Tap Water Results

Is Monrovia, CA tap water safe?

Data: U.S. EPA · How we read the data · How we check it

Summary

City of Monrovia Water Dept., the largest system here, had PFAS above the 2024 federal limits (PFOS) in EPA's 2023–2025 testing.

Is it an emergency? No: PFAS limits are about years of exposure, not a glass of water, and nothing in EPA's data calls for you to stop drinking the water today. If your utility issues a boil-water or do-not-drink notice, follow it.

3 public water systems serve parts of Monrovia. The largest, City of Monrovia Water Dept., serves 37,931 people, and 2 systems here had PFAS above a federal limit. Your water bill names your system.

Largest system

City of Monrovia Water Dept.

37,931 people · Groundwater · EPA ID CA1910090

Buys treated water from California American Water – Duarte, Metropolitan Water District of SO. Cal..

PFASHighest averageLimitStatus
PFOA
One sample above limit
2.7 ppt4 pptOne sample above limit
PFOS
Above limit
5.1 ppt4 pptAbove limit
PFHxS
Detected, below limit
1.75 ppt10 pptDetected, below limit
PFNA
Not detected
–10 pptNot detected
HFPO-DA (GenX)
Not detected
–10 pptNot detected

ppt = parts per trillion. "Highest average" is the highest average at any of the system's entry points, the way EPA compares results with the limits.

For context: the PFOS average is higher than at 84% of the California systems EPA tested.

Lead: 0 ppb at the 90th percentile (Dec 2024, and 9 in 10 homes sampled were at or below it) Below action level
Health-based violations since 2016: 0

Full City of Monrovia Water Dept. results

Across California, 129 of 691 water systems EPA tested had PFAS above a 2024 federal limit, and 26 systems were above the lead action level in results from the last five years. California results.

Monrovia homes and lead pipes

70%
of homes built before 1980 (California 56%, US 50%)
28%
built before 1950 (California 14%)
54%
of households rent (California 44%)

Lead service lines and lead solder were allowed until 1986, so homes from before then are the ones to check. Renting? Ask your landlord what the service line is made of, because it's their pipe to replace. How to check your own line.

Housing: Census American Community Survey 2020–2024 5-year estimates for Monrovia city (tables B25034, B25003). Estimates for small places have a margin of error.

Other water systems serving Monrovia

How nearby cities compare

CityMain water systemPFASLead (90th pct.)
Arcadia 4 mi
San Gabriel Valley Water Company – El Monte
San Gabriel Valley Water Company – El MonteNone above limits0 ppb
Azusa 4 mi
Azusa Light and Water
Azusa Light and WaterNone above limits0 ppb
Temple City 6 mi
San Gabriel Valley Water Company – El Monte
San Gabriel Valley Water Company – El MonteNone above limits0 ppb
El Monte 7 mi
San Gabriel Valley Water Company – El Monte
San Gabriel Valley Water Company – El MonteNone above limits0 ppb
Covina 8 mi
Suburban Water Systems-San Jose
Suburban Water Systems-San JoseNone above limits0 ppb
Glendora 8 mi
Golden State Water Company – San Dimas
Golden State Water Company – San DimasAbove limit2.1 ppb
Monrovia ZIP codes (1)
  • 91016

Questions

Is Monrovia tap water safe to drink?

City of Monrovia Water Dept. has had no health-based violations since 2016, and EPA testing found PFAS above the 2024 federal limits, which it must meet by 2029. Utility data can't show lead from your own pipes: if your home was built before 1986, test your tap. Your utility's annual Consumer Confidence Report is the official summary.

Who supplies water in Monrovia, CA?

3 public water systems serve parts of Monrovia. The largest is City of Monrovia Water Dept. (37,931 people). Your water bill names your system. The EPA ID is also on your utility's Consumer Confidence Report.

Does Monrovia tap water have PFAS?

Yes. EPA's 2023–2025 testing found entry-point averages above the 2024 federal limits for PFOS at City of Monrovia Water Dept.. Systems have until 2029 to meet them.

Do Monrovia homes have lead pipes?

Census estimates put 70% of Monrovia homes as built before 1980 (California: 56%). Lead service lines and lead solder were allowed until 1986, so older homes are more likely to have them. City of Monrovia Water Dept.'s service line inventory says what your line is made of. The only way to know for your home is to check the line where it enters the house and test your tap.

Source: U.S. EPA drinking water records and PFAS testing (UCMR 5). How we read the data.