Marshalltown, IA 50158
14 water systems • 34,979 residents
Moderate water quality - consider filtration
Score: 46/100
Graded on EPA violations, contaminants, severity, compliance, and enforcement history. See methodology.
Data updated June 2026 • Sources: EPA ECHO and EPA Envirofacts
40
Contaminants Detected
1,068
Violations on Record
233
Health-Based Violations
0
Recent Violations
Grade Breakdown
46 / 100 points
Recommended Water Filters
- ✓Point-of-Use Carbon Filter (NSF-certified for lead)
- ✓Reverse Osmosis or Ion Exchange Filter
- ✓Ultraviolet (UV) Purification
- ✓Activated Carbon Filter (disinfection byproducts)
Consult a water quality specialist for personalized recommendations.
Marshalltown vs IA & National Average
Detected Contaminants
40 contaminants detected across water systems serving this ZIP code
| Contaminant | Category |
|---|---|
| Atrazine | Agricultural |
| Nitrate | Agricultural |
| Nitrite | Agricultural |
| Simazine | Agricultural |
| Total Haloacetic Acids (HAA5) | Disinfection Byproduct |
| TTHM | Disinfection Byproduct |
| Antimony, Total | Heavy Metal |
| Arsenic | Heavy Metal |
| Barium | Heavy Metal |
| Beryllium, Total | Heavy Metal |
| Cadmium | Heavy Metal |
| Chromium | Heavy Metal |
| Lead and Copper Rule | Heavy Metal |
| Mercury | Heavy Metal |
| Selenium | Heavy Metal |
| Thallium, Total | Heavy Metal |
| Asbestos | Inorganic |
| CYANIDE | Inorganic |
| Fluoride | Inorganic |
| Coliform (TCR) | Microorganism |
| Revised Total Coliform Rule | Microorganism |
| 2,4-D | Other |
| 2,4,5-TP | Other |
| Benzo(a)pyrene | Other |
| Chlorine | Other |
| Consumer Confidence Rule | Other |
| Dalapon | Other |
| Di(2-ethylhexyl) adipate | Other |
| Di(2-ethylhexyl) phthalate | Other |
| Dinoseb | Other |
| Groundwater Rule | Other |
| LASSO | Other |
| Pentachlorophenol | Other |
| Picloram | Other |
| Public Notice | Other |
| Combined Radium (-226 and -228) | Radiological |
| Gross Alpha, Excl. Radon and U | Radiological |
| 1,2,4-Trichlorobenzene | Volatile Organic |
| Ethylbenzene | Volatile Organic |
| Xylenes, Total | Volatile Organic |
Water System Information
- Systems Serving This ZIP:
- CLARKSVILLE WATER SUPPLY, SWALEDALE WATER SUPPLY, ANDREW WATER SUPPLY, SILVER CITY WATER SUPPLY, ACKLEY MUNICIPAL WATER WORKS +5 more
- Population Served:
- 34,979
- Systems With Violations:
- 14 of 14
- Major Violations:
- 329
- Enforcement Actions:
- 1,049
Frequently Asked Questions
What does the grade mean?
Our A–F grade ranks this ZIP code's water quality against every other analyzed ZIP in the country, based on EPA data. A = among the best, F = among the most troubled.
Is my tap water safe to drink?
Water systems regulated by the EPA must comply with Safe Drinking Water Act standards. However, if you're concerned about water quality, consider a water filter appropriate for your contaminants.
How often is the data updated?
We update our data quarterly with the latest EPA ECHO and Envirofacts data. Historical violations are tracked to identify patterns.
What filters do you recommend?
Filter recommendations are based on detected contaminants in your area. See our Filter Guide for detailed information about different filter types.