Is Rancho Santa Margarita, CA tap water safe?
The short answer
None of the 3 utilities serving Rancho Santa Margarita has a result above a legal limit or action level, or a health-based violation since 2016, in EPA’s and California’s records.
Santa Margarita Water District, which serves the most people here, has 1 result above EPA’s health benchmark. The worst: Lithium at 50.1 ppb, above EPA’s health benchmark. A health benchmark is a level EPA screens with, not a legal limit.
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 Rancho Santa Margarita’s ZIP codes, from EPA’s estimates.
- Open report
Santa Margarita Water District
California · serves 165,275 people · about 35,300 in Rancho Santa Margarita
1 result above EPA’s health benchmark. The worst: Lithium at 50.1 ppb, above EPA’s health benchmark.
No health-based violations since 2016
- Open report
Trabuco Canyon Water District
California · serves 13,659 people · about 1,000 in Rancho Santa Margarita
1 result above the limit’s level with no violation recorded, 2 results above the health goal and 1 result above EPA’s health benchmark. The worst: Arsenic at 24 ppb, above the limit’s level, no violation. Hardness: very hard, typically 287 mg/L (16.8 grains per gallon).
No health-based violations since 2016
- Open report
Irvine Ranch Water District
California · serves 450,323 people · about 590 in Rancho Santa Margarita
3 results above the health goal and 1 result above EPA’s health benchmark. The worst: Lithium at 67.2 ppb, above EPA’s health benchmark. Hardness: very hard, 214 to 293 mg/L (12.5 to 17.1 grains per gallon).
No health-based violations since 2016
Water testing near Rancho Santa Margarita
The 3 labs California certifies closest to Rancho Santa Margarita, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.
Sierra Analytical Labs, Inc.
Laguna Hills, CA · about 6 miles
Certified for bacteria, nitrate, lead and copper, metals, minerals and other inorganics, organic chemicals
Onterris Laboratories, LLC
Orange, CA · about 19 miles
Certified for bacteria, nitrate, lead and copper, metals, minerals and other inorganics, organic chemicals, disinfection byproducts
Envirocheck, Inc.
Orange, CA · about 20 miles
Certified for lead and copper
Which ZIP codes are in Rancho Santa Margarita: 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 Rancho Santa Margarita
Other towns in Orange County with a page of their own.
What to do next
- Read Santa Margarita Water District’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