Tap Water Quality Report
Tap water quality in MERRILLVILLE, Indiana
Tap water in MERRILLVILLE, Indiana receives a grade of C (77/100) from TapWaterSafety.org. It's served by INDIANA AMERICAN WATER - NORTHWEST. The most significant water quality concerns are: Haloacetic acids (HAA9) significantly above health guideline; Total trihalomethanes (TTHMs) significantly above health guideline; Haloacetic acids (HAA5) significantly above health guideline. Data sources: EPA SDWIS, EPA ECHO, EWG Tap Water Database.
What's in MERRILLVILLE's tap water
Top water quality concerns identified by the EPA and Environmental Working Group across the utility serving MERRILLVILLE.
Haloacetic acids (HAA9) significantly above health guideline
Moderate concernHaloacetic acids (HAA9) detected at 19.0 ppb, 316x above the EWG health guideline of 0.06 ppb.
Total trihalomethanes (TTHMs) significantly above health guideline
Moderate concernTotal trihalomethanes (TTHMs) detected at 23.7 ppb, 158x above the EWG health guideline of 0.15 ppb.
Haloacetic acids (HAA5) significantly above health guideline
Moderate concernHaloacetic acids (HAA5) detected at 11.8 ppb, 118x above the EWG health guideline of 0.1 ppb.
Recommended filters for MERRILLVILLE
Filters matched to the specific contaminants in MERRILLVILLE's water supply.
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.
All contaminants detected in MERRILLVILLE'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 |
|---|---|---|---|---|---|---|---|---|
| Haloacetic acids (HAA9) Disinfection byproduct |
19.0 ppb | 0.06 | — | — | — | — | — | 316× over |
| Total trihalomethanes (TTHMs) Disinfection byproduct |
23.7 ppb | 0.15 | 80.0 | 100 | — | — | — | 158× over |
| Haloacetic acids (HAA5) Disinfection byproduct |
11.8 ppb | 0.1 | 60.0 | 60 | — | — | — | 118× over |
| Chromium (hexavalent) Heavy metal |
0.303 ppb | 0.02 | — | — | — | — | — | 15× over |
| Nitrate Inorganic |
0.853 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 6.1× over |
| Nitrate and nitrite Inorganic |
0.345 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 2.5× over |
| 1,4-Dioxane Semi-volatile organic compound |
0.0588 ppb | 0.35 | — | — | 50 | 1 | — | Below guideline |
| Molybdenum Other |
1.36 ppb | 40.0 | — | — | — | — | — | Below guideline |
| Strontium Radiological |
0.114 ppb | 1500.0 | — | — | — | — | — | Below guideline |
| Fluoride Inorganic |
0.37 ppm | — | 4.0 | 1.5 | 1.5 | — | — | Below guideline |
| Testosterone Other |
0.018 ppt | — | — | — | — | — | — | 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 INDIANA AMERICAN WATER - NORTHWEST.