Is Claremont, CA Tap Water Safe to Drink?
Graded A-, with 5 unresolved violations on record. See what was cited — and what it means for your tap. What to do next ↓
89/100
waterverge.com Claremont, CA — Water Quality Report
Claremont's drinking water received a grade of A- (89 out of 100), indicating good water quality. The city's 4 water systems serve approximately 1,789 residents using purchased surface water.
Lead levels were measured at 1.7 ppb (90th percentile), well within EPA limits. This system has not yet been tested for PFAS under the EPA UCMR 5 program.
The system has 73 violations on record, including 19 health-based violations. 5 remain unresolved.
What to know about Claremont's water
Claremont ranks #171 out of 694 cities in California for water quality, placing it above average in the state.
The city draws from surface water sources, which are more susceptible to seasonal runoff and agricultural contamination, requiring extensive multi-barrier treatment including coagulation, filtration, and disinfection.
As a small community water system, Claremont may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
Water quality score
See methodology →Is Claremont, CA water safe to drink?
Claremont's drinking water has significant quality concerns based on EPA testing data. With a grade of A- (89/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 4 water systems serve approximately 1,789 residents using surface water (rivers, lakes, or reservoirs).
Recent water quality updates for Claremont
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Claremont's water quality assessment. Grade: A- (89/100).
Federal disaster declaration (FEMA DR-3592). Flood event — may have impacted local water infrastructure.
Federal disaster declaration (FEMA DR-4683). Flood event — may have impacted local water infrastructure.
Contaminants: Revised Total Coliform Rule.
Contaminants: Coliform (TCR).
Key contaminant findings
Based on the most recent EPA sampling data for Claremont's water supply.
Well within EPA limits.
Violation history
Claremont's water system has 73 total violations on record, including 19 health-based violations. 5 remain unresolved.
Flood & environmental risk
Los Angeles County has experienced 10 federally declared disasters since 1980. Flooding and severe storms can overwhelm water treatment plants, cause sewage overflows, and introduce agricultural runoff, bacteria, and sediment into drinking water supplies. Local water sources include San Antonio C A Riverside Drive Nr Chino, Chino C A Schaefer Avenue Nr Chino, Cucamonga C Nr Upland, Cucamonga C Nr Mira Loma.
Where does Claremont's water come from?
Claremont's drinking water comes from surface water (rivers, lakes, or reservoirs), supplied by 4 water systems serving approximately 1,789 people. Surface water sources are more susceptible to contamination from runoff, industrial discharge, and algal blooms, requiring extensive treatment. Nearby water bodies include San Antonio C A Riverside Drive Nr Chino (river), Chino C A Schaefer Avenue Nr Chino (river), Cucamonga C Nr Upland (river), Cucamonga C Nr Mira Loma (river).
What Claremont residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in Claremont's water.
Your water utility is required to publish an annual Consumer Confidence Report (CCR) with detailed testing results. Ask for the latest copy or check your utility's website.
Claremont's area has a history of flooding. After severe weather, watch for boil water advisories from your local utility.
Data: EPA SDWIS, UCMR 5 (PFAS), FEMA, NOAA. Last updated May 2026.
Top contaminants to know
View all ↓Violation summary
Violations & advisories
Top industrial polluters within 10 miles of Claremont
Industrial polluters nearby
Reported releases to surface water by facilities near Claremont, ranked by pounds discharged annually.
Total reported releases to surface water: 1 lbs
| Facility | Top chemical | To surface water (lbs/yr) | Distance |
|---|---|---|---|
SCHLOSSER FORGE CO RANCHO CUCAMONGA, CA91730 | Nickel | 1 | 9.6 mi |
HOLLIDAY ROCK - CHINO CHINO, CA91710 | — | — | 8.4 mi |
GENLABS CHINO, CA91710 | — | — | 8.5 mi |
HUSSMANN CORP CHINO, CA91710 | — | — | 8.4 mi |
BLUESCOPE COATED PRODUCTS LLC RANCHO CUCAMONGA, CA91730 | — | — | 8.1 mi |
Source: EPA Toxic Release Inventory (TRI) 2023
Flood & disaster history
Los Angeles County has experienced 10 federally declared disasters since 1980. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
Full contaminants report
| Contaminant | Detected Level | EPA Limit | Unit | Category | Status |
|---|---|---|---|---|---|
| Lead (90th percentile) LeadHeavy Metal A toxic heavy metal that can leach into drinking water from older pipes, solder, and fixtures. No amount of lead in water is considered safe. Health EffectsBrain and nervous system damage in children, kidney damage, high blood pressure, and reproductive problems in adults. EPA Limit15 ppb action level Common SourcesCorrosion of lead pipes, lead solder, brass faucets, and household plumbing. | 1.7 | 15 | ppb | Inorganic | Safe |
Lead level trend (90th percentile)
See how Claremont compares by contaminant
Explore where Claremont ranks among all California cities for specific contaminants.
Water source & infrastructure
Where Claremont's water comes from
Claremont's drinking water comes primarily from surface water sources such as rivers, lakes, or reservoirs.
Surface water systems require multi-stage treatment including coagulation, sedimentation, filtration, and disinfection to meet EPA Safe Drinking Water Act standards.
These sources can be impacted by seasonal changes, stormwater runoff, upstream agriculture, and industrial discharge.
The system is operated by private ownership and serves approximately 1,789 people through 4 water systems.
Water bodies near Claremont
Claremont is located near 4 notable water bodies. As a surface water system, these water bodies may directly influence the city's drinking water supply.
Water systems serving Claremont
| System Name | PWSID | Population | Source |
|---|---|---|---|
| SONORA WATER RESOURCES, INC | CA5510024 | 1,154 | SWP |
| SIERRA WATER RESOURCES - SIERRA CITY | CA4600017 | 324 | GW |
| OWENS VALLEY WATER RESOURCES, INC. | CA1400005 | 311 | GW |
| THREE VALLEYS MWD | CA1910041 | — | SW |
How Claremont compares
Full California rankings →Claremont's score of 89/100 is above the average of 57/100 among major California cities. It outscores 8 of 10 nearby cities.
Nearby cities
View California rankings →About Claremont, CA
Wikipedia →Claremont is a suburban city in eastern Los Angeles County, California, United States, 30 miles (48 km) east of Los Angeles. It lies in the Pomona Valley at the foothills of the San Gabriel Mountains. As of the 2010 census, it had a population of 34,926, and in 2020 the population was 37,266.
Learn more about your water
Guides and resources related to Claremont's water quality findings.
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Frequently asked questions
Is Claremont, CA tap water safe to drink?
Claremont's water quality earned a grade of A- (89/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #171 out of 694 cities tested in California.
What contaminants are in Claremont's water?
Lead was measured at 1.7 ppb (90th percentile). 73 violations are on record.
How is Claremont's water quality grade calculated?
The grade is based on four factors: violation history (40%), lead and copper levels (25%), PFAS contamination (25%), and regulatory compliance (10%). The score is also adjusted based on how complete the available data is. See our methodology page for full details.
Do I need a water filter in Claremont?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Claremont's water come from?
Claremont's water is sourced from Purchased surface water. The city has 4 water systems serving approximately 1,789 residents.
What health violations has Claremont's water system had?
Claremont has 19 health-based violations on record. The most recent violation was recorded in August 2017. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 5 violations remain unresolved.
How does Claremont's water compare to other cities?
Claremont ranks #171 out of 694 cities in California (better than 75% of state cities) and #3117 out of 15744 cities nationally (80th percentile). The grade of A- reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.