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Not health advice. Contact your local water utility for concerns.
Data from EPA Water Quality Reports. For official information, contact your water utility or health department.
Water quality data for 5 cities serving 421,803 residents
Polk County in Iowa has an average water quality score of 82/100 (Grade B+) based on analysis of 5 municipal water systems. The county's water systems serve approximately 421,803 residents.
Overall, Polk County demonstrates good water quality standards. 3 of 5 cities exceed the county average, with West Des Moines leading with a score of 96/100.
5 cities ranked by water quality score
| Rank | City | Score | Grade | Population |
|---|---|---|---|---|
| 1 | West Des Moines Top concern: Fluoride (17.4% of limit) | 96 | A+ | 72,301 |
| 2 | Ankeny Top concern: Fluoride (17.9% of limit) | 88 | A- | 72,279 |
| 3 | Johnston Top concern: Fluoride (17.6% of limit) | 87 | A- | 19,915 |
| 4 | Urbandale Top concern: Fluoride (25.9% of limit) | 70 | B- | 41,404 |
| 5 | Des Moines Top concern: Total Trihalomethanes (38.2% of limit) | 69 | C+ | 215,904 |
Top detected contaminants across county water systems
| Contaminant | Avg Level | Max Level | EPA Limit | % of Limit | Cities |
|---|---|---|---|---|---|
| Fluoride | 0.794 mg/L | 1.037 mg/L | 4 mg/L | 19.9% | 5 |
| Total Trihalomethanes | 15.545 ug/L | 30.593 ug/L | 80 ug/L | 19.4% | 5 |
| Nitrate | 1.429 mg/L | 1.836 mg/L | 10 mg/L | 14.3% | 5 |
| Chromium | 0.014 mg/L | 0.029 mg/L | 0.1 mg/L | 14.2% | 4 |
| Lead | 0.002 mg/L | 0.005 mg/L | 0.015 mg/L | 13.2% | 5 |
| Copper | 0.171 mg/L | 0.256 mg/L | 1.3 mg/L | 13.2% | 4 |
| Nitrite | 0.116 mg/L | 0.176 mg/L | 1 mg/L | 11.6% | 4 |
| Arsenic | 0.001 mg/L | 0.002 mg/L | 0.01 mg/L | 9.2% | 5 |
Recent violations across county water systems
Showing 10 of 13 recent violations
Water quality in Polk County, Iowa reflects the region's unique combination of water sources, treatment infrastructure, and environmental factors. Our comprehensive analysis examines 5 municipal water systems serving a combined population of over 421,803 residents.
The county shows strong water quality performance, with scores ranging from 69/100 in Des Moines to 96/100 in West Des Moines. This 27-point spread indicates significant variation in water quality across the county, suggesting different water sources or treatment approaches.
The most prevalent contaminants detected across Polk County water systems include Fluoride, Total Trihalomethanes, Nitrate. All monitored contaminants remain within acceptable levels relative to EPA Maximum Contaminant Levels (MCLs).
Polk County's water quality is generally good. Residents can feel confident in their tap water quality, though those with specific health concerns or sensitivity to certain contaminants may still benefit from filtration. Regular review of your city's annual Consumer Confidence Report is recommended.
Polk County has an average water quality score of 82/100 (Grade B+) based on analysis of 5 municipal water systems serving 421,803 residents.
West Des Moines has the highest water quality score in Polk County at 96/100. View the detailed report for West Des Moines.
Most cities in Polk County have water that meets EPA standards. However, a water filter can provide additional protection and improve taste. The need depends on your specific city and any personal health considerations.
Click on any city in the rankings table above to view its detailed water quality report, including contaminant levels, EPA compliance history, and filter recommendations.