SubscribeJim Allen reviews water sources for medium size breweries as concern over water cost and quality raises issues.
Now is a good time to revisit the old brewery well as there may be significant financial gains to be made, together with environmental and marketing PR opportunities. Traditionally breweries were sited where the local water was suitable for brewing and they drew their supply from their own well or borehole. In recent years a combination of the move to lager brewing, and in some areas concern over water quality, has resulted in many breweries sourcing their supply from the mains. The failure of an old pump or pipe work often meant that a move to mains was an emergency low cost option. Whatever the source, water systems and disposal are strictly regulated.
The Use Of Recycled And Recovered Water
Recently water has become a high profile topic especially in the South East of the UK with restrictions of water supply. Mains supply is now the first option although continuity of supply in some areas is becoming a concern. The alternative option, even where there has been an issue over ground water quality, is to return to original borehole or well sources which are now feasible using current technology. Sinking of new boreholes in some areas may be a cost effective solution. The use of recycled and recovered water can complement either approach. The cost of town water has increased in recent years and the cost of its disposal as effluent can be even higher than the cost of its supply depending on local charges. The financial pressure is therefore to reduce the cost of supply, maximise the efficiency of use and minimise the cost of disposal.
Well Or Borehole Supplies
Breweries still using their well or borehole supply will be already benefiting from the relatively low cost of supply, based on the revenue maintenance and abstraction licence costs. It is important to note that authorities may not renew licences where wells are not being used. On some sites the use of the old supply has been restricted to utilities plant due to concern over water quality. This may be due to possible ground water contamination by industrial or agricultural pollution or in some areas reduction in the water level resulting in salt water ingress. Water treatment technology has moved forward significantly and now provides the opportunity to utilise old supplies reliably and to current quality standards. The return to or increased use of old brewery supplies is now a practical and economic option. Whether recommissioning or operating private supplies, the Environmental Agency guidance on well head design should be taken into account to minimise the risk of contamination of the supply. Redundant boreholes and wells should be decommissioned in line with the Environment Agency guidance.
Local authorities have the responsibility for checking quality of private water supplies. Abstraction licences and ground water consents are covered by the Water Resources Act 1991. NB It is a criminal offence to “cause or knowingly permit” groundwater to be polluted.
In considering use of the private supply it will be necessary to analyse the raw water and review the operational requirements. A target analytical and microbiological specification should be set for key parameters. Breweries generally only analyse a few key parameters and it is worth reviewing these in comparison to the detailed EEC 98/83/EC directive. In setting specifications it is prudent to consider what has been used in previous years and to reflect on any operational issues that have arisen. Sampling unused well supplies will entail pumping significant volumes to identify the steady state analysis of the raw water.
Breweries operating with town water may also need to carry out water treatment in order to achieve quality specifications. The mains water is only required to be potable and existing mains water quality may be both variable and potentially unsuitable for brewing. The move to lager brewing has necessitated many breweries installing water treatment of mains water for brewing. Variability in supply quality can also cause problems with detergent compatibility and the operation of utilities equipment. This can be a particular problem where the mains supply is from very different sources. Local water authorities are not required to give notification of such changes in supply, and may be unable to do so where supply networks are dual sourced. Many smaller brewing companies are now brewing under franchise and may be required to carry out additional water treatment for franchise beers. The requirement to carry out carbon filtration, typically for removal of THM (trihalomethanes) on mains supplies, removes the residual mains chlorine. In these circumstances additional water treatment is advised to maintain microbiological stability.
When setting specifications for water quality, targets and acceptable ranges should be established. In reviewing these, historical data is important; however the frequency of water analysis is often quite low and restricted to a few key parameters, especially by users of mains supply. With water as a key raw material, surprisingly the daily tasting of brewing water and product dilution water is often the only frequent quality check carried out.
Specifications should be set for:
Brewing liquor
Product dilution water
Process water
Utilities (including domestic supplies) water
In setting the specification, it is important to consult with existing suppliers of chemicals for processes that use the site water supply. They may be able to provide alternative materials, possibly at lower cost, if the water analysis changes. Typically such suppliers will be detergent and conveyor lubricant suppliers, together with the existing water treatment contractor for the boiler water and cooling systems, who may be significantly affected by water quality changes. Early involvement of proposed water treatment equipment suppliers with regard to setting specifications is recommended. They can advise on the economic impact of any proposed plant or change in feed water.
Well water treatment in breweries will generally be based on filtration, chemical and microbiological steps depending on the raw water quality and the target specification set. Initial coarse filtration will protect downstream equipment. Carbon filtration is advised where there is a risk of organic / pesticide contamination. The services of an expert may be required to assess the risk to the ground water supply as the water table may be fed from agricultural land many miles away. The Environment Agency can provide guidance and will protect the source from new activities that could potentially affect the source.
The two main options for adjustment of the analytical parameters are ion exchange and reverse osmosis. Current technology now provides highly automated and reliable installations for both systems with reverse osmosis becoming the preferred option. A proportion of blended back raw water provides the scope to match the target analytical specification. The use of Burtonization (addition of calcium sulphate and sometimes sodium chloride) is long established to match the classic Burton brewing liquor.
Cost Effective Water Treatment
The choice between ion exchange and reverse osmosis really depends on the composition of the raw water supply, the type of products brewed and the site’s view of chemical storage. For some breweries, the traditional dealkalisation ion exchange with sulphuric or hydrochloric regeneration still provides cost effective water treatment. For others, particularly where the water may be high in conductivity or from non potable sources, reverse osmosis may be more appropriate.
All water supplies and treatment systems generally require the installation of break tanks to buffer supply against peak demand. In breweries the design of these and in particular the pipe work layout is important to maintain cleanliness. Deadlegs and unused pipe work should be avoided and tanks should be designed to ensure effective through flow to minimise stagnation. All systems in commercial and industrial premises that use and store water are covered by the Approved Code of Practice for the control of legionella bacteria. The storage of water above 20oC and aerosol generation should be avoided and a risk assessment of the system is required. System design for mains water users is covered by the Water Supply (Water Fittings) Regulations 1999 and the Water Supply (Water Quality) Regulations 2000 under the Water Industry Act 1991.
Microbiological Treatment
Microbiological treatment historically has been based on chlorination. The equipment and procedures were well proven and operational costs relatively low. The use of chlorine always gives rise to product quality concerns when there is a risk to product. Chlorine is potentially corrosive to pipe work and precautions are required particularly at the point of addition and downstream prior to mixing being achieved. Some grades of stainless steel are especially susceptible. Many larger breweries have moved towards the use of chlorine dioxide which allows the use of a lower treatment concentration. Chlorine dioxide is also less affected by organic material and has minimal taint risk to product. UV treatment is a strong contender with the most recent equipment providing a reliable performance. Here the physical quality of the water is critical to the effective operation of the UV unit. There is no product taint risk, however the treatment has no residual effect and downstream connections may need secondary microbiological treatment to maintain an acceptable microbiological quality in critical areas. A small number of companies are using ozone. This is a very effective sterilant, the use of which is new to the brewing industry. Bulk chlorine, chlorine dioxide and ozone are all hazardous materials but there is widespread operational experience of the use of chlorine and chlorine dioxide and their safety issues. Breweries are therefore more likely to continue with materials, the safety risks of which are understood and already managed.
In recent years the awareness of the risk of Cryptosporidium contamination of natural water sources has increased. This is a specialist area since the organism is particularly difficult to remove and additional precautions are required if there is a significant risk. The use of agricultural land for animals above the water table area increases the risk.
CIP Equipment
In reviewing potential water sources, the re-use of water is a key opportunity. The recycling of water within equipment like CIP units is well established and recent tunnel pasteuriser installations have often fitted been with an associated evaporative condenser for excess heat removal, avoiding the requirement to pour large volumes of water to drain. It is however worth revisiting CIP equipment as many older plants are still operating some CIP plant without final rinse recovery. It may now be appropriate to consider retrofitting water recovery if CIP plant replacement is not imminent. Historically with low water and effluent costs the capital cost of water recovery may not have been attractive; however the drive on environmental standards for water courses has forced local authorities to address effluent treatment. The cost of this varies significantly across the UK and will affect financial decision making. Water ratios between 8 and 10 are probably not unusual in medium sized breweries. This provides significant savings opportunities. A basic site wide flow diagram, showing all equipment using water and the discharges, is a good start in identifying the potential savings. The recent article in the Brewer & Distiller on the Yatala brewery in Australia shows the scope with a 2.2 to 1 water usage ratio.
CIP equipment with high demand (e.g. FV and BBT cleans) rather than those carrying out weekly mains cleans should be reviewed first. Most brewers have already reviewed rinse cycles to minimise water use even when operating systems with water recovery. The opportunity for further reductions on acid detergent systems, with PAA as the terminal sterilant is often missed – the post detergent (pre-sterilant) rinse can be very short and the carry over of low levels of PAA into the detergent tank is beneficial microbiologically where the acid detergent is compatible. The reduction of rinse times provides secondary benefits of reduced overall CIP time and lower electrical energy costs. Any such changes should be carried out only after discussion with the detergent supplier and a full CIP cycle audit.
The historical dayshift packaging and five day operation of medium sized breweries in comparison to the current 24/7 mode of the large breweries means that CIP regimes tend to be daily / weekly based. Larger breweries have moved towards CIP as required, with keg plants perhaps running 72 hours between cleans and brewhouses up to 10 days (except for their coppers). This results in a reduced water consumption ratio. The operation of packaging plants on a 24 hour basis provides dramatic line efficiency improvement gains where real start up / shutdown times are in practise much longer than planned. The impact of priming and post production flushing volumes is increased as the length of the production run is reduced. Another area where large plants win is that they run much longer batches avoiding additional between product purges. The drive towards best before labelling and just in time philosophies has made this worse. It may now be time for brewers in medium sized breweries to take a step back and review all production operations, with a wider view, balancing all the parameters affecting quality and cost.
The Re-Use Of Water
Within the UK there has been little pressure for the re-use of water other than within equipment. In contrast Southern European and Australian brewers have always operated in areas of low water availability. All new capital projects should include the consideration of water consumption minimisation / recycling and re-use opportunities as a key step in the design process. It is invariably more cost effective to design features in from the outset and the cost of water supply and effluent disposal is likely to rise over the lifetime of the equipment.
Re-use water as a water source can be very cost effective, its supply cost having already been covered. In the past, using existing site mains or well supply would be the natural choice. The potential to use re-use water should be considered for all new installations and existing systems should be reviewed. The use of re-use supply may not even require any additional treatment. Some water that has already been used is still suitable for further use without any pre-treatment. The pre-filler rinse water used for cans, non returnable glass and PET bottles may for example only require a very basic filter to be suitable to feed the line conveyor lubricant system. The cost of installation of reuse systems very much depends on local layout arrangements and is best kept simple. Larger volumes of high quality water may be available from final CIP rinses if these cannot be fully recovered within the CIP system.
As effluent and water costs rise in some areas, the full treatment of selected discharged water and potentially all site effluent for utilities and process purposes will become financially viable.
In conclusion, it is now the time to revisit the old brewery well as there may be significant financial gains to be made, together with environmental and marketing PR opportunities. Whatever the water source, the scope for minimising use, recycling and re-use should all be reviewed.