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City of Bloomington Officials Report September 2016 Disinfectant Byproduct Levels

October 17, 2016

For more information please contact:
Vic Kelson, City of Bloomington Utilities Director,, 812-349-3650

City of Bloomington Officials Report September 2016 Disinfectant Byproduct Levels

Bloomington, Ind. - The monthly disinfectant byproduct (DBP) test results for September have been released, and the contaminant levels continue to be lower than the water-quality standard. September's measurement of both haloacetic acids (HAA5) and trihalomethanes (THM) remained comparable to last month's testing.

According to Utilities Director Vic Kelson, "These results indicate that changing the point of chlorine addition, combined with our process optimization efforts, is allowing us to manage the formation of disinfectant byproducts. As the warm weather season comes to an end, we expect a seasonal downward trend in DBP formation. Over the winter, we will continue to focus on improving water quality and eliminating the operational side effects of this year's process changes."

"We're pleased with the ongoing downward trend of these numbers. Since we started testing more frequently and making changes in the water purification process our water quality has improved, but we will certainly continue our attention and efforts. I appreciate the hard work of our employees to get us to this point," commented Mayor John Hamilton.

The August 2016 findings revealed the concentration of HAA5 levels at the eight testing sites ranged from 38.0 ppb to 45.0 ppb and the THM levels were between 52.0 ppb and 57.3 ppb. In September 2016, the most recent test month, findings showed the concentration of HAA5 ranged from 39.0 ppb to 45.0 ppb, and the THM levels were between 50.7 ppb and 60.4 ppb.

Monthly water testing was initiated in January of this year in an effort to better track water quality, specifically DBPs. Over the January - September 2016 period no individual sample has exceeded the maximum contaminant level (MCL).

September's lab report also included quarterly results that, when compared to the same period in 2015, indicate much improved levels of contamination. The level of HAA5 for the third quarter 2015 ranged from 52 ppb to 60 ppb, while THM levels were between 84.3 ppb and 95.5 ppb. The third quarter 2016 data levels ranged from 38.6 ppb to 45.3 ppb for HAA5, and between 52.4 ppb and 59.6 ppb for THM.

Results from the last three months are well below the maximum contaminant levels of 60 ppb for haloacetic acids and 80 ppb for trihalomethanes. The figures below compare the average concentrations for the third quarter 2016 to summer values in 2012-2015.

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The continuing improvement in the quality of Bloomington's water is due in large part to the responsiveness of CBU staff. It is anticipated that with the coming fall and winter months, the contaminant levels will continue to show improvement and remain within acceptable limits. Traditionally the warmer months of the year have made the control of DBPs more challenging.

Testing of CBU water is conducted by a private, independent laboratory. All water quality test results are available online at under "Utilities."