Wineries generate a strong organic wastewater that is highly depending on production activities. Dissolved constituents in the wastewater include sugars, ethanol, organic acids, aldehydes, other microbial fermentation products, and soaps and detergents from cleanup operations.
Large suspended matter consists of grape skins, leaves, stems, and seeds, while smaller suspended particles are primarily dead yeast cells and cell fragments (lees), grit, dirt, diatomaceous earth, and bentonite.
Winery wastewater typically is low in pH because of organic acids produced in the fermentation process. Winery wastewater generally has sufficient phosphorus but is deficient in nitrogen and other trace minerals, which are necessary for efficient biological treatment.
Variability in wastewater composition depends mainly on the season and the particular operations being conducted at any given time. Maximum organic loading usually occurs from early September through early November (harvest season). Certain winemaking operations – such as cleaning of the crusher, pomace conveyors, presses, and
fermentation tanks – can also generate high strength wastewaters.
Other process wastewater includes washing of storage tanks, bottling and other equipment, and wine racking. Total Hess Collection Winery wastewater includes the process wastewater, cooling water, and sanitary wastewater from about 50 employees, more than 100 daily visitors, and 100 residents of an onsite monastery.
Total average daily wastewater flow rates are approximately 10,000 gallons per day (gpd) during the wine bottling period (January through early September). During harvest, total wastewater flow rates generally average about 26,000 gpd. The highest BOD5 (biochemical oxygen demand) loadings are approximately 1,000 to 10,000 mg/L (200 to 2,200 lb/day). In December, facility cleaning contributes to about 30,000 gpd of total wastewater.