Water Quality Report · Updated May 12, 2026
MERIDIAN WATER DEPT
MERIDIAN WATER DEPT delivers tap water graded C (65/100) by TapWaterSafety.org. The utility serves approximately 147,340 residents in MERIDIAN, Idaho using groundwater. The most significant water quality concerns are: Arsenic significantly above health guideline; Haloacetic acids (HAA9) significantly above health guideline; Total trihalomethanes (TTHMs) significantly above health guideline. For questions, the utility can be reached at 208-985-1200.
Is MERIDIAN tap water safe to drink?
MERIDIAN WATER DEPT delivers tap water that earns a grade of C (65/100) from TapWaterSafety.org — an average rating, with several contaminants above health guidelines but generally compliant with US legal limits.
The utility serves 147,340 residents in MERIDIAN, drawing from groundwater. Despite being legal under US EPA standards, this water would fail the European Union's Drinking Water Directive, primarily due to arsenic significantly above health guideline.
Public testing data identifies 13 contaminants in this water above EWG's health-based guidelines, including: Arsenic, Haloacetic acids (HAA9), Total trihalomethanes (TTHMs), Uranium, Dibromochloromethane, Dibromoacetic acid, Bromodichloromethane, Nitrate and nitrite, Nitrate, Chromium (hexavalent), Radium, combined (-226 and -228), Haloacetic acids (HAA5), Bromoform. 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 MERIDIAN residents
Top concerns in this water
Based on the most recent EPA and EWG data, these are the most significant water quality issues for MERIDIAN WATER DEPT.
Arsenic significantly above health guideline
Moderate concernArsenic detected at 0.853 ppb, 213x above the EWG health guideline of 0.004 ppb.
Haloacetic acids (HAA9) significantly above health guideline
Moderate concernHaloacetic acids (HAA9) detected at 5.11 ppb, 85x above the EWG health guideline of 0.06 ppb.
Total trihalomethanes (TTHMs) significantly above health guideline
Moderate concernTotal trihalomethanes (TTHMs) detected at 4.06 ppb, 27x above the EWG health guideline of 0.15 ppb.
Contact MERIDIAN WATER DEPT
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 MERIDIAN
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.
Carbon block (NSF/ANSI 42 + 53)
$40-$750Activated carbon is highly effective for disinfection byproducts like TTHM and HAA5.
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 65/100 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 |
0.853 ppb | 0.004 | 10.0 | 10 | 10 | 0.004 | — | 213× over |
| Haloacetic acids (HAA9) Disinfection byproduct |
5.11 ppb | 0.06 | — | — | — | — | — | 85× over |
| Total trihalomethanes (TTHMs) Disinfection byproduct |
4.06 ppb | 0.15 | 80.0 | 100 | — | — | — | 27× over |
| Uranium Radiological |
10.23 pCi/L | 0.43 | 20.0 | 30 | 30 | 0.43 | — | 24× over |
| Dibromochloromethane Disinfection byproduct |
1.11 ppb | 0.1 | — | — | — | — | — | 11× over |
| Dibromoacetic acid Disinfection byproduct |
0.311 ppb | 0.03 | — | — | — | — | — | 10× over |
| Bromodichloromethane Disinfection byproduct |
0.556 ppb | 0.06 | — | — | — | — | — | 9.3× over |
| Nitrate and nitrite Inorganic |
1.29 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 9.2× over |
| Nitrate Inorganic |
1.25 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 8.9× over |
| Chromium (hexavalent) Heavy metal |
0.122 ppb | 0.02 | — | — | — | — | — | 6.1× over |
| Radium, combined (-226 and -228) Radiological |
0.16 pCi/L | 0.05 | 5.0 | — | — | — | — | 3.2× over |
| Haloacetic acids (HAA5) Disinfection byproduct |
0.211 ppb | 0.1 | 60.0 | 60 | — | — | — | 2.1× over |
| Bromoform Disinfection byproduct |
0.836 ppb | 0.5 | — | — | — | — | — | 1.7× over |
| Chloroform Disinfection byproduct |
0.325 ppb | 0.4 | — | — | — | — | — | Below guideline |
| Manganese Heavy metal |
52.6 ppb | 100.0 | — | 50 | 80 | — | — | Fails EU |
| Bromochloromethane Other |
0.0156 ppb | 0.06 | — | — | — | — | — | Below guideline |
| Atrazine Pesticide/Herbicide |
0.0236 ppb | 0.1 | 3.0 | 0.1 | 100 | 0.15 | — | Below guideline |
| Chlorate Disinfection byproduct |
47.3 ppb | 210.0 | — | — | — | — | — | Below guideline |
| Barium Heavy metal |
61.4 ppb | 700.0 | 2000.0 | — | 1300 | 2000 | — | Below guideline |
| Dichloroacetic acid Disinfection byproduct |
0.0167 ppb | 0.2 | — | — | — | — | — | Below guideline |
| Molybdenum Other |
1.63 ppb | 40.0 | — | — | — | — | — | Below guideline |
| Vanadium Other |
0.773 ppb | 21.0 | — | — | — | — | — | Below guideline |
| 1,4-Dioxane Semi-volatile organic compound |
0.0044 ppb | 0.35 | — | — | 50 | 1 | — | Below guideline |
| Cobalt Other |
0.0236 ppb | 70.0 | — | — | — | — | — | Below guideline |
| Strontium Radiological |
0.284 ppb | 1500.0 | — | — | — | — | — | Below guideline |
| Di(2-ethylhexyl) adipate Other |
0.00815 ppb | 200.0 | 400.0 | — | — | — | — | Below guideline |
| Bromomethane Other |
0.00872 ppb | — | — | — | — | — | — | Below guideline |
| Chromium (total) Heavy metal |
0.137 ppb | — | 100.0 | — | — | — | — | Below guideline |
| Fluoride Inorganic |
0.34 ppm | — | 4.0 | 1.5 | 1.5 | — | — | Below guideline |
| Germanium Other |
0.165 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.
MERIDIAN WATER DEPT service area
This water system serves 1 community in Ada County, Idaho. Click any city for its dedicated tap water quality page.
Find the right filter for MERIDIAN water
Browse filter categories by water-quality concern. Each option below is NSF-certified for the matched contaminant type.