Troubleshooting A Sudden Fecal Coliform Non-Compliance Event

In 2017, a municipal wastewater treatment plant experienced a sudden increase in fecal coliform exceedances. Plant staff had hypothesized that the issue was associated with excessive biomass in the bioreactor. To combat the exceedances the chlorine dose was doubled, and a plan was developed to increase waste rates from the bioreactor. Prior to additional wasting, a chlorination system audit was done using 2nd Generation ATP.