Water system

Big Basin Water Company

Name: Big Basin Water Company drinking water quality
Creator: TapWaterZip
License: https://www.usa.gov/government-works

California EPA ID CA4410001 1,120 people Groundwater

What this means for you

Is it safe to drink right now?: Based on the latest EPA data, Big Basin Water Company 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. Lead results are high enough that a certified lead-reduction filter is a sensible precaution.
What kind of filter?: For lead, choose NSF/ANSI 53 certified for lead reduction (or RO under 58). 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; 4 monitoring/reporting violations; No UCMR 5 PFAS results on file; Lead 90th percentile above the new 10 ppb action level (LCRI, effective Nov 1, 2027); Lead 90th percentile below the action level (2025).

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

PFAS (“forever chemicals”), EPA UCMR 5

No UCMR 5 results on file (mostly smaller systems weren’t required to test).

Lead and copper

Lead 90th percentile12 ppb2025-12-31

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

Above the new 10 ppb lead action level under EPA’s Lead and Copper Rule Improvements (compliance date November 1, 2027). Today’s enforceable action level is still 15 ppb.

Violations (last 5 years)

Began	Type	Contaminant / rule	Status
2022-06-01	Missed or late testing	Revised Total Coliform Rule	Resolved
2022-01-01	Missed or late testing/reporting	TTHM	Resolved
2022-01-01	Missed or late testing/reporting	Total Haloacetic Acids (HAA5)	Resolved
2021-10-01	Missed or late testing	Revised Total Coliform Rule	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.