Orange County
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Orange County · tap water by city

Orange County tap water, city by city.

FilteredWTR tracks 31 public water systems in Orange County, and their own population counts add up to 3,193,512 people. None of them has a health-based violation on its EPA record from the last three years. In the latest round of lead testing, 20 systems reported a 90th-percentile result of zero. One came in at or above 0.0075 mg/L, half the federal action level of 0.015 mg/L.

Water systems in Orange County

The largest systems come first. Lead is each system's most recent 90th-percentile result from the federal Lead and Copper Rule, and the last column counts health-based violations from the last three years. Systems sample on their own schedules, so their monitoring periods end anywhere from 2023 to 2026.

Water systemCities servedPeople servedLatest lead (90th percentile)Recent health violations
Irvine Ranch Water DistrictIrvine450,323Not detected, period ending 20250
City of AnaheimAnaheim350,254Not detected, period ending 20240
City of Santa AnaSanta Ana316,184Not detected, period ending 20240
City of Huntington BeachHuntington Beach201,000Not detected, period ending 20240
City of Garden GroveGarden Grove174,226Not detected, period ending 20250
Moulton Niguel Water DistrictAliso Viejo, Laguna Hills, Laguna Niguel, Mission Viejo168,315Not detected, period ending 20240
Santa Margarita Water DistrictCoto De Caza, Ladera Ranch, Rancho Santa Margarita165,275Not detected, period ending 20240
City of FullertonFullerton140,0540.0015 mg/L, period ending 20240
City of OrangeOrange120,7700.00233 mg/L, period ending 20240
Golden State WC - West Orange CountyCypress, Stanton114,6930.0022 mg/L, period ending 20250
Mesa Water DistrictCosta Mesa110,000Not detected, period ending 20260
City of WestminsterWestminster93,5910.0047 mg/L, period ending 20240
Yorba Linda Water DistrictYorba Linda84,292Not detected, period ending 20240
City of Buena ParkBuena Park82,667Not detected, period ending 20240
City of Newport BeachNewport Beach69,520Not detected, period ending 20240
City of TustinTustin65,143Not detected, period ending 20240
City of La HabraLa Habra61,202Not detected, period ending 20240
City of Fountain ValleyFountain Valley56,7470.006 mg/L, period ending 20240
El Toro Water DistrictEl Toro, Laguna Woods, Lake Forest53,4150.0008 mg/L, period ending 20230
City of San ClementeSan Clemente51,545Not detected, period ending 20250
Golden State WC - Placentia/Yorba LindaPlacentia50,8040.0025 mg/L, period ending 20250
City of BreaBrea47,454Not detected, period ending 20260
South Coast Water DistrictDana Point, San Juan Capistrano41,194Not detected, period ending 20230
Santa Margarita Water District-ID9San Juan Capistrano35,309Not detected, period ending 20240
City of Seal BeachSeal Beach24,937Not detected, period ending 20240
Laguna Beach County WDLaguna Beach18,862Not detected, period ending 20260
City of La PalmaLa Palma15,9480.0041 mg/L, period ending 20240
Trabuco Canyon Water DistrictTrabuco Canyon13,6590.0039 mg/L, period ending 20240
Golden State WC - Cowan HeightsNorth Tustin7,0060.0084 mg/L, period ending 20250
Serrano Water DistrictVilla Park5,659Not detected, period ending 20230
East Orange County WD - RZNot listed3,4640.00547 mg/L, period ending 20240

Find your city

Each report covers the water system that serves that city, with its measured results and its full EPA compliance history.

What these numbers mean

Every system has to collect tap samples from a set list of homes and report the lead level at the 90th percentile. Nine out of ten sampled homes came in at or below that figure. The federal action level is 0.015 mg/L, and a system that goes over it has to take corrective steps and tell its customers. A zero means the samples came back below what the lab can detect.

A health-based violation means the system broke a rule tied to health, such as going over a contaminant limit or missing a required treatment step. Late paperwork and skipped reports go on the EPA record too, and this page leaves those out.

These figures describe the water each system sends out, and the water at your own faucet can test differently. Lead most often enters from a home's own pipes and fixtures, so houses built before 1986 are worth a closer look. Chlorine levels also drift with how far a street sits from the treatment plant.

Free local water test

See your own water in person before spending money on treatment.

A local FilteredWTR tech screens the water at your faucet for hardness, chlorine and sediment and explains each reading while you watch. The visit is free, and afterward the decision stays yours.

Text 949-414-9944 for a free water test

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