Community treatment combats saltwater intrusion and recharges aquifer
Problem: The coastal community of Los Osos, California, had outdated wastewater systems and a history of nitrogen issues.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
