Water Quality Report · Updated May 12, 2026
NAMPA CITY OF
NAMPA CITY OF delivers tap water graded D (60/100) by TapWaterSafety.org. The utility serves approximately 100,200 residents in NAMPA, Idaho using groundwater. The most significant water quality concerns are: Arsenic significantly above health guideline; Chromium (hexavalent) significantly above health guideline; Dibromoacetic acid significantly above health guideline. For questions, the utility can be reached at 208-468-5860.
Is NAMPA tap water safe to drink?
NAMPA CITY OF delivers tap water that earns a grade of D (60/100) from TapWaterSafety.org — a below-average rating, with multiple concerns including arsenic significantly above health guideline.
The utility serves 100,200 residents in NAMPA, drawing from groundwater.
Public testing data identifies 12 contaminants in this water above EWG's health-based guidelines, including: Arsenic, Chromium (hexavalent), Dibromoacetic acid, Total trihalomethanes (TTHMs), Haloacetic acids (HAA9), Uranium, Nitrate, Haloacetic acids (HAA5), Radium, combined (-226 and -228), Bromoform, Dibromochloromethane, Nitrate and nitrite. For most residents, a properly certified home filter at the kitchen tap is the most cost-effective way to reduce exposure to whatever's in your water. See our filter recommendations below, matched specifically to this utility's contaminant profile.
Quick actions for NAMPA residents
Top concerns in this water
Based on the most recent EPA and EWG data, these are the most significant water quality issues for NAMPA CITY OF.
Arsenic significantly above health guideline
Moderate concernArsenic detected at 4.74 ppb, 1184x above the EWG health guideline of 0.004 ppb.
Chromium (hexavalent) significantly above health guideline
Moderate concernChromium (hexavalent) detected at 2.62 ppb, 131x above the EWG health guideline of 0.02 ppb.
Dibromoacetic acid significantly above health guideline
Moderate concernDibromoacetic acid detected at 1.17 ppb, 39x above the EWG health guideline of 0.03 ppb.
Contact NAMPA CITY OF
Reach the utility directly for service issues, water quality concerns, or to request your Consumer Confidence Report.
General Contact
Treatment Plant
Recommended water filters for NAMPA
Filters matched to the specific contaminants in this water supply.
Reverse Osmosis
$249-$750Arsenic is most effectively removed by reverse osmosis. Some specialized adsorptive filters also work.
Disclosure: TapWaterSafety earns a commission from purchases made through these links. This does not influence our scoring methodology or filter selection.
Score breakdown
This utility's overall score of 60/100 breaks down across five weighted components. Read the full methodology →
Contaminants detected — international standards comparison
Every contaminant detected, compared side-by-side against US EPA legal limits, the EU Drinking Water Directive (2020/2184), WHO Guidelines, and California's Public Health Goal (the strictest US benchmark). 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 |
4.74 ppb | 0.004 | 10.0 | 10 | 10 | 0.004 | — | 1184× over |
| Chromium (hexavalent) Heavy metal |
2.62 ppb | 0.02 | — | — | — | — | — | 131× over |
| Dibromoacetic acid Disinfection byproduct |
1.17 ppb | 0.03 | — | — | — | — | — | 39× over |
| Total trihalomethanes (TTHMs) Disinfection byproduct |
4.1 ppb | 0.15 | 80.0 | 100 | — | — | — | 27× over |
| Haloacetic acids (HAA9) Disinfection byproduct |
1.36 ppb | 0.06 | — | — | — | — | — | 23× over |
| Uranium Radiological |
9.49 pCi/L | 0.43 | 20.0 | 30 | 30 | 0.43 | — | 22× over |
| Nitrate Inorganic |
2.22 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 16× over |
| Haloacetic acids (HAA5) Disinfection byproduct |
1.1 ppb | 0.1 | 60.0 | 60 | — | — | — | 11× over |
| Radium, combined (-226 and -228) Radiological |
0.53 pCi/L | 0.05 | 5.0 | — | — | — | — | 11× over |
| Bromoform Disinfection byproduct |
3.46 ppb | 0.5 | — | — | — | — | — | 6.9× over |
| Dibromochloromethane Disinfection byproduct |
0.636 ppb | 0.1 | — | — | — | — | — | 6.4× over |
| Nitrate and nitrite Inorganic |
0.5 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 3.6× over |
| Vanadium Other |
11.4 ppb | 21.0 | — | — | — | — | — | Below guideline |
| Bromochloromethane Other |
0.0123 ppb | 0.06 | — | — | — | — | — | Below guideline |
| Molybdenum Other |
3.09 ppb | 40.0 | — | — | — | — | — | Below guideline |
| Barium Heavy metal |
52.2 ppb | 700.0 | 2000.0 | — | 1300 | 2000 | — | Below guideline |
| Manganese Heavy metal |
2.75 ppb | 100.0 | — | 50 | 80 | — | — | Below guideline |
| Chlorate Disinfection byproduct |
2.01 ppb | 210.0 | — | — | — | — | — | Below guideline |
| Strontium Radiological |
0.254 ppb | 1500.0 | — | — | — | — | — | Below guideline |
| Chromium (total) Heavy metal |
1.22 ppb | — | 100.0 | — | — | — | — | Below guideline |
| Fluoride Inorganic |
0.582 ppm | — | 4.0 | 1.5 | 1.5 | — | — | Below guideline |
| Germanium Other |
0.85 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 (4th ed.), California OEHHA PHGs, EWG Tap Water Database.
NAMPA CITY OF service area
This water system serves 1 community in Canyon County, Idaho. Click any city for its dedicated tap water quality page.
Find the right filter for NAMPA water
Browse filter categories by water-quality concern. Each option below is NSF-certified for the matched contaminant type.