Tap Water Quality Report
Tap water quality in JOHNSON RANCH, Arizona
Tap water in JOHNSON RANCH, Arizona receives a grade of D (65/100) from TapWaterSafety.org. It's served by EPCOR - SAN TAN. The most significant water quality concerns are: Arsenic significantly above health guideline; Chromium (hexavalent) significantly above health guideline; Nitrate and nitrite significantly above health guideline. Data sources: EPA SDWIS, EPA ECHO, EWG Tap Water Database.
What's in JOHNSON RANCH's tap water
Top water quality concerns identified by the EPA and Environmental Working Group across the utility serving JOHNSON RANCH.
Arsenic significantly above health guideline
Moderate concernArsenic detected at 3.78 ppb, 946x above the EWG health guideline of 0.004 ppb.
Chromium (hexavalent) significantly above health guideline
Moderate concernChromium (hexavalent) detected at 3.47 ppb, 173x above the EWG health guideline of 0.02 ppb.
Nitrate and nitrite significantly above health guideline
Moderate concernNitrate and nitrite detected at 6.21 ppm, 44x above the EWG health guideline of 0.14 ppm.
EPA compliance record
Official U.S. EPA records for EPCOR - SAN TAN (system ID AZ0411128) for the last 3 years. Checked 2026-10-07.
| Rule | Type | Since | Status |
|---|---|---|---|
| Stage 1 Disinfectants and Disinfection Byproducts Rule | Missed testing or reporting | 04/01/2024 | Open |
| Volatile Organic Chemicals | Missed testing or reporting | 01/01/2024 | Open |
| Nitrate Rule | Missed testing or reporting | 01/01/2024 | Open |
Source: U.S. EPA Enforcement and Compliance History Online (ECHO), from the Safe Drinking Water Information System. See EPA's full report.
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Filters matched to the specific contaminants in JOHNSON RANCH's water supply.
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All contaminants detected in JOHNSON RANCH's tap water
Every contaminant identified, compared side-by-side against US EPA legal limits, the EU Drinking Water Directive (2020/2184), WHO Guidelines, and California's Public Health Goal. Why we show multiple standards →
| Contaminant | Detected | EWG US health-based |
EPA US legal |
EU DWD Europe |
WHO global |
CA PHG strictest US |
Tested sample year |
Status |
|---|---|---|---|---|---|---|---|---|
| Arsenic Heavy metal |
3.78 ppb | 0.004 | 10.0 | 10 | 10 | 0.004 | — | 946× over |
| Chromium (hexavalent) Heavy metal |
3.47 ppb | 0.02 | — | — | — | — | — | 173× over |
| Nitrate and nitrite Inorganic |
6.21 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 44× over |
| Nitrate Inorganic |
5.81 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 41× over |
| Haloacetic acids (HAA9) Disinfection byproduct |
1.02 ppb | 0.06 | — | — | — | — | — | 17× over |
| Uranium Radiological |
4.89 pCi/L | 0.43 | 20.0 | 30 | 30 | 0.43 | — | 11× over |
| Total trihalomethanes (TTHMs) Disinfection byproduct |
1.29 ppb | 0.15 | 80.0 | 100 | — | — | — | 8.6× over |
| Radium, combined (-226 and -228) Radiological |
0.31 pCi/L | 0.05 | 5.0 | — | — | — | — | 6.1× over |
| Dibromochloromethane Disinfection byproduct |
0.375 ppb | 0.1 | — | — | — | — | — | 3.8× over |
| Bromoform Disinfection byproduct |
1.15 ppb | 0.5 | — | — | — | — | — | 2.3× over |
| Vanadium Other |
13.6 ppb | 21.0 | — | — | — | — | — | Below guideline |
| Barium Heavy metal |
40.5 ppb | 700.0 | 2000.0 | — | 1300 | 2000 | — | Below guideline |
| Molybdenum Other |
1.5 ppb | 40.0 | — | — | — | — | — | Below guideline |
| Selenium Heavy metal |
1.07 ppb | 30.0 | 50.0 | 20 | 40 | 30 | — | Below guideline |
| Manganese Heavy metal |
1.04 ppb | 100.0 | — | 50 | 80 | — | — | Below guideline |
| Chlorate Disinfection byproduct |
2.0 ppb | 210.0 | — | — | — | — | — | Below guideline |
| Strontium Radiological |
0.83 ppb | 1500.0 | — | — | — | — | — | Below guideline |
| Chromium (total) Heavy metal |
3.37 ppb | — | 100.0 | — | — | — | — | Below guideline |
| Fluoride Inorganic |
0.453 ppm | — | 4.0 | 1.5 | 1.5 | — | — | Below guideline |
| Germanium Other |
0.385 ppb | — | — | — | — | — | — | Below guideline |
| Lithium Other |
112.7 ppb | — | — | — | — | — | — | Below guideline |
All values in the unit of the detected level. Red cells indicate the detected level exceeds that standard. Some contaminants have limits in some jurisdictions but not others (shown as —). The "Tested" column shows the year each contaminant sample was collected.
Sources: US EPA, EU Drinking Water Directive 2020/2184, WHO Guidelines, California OEHHA PHGs, EWG Tap Water Database.
Treatment plant contact info
For service issues, water quality concerns, or to request a Consumer Confidence Report from EPCOR - SAN TAN.