The financial benefits of closing the loop on water waste
May 28th 2010 Envirowise water specialist Kate Davis discusses the vast potential for water recovery and re-use technology, exploring how options such as membrane filtration could help UK plc to boost the bottom line and prepare for future challenges
In recent years a growing number of organisations have been discovering the benefits of water-efficient technology, with areas such as rainwater harvesting getting an increasing amount of public and media attention. Even simple steps such as upgrading toilets and taps are reaping real environmental and economic rewards for a number of companies.
However, while more and more businesses are starting to incorporate steps to reduce water use in their environmental management plans, many have yet to explore the potential for the re-use of water within their operations.
The recovery and re-use of wastewater streams via physical collection and appropriate treatments can bring enormous commercial benefits. Not only can it save money by reducing consumption of mainssupplied water and cutting effluent discharge costs,with payback periods starting as low as 12 months, it could also become a key risk management tool for businesses as climate change, population growth and evolving regulation increase the potential for UK plc to face future water shortages.
According to the Environment Agency, it is predicted that UK groundwater will begin to decrease by 2025, with the overall amount of water available in English and Welsh rivers reducing by 15 per cent by 2050.
Some areas in the South East already have less available water per person than Spain and Morocco, while businesses based in regions with higher water availability could feel the impact of water shortages through their supply chains. Many companies could also face potential changes to licences granted to allow water abstraction as result of the Water Act 2003.
One of the most adaptable water recovery and re-use technologies is membrane filtration, which enables companies to re-use a large percentage of their wastewater and is particularly suitable for sectors such as food and drink, printing, chemicals, construction, electronics, ceramics and metal finishing.
Membrane filtration is the process of separating mixtures of materials depending on the particle size. When used for wastewater treatment, it offers a high level of purification and allows wastewater to be recovered and re-used for a number of purposes. For instance, many industrial processes such as heating, cooling, quenching and cleaning do not require the same water quality levels as that destined for potable consumption, so membrane filtration can allow water to be purified to an acceptable level for re-use. However, such is the potential for membrane filtration that wastewater can be purified to very stringent, almost potable levels when required.
Membrane filtration is in fact a generic term which covers several different technologies, including microfiltration, ultra-filtration, nano-filtration and reserve osmosis. Typically, a complete ‘system’ for wastewater treatment, recovery and re-use using membrane filtration technology consists of a feed tank, permeate and reject handling facilities, monitoring and control units and a cleaning-in-place system. Pre- and posttreatment may also be incorporated into the process depending on the level of quality and purification required for re-use.
The type of system chosen will depend on factors such as cost and the type of wastewater to be treated,but any re-use technology incorporated into the system enables companies to significantly reduce the amount of mainssupplied water needed. Moreover, the technology has low energy requirements, leading to reduced running costs and carbon emissions, and can operate in low temperatures, making it particularly suitable for heatsensitive environments, such as those often found in food and drink manufacturing. In some instances membrane filtration can also allow product to be recovered and re-used in the manufacturing process, reducing raw material consumption and associated costs.
The quantity of water re-used at a particular site is dependent on the level of treatment, which is directly related to the characteristics of the site effluent and the application required for the treated water. Typical recovery and re-use efficiencies obtained by membrane filtration processes can range up to 90% and it is already being widely used by the water treatment industry itself.
The financial returns of recovery and re-use systems are not just available through mains supply and effluent savings, however, as these systems are also eligible for tax relief through the Water Technology List (WTL).
Managed by Defra and HM Revenue & Customs in partnership with Envirowise, the WTL provides a selection of technologies that meet published eligibility criteria. The web-based list is part of the Enhanced Capital Allowance (ECA) scheme for water-saving technologies,enabling UK businesses which pay income or corporation tax to claim 100 per cent first-year capital allowances when they purchase products and systems specified on the WTL that are included in the scheme for use in their business. This provides a helpful cash flow boost and results in a shortened payback period, allowing companies to quickly reap the cost benefits of water efficiency.
Since its launch in 200 3, the WTL has grown to encompass more than 1,900 products which qualify for tax relief. These cover categories ranging from efficient taps and toilets to mechanical seals, efficient washing machines and vehicle wash reclaim units.
When it comes to membrane filtration, the ECA is available not just on the membrane filtration technology itself but on the complete treatment system, providing it meets the published eligibility criteria set out on the WTL website. If an application is successful, the business making the investment will receive a ‘certificate of environmental benefit’ from Defra, which certifies the system as qualifying for the ECA. The type of membrane filtration systems that can qualify for support under the scheme include microfiltration, ultra-filtration, nano-filtration, reverse osmosis and membrane bioreactors, providing the system is installed for the treatment of wastewater to enable the recovery and re-use of at least 40% of the treated effluent on the site.
Water is set to become one of the most dramatically affected resources as the impact of climate change takes hold, but there are many steps which companies can take to manage the risk. Installing water recovery and reuse technology could not only lead to short-term cost benefits, but also pay enormous dividends in future years – aiding the environment and the bottom line alike.
To find out more about purchasing products from the WTL, to register a product for inclusion or to apply for certification for a membrane filtration or recovery and re-use system, visit www.businesslink.gov.uk/wtl or call 0800 585794.
HMRC has also published detailed guidance on the ECA scheme on its website
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