3 Method and case studies
4.4 Transformation processes
4.4.1 Drivers for change
The main focus of this thesis is on the assessment of specific criteria related to efficient resource use. However, changes in the current water and wastewater system can occur due to a variety of drivers and evolutionary (economic and social) transformation processes. Therefore, this section aims at assessing the described systems regarding their behaviour related to such possible changes in the economic, environmental and social framework. Several authors have discussed the current transformation processes and the need for a paradigm change in wastewater management in Germany (see, for example, Herbst, 2008; Koziol et al., 2006; Libbe, 2007; Riße and Herbst, 2004; Schaller et al., 2007). A task group on new sanitation concepts of the DWA (German Water Association), carried out a Delphi study assessing the importance of certain criteria acting as drivers for, or barriers to the implementation of new sanitation concepts (DWA (ed.), 2008). The study shows that the drivers are anticipated to change over time and that it is expected that several criteria such as resource recovery and resource use will gain importance over the next 20 years. Considering the systems investigated in
103 According to supplier information the costs for such a system decrease with number of connected showers. With three connected showers the specific investment cost is about 580 € p‐1 and with 20 connected showers it is about 370 € p‐1 (Haase, I., 2009, Kosten ThermoCycle WRG, pers.comm.).
this study, the following factors might act as drivers for the transformation104 of the current water and wastewater system in Germany:
Emissions: Emissions to surface waters and groundwater, e.g. via combined sewer overflows or WWTP effluents, need to be further reduced to improve water quality as postulated by the European Water Framework Directive. Hamburg has already invested about 800 million € to reduce the pollution from combined sewer overflows (HSE, 2004).
Natural water cycles: Global climate change has an impact on the German water system. On the one hand, the increased occurrence of heavy rains together with increased sealing of surface areas aggravates the risk of flooding. On the other hand, dry periods can lead to pressure on natural water resources in certain regions. In Hamburg, every year more than 130 ha of land is developed for settlement and infrastructure, increasing rainwater runoff. At the same time, more and more intense rainfalls are observed leading to flooding of streets and houses (Kopp, 2007).
Decentralised systems for rainwater (and greywater) management present a chance to counter these challenges. Authorities in Hamburg have therefore already started to emphasise the need for a shift in rainwater management (BSU, 2006).
Limited phosphorus reserves: As discussed in Section 2.4.1 there are major concerns regarding the availability of phosphate rock reserves that are economically viable for extraction. With increasing scarcity prices will increase; alternative sources of phosphorus must therefore be developed.
Finite fossil fuel reserves: Prices on the energy market are expected to increase due to increased demand and increased fossil fuel scarcity. In addition to the further exploitation of renewable energy sources, energy saving and more efficient use of energy become mandatory.
Micropollutants: Micropollutants, e.g. from pharmaceuticals and personal care products, are entering wastewater and pose a risk to human health as they are contaminating natural water resources. They are evermore becoming a concern and innovative strategies for either eliminating them at source or reducing them at the end of the pipe are needed.
104 It s interesting to note that Libbe (2006) distinguishes between adaptation processes with moderate modernisations on the one hand and transformation processes on the other hand that are always connected with disruptions and transitions comprising a high degree of uncertainty.
Demographic change: Demographic change is related to shrinking cities in many regions of Germany (in only a few regions, like Hamburg, are populations growing), suburbanisation processes and an aging population. But also behavioural change, e.g.
decreasing water consumption, can jeopardize the operability of the current system.
For example, per capita water consumption in Hamburg is expected to decline to about 100 l p‐1 d‐1 in the next 20 years (Maass, 2008). Infrastructure systems that are flexible to react to these changes show advantages compared to systems designed for static conditions and with long depreciation periods.
Reinvestments and rehabilitation: Many facilities of the German wastewater infrastructure have reached the end of their economic lifetime. Therefore, per capita expenditures for reinvestments are expected to increase in the coming decades.
Particularly sewer rehabilitations are going to present high costs for the German water sector105. Capital‐intensive (re)investments such as large sewer systems or treatment plants always represent high sunk costs. A positive response to system transformation opens up opportunities for long‐term cost‐savings.
Export of expertise and equipment: The water and sanitation sector in Germany could represent a lead market if innovations are taken up and specific requirements for export are integrated into the design of the systems. Experience with more decentralised and more flexible systems is expected to result in greater export possibilities. Hamburg Wasser is already involved in the implementation of innovative sanitation concepts in countries such as China and India. There are many regions worldwide that are in need of upgrading their sanitation systems, e.g. Eastern Europe, South America, Africa.
The investigated systems are evaluated against the above‐mentioned drivers (see Table 4.14). The scoring indicates to which degree one particular driver is favourable to the respective systems. The indicators according to which scores are allocated, are shown in the table.
105 In addition, private sewers are going to require immense re‐investment in the near future. Thoma (2006) estimates that about 1250 to 2500 € p‐1 of private investments will be required for inspection and renovation in the coming 20 to 40 years.
Table 4.14: Evaluation of the systems regarding possible drivers for transformation (0 = system shows no advantage, + = system is beneficial, ++ = system is very beneficial)
2 NuRS 3 NuRU 4 CoDig 5 BlaD 6 CompU Indicator
Emissions 0 + + ++ ++
N&P emissions to surface waters, see Table 4.5 & Table 4.6
Natural water
cycles 0 + + ++ ++
Groundwater extraction, see Figure 4.14, &
decentralised rainwater management
Phosphorus ++ + ++ ++ ++ Recovered P, see Figure 4.12
Fossil fuel 0 ++ 0a) 0a) 0 Energy consumption, see Figure 4.15
Micropollutantsb) 0 + ++ 0 0
Separation of urine &
faeces from wastewater, use of treated products
Demographic
change 0 0 + ++ ++
Higher degree of decentralisation, more flexibility
Reinvestmentsc) 0 0 + + +
Decentralised facilities, omission of sewer renovation
Export 0 + + ++ ++
Low water use, innovative & flexible technology
a) This system can be adapted to become more energy efficient as described in Section 4.3.3 b) Particularly micropollutants in urine and faeces such as pharmaceuticals are considered
c) From a pure cost perspective none of the systems is more advantageous than the current system
4.4.2 Preconditions
The implementation of alternative106, more resource efficient water and wastewater systems depends greatly on committed policy entrepreneurs or “enthusiasts” with a long‐term vision (Tidaker, 2007). They will aim to create political support on a local and regional level to start transformation processes. Public law might need to be adapted (especially regarding reuse) and particularly for pilot installations financial support needs to be provided. Tidaker (2007) mentions that a shared perspective and a coordinated approach are important prerequisites for successful system change. For this, it is essential to involve all stakeholders already at an early phase to initiate the
106 The focus of the following discussions is particularly on systems requiring a more radical change such
as systems 3 to 6, and not on purely technical adaptations as in system 2 NuRS.
transformation process. In the case of changing the current wastewater system, this includes not only municipalities, water authorities and water utilities, but also real estate developers, housing associations, inhabitants, architects, craftsmen and manufacturers. In addition, it is indispensable to involve agricultural stakeholders from the very beginning if wastewater products are expected to replace mineral fertiliser and to be integrated into farming activities. For farmers to become actively involved, sufficiently large volumes might be needed to make their efforts worthwhile. Therefore, projects need to be large enough to generate sufficient recovery volumes. As has been shown in the analysis of nutrient recovery potential, mineral fertiliser can never be fully replaced. Therefore, a thorough understanding of what can and what cannot be achieved by alternative systems is important.