Environmental Progress - Fall 1999

State Atrazine Violations Drop From 53 to One, Report Shows

Several causes probably can account for unusually sharp drop

This is the first year that such a decline has been recorded, and no single clear-cut reason for the drop has been identified. Rather, said Roger Selburg, manager of the Agency's Division of Public Water Supplies, it probably reflects several factors: ongoing efforts by farmers to reduce runoff from farm fields by installation of buffer strips between fields and streams; a reduction in the amounts of farm chemicals that farmers are applying; and favorable weather conditions without heavy rains just after the pesticide was applied. Dry weather conditions and gentle rains allow the chemicals to be absorbed into the soil; heavy rains shortly after application can wash the materials off fields and into nearby water bodies.

Numbers of nitrate violations also dropped During the same period, violations of nitrate limits dropped from 19 to eight. Only two public water supplies were found to have levels of volatile organic chemicals that exceeded federally-determined maximum contaminant levels (MCLs). One of those supplies is no longer in service and the other has returned to compliance.

The SDWA 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 some-thing we in Illinois tend to take for granted,” Illinois EPA Director Thomas Skinner said. “However, having safe, clean water flow from our taps requires day-to-day efforts by many people.”

To meet the SDWA goal, Illinois has an objective of having more than 95 percent of its community water supply consumers receiving water that has neither short-term (acute) nor long-term (chronic) potential adverse health effects, by the year 2005. During 1998, more than 92 percent of the Illinois user population was served by supplies which were in compliance with all health requirements. In most cases where non-compliance occurred, duration was brief and the potential for health risk was minimized by prompt corrective action by the water supplies.

Supplies with microbial problems (either bacterial or turbidity non-compliance) are required to issue boil orders. Supplies that exceed maximum contaminant levels for nitrate are required to provide bottled water for infants under six months of age until the levels are consistently well below the MCL.

In Illinois, the Illinois EPA regulates operations of 1,807 community water supplies that serve 25 or more residents year round, ranging from small mobile home parks to major metropolitan areas.

During 1998, 1,723 of the state's water supplies, serving 98 percent of the population, distributed water that was below the 15 parts per billion federal action level for lead. Lead contamination of drinking water usually is caused by plumbing in the users' home and monitoring is conducted by collecting samples from in-house taps. If more than 10 percent of a supply's high risk samples exceed the action level, the supply must implement treatment techniques or take other steps to prevent anticipated adverse health effects.

Standards for drinking water are determined by U.S. EPA after extensive research and are set with significant built-in safety factors to protect public health.

Presently, community water supplies are required to monitor for a total of 85 parameters. Failure to monitor is itself a violation, and a large percentage of the violations during 1998 fell into this category. The latest figures show that 73 systems had 2,122 monitoring violations, while 129 of the total number of systems had 174 actual violations of the various standards, known as maximum contaminant levels or MCLs.

Copies of the summary or complete annual water system compliance reports can be obtained by contacting the Illinois EPA's Division of Public Water Supplies, #13, P.O. Box 19276, Springfield, IL 62794-9276.