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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 2 cities serving 183,987 residents
Linn County in Iowa has an average water quality score of 99/100 (Grade A) based on analysis of 2 municipal water systems. The county's water systems serve approximately 183,987 residents.
Overall, Linn County demonstrates good water quality standards. 1 of 2 cities exceed the county average, with Cedar Rapids leading with a score of 100/100.
2 cities ranked by water quality score
| Rank | City | Score | Grade | Population |
|---|---|---|---|---|
| 1 | Cedar Rapids | 100 | A | 142,364 |
| 2 | Marion Biggest deduction: Lead 90th-percentile tap result 8.3 ppb for 2022-01-01–2024-12-31, below the 15 ppb action level (−3 pts) | 97 | A | 41,623 |
Real EPA readings across county water systems (lead: latest 90th percentile; PFAS: UCMR5 2023–2026; others: 2012–2019 averages)
| Contaminant | Avg Level | Max Level | EPA Limit | % of Limit | Cities |
|---|---|---|---|---|---|
| Lead (90th percentile) | 4.96 ppb | 8.3 ppb | 15 ppb | 33.1% | 2 |
| Fluoride (2012–2019 avg) | 1.1 mg/L | 1.1 mg/L | 4 mg/L | 27.5% | 1 |
| HAA5 (2012–2019 avg) | 5.75 ug/L | 5.75 ug/L | 60 ug/L | 9.6% | 1 |
| PFAS (PFOA/PFOS max, UCMR5) | 0 ppt | 0 ppt | 4 ppt | 0% | 2 |
| TTHM (2012–2019 avg) | 0 ug/L | 0 ug/L | 80 ug/L | 0% | 1 |
Recent violations across county water systems
Water quality in Linn County, Iowa reflects the region's unique combination of water sources, treatment infrastructure, and environmental factors. Our comprehensive analysis examines 2 municipal water systems serving a combined population of over 183,987 residents.
The county shows strong water quality performance, with scores ranging from 97/100 in Marion to 100/100 in Cedar Rapids. This 3-point spread indicates relatively consistent water quality standards across municipal systems.
The most prevalent contaminants detected across Linn County water systems include Lead (90th percentile), Fluoride (2012–2019 avg), HAA5 (2012–2019 avg). Every county-wide average sits below 50% of its EPA Maximum Contaminant Level (MCL).
Linn 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.
Linn County has an average water quality score of 99/100 (Grade A) based on analysis of 2 municipal water systems serving 183,987 residents.
Cedar Rapids has the highest water quality score in Linn County at 100/100. View the detailed report for Cedar Rapids.
Most cities in Linn 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.