Urgent Pretreatment Solution for Failing System

/Urgent Pre-Treatment Solution for Failing System
Urgent Pre-Treatment Solution for Failing System2018-08-19T10:28:47-05:00

Facility Overview & History

Faced with structural failure of a dated system, our client in central Wisconsin turned to The Probst Group for an urgent, cost-effective solution for their wastewater pretreatment needs.

Operating a blended and dry food ingredient production facility produces process wastewater as a byproduct of the production process. Prior to updates, process wastewater was pretreated (to below domestic strength), using an activated sludge process, before being sent to the local publicly owned treatment works (POTW) for further treatment. Segregated high strength wastewater and waste activated sludge were managed through land application.


The pretreatment facility had utilized pre-existing tanks that were originally constructed in the 1940’s. After suffering from structural failure, a new pretreatment facility was necessary. Between the failure of the existing tanks and the start-up of a new pretreatment facility, all process wastewater needed to be hauled off-site for disposal, as the local POTW was not able to accept factory wastewaters without biological pretreatment.

The Probst engineers were tasked with urgently designing a new, cost-effective pretreatment facility that could anticipate and meet current and future discharge limits, including ultra-low phosphorus limits. Each passing day meant high fees associated with hauling industrial strength wastewater to alternate disposal sites.


Probst worked rapidly to design a new facility that would be cost-effective and able to produce effluent compliant with current and future discharge limits.

The treatment unit processes implemented in the facility included:

  • Wastewater lift station
  • Automated debris screening
  • Anoxic selector
  • Aerobic activated sludge with advanced slot aeration technology
  • Solid-liquid separation provided by ultra-filtration (UF) membranes
  • Aerated sludge storage tank

Offering an innovative approach, Probst designed a system that would provide flexibility for plant operators and allow the treatment process to be easily monitored and adjusted, using customized controls and instruments.

In addition to the wastewater treatment plant design and construction, The Probst Group also provided laboratory equipment and training. Facility operators were trained to accurately handle lab equipment and understand procedures, enabling the operators to gather test data at the facility. These new capabilities provided the information necessary to make changes to the plant operations and accommodate fluctuating influent quality.

After rapid design and construction of the new industrial pretreatment facility, wastewaters are being pretreated and discharged to the local POTW – immediately saving the daily expenses associated with hauling the wastewater off-site for disposal. Sludge produced by the facility is being land applied, providing nutrients to the soil.

The facility has consistently produced effluent far exceeding the original design criteria since it has been in operation. As our teams continue to work together to obtain permits for surface discharge, we look forward to assisting in further cost reduction for the facility as well as increased operation efficiency.