University of Minnesota
Minnesota Technical Assistance Program

Analyzing and Reducing your BOD and TSS Loading

Biochemical oxygen demand (BOD) is a measure of how much oxygen is required to biologically decompose organic matter in the water. Total suspended solids (TSS) is the total amount of suspended materials in the water. Both measure the strength of wastewater discharges. Your company can get charged twice when waste goes down the drain, first in product loss and second in strength charges. Implementing new equipment and processes may be one way to help your facility reduce the amount of waste being discharged and ultimately save you money. MnTAP offers the following resources to help you determine what equipment and/or processes might help your facility.

  • Fact Sheet: Membrane Filtration Systems (2008). Membrane filtration removes particles that are too small for conventional cartridge filters to remove.
  • Reference List: Emulsified Oil and Water Separating Products (2010). Use this list to find products that can separate emulsified oil and water to help extend the usefulness of process fluid or pre-treat wastewater prior to sewering.

Case Studies

A variety of companies have worked with MnTAP to reduce their BOD and TSS loading as well as to save money. The following case studies are presented here to provide you with ideas of techniques and strategies that may work in your facility.

Food Processing Examples

  • Case Study: Supermom's Saves $235,000 Yearly by Reducing Waste (2009). Supermom's worked to reduce their water use, wastewater loading, and energy use to save at least $235,000 a year.
  • Fact Sheet: Phosphorus: Reducing Releases from Poultry Processing Plants (2008). Poultry processing plants can contribute large BOD loads, as well as TSS and phosphorus to wastewater. This fact sheet outlines a number of steps that can be taken to reduce poultry processing plant waste and includes examples from past projects.
  • Intern Summary: Dairy Plant Reduces Water Use and BOD Saving Over $26,000 (1997). The facility decreased water use by fine tuning the computer programming that ran its clean-in-place (CIP) systems, which sanitize equipment. Saved over 8.5 million gallons of water, decreased BOD loading by 2.5%, and saved over $26,000 annually.

Examples from Other Facilities

  • Case Study: Ver-tech Labs (2009). The company reduced the BOD and total suspended solids (TSS) loading by over 15,000 lbs per year.
  • Source Article: Kerry Bio-Science (2004). Kerry Bio-Science was among the companies asked to evaluate its effluent and found that water scrubbers, cooling applications, and extensive-cleaning needs generate significant amounts of effluent.
  • Source Article: Stora Enso Reclaims Solids for Wastewater for Reuse (2002). Reclaiming usable raw materials from its wastewater, the papermaker reduced the amount of solids released to the sewer and justified a $134,000 project.

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