Is Keyes, CA tap water safe?
The short answer
3 of the 3 utilities serving Keyes have a result above a legal limit or action level, or a health-based violation since 2016, in EPA’s and California’s records: Keyes Community Services Dist., City of Ceres and City of Turlock.
Keyes Community Services Dist., which serves the most people here, has 1 result above the legal limit and 2 results above the health goal. The worst: Arsenic at 8.6 ppb, above the legal limit.
The water from Keyes Community Services Dist. is soft to moderately hard depending on the source, 53 to 112 mg/L (3.1 to 6.5 grains per gallon). How California’s water compares.
A town can be served by more than one utility, and some homes are on private wells. The name on your water bill tells you which is yours, and your ZIP code narrows it down. They are listed by how many people each serves in Keyes’s ZIP codes, from EPA’s estimates.
- Open report
Keyes Community Services Dist.
California · serves 5,672 people · about 3,600 in Keyes
1 result above the legal limit and 2 results above the health goal. The worst: Arsenic at 8.6 ppb, above the legal limit. Hardness: soft to moderately hard depending on the source, 53 to 112 mg/L (3.1 to 6.5 grains per gallon).
17 health-based violations since 2016
- Open report
City of Ceres
California · serves 54,513 people · about 490 in Keyes
2 results above EPA’s new limit, which takes effect in 2029, 3 results above the health goal and 1 result above EPA’s health benchmark. The worst: PFOS at 24 ppt, above EPA’s new limit, which takes effect in 2029. Hardness: soft to very hard depending on the source, 47 to 478 mg/L (2.8 to 27.9 grains per gallon).
1 health-based violation since 2016
- Open report
City of Turlock
California · serves 72,888 people · about 460 in Keyes
3 results above the health goal. The worst: Arsenic at 8.2 ppb, above the health goal. Hardness: moderately hard to hard depending on the source, 64 to 152 mg/L (3.7 to 8.9 grains per gallon).
1 health-based violation since 2016
What handles it
Each of these is certified, on a certifier’s listing, for a result above a line in Keyes Community Services Dist.’s water, which serves the most people here. Another utility’s report names what handles its own results.
Disclosure: TapBuff earns a commission if you buy through some links on this page. It does not change which standard or filter we name. As an Amazon Associate, TapBuff earns from qualifying purchases. How TapBuff makes money
Countertop reverse osmosis
- IAPMO listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 58NSF/ANSI 401checked Oct. 4, 2026
Certified for: Arsenic, Nitrate, Lead
Aquasana SmartFlow Reverse Osmosis (AQ-SFRO2)
Under-sink reverse osmosis
- WQA listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 58NSF/ANSI 401checked Oct. 9, 2026
Certified for: Arsenic, Nitrate, Lead
Brondell Capella RC250 Reverse Osmosis System
Under-sink reverse osmosis
- WQA listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 58NSF/ANSI 401checked Oct. 9, 2026
Certified for: Arsenic, Lead
Water testing near Keyes
The 3 labs California certifies closest to Keyes, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.
Microbac Laboratories, Inc. - Turlock
Turlock, CA · about 4 miles
Certified for bacteria, nitrate, lead and copper, metals, minerals and other inorganics, organic chemicals, disinfection byproducts, radioactivity
Certified Laboratories - Turlock
Turlock, CA · about 4 miles
Certified for bacteria
Aemtek, Inc.
Modesto, CA · about 12 miles
Certified for bacteria
Which ZIP codes are in Keyes: Census 2020 relationship files. Which utilities serve them, and how many people: EPA SDWIS and EPA’s service area map. Each utility’s results: EPA UCMR 5, EPA SDWIS, and EPA’s and the state’s compliance monitoring, as its report lists them. How they are measured: methodology. Certified labs: California State Water Resources Control Board, ELAP accredited laboratories and their fields of accreditation; distances from the Census 2020 ZIP code tabulation area gazetteer.
Near Keyes
Other towns in Stanislaus County with a page of their own.
What to do next
- Read Keyes Community Services Dist.’s full reportEvery result with its dates, the violations, and the certification claim that handles each finding.Open the report
- Filters for ArsenicRanked by certification and what they cost over five years.The best reverse osmosis systems, ranked
- On a private well?No utility tests a well. A certified lab test is the first step.How to test well water