Iowa drinking water report released

More than 2.6 million Iowans served by public water supplies received safe drinking water in 2010, according to the annual DNR public drinking water program's compliance report. The report was presented to the Iowa Environmental Protection Commission on Aug. 16.

Iowans can view the report online here. The report lists each of Iowa's 1,966 public water supplies that incurred a violation in 2010 of a health-based standard or of a major monitoring or reporting requirement.

“As people look at the report, they should understand that exceeding the maximum allowed level of contamination just one time for one contaminant causes a public water supply to be out of compliance,” said Dennis Alt, supervisor of the DNR's water supply engineering section.

The contaminants found in Iowa which can cause an immediate health risk are coliform bacteria from a fecal source, nitrate and nitrite.  Fecal bacterial contamination typically poses a risk to children, elderly people and anyone with a weakened immune system. In 2010, the number of systems with an acute fecal coliform or E. coli bacteria violation returned to 2008 levels, with 24 systems having 26 violations.

The trend in nitrate violations remained flat from 2009, with 14 systems reporting 29 acute nitrate violations in 2010, virtually identical numbers to 2009. However, only two systems from the 2009 list were still on the 2010 list. Excessive nitrate and nitrite levels pose a risk to infants and to women who are pregnant.

There were 81.6% of systems in compliance with all major monitoring and reporting violations in 2010, with the lowest number of violations in the past 10 years.  The overall decrease in the monitoring and reporting violations occurred despite the first full year of implementation of the Groundwater Rule, a recent federal rule affecting all groundwater systems. In 2010, this rule required sampling untreated well water at 290 systems during 468 events when coliform bacteria were detected in the distribution systems. A significant number of potential violations were prevented through diligent efforts of the DNR water supply program staff, water operators and laboratories.

“Overall, the public water supplies in Iowa are serving safe water,” said Alt. “The drinking water industry is very complicated with many requirements. Iowa is fortunate to have dedicated, qualified water treatment and water distribution system operators, and state drinking water staff. We are making forward progress but still have more work to do.”

The federal Safe Drinking Water Act requires the State of Iowa to publish an annual report of the status of its drinking water program.