Q: What Do All Breweries Have in Common? A: Water

(This is the first of a four-part series on the air emissions and water/waste management requirements and challenges for the brewery industry. In this issue, we address wastewater discharges.)

What do thousands of breweries, mainstream and craft brewers alike, throughout the United States have in common?

As one of the fastest growing sectors of the food and beverage industry, the main ingredient of these breweries is water. It is standard operating procedure for a brewery to have fresh water intake and produce wastewater during the production cycle. Municipalities must provide and manage this water, but brewers need to understand the requirements associated with water management. In this four-part series focused on breweries, we will provide some information about the requirements and challenges of air emissions, and water and waste management, beginning with wastewater discharges.

Why treat brewery wastewater? Why not just discharge it to a nearby stream or river, or send it down the sewer and let the city deal with it?

There is more to it because of the Clean Water Act (CWA), which regulates direct and indirect wastewater discharges to U.S. waters.

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Clean Water Act (direct and indirect discharges)

• NPDES Permit Program regulates point sources (e.g., pipe) that discharge pollutants to U.S. waters
• Effluent Limitations Guidelines are national standards for industrial wastewater discharges to surface waters and publicly owned treatment works (POTW)
• Pre-treatment programs for the control of industrial discharges into sewage collection systems
• Sewage Sludge (Biosolids) Rule regulates the final use or disposal of sewage sludge
• Total Maximum Daily Load (TMDL) and Impaired Waters Rules for states, territories, and authorized tribes to provide water quality standards for impaired waters to ensure they are not further degraded.[/callout]

There are several programs that drive what brewers are required to do under the CWA. The bottom line is that even if the brewery is not discharging directly to surface water, but rather via a publicly owned treatment works (POTW), there are guidelines and limitations to follow that are passed down from the treatment plant based on its National Pollutant Discharge Elimination System (NPDES) permit. And if not issuing a permit, the POTW can set limits on the strength/volume of water it will accept and issue a surcharge to the brewery.

What are the concerns in brewery discharges that would require a permit or discharge criteria (and some causes of those concerns)?

BOD = Biological Oxygen Demand
COD = Chemical Oxygen Demand
TSS = Total Suspended Solids

Passivation is an important part of the brewing process where the brewer will clean equipment to allow for a uniform finish of the surface. Cleaning with acid, for example, can cause low pH spike.

Q: All brewery wastewater discharges are alike, correct? A: No!

Knowing the source(s) of the wastewater in the effluent is not enough. How do you determine the actual quality of the untreated effluent? Once the brewery understands how it is regulated under the CWA, sampling and analyzing the wastewater discharge is the first step to knowing how to comply. Also, several rounds of sampling may be needed to accurately characterize the wastewater.

• Understanding the quality of wastewater at all times is critical as it will change through a typical day, week, and month as activities cycle in the brewery.
• Monitoring key parameters allows the brewery to better recognize changing water quality and volumes; ensuring it meets effluent requirements OR identifying needed improvements.
• Analyzing some parameters, such as pH, are simple and can be done in-house; others may require an outside laboratory (e.g., TSS, BOD/COD), which can take several days to get results.

Prior to discharge, municipalities will require reduction in concentrations or charge a premium (surcharge) for regulated pollutants. See below for a few examples of common discharge criteria for brewers, what untreated brewery “end-of-pipe” wastewater effluent looks like, and some options for treatment to meet permit limitations.

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Example Discharge Criteria and Treatment Systems: BOD/COD and TSS

Relative to domestic sewerage, BOD/COD and TSS concentrations in brewery effluent can be 1 to 2 orders of magnitude higher than acceptable discharge criteria (e.g., 150 ppm), with untreated brewery effluent reaching 1,500 ppm (TSS) to 5,000 ppm (BOD/COD).

• Treatment for BOD and TSS requires an aeration tank (large holding capacity), and energy (bubblers) to add oxygen to promote biological activity to reduce the BOD (from sugars, etc.) and creates a sludge (requiring disposal); can achieve 80% reduction.
• Anaerobic digesters can be used, which can generate methane as a fuel source.[/callout]

An audit to systematically assess wastewater discharges can be beneficial for many reasons. Improving water quality and reducing amount discharged (e.g., lowering concentrations and solids), lowering capital expenditures through proper treatment and efficiencies, avoiding delays, and greater recovery of material can ultimately reduce environmental impact and increase the bottom line.

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Example of Discharge Criteria and Treatment Systems: pH

Acceptable range is commonly 6 to 9, but brewery discharges can range from 3 to 12 depending on the activity.

Adding chemicals can buffer (NaOH or sulfuric acid), but have associated issues (e.g., corrosive, storage restrictions, cost).

• Holding tanks can provide a buffer capacity allowing wastewater streams to blend (buffering pH, etc.) before discharging to sewer.
• Passivation can cause fluctuations of pH from 3 to 12 depending on the use of acid and alkaline cleaning agents.[/callout]

You are the brewing experts and understand your business, but don’t ignore wastewater management. The proper assessment and management techniques can result in potential cost savings for your business. Consider using a trusted advisor to assist you with:

• Water audits – identify opportunities for savings, reuse, and waste management options
• Monitoring (setting up a program, sampling and data review)
• Regulatory interpretation (do you need a permit?)
• Agency interaction
• Applying for and renewing permits
• Preparing water management plans
• Planning impacts from upgrades or changes to operations