A high groundwater table across much of the Big Mesa in Bolinas presents a barrier for homeowners wishing to upgrade their septic systems—a necessary and an expensive step in creating an accessory dwelling unit. 

Now, the Bolinas Community Land Trust has permission from the county to launch a pilot program designed to help 22 homeowners make septic upgrades, enabling the creation of accessory dwelling units deed-restricted for affordable housing. 

“This is a very exciting project,”…