Is Shonto, AZ Tap Water Safe to Drink?
Graded B+, with 15 unresolved violations on record. See what was cited — and what it means for your tap. What to do next ↓
84.3/100
waterverge.com Shonto, AZ — Water Quality Report
Shonto's drinking water received a grade of B+ (84.3 out of 100), indicating good water quality. The city's 2 water systems serve approximately 1,061 residents using groundwater.
Lead levels were measured at 1.1 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 110 violations on record, including 0 health-based violations. 15 remain unresolved.
What to know about Shonto's water
Shonto ranks #92 out of 292 cities in Arizona for water quality, placing it mid-range in the state.
Shonto 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.
As a small community water system, Shonto may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
Water quality score
See methodology →Is Shonto, AZ water safe to drink?
Shonto's drinking water has significant quality concerns based on EPA testing data. With a grade of B+ (84.3/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 2 water systems serve approximately 1,061 residents using groundwater (wells).
Recent water quality updates for Shonto
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Shonto's water quality assessment. Grade: B+ (84.3/100).
Contaminants: Revised Total Coliform Rule.
Contaminants: Revised Total Coliform Rule.
Contaminants: Revised Total Coliform Rule.
Federal disaster declaration (FEMA DR-4620). 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 Shonto's water supply.
Well within EPA limits.
Violation history
Shonto's water system has 110 total violations on record, including 0 health-based violations. 15 remain unresolved. 3 violations were issued in the last 5 years.
Flood & environmental risk
Navajo County has experienced 8 federally declared disasters since 1970. 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 Shonto's water come from?
Shonto's drinking water comes from groundwater (wells), supplied by 2 water systems serving approximately 1,061 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate.
What Shonto residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in Shonto'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.
Shonto'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
Navajo County has experienced 8 federally declared disasters since 1970. 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. | 1.1 | 15 | ppb | Inorganic | Safe |
Lead level trend (90th percentile)
See how Shonto compares by contaminant
Explore where Shonto ranks among all Arizona cities for specific contaminants.
Water source & infrastructure
Where Shonto's water comes from
Shonto'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 1,061 people through 2 water systems.
Water systems serving Shonto
| System Name | PWSID | Population | Source |
|---|---|---|---|
| Shonto Preparatory Boarding School BIA | NN0433016 | 664 | GW |
| Shonto NTUA | NN0400322 | 397 | GW |
How Shonto compares
Full Arizona rankings →Shonto's score of 84.3/100 is above the average of 42/100 among major Arizona cities. It outscores 10 of 10 nearby cities.
Nearby cities
View Arizona rankings →About Shonto, AZ
Learn more about your water
Guides and resources related to Shonto's water quality findings.
Frequently asked questions
Is Shonto, AZ tap water safe to drink?
Shonto's water quality earned a grade of B+ (84.3/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #92 out of 292 cities tested in Arizona.
What contaminants are in Shonto's water?
Lead was measured at 1.1 ppb (90th percentile). 110 violations are on record.
How is Shonto'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 Shonto?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Shonto's water come from?
Shonto's water is sourced from Groundwater. The city has 2 water systems serving approximately 1,061 residents.
Is Shonto's groundwater at risk of contamination?
Shonto 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 110 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 Shonto's water compare to other cities?
Shonto ranks #92 out of 292 cities in Arizona (better than 68% of state cities) and #5991 out of 15744 cities nationally (62th percentile). The grade of B+ reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.