Distillery tasting rooms – Alcohol’s effects on septic systems

October 03, 2022

By Sara Heger

Distilleries are popping up from across the U.S. with over 2,200 locations making and selling their own brand of products to the public in 2022. These distilleries produce two main types of waste:

  1. Wastewater related to distilling
  2. Wastewater from tasting rooms and/or restaurants

The wastewater from distilling is typically composed of both spent grain, which is handled as a solid, and liquid waste from distilling and sanitizing. Depending on the size of the distillery and its location the volume may not be appropriate for a septic system and this waste may fall under different regulations since no human waste has entered the stream.   

There are more small distilleries that are operating outside of access to municipal wastewater treatment plants and questions are arising as to the characteristics of wastewater from tasting rooms. In typical tasting rooms there is distilled alcohol that is not consumed, and wastewater from bathrooms. If the tasting room involves a kitchen that would also be adding to the load. The University of Minnesota did a small study to see what the alcohol portion may be adding to the wastewater stream. Unconsumed alcohol is not only a source at tasting rooms but any establishment serving hard liquor. The study tested commercially available brands of vodka, rum and whiskey.

It is important to note that data from this study represents straight alcohol that has not been mixed with another beverage, water or ice. The most concerning data from this table are the oxygen demand (BOD and COD) of the samples. Even small amounts of distilled alcohol that is put down the drain will add oxygen demand to the system. Care should be taken when working with owners of such establishments to limit the amount of alcohol going down the drain, test the effluent from existing facilities, and then design and manage for the loading.