Is Three Rivers, CA Tap Water Safe to Drink?
Graded F — but Copper was detected above EPA limits. Here's what's in the water and how to remove it. What to do next ↓
43.5/100
waterverge.com Three Rivers, CA — Water Quality Report
Three Rivers's drinking water received a grade of F (43.5 out of 100), indicating failing water quality. The city's 12 water systems serve approximately 10,513 residents using groundwater.
Lead levels were measured at 3.0 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 348 violations on record, including 177 health-based violations. 44 remain unresolved.
What to know about Three Rivers's water
Three Rivers ranks #653 out of 694 cities in California for water quality, placing it among the lowest-rated in the state.
Three Rivers relies on groundwater, which is generally less vulnerable to surface contamination but can be affected by naturally occurring minerals like arsenic and nitrate, as well as agricultural and industrial runoff.
The system has seen 42 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.
Water quality score
See methodology →Is Three Rivers, CA water safe to drink?
Three Rivers's drinking water has significant quality concerns based on EPA testing data. With a grade of F (43.5/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 12 water systems serve approximately 10,513 residents using groundwater (wells).
Recent water quality updates for Three Rivers
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Three Rivers's water quality assessment. Grade: F (43.5/100).
1 health-based. Contaminants: Consumer Confidence Rule, Lead and Copper Rule, Arsenic.
1 health-based. Contaminants: LEAD AND COPPER RULE REVISIONS, Consumer Confidence Rule, Arsenic.
Contaminants: TTHM, Total Haloacetic Acids (HAA5).
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.
Key contaminant findings
Based on the most recent EPA sampling data for Three Rivers's water supply.
Well within EPA limits.
Exceeds EPA action level. Copper can leach from household plumbing — flush taps for 30 seconds before drinking.
Violation history
Three Rivers's water system has 348 total violations on record, including 177 health-based violations. 44 remain unresolved. 42 violations were issued in the last 5 years.
Flood & environmental risk
Tulare County has experienced 9 federally declared disasters since 1967. Flooding and severe storms can overwhelm water treatment plants, cause sewage overflows, and introduce agricultural runoff, bacteria, and sediment into drinking water supplies.
Where does Three Rivers's water come from?
Three Rivers's drinking water comes from groundwater (wells), supplied by 12 water systems serving approximately 10,513 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate.
What Three Rivers residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in Three Rivers'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.
Three Rivers'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
Flood & disaster history
Tulare County has experienced 9 federally declared disasters since 1967. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
Recommended water filters
Based on contaminants detected in Three Rivers's water supply, we recommend the following filter types.
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. | 3.0 | 15 | ppb | Inorganic | Safe |
| Copper (90th percentile) CopperInorganic A metal that enters drinking water mainly through corrosion of copper plumbing. Small amounts are essential for health, but excess levels are harmful. Health EffectsGastrointestinal distress (nausea, vomiting, diarrhea) at short-term high levels; liver and kidney damage from long-term exposure. EPA Limit1.3 mg/L action level Common SourcesCorrosion of copper household plumbing, erosion of natural deposits. | 1.56 | 1.3 | mg/L | Inorganic | Over Limit |
Lead level trend (90th percentile)
Copper level trend (90th percentile)
See how Three Rivers compares by contaminant
Explore where Three Rivers ranks among all California cities for specific contaminants.
Water source & infrastructure
Where Three Rivers's water comes from
Three Rivers's drinking water is drawn from underground aquifers through wells.
Groundwater is naturally filtered through rock and soil layers, generally requiring less treatment than surface water. However, it can contain naturally occurring contaminants like arsenic, radon, and minerals.
Agricultural activity, septic systems, and industrial operations near well fields can introduce nitrates, pesticides, and volatile organic compounds.
The system is operated by federal ownership and serves approximately 10,513 people through 12 water systems.
Water systems serving Three Rivers
| System Name | PWSID | Population | Source |
|---|---|---|---|
| NPS-GRANT GROVE | CA1010501 | 2,950 | GW |
| NPS-WOLVERTON | CA5410503 | 2,940 | SW |
| NPS-ASH MOUNTAIN | CA5410513 | 2,930 | GU |
| NORTH KAWEAH MUTUAL WATER COMPANY | CA5400506 | 560 | GU |
| SOUTH KAWEAH MUTUAL WATER COMPANY | CA5400754 | 384 | GW |
| SIERRA KING HOMEOWNERS ASSN | CA5400940 | 260 | GW |
| IMPROVEMENT DISTRICT NO. 1 | CA5400968 | 200 | SW |
| SOUTH FORK ESTATES MUTUAL WATER CO | CA5403113 | 106 | GW |
| DEER MEADOW MUTUAL WATER COMPANY | CA5401026 | 70 | GW |
| RIVER RETREAT MUTUAL WATER COMPANY | CA5400556 | 40 | GW |
| EAST THREE RIVERS MUTUAL WATER CORP | CA5400744 | 40 | GW |
| VILLAGE APARTMENTS | CA5400875 | 33 | GW |
How Three Rivers compares
Full California rankings →Three Rivers's score of 43.5/100 is below the average of 57/100 among major California cities. It outscores 5 of 10 nearby cities.
Nearby cities
View California rankings →About Three Rivers, CA
Wikipedia →Three Rivers is an unincorporated community and census-designated place (CDP) in Tulare County, California, United States. Located in the foothills of the Sierra Nevada at the edge of the San Joaquin Valley, the town is near the entrance to the national parks of Sequoia and Kings Canyon. The town's name comes from its location near the junction of the North, Middle, and South Forks of the Kaweah River.
Learn more about your water
Guides and resources related to Three Rivers's water quality findings.
Explore water quality across Fresno
Frequently asked questions
Is Three Rivers, CA tap water safe to drink?
Three Rivers's water quality earned a grade of F (43.5/100). Significant issues have been found. A water filter is strongly recommended. The city ranks #653 out of 694 cities tested in California.
What contaminants are in Three Rivers's water?
Lead was measured at 3.0 ppb (90th percentile). 348 violations are on record.
How is Three Rivers'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 Three Rivers?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Three Rivers's water come from?
Three Rivers's water is sourced from Groundwater. The city has 12 water systems serving approximately 10,513 residents.
What health violations has Three Rivers's water system had?
Three Rivers has 177 health-based violations on record. The most recent violation was recorded in October 2025. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 44 violations remain unresolved.
Is Three Rivers's groundwater at risk of contamination?
Three Rivers uses groundwater, which can be affected by naturally occurring contaminants like arsenic, radon, and nitrate, as well as agricultural runoff and industrial activity. The system has 348 violations on record that may relate to groundwater quality. Groundwater systems are generally less susceptible to surface contamination but should be monitored for emerging contaminants like PFAS.
How does Three Rivers's water compare to other cities?
Three Rivers ranks #653 out of 694 cities in California (better than 6% of state cities) and #14559 out of 15744 cities nationally (8th percentile). The grade of F reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.