Is La Puente, CA tap water safe?
The short answer
1 of the 5 utilities serving La Puente has a result above a legal limit or action level, or a health-based violation since 2016, in EPA’s and California’s records: San Gabriel Valley Water Co. - El Monte.
Suburban Water Systems - San Jose, 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 56 ppb, above EPA’s health benchmark. Health goals are stricter than legal limits and are not enforced.
The water from Suburban Water Systems - San Jose is hard to very hard depending on the source, 147 to 290 mg/L (8.6 to 17 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 La Puente’s ZIP codes, from EPA’s estimates.
- Open report
Suburban Water Systems - San Jose
California · serves 170,523 people · about 18,100 in La Puente
3 results above the health goal and 1 result above EPA’s health benchmark. The worst: Lithium at 56 ppb, above EPA’s health benchmark. Hardness: hard to very hard depending on the source, 147 to 290 mg/L (8.6 to 17 grains per gallon).
No health-based violations since 2016
- Open report
La Puente Valley CWD
California · serves 8,276 people · about 2,700 in La Puente
3 results above the health goal. The worst: Nitrate at 18 ppm, above the health goal. Hardness: very hard, typically 221 mg/L (12.9 grains per gallon).
No health-based violations since 2016
- Open report
San Gabriel Valley Water Co. - El Monte
California · serves 240,000 people · about 2,700 in La Puente
3 results above the health goal. The worst: Nitrate at 23 ppm, above the health goal. Hardness: moderately hard to very hard depending on the source, 91 to 340 mg/L (5.3 to 19.9 grains per gallon).
2 health-based violations since 2016
- Open report
Rowland Water District
California · serves 56,100 people · about 1,600 in La Puente
1 result above EPA’s health benchmark. The worst: Lithium at 48 ppb, above EPA’s health benchmark.
No health-based violations since 2016
- Open report
City of Industry Waterworks Systems
California · serves 6,151 people · about 680 in La Puente
2 results above the health goal. The worst: Uranium at 8.0 ppb, above the health goal. Hardness: very hard, 346 mg/L (20.2 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 Suburban Water Systems - San Jose’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 La Puente
The 3 labs California certifies closest to La Puente, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.
Weck Laboratories, Inc.
City of Industry, CA · about 2 miles
Certified for bacteria, nitrate, lead and copper, metals, minerals and other inorganics, organic chemicals, disinfection byproducts, PFAS, radioactivity
Eurofins Pomona
Pomona, CA · about 9 miles
Certified for bacteria, nitrate, lead and copper, metals, minerals and other inorganics, organic chemicals, disinfection byproducts, PFAS, radioactivity
Michelson Laboratories, Inc.
Commerce, CA · about 11 miles
Certified for bacteria, nitrate, lead and copper, metals, minerals and other inorganics
Which ZIP codes are in La Puente: 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 La Puente
Other towns in Los Angeles County with a page of their own.
What to do next
- Read Suburban Water Systems - San Jose’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