adopts noise ordinance setting overnight decibel limits, sheriff cautions on enforcement costs

The Mendocino County Board of Supervisors voted unanimously on March 24 to introduce and advance a new countywide noise ordinance that sets overnight decibel thresholds and creates an infraction-based enforcement path intended for sheriff's deputies.

Deputy County Counsel Brina Blanton summarized the ordinance as prohibiting disturbances "which exceed 60 dBA constant or 75 dBA intermittent as measured from an adjacent residential property line using a sound decibel meter, if occurring between the hours of 10 p.m. and 7 a.m." The proposal creates an infraction for violations and allows civil enforcement steps for repeat offenders under county nuisance procedures.

Sheriff's office representatives told the board the measure would give deputies enforcement tools lacking under existing penal-code practice, but they cautioned that durable, legally defensible decibel meters must be purchased and maintained and that responding to new calls will affect staffing and potentially add overtime. "We're definitely going to have to invest some money...we're talking about a decibel meter that is going to have to be calibrated and is going to have to be able to withstand any type of legal challenge," a sheriff's representative said.

The ordinance contains exemptions for school activities, public-entity operations, activities protected by the county's right-to-farm and industry ordinances, declared emergencies, and activities preempted by state or federal law. County counsel and planning staff said the measure was drafted in consultation with sheriff's staff to fit into existing enforcement practices.

Board members asked for future clarifications on the definition of "constant" versus "intermittent" sounds and for staff to coordinate equipment needs with the sheriff. The board adopted the ordinance language for initial reading and directed staff to finalize implementation details.