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Tap water quality report

Rancho Mission Viejo, CA

EPA monitoring detected 15 contaminants across the 1 water supplier serving Rancho Mission Viejo. A detection doesn't automatically mean the water is unsafe — see the level at the main supplier for each below, with its EPA source and period.

1
water supplier
210
people served
15
contaminants found
California rankings Lead in California PFAS in California

What was found in Rancho Mission Viejo's water

The level at the city's main supplier, the highest level anywhere in the city, the EPA limit for each, and where every figure comes from.

ContaminantLevel vs EPA limitSuppliersSource
Nitrate
10885 µg/L 109%
of the EPA limit, at the 95th percentile of samples — 10000 µg/L
Main supplier: RANCHO CARRILLO MWC · 210 people · 2019
1/1 SYR4
Fluoride
364 µg/L 9.1%
of the EPA limit 4000 µg/L
Main supplier: RANCHO CARRILLO MWC · 210 people · 2018
1/1 SYR4
Copper
240 µg/L 18%
of the EPA limit 1300 µg/L
Main supplier: RANCHO CARRILLO MWC · 210 people · 2018
1/1 SYR4
Barium
151.27 µg/L 7.6%
of the EPA limit 2000 µg/L
Main supplier: RANCHO CARRILLO MWC · 210 people · 2018
1/1 SYR4
Thallium, Total
120 µg/L 6000%
of the EPA limit, at the 95th percentile of samples — 2 µg/L
Main supplier: RANCHO CARRILLO MWC · 210 people · 2018
1/1 SYR4
Lead
102.5 µg/L 683%
of the EPA limit, at the 95th percentile of samples — 15 µg/L
Main supplier: RANCHO CARRILLO MWC · 210 people · 2018
1/1 SYR4
Antimony, Total
90.203 µg/L 1503%
of the EPA limit, at the 95th percentile of samples — 6 µg/L
Main supplier: RANCHO CARRILLO MWC · 210 people · 2018
1/1 SYR4
Chromium
55.5 µg/L 56%
of the EPA limit 100 µg/L
Main supplier: RANCHO CARRILLO MWC · 210 people · 2018
1/1 SYR4
Selenium
5.03 µg/L 10%
of the EPA limit 50 µg/L
Main supplier: RANCHO CARRILLO MWC · 210 people · 2018
1/1 SYR4
Arsenic
4.824 µg/L 48%
of the EPA limit 10 µg/L
Main supplier: RANCHO CARRILLO MWC · 210 people · 2018
1/1 SYR4
Dichloromethane
2.862 µg/L 57%
of the EPA limit 5 µg/L
Main supplier: RANCHO CARRILLO MWC · 210 people · 2018
1/1 SYR4
Mercury
2.08 µg/L 104%
of the EPA limit, at the 95th percentile of samples — 2 µg/L
Main supplier: RANCHO CARRILLO MWC · 210 people · 2018
1/1 SYR4
Combined Uranium
1.35292 µg/L 4.5%
of the EPA limit 30 µg/L
Main supplier: RANCHO CARRILLO MWC · 210 people · 2018
1/1 SYR4
Nitrite
0.0333 µg/L 0%
of the EPA limit 1000 µg/L
Main supplier: RANCHO CARRILLO MWC · 210 people · 2018
1/1 SYR4
Lead
0.0050 mg/L 33%
of the EPA limit 0.0150 mg/L
Main supplier: RANCHO CARRILLO MWC · 210 people · 2023
1/1 LCR
Each bar shows the measured level as a share of the EPA limit: green is well under, amber is close to it, red is over. For lead and copper the limit applies to exactly the 90th-percentile figure shown, so red there means a real exceedance. For everything else the limit applies to a running annual average while the figure is the 95th percentile of the system's samples — over 100% is worth reading, but is not by itself a violation. Formal violations are listed separately. These are the utilities' own EPA-reported results, not a city-wide average. A detection means the lab measured the substance — it isn't the same as exceeding a legal limit. Hover a source tag to see the EPA program and years behind each figure.

Water suppliers serving Rancho Mission Viejo

SupplierPopulation served
RANCHO CARRILLO MWC 210

Frequently asked questions about Rancho Mission Viejo tap water

Is Rancho Mission Viejo tap water safe to drink?

EPA testing detected 15 contaminants in the water serving Rancho Mission Viejo. A detection isn't the same as a violation — most detected levels are within federal limits. Check the level and source for each contaminant above, and your utility's annual Consumer Confidence Report for the official compliance status.

How many water suppliers serve Rancho Mission Viejo?

1 public water supplier report drinking-water monitoring for Rancho Mission Viejo, California to the EPA. Each is listed above with its population served.

What contaminants are in Rancho Mission Viejo's water?

The contaminants EPA monitoring detected in Rancho Mission Viejo include Nitrate, Fluoride, Copper, Barium, Thallium, Total. The full list, with the level at the main supplier and the data source, is in the table above.

Where does this data come from?

Every figure is official EPA drinking-water monitoring — the Lead & Copper Rule, the UCMR-5 nationwide testing program, and the EPA Six-Year Review — not our own testing. Each number is labelled with its source and period.