Is Cottonwood, CA tap water safe?
The short answer
3 of the 6 utilities serving Cottonwood have a result above a legal limit or action level, or a health-based violation since 2016, in EPA’s and California’s records: Cottonwood Water District, Greenfield County WD and Saddleback Mutual Water Co..
Cottonwood Water District, which serves the most people here, has 1 result above the health goal. The worst: Arsenic at 1.7 ppb, above the health goal. Health goals are stricter than legal limits and are not enforced.
The water from Cottonwood Water District is soft to moderately hard depending on the source, 38 to 69 mg/L (2.2 to 4 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 Cottonwood’s ZIP codes, from EPA’s estimates.
- Open report
Cottonwood Water District
California · serves 3,316 people · about 310 in Cottonwood
1 result above the health goal. The worst: Arsenic at 1.7 ppb, above the health goal. Hardness: soft to moderately hard depending on the source, 38 to 69 mg/L (2.2 to 4 grains per gallon).
2 health-based violations since 2016
- Open report
Cws - Bakersfield
California · serves 268,129 people · about 200 in Cottonwood
2 results above EPA’s new limit, which takes effect in 2029 and 3 results above the health goal. The worst: PFOS at 14 ppt, above EPA’s new limit, which takes effect in 2029. Hardness: soft to very hard depending on the source, 55 to 325 mg/L (3.2 to 19 grains per gallon).
No health-based violations since 2016
- Open report
Rio Alto Water District
California · serves 3,377 people · about 180 in Cottonwood
1 result above the health goal. The worst: Arsenic at 3.0 ppb, above the health goal. Hardness: soft to moderately hard depending on the source, 56 to 89 mg/L (3.3 to 5.2 grains per gallon).
No health-based violations since 2016
- Open report
Greenfield County WD
California · serves 11,590 people · under 100 in Cottonwood
2 results above the health goal. The worst: Arsenic at 7.0 ppb, above the health goal. Hardness: soft to hard depending on the source, 53 to 170 mg/L (3.1 to 9.9 grains per gallon).
14 health-based violations since 2016
- Open report
White Oak Mutual Water Company
California · serves 415 people · under 100 in Cottonwood
1 result above the health goal. The worst: Lead at 1.6 ppb, above the health goal. Hardness: soft to moderately hard depending on the source, 58 to 62 mg/L (3.4 to 3.6 grains per gallon).
No health-based violations since 2016
- Open report
Saddleback Mutual Water Co.
California · serves 90 people · under 100 in Cottonwood
1 result above the health goal. The worst: Arsenic at 2.0 ppb, above the health goal. Hardness: moderately hard, typically 96 mg/L (5.6 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 Cottonwood Water District’s water, which serves the most people here. Another utility’s report names what handles its own results.
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Countertop reverse osmosis
- IAPMO listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 58NSF/ANSI 401checked Oct. 4, 2026
Certified for: Arsenic
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
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
Water testing near Cottonwood
The 3 labs California certifies closest to Cottonwood, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.
Aemtek, Inc.
Modesto, CA · about 18 miles
Certified for bacteria
Institute of Environmental Health, Inc. dba IEH-JL Analytical
Modesto, CA · about 21 miles
Certified for bacteria, nitrate, minerals and other inorganics
Microbac Laboratories, Inc. - Turlock
Turlock, CA · about 23 miles
Certified for bacteria, nitrate, lead and copper, metals, minerals and other inorganics, organic chemicals, disinfection byproducts, radioactivity
Which ZIP codes are in Cottonwood: 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 Cottonwood
Other towns in Kern County with a page of their own.
What to do next
- Read Cottonwood Water District’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