Is El Monte, CA tap water safe?
The short answer
4 of the 7 utilities serving El Monte have 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, Del Rio Mutual, Hemlock Mutual Water Co. and 1 more.
San Gabriel Valley Water Co. - El Monte, which serves the most people here, has 3 results above the health goal. The worst: Nitrate at 23 ppm, above the health goal. Health goals are stricter than legal limits and are not enforced.
The water from San Gabriel Valley Water Co. - El Monte is moderately hard to very hard depending on the source, 91 to 340 mg/L (5.3 to 19.9 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 El Monte’s ZIP codes, from EPA’s estimates.
- Open report
San Gabriel Valley Water Co. - El Monte
California · serves 240,000 people · about 66,400 in El Monte
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
El Monte - City, Water Dept.
California · serves 23,000 people · about 12,900 in El Monte
1 result above EPA’s new limit, which takes effect in 2029 and 3 results above the health goal. The worst: PFOS at 4.4 ppt, above EPA’s new limit, which takes effect in 2029. Hardness: very hard, typically 252 mg/L (14.7 grains per gallon).
No health-based violations since 2016
- Open report
Cal/Am Water Company - San Marino
California · serves 48,065 people · about 7,100 in El Monte
3 results above the health goal and 1 result above EPA’s health benchmark. The worst: Lithium at 91.9 ppb, above EPA’s health benchmark. Hardness: moderately hard to very hard depending on the source, 76 to 340 mg/L (4.4 to 19.9 grains per gallon).
No health-based violations since 2016
- Open report
Gswc - South Arcadia
California · serves 27,430 people · about 2,800 in El Monte
2 results above EPA’s new limit, which takes effect in 2029 and 3 results above the health goal. The worst: PFOS at 22 ppt, above EPA’s new limit, which takes effect in 2029. Hardness: hard to very hard depending on the source, 135 to 200 mg/L (7.9 to 11.7 grains per gallon).
No health-based violations since 2016
- Open report
Del Rio Mutual
California · serves 700 people · nearly all in El Monte
2 results above the health goal. The worst: Arsenic at 2.1 ppb, above the health goal. Hardness: very hard, 275 mg/L (16.1 grains per gallon).
1 health-based violation since 2016
- Open report
Hemlock Mutual Water Co.
California · serves 686 people · nearly all in El Monte
2 results above the health goal. The worst: Arsenic at 1.1 ppb, above the health goal. Hardness: hard, typically 150 mg/L (8.8 grains per gallon).
1 health-based violation since 2016
- Open report
Sterling Mutual Water Company
California · serves 198 people · nearly all in El Monte
2 results above the health goal. The worst: Arsenic at 2.6 ppb, above the health goal. Hardness: very hard, typically 213 mg/L (12.5 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 San Gabriel Valley Water Co. - El Monte’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 Monte
The 3 labs California certifies closest to El Monte, 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 5 miles
Certified for bacteria, nitrate, lead and copper, metals, minerals and other inorganics, organic chemicals, disinfection byproducts, PFAS, radioactivity
EMSL Analytical, Inc. (LA Testing)
South Pasadena, CA · about 8 miles
Certified for bacteria, asbestos
Michelson Laboratories, Inc.
Commerce, CA · about 8 miles
Certified for bacteria, nitrate, lead and copper, metals, minerals and other inorganics
Which ZIP codes are in El Monte: 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 Monte
Other towns in Los Angeles County with a page of their own.
What to do next
- Read San Gabriel Valley Water Co. - El Monte’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