Is Naco, AZ Tap Water Safe to Drink?
Graded C-, with 30 unresolved violations on record. See what was cited — and what it means for your tap. What to do next ↓
59.8/100
waterverge.com Naco, AZ — Water Quality Report
Naco's drinking water received a grade of C- (59.8 out of 100), indicating poor water quality. The city's 2 water systems serve approximately 733 residents using groundwater.
Lead levels were measured at 0.0 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 112 violations on record, including 4 health-based violations. 30 remain unresolved.
What to know about Naco's water
Naco ranks #164 out of 292 cities in Arizona for water quality, placing it below average in the state.
Naco 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, Naco may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
The system has seen 14 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.
Water quality score
See methodology →Is Naco, AZ water safe to drink?
Naco's drinking water has significant quality concerns based on EPA testing data. With a grade of C- (59.8/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 2 water systems serve approximately 733 residents using groundwater (wells).
Recent water quality updates for Naco
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Naco's water quality assessment. Grade: C- (59.8/100).
Contaminants: Consumer Confidence Rule.
Contaminants: Consumer Confidence Rule.
Contaminants: Public Notice, E. COLI.
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 Naco's water supply.
Well within EPA limits.
Violation history
Naco's water system has 112 total violations on record, including 4 health-based violations. 30 remain unresolved. 14 violations were issued in the last 5 years.
Flood & environmental risk
Maricopa County has experienced 10 federally declared disasters since 1966. 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 Naco's water come from?
Naco's drinking water comes from groundwater (wells), supplied by 2 water systems serving approximately 733 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate.
What Naco residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in Naco'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.
Naco'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 Naco
Industrial polluters nearby
Reported releases to surface water by facilities near Naco, ranked by pounds discharged annually.
| Facility | Top chemical | To surface water (lbs/yr) | Distance |
|---|---|---|---|
U.S. CBP BRIAN A. TERRY (NACO) BORDER PATROL STN #AZ0040 BISBEE, AZ85603 | — | — | 2.1 mi |
Source: EPA Toxic Release Inventory (TRI) 2023
Drought conditions
D1 — moderate droughtCochise County is currently in D1 (moderate drought) per the U.S. Drought Monitor (week of May 5, 2026). Drought can elevate disinfection-byproduct (TTHM/HAA5) levels and taste/odor issues as utilities draw from lower reservoirs.
Source: U.S. Drought Monitor, updated weekly by NDMC, USDA, and NOAA.
Flood & disaster history
Maricopa County has experienced 10 federally declared disasters since 1966. 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. | 0.0 | 15 | ppb | Inorganic | Safe |
Lead level trend (90th percentile)
See how Naco compares by contaminant
Explore where Naco ranks among all Arizona cities for specific contaminants.
Water source & infrastructure
Where Naco's water comes from
Naco'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 private ownership and serves approximately 733 people through 2 water systems.
Water systems serving Naco
| System Name | PWSID | Population | Source |
|---|---|---|---|
| NACO WATER CO MAIN | AZ0402024 | 658 | GW |
| NACO ESTATES | AZ0402345 | 75 | GW |
How Naco compares
Full Arizona rankings →Naco's score of 59.8/100 is above the average of 42/100 among major Arizona cities. It outscores 10 of 10 nearby cities.
Nearby cities
View Arizona rankings →About Naco, AZ
Wikipedia →Glendale is a city in Maricopa County, Arizona, United States. Located about nine miles northwest of the state capital, as a suburb of Phoenix, Glendale is known for State Farm Stadium, which is the home of the Arizona Cardinals football team. The city also contains the Arrowhead Towne Center shopping mall. As of the 2020 census, Glendale had a population of 248,325.
Learn more about your water
Guides and resources related to Naco's water quality findings.
Explore water quality across Cochise
Frequently asked questions
Is Naco, AZ tap water safe to drink?
Naco's water quality earned a grade of C- (59.8/100). Significant issues have been found. A water filter is strongly recommended. The city ranks #164 out of 292 cities tested in Arizona.
What contaminants are in Naco's water?
Lead was measured at 0.0 ppb (90th percentile). 112 violations are on record.
How is Naco'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 Naco?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Naco's water come from?
Naco's water is sourced from Groundwater. The city has 2 water systems serving approximately 733 residents.
What health violations has Naco's water system had?
Naco has 4 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. 30 violations remain unresolved.
Is Naco's groundwater at risk of contamination?
Naco 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 112 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 Naco's water compare to other cities?
Naco ranks #164 out of 292 cities in Arizona (better than 44% of state cities) and #12145 out of 15744 cities nationally (23th percentile). The grade of C- reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.