A new state report on Iowa drinking water supplies details 120 health standard violations and 520 monitoring violations among the state’s 1,855 public water supplies in 2019.
The report shows that the systems’ failure to properly assess or treat bacteria led to 29% of the violations. High levels of copper accounted for 16.7%, arsenic, 12.5%, and nitrate, 10.8%. Violations of the lead limits accounted for 6.7%.
In raw numbers, there were 21 systems that had violations of bacteria treatment rules, 15 with excessive copper at one point or another, 14 that didn’t properly assess bacteria at times, eight with high lead levels, eight that recorded high nitrate violations and five that had high arsenic levels at times.
No waterborne diseases or deaths due to drinking water contaminants were reported in 2019, the Iowa Department of Natural Resources reported.
There were 83 public water supplies that had 120 violations of a health-based drinking water standard, maximum residual disinfectant level, treatment technique, or action level for a specific contaminant, the Iowa Department of Natural Resources reported. And 267 systems together amassed 520 major monitoring violations, meaning at some point they failed to draw samples to test a contaminant level, as required.
Most of the systems with violations are small municipal utilities or community sources such as restaurants or offices. For example, the town of Mallard had violations for arsenic levels. McCallsburg had excessive trihalomethane, a toxic byproduct of disinfection that can cause damage to the central nervous system and the liver.
Lake Macbride Golf Course was cited for bacteria problems. The Dedham water system initially failed to issue a required annual compliance report to customers, and had high levels of selenium, which can cause nervous system problems. Chariton had excess nitrite, which can reduce the blood’s ability to carry oxygen.
Generally, the violations were for brief periods and the problems were fixed. Water standards and the associated risks are set based on a person drinking two liters a day of the same water for 70 years.
Over 2.8 million of the 2.96 million Iowans who are on public systems got their water from sources that met all health-based drinking water standards.
Overall, 95.5% of the 1,855 public systems met all health standards. The 10-year average is 94%.