Residents of the Woodacre Flats are crossing their fingers and plugging their noses as Marin County and Questa Engineering mull options and gather input on how to put an end to leaky septic systems and pumping costs that have afflicted the neighborhood for decades. 

A feasibility study evaluating community wastewater solutions was originally set to be published last June after the San Geronimo Flats were nixed from the project. But last month, Questa was…