By Michael Cairns
For the Oregon Beer Growler
Does spent yeast constitute a water quality issue for Oregon streams, and a financial burden on the state’s craft breweries? A September 2014 beer blog post described how two Austin, Texas breweries faced a fee of $5000 for “improper yeast disposal.” The piece made this writer want to do a little investigation to understand whether Oregon’s brewers are in danger of also getting slapped with hefty fines.
To understand why yeast would be considered a pollutant, a very brief science lesson is in order. Yeast, along with cleaning water, spent mash and hops that remain after the brewing process is complete, is usually discharged into municipal wastewater systems. Note that in Oregon most spent grains and hops, along with the yeast, are usually sold or given to farmers for animal feed — it’s organic and very nutritious. And yeast is ‘harvested’ for reuse in many breweries. These practices limit a lot of waste discharge, but not all of it. So where does the science come in? Well, the federal Clean Water Act of 1972 regulates the discharge of pollutants to the nation’s waterways. More specifically in this case, it’s the discharge of organic materials that may contribute to biological oxygen demand, which can stimulate the growth of algae in streams, lakes and oceans. This, in turn, can lead to a decrease in dissolved oxygen, which is bad for fish and other aquatic life. High concentrations of total suspended solids that could come from breweries pose another threat to waterways and wildlife. Acidity, expressed as pH, is an additional concern. OK, enough of the science lesson.
To determine whether Oregon breweries are in danger of being fined or required to pay special fees for their discharges, I did some digging and got some of my questions answered. First, Steve Schnurbusch of the Oregon Department of Environmental Quality (DEQ) told me that there are no requirements specific to yeast effluents, nor to brewery wastewater discharges in general. He spoke of ‘loading,’ a measure of the total amounts of organic matter discharged to streams in relation to the size of any particular wastewater treatment plant from a brewery and other industrial sources. In other words, if a large brewery is located in a small community with a small treatment plant, then there could be a problem. Schnurbusch noted that the DEQ mainly regulates end-of-pipe discharges to receiving waters — for instance, from treatment plants, rather than discharges from breweries to municipal sewer systems. He suggested I should speak to city officials who operate those treatment plants.
This suggestion led me to the City of Salem, where Nitin Joshi of Salem Environmental Services reiterated some of what I had learned from the DEQ representative. The City of Salem does not have regulations specific to yeast, or even to breweries. Salem breweries are considered commercial, rather than industrial, users. Unless a particular plant, or brewery in our case, discharges more than 25,000 gallons per day, then there are no permits required. Finally, I decided to speak to a brewer to get that perspective.
Santiam Brewing’s head brewer, Jerome Goodrow, was kind enough to talk to me as he was in the process of cleaning tanks after a brew and discharging the rinse water. Like most breweries, the spent grain and hops are used for farm animal feed, and some of the yeast is harvested. He noted that the cleaning solution, or disinfectant, is quite acidic, although it’s neutralized by use of a caustic solution, thereby creating a final effluent that is nearly pH neutral. Goodrow reiterated that they do not discharge enough volume into the city’s sewer system to qualify as an industrial customer, nor do any of the other Salem breweries. There are no issues specific to yeast discharge at Santiam.
So, the bottom line based on my limited research: yeast discharge to sewer systems does not seem to be an issue in Oregon. I’m confident that Oregon’s craft brewers are attuned to the potential and are very conscientious about recycling and limiting their discharge of both wastewater and organic materials. Further investigation may find a very large brewery in a very small community where discharge could create problems with biological oxygen demand, total suspended solids or pH conditions in the receiving waters, but that doesn’t seem to be the case at this point.
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