Is Riverbank, CA tap water safe?
The short answer
1 of the 3 utilities serving Riverbank 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 Riverbank.
City of Riverbank, which serves the most people here, has 1 result above the legal limit, 1 result above the action level and 2 results above the health goal. The worst: Nitrate at 21 ppm, above the legal limit.
The water from City of Riverbank is soft to very hard depending on the source, 59 to 210 mg/L (3.5 to 12.3 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 Riverbank’s ZIP codes, from EPA’s estimates.
- Open report
City of Riverbank
California · serves 25,625 people · about 15,300 in Riverbank
1 result above the legal limit, 1 result above the action level and 2 results above the health goal. The worst: Nitrate at 21 ppm, above the legal limit. Hardness: soft to very hard depending on the source, 59 to 210 mg/L (3.5 to 12.3 grains per gallon).
1 health-based violation since 2016
- Open report
Park Heights Mutual Water Co
California · serves 250 people · about 180 in Riverbank
2 results above the health goal. The worst: Uranium at 12.4 ppb, above the health goal. Hardness: hard to very hard depending on the source, 148 to 199 mg/L (8.7 to 11.6 grains per gallon).
No health-based violations since 2016
- Open report
City of Modesto
California · serves 218,915 people · about 120 in Riverbank
2 results above EPA’s new limit, which takes effect in 2029, 4 results above the health goal and 1 result above EPA’s health benchmark. The worst: PFOS at 26 ppt, above EPA’s new limit, which takes effect in 2029. Hardness: soft to very hard depending on the source, 35 to 388 mg/L (2 to 22.7 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 Riverbank’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, Lead, 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, Lead, 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, Lead
Water testing near Riverbank
The 3 labs California certifies closest to Riverbank, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.
Aemtek, Inc.
Modesto, CA · about 5 miles
Certified for bacteria
Institute of Environmental Health, Inc. dba IEH-JL Analytical
Modesto, CA · about 8 miles
Certified for bacteria, nitrate, minerals and other inorganics
Microbac Laboratories, Inc. - Turlock
Turlock, CA · about 14 miles
Certified for bacteria, nitrate, lead and copper, metals, minerals and other inorganics, organic chemicals, disinfection byproducts, radioactivity
Which ZIP codes are in Riverbank: 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 Riverbank
Other towns in Stanislaus County with a page of their own.
What to do next
- Read City of Riverbank’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