Is El Rio, CA tap water safe?
The short answer
2 of the 9 utilities serving El Rio have a result above a legal limit or action level, or a health-based violation since 2016, in EPA’s and California’s records: Vineyard Ave Estates MWC and Vineyard Avenue Acres MWC.
Oxnard Water Dept, which serves the most people here, has 3 results above the health goal and 1 result above EPA’s health benchmark. The worst: Lithium at 39 ppb, above EPA’s health benchmark. Health goals are stricter than legal limits and are not enforced.
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 El Rio’s ZIP codes, from EPA’s estimates.
- Open report
Oxnard Water Dept
California · serves 200,232 people · about 2,100 in El Rio
3 results above the health goal and 1 result above EPA’s health benchmark. The worst: Lithium at 39 ppb, above EPA’s health benchmark.
No health-based violations since 2016
- Open report
Cal American WC - Rio Plaza
California · serves 1,712 people · about 140 in El Rio
1 result above the health goal. The worst: Uranium at 15 ppb, above the health goal. Hardness: very hard, typically 554 mg/L (32.4 grains per gallon).
No health-based violations since 2016
- Open report
Nyeland Acres Mutual Water Co
California · serves 975 people · under 100 in El Rio
2 results above the health goal. The worst: Uranium at 12.4 ppb, above the health goal. Hardness: very hard, 464 mg/L (27.1 grains per gallon).
No health-based violations since 2016
- Open report
Vineyard Ave Estates MWC
California · serves 1,200 people · under 100 in El Rio
2 results above the health goal. The worst: Nitrate at 20.1 ppm, above the health goal. Hardness: very hard, 453 mg/L (26.5 grains per gallon).
1 health-based violation since 2016
- Open report
Garden Acres Mutual Water Co
California · serves 1,335 people · under 100 in El Rio
1 result above the health goal. The worst: Uranium at 7.9 ppb, above the health goal. Hardness: very hard, typically 569 mg/L (33.2 grains per gallon).
No health-based violations since 2016
- Open report
Rio Manor Mutual Water Co
California · serves 983 people · under 100 in El Rio
2 results above the health goal. The worst: Uranium at 17 ppb, above the health goal. Hardness: very hard, typically 551 mg/L (32.2 grains per gallon).
No health-based violations since 2016
- Open report
Cloverdale Mutual Water Co.
California · serves 455 people · under 100 in El Rio
1 result above the health goal. The worst: Uranium at 7.7 ppb, above the health goal. Hardness: very hard, typically 531 mg/L (31.1 grains per gallon).
No health-based violations since 2016
- Open report
Vineyard Avenue Acres MWC
California · serves 1,820 people · under 100 in El Rio
1 result above the health goal. The worst: Uranium at 8.5 ppb, above the health goal. Hardness: very hard, typically 550 mg/L (32.2 grains per gallon).
2 health-based violations since 2016
- Open report
Strickland Mutual Water Company
California · serves 429 people · under 100 in El Rio
2 results above the health goal. The worst: Uranium at 7.9 ppb, above the health goal. Hardness: very hard, typically 545 mg/L (31.8 grains per gallon).
No health-based violations since 2016
What handles it
Each of these is certified, on a certifier’s listing, for a result above a line in Oxnard Water Dept’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: Nitrate, 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: Nitrate, Arsenic
Culligan 10-Cup Pitcher with ZeroWater Technology (ZEROP10)
Pitcher
- IAPMO listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 401checked Oct. 9, 2026
Certified for: Nitrate
Water testing near El Rio
The 3 labs California certifies closest to El Rio, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.
Ventura County Public Health Laboratory
Oxnard, CA · about 3 miles
Certified for bacteria
Capco Analytical Services
Ventura, CA · about 3 miles
Certified for bacteria, nitrate, metals, minerals and other inorganics
Fruit Growers Laboratory, Inc.
Santa Paula, CA · about 9 miles
Certified for bacteria, nitrate, lead and copper, metals, minerals and other inorganics, organic chemicals, disinfection byproducts, radioactivity
ZIP codes in El Rio
Which ZIP codes are in El Rio: 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 El Rio
Other towns in Ventura County with a page of their own.
What to do next
- Read Oxnard Water Dept’s full reportEvery result with its dates, the violations, and the certification claim that handles each finding.Open the report
- About LithiumWhat it does to health, where it comes from, and the certification claim that addresses it.About Lithium
- On a private well?No utility tests a well. A certified lab test is the first step.How to test well water