01The verdict: is Bonita water safe?
Bonita's drinking water has significant quality concerns based on EPA testing data. With a grade of D (45/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 1 water system serves approximately 800 residents using groundwater (wells).
34 unresolved violations on record
EPA records show open compliance items for this system. Most are administrative, but unresolved items are worth watching.
See what was cited ↓Monitoring is on schedule
The system is meeting its EPA monitoring and reporting requirements — testing is happening when it should.
See the score ↓42 violations in the last five years
Recent compliance history is the best predictor of future problems — the year-by-year record is below.
See the record ↓Bonita's drinking water received a grade of D (45 out of 100), indicating poor water quality. The city's 1 water system serves approximately 800 residents using groundwater.
Lead levels were measured at 9.5 ppb (90th percentile), which is within EPA limits but above recommended levels. This system has not yet been tested for PFAS under the EPA UCMR 5 program. The system has 937 violations on record, including 4 health-based violations. 34 remain unresolved.
Bonita ranks #233 out of 271 cities in Arizona for water quality, placing it among the lowest-rated in the state. Bonita 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. While lead levels are within EPA limits, they are above the recommended 5 ppb threshold that health organizations consider ideal. A point-of-use filter adds an extra layer of protection. As a small community water system, Bonita may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities. The system has seen 42 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.
02What's in Bonita's water
Every contaminant flagged in Bonita, on one shared scale: distance to its own legal limit. The red line is the limit — anything past it is out of compliance, and the closer a bar gets, the less headroom the system has.
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. | 9.5 | 15 | ppb | Inorganic | Safe |
Cities ranked by 90th-percentile lead PF PFAS in Arizona
Cities ranked by compounds detected Cu Copper in Arizona
Cities ranked by 90th-percentile copper
03Bonita's ten-year track record
Each box is one year. A green check means no EPA violations; a numbered badge counts that year's violations — red if any were health-based, amber if they were monitoring or paperwork issues. The system has 937 violations on record, including 4 health-based violations. 34 remain unresolved.
2 of the last ten years were clean. The numbered years had EPA violations — red when any were health-based, amber when they were paperwork or missed-testing issues.
▲ Up 4.5 ppb since 2002. Latest reading: 9.5 ppb (2024) — 63% of the action level. Sampled at higher-risk homes (90th percentile).
04Where Bonita's water comes from
Bonita's drinking water is drawn from underground aquifers through wells.
Groundwater
Underground aquifers reached by wells — naturally filtered, but can carry minerals like arsenic and nitrate.
Local treatment
Groundwater generally needs less treatment — typically disinfection and, where needed, mineral removal.
1 system
1 water system, operated under state ownership.
800 people
Residents served across Bonita's service area.
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 state ownership and serves approximately 800 people through 1 water system.
| System name | PWSID | Population | Source |
|---|---|---|---|
| ADOC ASPC FORT GRANT | AZ0405303 | 800 | Groundwater |
Water bodies near Bonita
These water bodies shape the regional watershed and can indirectly affect groundwater quality.
05Pressure on Bonita's watershed
Outside forces that shape what reaches the treatment plant. None of these is a verdict on the tap by itself — but each adds pressure worth knowing about.
Flood & storm history
8 federal disaster declarations on record for Graham County. Flooding and severe storms can overwhelm treatment plants, cause sewage overflows, and push runoff into supplies.
Drought
Graham County is in D2 (severe drought) per the U.S. Drought Monitor (week of Jul 2026). Drought can raise disinfection-byproduct levels and taste/odor issues as utilities draw from lower reservoirs.
06How Bonita compares
Scores for nearby Arizona cities on one line, with the average marked.
dashed line = Arizona average (41/100)
Bonita scores 45/100 — on par with the Arizona average of 41/100. It outscores 8 of 10 nearby cities. Full Arizona rankings →
37.5 / 100FTucson, AZ
38.1 / 100FMesa, AZ
40.6 / 100FChandler, AZ
40.5 / 100FGilbert, AZ
34.8 / 100FScottsdale, AZ
43 / 100
Compare all cities in the county — grades, violations, and contaminant data side by side.→
07What to do at home
Steps matched to what testing actually found in Bonita's water — not generic advice.
Filter drinking & cooking water
NSF-certified water filter. Lead detected at 9.5 ppb
Compare tested filters →Flush taps & check your service line
Lead leaches from pipes as water sits. Run cold water 30 seconds before drinking (especially mornings), and ask the utility whether your address still has a lead service line.
Lead risks explained →Watch for Bonita alerts
This area has a history of flood declarations — after severe weather, watch for boil-water advisories from the utility, and check the live alerts on this page.
All water alerts →Frequently asked questions
Is Bonita, AZ tap water safe to drink?
Bonita's water quality earned a grade of D (45/100). Significant issues have been found. A water filter is strongly recommended. The city ranks #233 out of 271 cities tested in Arizona.
What contaminants are in Bonita's water?
Lead was measured at 9.5 ppb (90th percentile). 937 violations are on record.
How is Bonita'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 Bonita?
While lead levels are within EPA limits, a filter adds extra protection. Based on current data, basic filtration should suffice for additional peace of mind.
Where does Bonita's water come from?
Bonita's water is sourced from Groundwater. The city has 1 water system serving approximately 800 residents.
What health violations has Bonita's water system had?
Bonita has 4 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. 34 violations remain unresolved.
Is Bonita's groundwater at risk of contamination?
Bonita 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 937 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 Bonita's water compare to other cities?
Bonita ranks #233 out of 271 cities in Arizona (better than 14% of state cities) and #14006 out of 15382 cities nationally (9th percentile). The grade of D reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.
Does Bonita's small water system affect quality?
Bonita's system serves approximately 800 residents. Small community water systems (under 3,300 people) may have fewer financial resources for infrastructure upgrades and advanced treatment technologies. However, they are held to the same EPA drinking water standards as larger systems. This system has 937 violations on record.