Waste: Flush or Treat?
How a brewery chooses to handle process wastewater will directly influence profitability. The basic choices are to discharge untreated waste or provide some type of pretreatment to reduce quantities of contaminants being discharged. There are costs associated with either choice.
Discharging wastewater to a Publicly Owned Treatment Works or POTW is perhaps the most common situation for breweries. Standard monthly fees cover basic discharge costs. If a brewer discharges excessive quantities of selected contaminants to a POTW, that agency can request a surcharge in addition to normal treatment fees. The magnitude of surcharge fees can provide a basis for deciding whether to pretreat and what technology to use. When a brewer decides to pretreat, they must select one or more of the multiple options available for consideration. No single option will apply to all brewers.
Brewers discharging very small volumes to a sewer will find that POTW fees do not support a decision to install pretreatment equipment. The return on investment is simply unattractive. Brewers with larger wastewater flows may incur enough POTW expenses to justify investing in simple pretreatment systems. The following data describes costs indicative of the magnitude of surcharges a brewer might expect for selected contaminants.
Assume that wastewater concentrations for three constituents exceed discharge limits: BOD (Biological Oxygen Demand) exceeds by 1,250 mg/L; TSS (Total Suspended Solids) by 150 mg/L; and Phosphorus by 15 mg/L. A brewer discharging 2,000 gallons per day will need to pay approximately $2,400 annually in surcharge fees in addition to normal wastewater treatment costs. That surcharge might motivate a brewer to look for ways to reduce costs through simple measures such as conserving water, reducing peak contaminant concentrations, or concentrating wastes for offsite disposal. Depending on circumstances, the right option may be to change nothing and pay the surcharges.
Using the same discharge parameters as listed above, a brewer discharging 20,000 gallons per day could pay approximately $24,000 annually in surcharge fees. This expense would make it easier to justify the costs of installing a wastewater pretreatment system.
Note that the costs cited above are presented as examples. Surcharge limits and fees are set by local authorities having jurisdiction over each POTW and should be checked for individual locations.
To learn more about wastewater removal options, contact Bruce Smith at 231.670.1465.