Tap Water Quality Report
Tap water quality in CALDWELL, Idaho
Tap water in CALDWELL, Idaho receives a grade of C (73/100) from TapWaterSafety.org. It's served by CALDWELL CITY OF. The most significant water quality concerns are: Arsenic significantly above health guideline; Chromium (hexavalent) significantly above health guideline. Data sources: EPA SDWIS, EPA ECHO, EWG Tap Water Database.
What's in CALDWELL's tap water
Top water quality concerns identified by the EPA and Environmental Working Group across the utility serving CALDWELL.
Arsenic significantly above health guideline
Moderate concernArsenic detected at 8.3 ppb, 2075x above the EWG health guideline of 0.004 ppb.
Chromium (hexavalent) significantly above health guideline
Moderate concernChromium (hexavalent) detected at 3.08 ppb, 154x above the EWG health guideline of 0.02 ppb.
EPA compliance record
Official U.S. EPA records for CALDWELL CITY OF (system ID ID3140013) for the last 3 years. Checked 2026-10-07.
| Rule | Type | Since | Status |
|---|---|---|---|
| Lead and Copper Rule | Missed testing or reporting | 09/29/2018 | Open |
Source: U.S. EPA Enforcement and Compliance History Online (ECHO), from the Safe Drinking Water Information System. See EPA's full report.
Recommended filters for CALDWELL
Filters matched to the specific contaminants in CALDWELL's water supply.
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All contaminants detected in CALDWELL'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 |
8.3 ppb | 0.004 | 10.0 | 10 | 10 | 0.004 | — | 2075× over |
| Chromium (hexavalent) Heavy metal |
3.08 ppb | 0.02 | — | — | — | — | — | 154× over |
| Uranium Radiological |
4.02 pCi/L | 0.43 | 20.0 | 30 | 30 | 0.43 | — | 9.3× over |
| Nitrate Inorganic |
0.71 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 5.1× over |
| Nitrate and nitrite Inorganic |
0.3 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 2.1× over |
| Vanadium Other |
8.93 ppb | 21.0 | — | — | — | — | — | Below guideline |
| Chlorate Disinfection byproduct |
29.6 ppb | 210.0 | — | — | — | — | — | Below guideline |
| Molybdenum Other |
2.85 ppb | 40.0 | — | — | — | — | — | Below guideline |
| Manganese Heavy metal |
1.41 ppb | 100.0 | — | 50 | 80 | — | — | Below guideline |
| Strontium Radiological |
0.164 ppb | 1500.0 | — | — | — | — | — | Below guideline |
| Fluoride Inorganic |
0.4 ppm | — | 4.0 | 1.5 | 1.5 | — | — | Below guideline |
| Germanium Other |
0.228 ppb | — | — | — | — | — | — | Below guideline |
| Lithium Other |
7.36 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 CALDWELL CITY OF.