Environmental Progress - Summer 2001

Illinois Drinking Water Safety Figures Good

89 percent of community water supplies met all health requirements in 2000

Compliance data for the calendar year 2000 shows that the state continues to make progress toward its 2005 goal of having at least 95 percent of public water supply customers receiving drinking water with neither short or long term adverse health effects.

Broken down by acute (short term) and chronic (long term) health standards, the Agency figures show that during calendar year 2000, more than 99 percent of the population served by community water supplies received drinking water meeting all short term health requirements, and more than 93 percent received water meeting long term health requirements.

It is important to note that most non-compliance for all requirements was short in duration and the potential for health risk was minimized through prompt corrective action by the supplies.

The compliance information, provided by the nearly 1,800 IEPA-regulated community water supplies serving Illinois users, shows that between Jan. 1 and Dec. 31, 2000, a total of 1, 601 or 89 percent of the supplies regulated by IEPA, had been in full compliance with all health requirements during the period.

Translated to numbers of users, the figures reflect a 1.5 percent improvement compared with the previous year, with 93.14 percent of the persons served by the community water supplies receiving water that met all health requirements. These requirements include compliance with maximum contaminant levels, treatment techniques and health advisories that have been in effect for more than three years.

Major contributing factors for the improvement were identified as a reduction in short-term nitrate excursions as well as a reduction in bacteriologic violations. Supplies where bacterial or turbidity non-compliance are identified must issue boil orders. Supplies that exceed the nitrate maximum contaminant level are required to provided bottled water for all infants six months old and younger until the levels consistently drop well below the maximum contaminant level.

Compliance with limits for lead in drinking water are measured by different techniques, since the problem is not with water distributed by the water supply, but originates in the home of the consumer when the water stands in contact for long periods of time with household plumbing containing lead or lead solder. When more than 10 percent of the samples, which must be collected at taps in conSummers' homes, exceed the action level of 15 parts per billion, the water supply must initiate a treatment technique to prevent the likelihood of the water leaching lead from pipes where it is present. In 2000, 1,753 water supplies, serving 99 percent of the state's population, were below the lead action level. For the third year, supplies that installed treatment related to lead levels were required to take daily or bi-weekly measurements to meet water quality parameter ranges. These measurements showed that treatment was effective for 121 public water supplies, while 21 supplies serving a total population of 160,606 were outside a water quality parameter range at some point during the year.

The figures are part of an annual report required under the 1996 amendments to the federal Safe Drinking Water Act (SDWA). The Act says states like Illinois with primary enforcement authority for the federal regulations must issue yearly public reports of their progress toward providing every customer of a public water system with water that is consistently safe to drink, without adverse health effects.

"A plentiful supply of safe drinking water is something we in Illinois tend to take for granted," Illinois EPA Director Thomas Skinner said. "However, having safe, clean water flow from our taps requires conscientious day-to-day efforts by many people"

As in previous years, the largest cause of violations was failure to monitor as required or to take mandatory follow-up actions such as public notice or public education efforts, rather than actual failure to meet established substance limits in finished water distributed to users.

Copies of the summary or complete annual water system compliance reports, which must be filed by July 1 with U.S. EPA, can be obtained by contacting the Illinois EPA's Division of Public Water Supplies, #13, P.O. Box 9276, Springfield, IL 62794-9276.