01The verdict: is Circle City water safe?
Circle City's drinking water has significant quality concerns based on EPA testing data. With a grade of B+ (83.4/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 1 water system serves approximately 815 residents using groundwater (wells).
21 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 ↓Lead is well under the limit
90th-percentile lead is 0.0 ppb — beneath the 15 ppb federal action level and under the 5 ppb watch threshold.
See the trend ↓3 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 ↓Circle City's drinking water received a grade of B+ (83.4 out of 100), indicating good water quality. The city's 1 water system serves approximately 815 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 56 violations on record, including 1 health-based violation. 21 remain unresolved.
Circle City ranks #98 out of 271 cities in Arizona for water quality, placing it mid-range in the state. Circle City 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, Circle City may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
02What's in Circle City's water
Every contaminant flagged in Circle City, 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. | 0.0 | 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
03Circle City'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 56 violations on record, including 1 health-based violation. 21 remain unresolved.
4 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.
▼ Down 0 ppb since 2004. Latest reading: 0 ppb (2026) — 0% of the action level. Sampled at higher-risk homes (90th percentile).
04Where Circle City's water comes from
Circle City'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 private ownership.
815 people
Residents served across Circle City'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 private ownership and serves approximately 815 people through 1 water system.
| System name | PWSID | Population | Source |
|---|---|---|---|
| BROOKE WATER LLC - CIRCLE CITY WC | AZ0407112 | 815 | Groundwater |
Water bodies near Circle City
These water bodies shape the regional watershed and can indirectly affect groundwater quality.
05Pressure on Circle City'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
9 federal disaster declarations on record for Pima County. Flooding and severe storms can overwhelm treatment plants, cause sewage overflows, and push runoff into supplies.
Drought
Maricopa 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 Circle City compares
Scores for nearby Arizona cities on one line, with the average marked.
dashed line = Arizona average (41/100)
Circle City scores 83.4/100 — above the Arizona average of 41/100. It outscores 10 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 Circle City's water — not generic advice.
A basic carbon filter still helps
Circle City's water meets federal standards, but a simple carbon filter improves taste and adds a margin of safety against short-term issues.
Compare tested filters →Read your utility's annual report
Every utility must publish a yearly Consumer Confidence Report with its own testing results. It pairs well with the independent data on this page.
How to read a CCR →Watch for Circle City 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 Circle City, AZ tap water safe to drink?
Circle City's water quality earned a grade of B+ (83.4/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #98 out of 271 cities tested in Arizona.
What contaminants are in Circle City's water?
Lead was measured at 0.0 ppb (90th percentile). 56 violations are on record.
How is Circle City'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 Circle City?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Circle City's water come from?
Circle City's water is sourced from Groundwater. The city has 1 water system serving approximately 815 residents.
What health violations has Circle City's water system had?
Circle City has 1 health-based violation on record. The most recent violation was recorded in October 2023. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 21 violations remain unresolved.
Is Circle City's groundwater at risk of contamination?
Circle City 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 56 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 Circle City's water compare to other cities?
Circle City ranks #98 out of 271 cities in Arizona (better than 64% of state cities) and #6413 out of 15382 cities nationally (58th percentile). The grade of B+ reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.
Does Circle City's small water system affect quality?
Circle City's system serves approximately 815 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 56 violations on record.