Is Big River, AZ Tap Water Safe to Drink?
Graded D — but Copper was detected above EPA limits. Here's what's in the water and how to remove it. What to do next ↓
46/100
waterverge.com Big River, AZ — Water Quality Report
Big River's drinking water received a grade of D (46 out of 100), indicating poor water quality. The city's 1 water system serves approximately 3,550 residents using groundwater.
Lead levels were measured at 2.7 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 236 violations on record, including 7 health-based violations. 19 remain unresolved.
What to know about Big River's water
Big River ranks #232 out of 292 cities in Arizona for water quality, placing it among the lowest-rated in the state.
Big River 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 23 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.
Water quality score
See methodology →Is Big River, AZ water safe to drink?
Big River's drinking water has significant quality concerns based on EPA testing data. With a grade of D (46/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 1 water system serves approximately 3,550 residents using groundwater (wells).
Recent water quality updates for Big River
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Big River's water quality assessment. Grade: D (46/100).
Contaminants: Revised Total Coliform Rule.
Contaminants: Public Notice, Revised Total Coliform Rule.
Contaminants: Chlorine.
Federal disaster declaration (FEMA DR-4203). Flood event — may have impacted local water infrastructure.
Federal disaster declaration (FEMA DR-3241). Hurricane event — may have impacted local water infrastructure.
Key contaminant findings
Based on the most recent EPA sampling data for Big River'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
Big River's water system has 236 total violations on record, including 7 health-based violations. 19 remain unresolved. 23 violations were issued in the last 5 years.
Flood & environmental risk
La Paz County has experienced 3 federally declared disasters since 1983. 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 Crir Main Canal, Gardner Lateral Spill.
Where does Big River's water come from?
Big River's drinking water comes from groundwater (wells), supplied by 1 water system serving approximately 3,550 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate. Nearby water bodies include Crir Main Canal (stream), Gardner Lateral Spill (river).
What Big River residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in Big River'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.
Big River'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
La Paz County has experienced 3 federally declared disasters since 1983. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
Recommended water filters
Based on contaminants detected in Big River'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. | 2.7 | 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. | 1.50 | 1.3 | mg/L | Inorganic | Over Limit |
Lead level trend (90th percentile)
Copper level (90th percentile)
Latest reading: 1.500 mg/L (1993)
EPA action level: 1.3 mg/L
See how Big River compares by contaminant
Explore where Big River ranks among all Arizona cities for specific contaminants.
Water source & infrastructure
Where Big River's water comes from
Big River'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 native american ownership and serves approximately 3,550 people through 1 water system.
Water bodies near Big River
Big River is located near 2 notable water bodies. These water bodies contribute to the regional watershed and may indirectly affect groundwater quality.
Water systems serving Big River
| System Name | PWSID | Population | Source |
|---|---|---|---|
| Big River Development | 090600226 | 3,550 | GW |
How Big River compares
Full Arizona rankings →Big River's score of 46/100 is on par with the average of 42/100 among major Arizona cities. It outscores 9 of 10 nearby cities.
Nearby cities
View Arizona rankings →About Big River, AZ
Wikipedia →Parker is a city in and the county seat of La Paz County, Arizona, United States, on the Colorado River in Parker Valley. As of the 2020 census, the population of the city was 3,417.
Learn more about your water
Guides and resources related to Big River's water quality findings.
Frequently asked questions
Is Big River, AZ tap water safe to drink?
Big River's water quality earned a grade of D (46/100). Significant issues have been found. A water filter is strongly recommended. The city ranks #232 out of 292 cities tested in Arizona.
What contaminants are in Big River's water?
Lead was measured at 2.7 ppb (90th percentile). 236 violations are on record.
How is Big River'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 Big River?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Big River's water come from?
Big River's water is sourced from Groundwater. The city has 1 water system serving approximately 3,550 residents.
What health violations has Big River's water system had?
Big River has 7 health-based violations on record. The most recent violation was recorded in December 2025. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 19 violations remain unresolved.
Is Big River's groundwater at risk of contamination?
Big River 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 236 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 Big River's water compare to other cities?
Big River ranks #232 out of 292 cities in Arizona (better than 21% of state cities) and #13980 out of 15744 cities nationally (11th percentile). The grade of D reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.