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Organic solids increase the Biochemical Oxygen Demand (BOD) loadings in process water. Once in the wastewater stream, solids can accumulate, putrefy and require a significant amount of energy to treat.

Most wineries output ‘high-strength’ concentrations of BOD in their wastewater, especially during crush. When discharged to land or subsurface, high BOD loadings have the potential to generate odors, clog soil pores and impact groundwater. Publicly Owned Treatment Works (e.g., your local sewer authority) often charge extra fees for high levels of BOD and/or solids.

BOD   is a measure of the organic fraction in a water sample based on the amount of oxygen used by the microorganisms to degrade the organic matter during a five-day test. 


TYpical Sources of BOD.png

Source: Virginia Tech. Enology Notes #155. August 9, 2010.

Winemaking processes that can contribute solids and BOD include:

  • Crushing and Pressing

  • Barreling

  • Lees Handling

  • Fining

  • Filtration

  • Centrifuges

It is always more cost-effective to prevent solids and BOD from entering wastewater in the first place, to cut down on treatment needs. This can be achieved by:

  • Screening and separating solids before they enter the wastewater stream

  • Minimizing juice and wine spillage through staff training and Standard Operating Procedures

  • Reducing the use of solid material inputs in the winemaking process where appropriate


Organics that do make their way into wastewater can be reduced via aeration and other biological treatment systems, as well as advanced screening technologies and chemical treatment.

[Adapted from the Comprehensive Guide and Water & Wine.]


Use these guiding questions as you begin to evaluate opportunities for additional water quality actions in the winery.

  • Which activities in the winery have potential to generate solids?

  • Are there additional opportunities to install screens or filters that remove solids from the wastewater stream?

  • Are there procedures in place to separate and remove solids from equipment and floors before rinsing or washing?

  • How might the winery recycle or reuse the winemaking solids?

Visit the Resources page for more Key Questions.

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