Challenge: The Authority’s system served two significant industrial users; a food processing plant and an factory that frosted light bulbs. The Authority’s WWTP has effluent limits for ammonia. When the food processing plant closed, the WWTP began having difficulty meeting ammonia limits. The PA DEP found that high concentrations of fluoride were inhibiting nitrification at the WWTP.

Solution: After an evaluation, we found that the food processing plant’s wastewater had contributed sufficient alkalinity to the Authority’s WWTP for nitrification. When the food plant closed, the source of sufficient alkalinity was gone. We helped the Authority negotiate terms with the frosted light bulb factory to add alkalinity to its wastewater discharge.

The DEP required the Authority to develop an EPA-approved Industrial Wastewater Pretreatment Program. We prepared the program, including the analysis of 24-hour composite wastewater samples collected at non-industry impacted allocations in the sewage collection system, the frosted light bulb industry’s industrial wastewater, and the influent and effluent to the Authority’s WWTP. We used the EPA’s Pretreatment Spreadsheet Program to determine maximum industrial headworks loads for target pollutants and recommended maximum limits of these pollutants.

Outcome: We continue to assist the Authority with the implementation of its pretreatment program.