Duncan, AZ: 4 Health Violations — 74/100 (2026)
1 ZIP code · 3 water systems · Updated 2026-06-03
Based on current monitoring, Duncan holds an above-average drinking water safety record for AZ — violations are infrequent and typically minor when they do appear.
How Duncan Compares
Data: EPA SDWIS Last verified: 2026-06-03
What You Should Know About Duncan Water
- Your city's water systems recorded 42 violations in the past 5 years.
- Average lead level: 0.0035 mg/L.
- Homes built before 1986: 62% — older plumbing may contain lead solder.
- Estimated remediation: $2,200 per household.
- CDC health risk index: 11.24.
Who Supplies Your Water in Duncan
Duncan, AZ draws its residential water from 3 separate providers among the 3 federally tracked systems. Each operates independently, with its own infrastructure, rate structure, and compliance record.
Overview
We track water quality and home safety data for 1 ZIP code in Duncan, Arizona, covering 3 community water systems serving approximately 3,088 people.
1 of 1 ZIP code (100%) have recorded EPA violations. 4 health-based violations documented.
Home Safety Score
Average Home Safety Score for Duncan: B (74/100)
The score combines three factors:
| Factor | What It Measures |
|---|---|
| Water Quality | EPA violations and compliance history |
| Lead Levels | 90th percentile lead concentration vs EPA action level |
| Radon Risk | EPA radon zone classification |
Water Sources
Duncan water systems draw from: Groundwater.
Lead & Copper
- Average lead level (90th percentile): 0.0035 mg/L (EPA action level: 0.015 mg/L)
- 0 ZIP codes exceed the EPA lead action level
Radon Risk
Dominant radon zone: Zone 2 (Moderate Risk)
The EPA recommends testing homes in Zone 1 and Zone 2 areas for radon.
Top Contaminants
| Contaminant | Category | Violations | ZIPs Affected |
|---|---|---|---|
| Consumer Confidence Report Rule | Reporting | 24 | 1 |
| Surface Water Treatment Rule | Treatment Technique | 14 | 1 |
| Atrazine | Organic | 12 | 1 |
| Lead and Copper Rule | Treatment Technique | 10 | 1 |
| Revised Total Coliform Rule | Microbiological | 8 | 1 |
Areas with Most Violations
| ZIP Code | Safety Score | Violations | Health-Based | System |
|---|---|---|---|---|
| 85534 | B | 42 | 4 | Duncan Town of |
All ZIP Codes in Duncan
- 85534 [B] — 42 violations ⚠
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Lead/copper: EPA Lead and Copper Rule sampling data
- Radon: EPA Map of Radon Zones
Updated daily.
Health Outcomes in Duncan
Source: CDC PLACES (County-level estimates). Water contamination can correlate with respiratory and chronic health conditions.
Compared to National Average
Vertical line = national average. ■ Above national · ■ Below national
Top Contaminants in Duncan Water
Based on EPA violation records. Check your ZIP code report for system-specific contaminant data.
Housing & Infrastructure in Duncan
With 62% of homes built before 1986, lead solder in plumbing is a potential concern. The EPA banned lead solder in 1986, but many older homes retain original plumbing.
Source: U.S. Census Bureau American Community Survey (ACS).
Housing Age Profile
Duncan's housing stock is predominantly older, with a median build year of 1987 that reflects decades of construction before federal plumbing standards were tightened. The 1986 ban on lead solder and the pre-1970 era of lead service lines are both relevant benchmarks here — a significant share of the residential inventory predates one or both of those cutoffs, creating an elevated baseline for plumbing-related lead risk that aggregate water quality data may not fully reflect at the household level.
Over half of homes in Duncan were built before 1986, when lead solder was banned. Older plumbing may leach lead into drinking water, especially with corrosive water chemistry.
Source: U.S. Census Bureau ACS B25034.
Cost Context: What Remediation Means for Duncan Homeowners
The household financial perspective in Duncan reflects a moderate cost-to-value ratio — an equity share that is not trivially small but remains within the range where most homeowners can address documented water and safety issues by treating the expense as a real line item in property planning rather than a discretionary one.
Remediation costs are moderate relative to home values in Duncan. The estimated $1,100–$4,100 range is manageable for most homeowners but still worth budgeting for. Home values are 48% below the Arizona average.
Lead Exposure Risk for Children in Duncan
Why children are most at risk: The CDC states there is no safe level of lead exposure for children. Children under 6 absorb lead more readily than adults, and even low levels can cause developmental delays, learning difficulties, and behavioral problems.
Pulling a tap sample fills the gap that utility data cannot close, particularly here where 62% of housing dates from the pre-rule era and citywide monitoring sits at or above the regulatory mark in Duncan.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Flood & Climate Risk in Duncan
Multiple flood events have been recorded for Duncan through the NFIP — 37 claims in total, with 100% of ZIP codes in FEMA-designated zones — pointing to a flood exposure profile that merits inclusion in a water quality assessment without reaching high-severity planning territory.
Duncan has a moderate flood history with 37 FEMA claims averaging $12,516 per payout. 100% of ZIP codes fall within FEMA flood zones. Flood events can contaminate drinking water and overwhelm treatment systems.
How flooding affects water quality: Flood events can introduce sewage, agricultural runoff, and industrial chemicals into water supplies. Even after floodwaters recede, contamination can persist in wells and aging infrastructure. Flood damage can add significantly to the estimated <strong>$2,200</strong> remediation cost per household.
Residents in flood-prone areas should consider flood insurance even outside FEMA zones — over 25% of flood claims come from low-to-moderate risk areas. After any flood event, test your water before drinking.
Source: FEMA National Flood Insurance Program (NFIP) claims data, FEMA flood zone designations.
Deep Dive Reports
Detailed analysis for Duncan, AZ