Quality control at the Agency involves rigorous water quality monitoring and ongoing research for treatment process optimization. This focus ensures water safety, aesthetic quality and efficient operation.

A three‐pronged approach is used to monitor water quality.

First, numerous water analyses are performed on water throughout the treatment process. For example, each month the Agency’s Illinois Department of Public Health certified Laboratory and staff conduct more tests for E. Coli bacteria than are required by law. 

Second, independent laboratories, including the Illinois Environmental Protection Agency, also monitor water quality. These labs test for hundreds of potential contaminants in the tap water in excess of what is required by the United States Environmental Protection Agency.

Finally, water quality is assured through the extensive use of automatic water quality monitoring equipment. For example, nineteen instruments each monitor water clarity (turbidity) throughout the treatment process, twenty‐four hours a day, and seven days a week.