The different types of brewery wastewater

Brewery wastewater varies in composition and volume depending on the size of the brewery, the brewing methods used and the specific products being made. Even the water quality and the composition of the water used for beer production can affect the wastewater generated during the process. As such, any wastewater treatment process needs to be tailored to the brewery's specific requirements.

In general, brewery wastewater that falls into each of the following categories will contain the following products or pollutants that brewers must account for:

• Process water: This is the name given to the water used in various stages of the brewing process, from mashing and lautering to boiling and cooling. Its wastewater can contain residues of malt, hops, yeast and other brewing ingredients.
• Cleaning and rinsing water: Equipment like fermentation and conditioning tanks, tuns and pipelines are cleaned and rinsed with water that may then contain organic residues, cleaning agents (e.g., caustic soda, acids) or disinfectants. Water used to rinse bottles, cans and kegs during the packaging process can also produce wastewater containing small amounts of beer, organic residues and cleaning agents.
• Yeast and trub waste: Fermentation will generate wastewater containing spent yeast and trub (a mix of proteins, hop particles and other solids that settle out of the wort).
• Spillage: Spillages during filling and packaging can also contribute to wastewater. This will often contain beer or other brewing products and if spills are not suitably contained, this can breach environmental regulations and lead to legal challenges.
• Cooling water: Water used in cooling processes (e.g., in heat exchangers) can often be recycled, but may be contaminated with organic matter or chemicals, depending on the process it is involved in. Whether this constitutes wastewater or not depends on the brewery's approach. Water condensed from refrigeration units may also be collected and discharged as wastewater, though it is generally low in contaminants.
• Laboratory wastewater: Water used in laboratories for testing and quality control may contain chemical reagents, yeast cultures and other residues, and may need to be treated or disposed of.

In general, it is best to assume that any wastewater you generate contains cleaning chemicals or organic compounds. Treating wastewater in this way, no matter its source, will help you to avoid falling afoul of any brewing industry regulations or legal requirements.

The laws governing wastewater treatment

Because of the potential presence of organic compounds or chemical products in industrial wastewater, strict regulations govern how water must be treated and under what circumstances it can be discharged into the environment. The brewing sector is no exception, and both small and large breweries are subject to the same demands in this regard - although smaller craft breweries may not be subject to legislation like the Industrial Emissions Directive, which deals with large-scale pollution.

Laws that UK brewers must comply with include:

• The Environmental Permitting (England and Wales) Regulations 2016: Breweries must obtain an environmental permit if they discharge wastewater directly into surface waters or groundwater. The permit sets out conditions on the quality and quantity of wastewater that can be discharged, and brewery wastewater must be treated to the prescribed standards. Breweries are required to regularly monitor the quality of their effluent and report this data to the Environment Agency.
• Water Resources Act 1991: This legislation sets limits on the concentration of pollutants (such as biochemical oxygen demand, pH, and suspended solids) in wastewater discharges. Breweries discharging wastewater, whether into sewers or directly into surface water, must comply with these rules.
• Trade effluent consents: If a brewery discharges its wastewater into the public sewer system, it must obtain a trade effluent consent from its local water company. This consent outlines the conditions for discharge, including the volume, rate, and composition of the effluent, in line with the other legislative requirements listed here.
• Urban Waste Water Treatment Regulations 1994: These rules require that wastewater from breweries (and other industrial sources) undergoes appropriate treatment before discharge. They also specify different requirements for areas more prone to eutrophication, and set specific standards for wastewater discharge from breweries.
• The Environmental Protection Act 1990: These regulations place a duty of care on the brewing industry to manage waste responsibly. This includes storing, transporting and disposing of wastewater in a way that does not harm the environment. Breweries are responsible for preventing pollution and must take action to remediate any environmental damage caused by their wastewater discharges.
• The Industrial Emissions Directive (IED): Larger breweries may fall under the scope of the IED, which requires an integrated approach to pollution prevention and control. It governs not only wastewater, but energy consumption and other areas of potential environmental impact. It usually requires brewers to implement advanced wastewater treatment processes to reduce pollutant loads.

It is important to understand the regulations that govern brewery wastewater treatment before you begin beer production, as they could have a significant impact on your production facilities, processes and approach to treatment.

Solutions for the brewing industry

There are several standardised solutions that breweries can implement to effectively treat or reduce wastewater. A solution that large and small breweries alike should consider is separate high-strength wastewater streams (from brewing and fermentation) from lower-strength streams (such as from rinse water). This allows the high-strength wastewater stream to be treated separately, and can reduce overall treatment costs.

An on-site wastewater treatment plant can offer significant advantages, although working with professionals to collect and treat wastewater off-site is also an option in some cases. Wastewater treatment should take place in three stages:

• Primary treatment: This should start with the installation of screens and sedimentation tanks, which can remove large solids and particulate matter from wastewater before it enters further treatment stages. The dissolved air flotation process may also be suitable at this stage. It helps to separate suspended solids, oils, and greases from wastewater by introducing fine air bubbles that float contaminants to the surface for removal.
• Secondary treatment: Aerobic processes, where microorganisms break down organic matter in wastewater, should be the first stage of biological treatment. It can significantly reduce biological oxygen demand and chemical oxygen demand levels. Anaerobic treatment can be particularly effective for high-strength brewery wastewater. It also produces biogas, which can be used as a renewable energy source. Depending on your production capacity and volume, sequencing batch reactors may offer the most flexibility when it comes to handling loads of different sizes.
• Tertiary treatment: Use sand filters, membrane filtration (e.g., microfiltration, ultrafiltration) or another approach to remove any remaining suspended solids and pathogens from the treated effluent. It may be appropriate to apply UV disinfection, ozone treatment or chlorination to eliminate pathogens and make the wastewater safe for discharge or reuse.