Problem: The coastal community of Los Osos, California, had outdated wastewater systems and a history of nitrogen issues. Many lots in the community were too small for code-compliant septic systems. With existing systems far exceeding their design life, the regional water quality control board declared a prohibition zone that included a building moratorium. Meanwhile, farms were experiencing saltwater intrusion as groundwater was pumped to meet demand for irrigation and drinking water. 

Solution: Initial studies recommending an ocean outfall for a centralized wastewater treatment system raised concerns that saltwater intrusion would increase. Los Osos chose a decentralized solution from Infiltrator Water Technologies that discharges to a community drainfield, recharges groundwater, and minimizes saltwater intrusion. The system treats a design flow of 1.6 mgd. 

Result: Treated effluent is pumped to a large chamber dispersal field installed along a hillside with ideal soils to facilitate aquifer recharge. With this solution, the town-owned property was converted to open space walking trails. Therefore the land was still functional while providing active recharge to the aquifer. 800-221-4436; www.infiltratorwater.com