An innovative greywater treatment system for urban areas ... - SuSanA

3.8 FUTURE PROSPECTS
3.8.1 LEGAL FOUNDATION
To endorse the dissemination of greywater recycling legal measures are necessary.
Governments are developing policies with incentives and/or permits to stimulate water
recycling in an industrial context. Possible tools that can be deployed are: increasing taxes
on wastewater discharge, requiring the development of wastewater treatment techniques that
result in enhanced removal of a wide range of contaminants, and linking permits to
progressive use of alternative water sources (Van der Bruggen, 2010).
In Jordan the implementation of a greywater recycling plant in the “Dead Sea Spa” hotel
was so successful that greywater recycling shall now become compulsory for all hotels (GTZ,
2010). Even the government in Tokyo requires that water-saving measures be implemented
in new multi-storey buildings, such as rainwater collection systems which provide water for
the toilets and urinal flushing and greywater recycling systems (Asano, Burton, Leverenz,
Tsuchihashi, & Tchobanoglous, 2007). Moreover, for several years the operators of new
hotel edifices in Beijing are obliged to use purified greywater for toilet flushing. In big cities
shortages, such as interruption of water supply is on the agenda. Laws in China require hotel
operators of modern tourism facilities to recycle greywater. The demand for technology in
this sector is extremely high. Extreme water shortage is approaching more than 100 of the
660 cities in China (Weitlaner, 2005).
Thus, direct governmental funding for treatment plants via subsidies, allowances, loans for
plant investment, financial support or indirect incentives on greywater recycling including for
example tax reductions, rebates, minimised fresh and/or wastewater charges,
reimbursements of taxes or charges, can be vital instruments to support the dissemination of
this very useful technology.
3.8.2 FINANCIAL AND ECONOMIC ISSUES
In regions where no sewer systems exist, wastewater is collected in vaults and removed by
suction vehicles. For amortisation calculation, the implementation of a greywater recycling
plant shows good performance, because the removal and disposal via suction vehicles is
very expensive. The “Dead Sea Spa” hotel in Jordan using greywater recycling showed a
payback time of 5-6 years for the investment costs of approx. € 65,000 as water costs are
5 €/m 3 (Rothenberger et al., 2011).
But in many areas where water scarcity prevails, the drinking water and wastewater prices
are generally very low, due to governmental subsidies. Therefore, in such areas at first only
low cost savings result from the substitution of fresh water by recycled greywater. For these
regions the big advantage of a greywater reuse plant is mainly in independence from an
unstable water supply. For example 4 - to 5-star hotels can keep their business going, even
in times of water shortages or cuts in supply. This can be obtained by using the treated
greywater for various purposes such as toilet flushing and irrigation of hotel garden (Paris,
2009a). This is a stimulus to increase the demand for greywater treatment technology in the
context of protection of resources which are necessary for production plants, hotels, etc.
Therefore, the consideration to install a greywater recycling plant should not only be
decided based on the economic benefit. In different regions of the world the requirements
which shall be fulfilled by implementing such a system can be extremely variable. In
Germany the installation of MBR systems is mainly based on financial reasons. But in other
countries, the maintenance of secure water supply and protection of water resources from
exploitation can bring quite a different dimension into the decision-making process for such a
system.
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