Atrazine

As of July, 1991, the EPA’s rule for Atrazine requires water utilities to demonstrate that the running annual average of samples taken must not exceed 3.0 ppb (parts per billion). Samples may from time-to-time exceed 3.0 ppb, but as long as the utility can demonstrate that its running average does not exceed the MCL (maximum contaminant level), it will be in compliance with the regulation.

Water utilities are required to test quarterly for Atrazine levels. WaterOne sends samples to be analyzed by an outside contract laboratory on a monthly basis, with the frequency increasing to once a week during the months of June, July, and the first half of August when Atrazine concentration in the Kansas and Missouri Rivers are most likely to be at a maximum.

Over the past year, our tests have shown a running average of 0.30 ppb of Atrazine in the finished water from the Kansas River and 0.40 ppb from the Missouri River, which are both well below the EPA limit of 3.0 ppb. Our running annual average has never exceeded the EPA limit. We have always been in compliance with the EPA standard.

Atrazine is a herbicide used by farmers to kill weeds in corn and sorghum fields.

It enters our streams and rivers as runoff from rainfall. WaterOne guards against Atrazine in water by using powdered activated carbon at the point-of-withdrawal from the Missouri and Kansas Rivers and at the Treatment Facilities. We have used powdered activated carbon in treating water at the Treatment Plant since 1965, at the Missouri River Intake since it was built in 1984, and at the Kansas River Intake and Facility II since 1991.

WaterOne spends over a quarter of a million dollars annually to treat Atrazine.