Is Riverside, CA tap water safe?
The short answer
None of the 3 utilities serving Riverside has a result above a legal limit or action level, or a health-based violation since 2016, in EPA’s and California’s records.
City of Riverside, which serves the most people here, has 5 results above the health goal. The worst: Nitrate at 14 ppm, above the health goal. Health goals are stricter than legal limits and are not enforced.
The water from City of Riverside is soft to very hard depending on the source, 55 to 395 mg/L (3.2 to 23.1 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 Riverside’s ZIP codes, from EPA’s estimates.
- Open report
City of Riverside
California · serves 302,776 people · about 208,400 in Riverside
5 results above the health goal. The worst: Nitrate at 14 ppm, above the health goal. Hardness: soft to very hard depending on the source, 55 to 395 mg/L (3.2 to 23.1 grains per gallon).
No health-based violations since 2016
- Open report
Western MWD
California · serves 87,955 people · about 39,000 in Riverside
1 result above the health goal and 1 result above EPA’s health benchmark. The worst: Lithium at 16 ppb, above EPA’s health benchmark.
No health-based violations since 2016
- Open report
Riverside Highland Water Company
California · serves 19,053 people · about 3,000 in Riverside
2 results above EPA’s new limit, which takes effect in 2029 and 3 results above the health goal. The worst: PFOS at 19 ppt, above EPA’s new limit, which takes effect in 2029. Hardness: hard to very hard depending on the source, 160 to 280 mg/L (9.4 to 16.4 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 City of Riverside’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, PFOS, Arsenic, 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: Nitrate, PFOS, Arsenic, Lead
Culligan 10-Cup Pitcher with ZeroWater Technology (ZEROP10)
Pitcher
- IAPMO listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 401checked Oct. 9, 2026
Certified for: Nitrate, PFOS, Lead
Water testing near Riverside
The 3 labs California certifies closest to Riverside, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.
Babcock Laboratories, Inc.
Riverside, CA · about 5 miles
Certified for bacteria, nitrate, lead and copper, metals, minerals and other inorganics, organic chemicals, disinfection byproducts, PFAS, radioactivity
Clinical Laboratory of San Bernardino, Inc.
Grand Terrace, CA · about 8 miles
Certified for bacteria, nitrate, lead and copper, metals, minerals and other inorganics, organic chemicals, disinfection byproducts, radioactivity
BSK Associates - San Bernardino Analytical Laboratory
San Bernardino, CA · about 11 miles
Certified for bacteria
Which ZIP codes are in Riverside: 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 Riverside
Other towns in Riverside County with a page of their own.
What to do next
- Read City of Riverside’s full reportEvery result with its dates, the violations, and the certification claim that handles each finding.Open the report
- Filters for NitrateRanked 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