Flushes of the toilet in most West Marin homes usually send down mixtures of urine, excrement and water into a personal septic system. But in a few years time, up to 300 homes in the flats of Woodacre and San Geronimo might hook into a community system to handle the human effluent instead.
Such a system might pipe the wastewater to a leachfield northeast of the flats, but an alternative, which would shuttle the wastewater…