Water system

Atascadero State Hospital

Name: Atascadero State Hospital drinking water quality
Creator: TapWaterZip
License: https://www.usa.gov/government-works

California EPA ID CA4010832 1,100 people Groundwater

What this means for you

Is it safe to drink right now?: Based on the latest EPA data, Atascadero State Hospital has no unresolved health-based violations from the past year. Water that meets federal standards is generally considered safe to drink for most healthy people.
Should I use a filter?: Yes, we recommend considering one. Average PFOS was above the 4 ppt federal limit (compliance deadline April 2029). Other regulated PFAS (PFHxS) also exceeded 2024 limits.
What kind of filter?: For PFAS, look for NSF/ANSI 53 (with an explicit PFOA/PFOS or total PFAS claim) or NSF/ANSI 58 reverse osmosis. See matched standards and product picks.

This is general information from public EPA data, not medical advice. Lead often comes from a home’s own pipes, so only a test of your tap can tell your exposure. If you are pregnant, caring for an infant, or have a weakened immune system, ask your doctor or health department.

Summary: No health-based violations in the last 5 years; 1 monitoring/reporting violation; PFOA/PFOS average above the 4 ppt federal limit: PFOS; Other PFAS above 2024 limits (rule proposed for repeal): PFHxS, Hazard Index; Lead 90th percentile below the action level (2026).

EPA data snapshot 2026Q3. Grade is TapWaterZip's own score — see methods.

PFAS (“forever chemicals”), EPA UCMR 5

Chemical	Highest location average	Highest single sample	Federal limit	Detections/samples
PFOS	18.7 ppt	33 ppt	4 ppt	2/2
PFPeS	3.1 ppt	6.1 ppt	none	1/2
PFHxA	1.8 ppt	3.6 ppt	none	1/2
PFBS	4.6 ppt	5.5 ppt	none	2/2
PFHxS	19.2 ppt	34 ppt	10 ppt (proposed repeal)	2/2

3 PFAS tested and not detected

PFNA, HFPO-DA, PFOA (2 samples each, below EPA minimum reporting levels).

Hazard Index (PFHxS, PFNA, GenX, PFBS): 1.92 (limit 1.0, proposed for repeal).

Averages are per sampling location across UCMR 5 samples (non-detects counted as 0), approximating the rule’s running annual average. Not an official compliance determination; PFOA/PFOS MCL compliance begins April 26, 2029.

Lead and copper

Lead 90th percentile4.7 ppb2026-06-30

Current action level15 ppbLCRI lowers to 10 ppb on Nov 1, 2027

Copper 90th percentile1.58 mg/L2026-06-30 · action level 1.3 mg/L

Violations (last 5 years)

Began	Type	Contaminant / rule	Status
2023-01-01	Missed or late testing/reporting	Nitrate	Resolved

Filters matched to this water

FILTER PICKS

Look for filters certified (NSF, IAPMO or WQA) to these standards for the specific contaminant. Buttons open the maker’s page or an Amazon search; use “Check NSF listing” to verify a model’s claims. No affiliate links yet — grades are never sold.