Is Los Osos, California tap water safe?
4 water systems report serving Los Osos. Your water depends on which one serves your address. Check your bill if unsure. This list is matched from the ZIP codes in this place, so it may include nearby systems.
C
Los Osos Community Services District
Serves 7,086 people · Groundwater · Full report →
No health-based violations in the last 5 years; PFOA/PFOS average above the 4 ppt federal limit: PFOA, PFOS; Lead 90th percentile below the action level (2023).
A
Golden State Water Company - Los Osos
Serves 5,942 people · Groundwater · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2023).
A
S & T Mutual Water Company
Serves 591 people · Groundwater · Full report →
No health-based violations in the last 5 years; No UCMR 5 PFAS results on file; Lead 90th percentile below the action level (2024).
C
Gran Cielo Mutual Water Company
Serves 139 people · Groundwater · Full report →
No health-based violations in the last 5 years; No UCMR 5 PFAS results on file; Lead 90th percentile ABOVE the action level (2026).