Record-only indicator: D
Not a safety rating. Missing or old measurements can produce a high score.
Coverage: 8/8 mapped systems have a dated lead result; 0/8 have copper results; 1/8 have UCMR monitoring.
| Contaminant | Reported value or bound | Historical comparison value | Interpretation | Status |
|---|---|---|---|---|
| Lead |
<5.0 ppbPeriod end: 12/31/2025
|
15 ppb | Largest reported value or bound among mapped systems; not necessarily the largest actual concentration. | Reported bound |
UCMR5 occurrence results are screening information, not a finding of regulatory compliance or noncompliance. PFAS rules and compliance dates are evolving.
| Compound | Level | EPA MCL | Interpretation | Status |
|---|---|---|---|---|
| PFBS | 53.8 ppt | No standard | 100 ppt | No federal MCL shown |
Public-record summary
Record-only indicator — incomplete or old records can produce a high score. A score of 100 is not a safety finding. Coverage: 8/8 mapped systems have a dated lead result; 0/8 have copper results; 1/8 have UCMR monitoring. Tap water quality in San Carlos, Arizona (85550) receives an record-only indicator of D (Elevated record-based concern) with a score of 47 out of 100, based on analysis of EPA compliance data, contaminant testing, and violation history. This is 25 points below the Arizona state average of 72. The area is served by 8 water systems providing water to approximately 8,478 people, using groundwater sources. PFAS testing detected 1 compound, all below the EPA final MCL values used for comparison. Over the past 5 years, water systems here have accumulated 271 violations, including 56 health-based violations.
Grade D summarizes the records available to this model, not household safety. Missing, bounded or old measurements can produce a high score, including 100. Review coverage, dates and the current utility report before interpreting this indicator.
Health Information
Lead is a toxic metal that can leach from aging pipes and plumbing fixtures.
Even low levels of lead exposure can cause developmental delays in children, kidney damage, and cardiovascular effects in adults. The EPA action level is 15 ppb, but health experts recommend no safe level of lead in drinking water.
Lead enters water primarily through corrosion of lead service lines, lead solder, and brass fixtures — especially in homes built before 1986.
If lead is detected above 1 ppb, consider using a certified lead-removal filter (NSF/ANSI 53) for drinking and cooking water. Run cold water for 30 seconds before use if water has been sitting in pipes.
Common Questions
The record-only indicator is D (47/100). It cannot determine whether your tap water is safe. Missing, bounded or old measurements can produce a high score. Check the coverage and sampling dates below and your utility's current notices.
ZIP code 85550 is served by 8 water systems using groundwater sources, providing water to approximately 8,478 people. Groundwater is naturally filtered through rock and soil, often requiring less treatment. However, it can be vulnerable to contamination from underground sources like naturally occurring arsenic, nitrates from agriculture, or PFAS from industrial sites.
The largest reported lead value or bound is <5.0 ppb, for the sampling period ending 12/31/2025. This is a system-level 90th-percentile record, not a measurement at your tap. Compare the sampling date and original utility report before interpreting it.
1 PFAS compound were detected in water serving San Carlos, Arizona, with no result above the individual comparison values shown here; some compounds have no individual federal MCL. This comparison is informational: federal compliance timelines and the status of some PFAS standards are still evolving. Activated carbon or reverse osmosis filters can reduce some PFAS when appropriately certified and maintained.
Water systems serving San Carlos, Arizona have received 271 violations in the last 5 years, including 56 health-based violations. Violations can range from paperwork issues (monitoring & reporting) to serious health-based violations where contaminant levels exceeded safe limits. Review the violation details above for specifics.
This public-record indicator cannot select household treatment. Confirm your supplier, current utility report and tap-testing results first; match any treatment to a certified contaminant-reduction claim and follow its maintenance instructions.
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