Liquids Management: Wastewater pH Neutralization System Design, IPM Foods

Cleaning chemical pH issues requires industrial wastewater pretreatment to meet the POTW’s requirements in Wisconsin.


IPM Foods has a rigorous process to clean their food processing equipment to maintain the high quality of their soups and sustainable packaging. IPM has a clean-in-place system that uses high and low pH cleaners, high temperature, and sanitizing chemicals. The process ensures the high quality and safety of IPM Foods’ soups; however, the local Publicly Owned Treatment Works (POTW) determined it could no longer accept the wastewater because the cleaning process made the pH unacceptable.

The primary challenge was to bring the wastewater pH to a consistent level to meet the city’s POTW requirements as quickly as possible without compromising IPM’s quality and sustainability program. Meeting the pH level requirements was not an easy task; the POTW insisted on 24-hour monitoring of pH, with readings taken every minute.

IPM Foods chose SCS Engineers to help meet the challenges of designing and building an in-house wastewater equalization and pH neutralization system. SCS assessed the wastewater issues, set up data loggers to measure process flows, tested grab and 24-hour composite wastewater samples, conducted bench scale pH buffering tests and coordinated POTW staff communications.

By creating a cleaning chemical inventory SCS could provide options for IPM to consider to reduce the overall water and cleaning chemicals used throughout the process. Then SCS prepared engineering design drawings and specifications for the wastewater pH neutralization system. SCS helped the facility select wastewater pH neutralization equipment, conducted bidding and construction issue resolution, then reviewed the pretreatment system multi-week pilot testing results and all documentation required by the POTW.

SCS worked closely with the food processing staff to characterize ongoing water use because IPM Foods and the city needed to agree on the quantity of water used in the processes. SCS gathered data to assess the amount of water utilized and monitored the wastewater generation to perform a water use evaluation so the two parties could come to an agreement.

Outcomes and Benefits
IPM Foods and SCS met the tight deadlines imposed by the city and helps prevent violations resulting from the wastewater pH fluctuations IPM had previously experienced. IPM Foods’ pH neutralization system operates in full compliance.


“Timeliness and personal nature of the services – SCS really seemed concerned for our needs.” James Carroll, CFO, IPM Foods