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NEW HOUSING: DECISION SUPPORT FOR WATER & WASTEWATER MANAGEMENT
 
 By Roland Burkhard

Scottish Centre for Environmental Design Research (SEARCH)
Scott Sutherland School of Architecture
The Robert Gordon University
Garthdee Road, Aberdeen, AB10 7QB, United Kingdom
 

SITUATION

A resarch project is under way at the Scottish Centre for Environmental Design Research (SEARCH) into integrated water and wastewater management for new housing in rural areas. The UK Government projects some 4.2 million new homes by 2016, of which 40% will be built on greenfield sites. For example, the water resources in the South East of England are already under heavy strain since the migration patterns in the UK show a surplus for this region. Hence the management of water and wastewater will be an issue of foremost urgency for the private water industries in England and Wales.

Most of the water and wastewater management approaches are still done in the conventional way, which is illustrated in Figure 1:
Figure 1: Conventional Water Cycle
  There is a wealth of both conventional and alternative/ecological techniques, which are financially as well as ecologically viable. While some techniques, such as wetlands, are already accepted by some mainstream engineers and water utilities (such as Severn Trent or Yorkshire Water), others, such as greywater recycling systems are hardly known to the practising engineer.

It may hence be of interest to the water industry in the UK to have access to data on more ecological and possibly economical ways of dealing with water and wastewater management. Since the UK has also signed Agenda21 agreement, a pledge for a sustainable alternative to the problems of the old, conventional approach to urban development was made. To facilitate a sustainable approach for engineers, developers, planners and home owners, the following approach was found to be useful.
 

APPROACH

  • Identify both conventional and ecological water and wastewater management schemes.
  • Specify design figures for all techniques.
  • Definition of methods for evaluation of different management solutions.
  • Design modules for possible decision support tool.
  • Feasibility study.

The above list requires some explanations and clarifications. The identification of the different techniques can be carried out according to the conventional and modified water cycle as illustrated in Figure 2:
Figure 2: Modified Water Cycle
  Following the white arrows, conventional techniques can be identified. Following the shaded arrows, alternative and ecological techniques can be found. Each technique is described and the constraints are assessed. Design figures are drawn up to facilitate the evaluation of each technique with regard to the physical, economic and social environment.

The definition of the methods for evaluation of the different solutions is done with the different stakeholders in the decision process. These involve water utilities, developers, homeowners and planners. This is where the actual definition of sustainability takes place. To accommodate all stakeholders' ideas of sustainability, this has to be defined in collaboration with them. It involves natural sustainability, which is based on the mass flux as defined by physical laws. It also involves economic sustainability and maybe most important and difficult of all, social sustainability. Figure 3 shows the sustainability criteria as defined above:
Figure 3: Sustainability Criteria
  It is obvious that these three criteria are conflicting. Else the question of how we could create a more sustainable future would not be raised. It is this conflict that is fundamental to the problems we are facing today not only with regard to water shortages but also other, related problems, such as global warming etc.

The design of the actual decision support tool can be made once all the above criteria are fulfilled. All data is gathered in a database where information on each criteria is easily accessible. The tool is intended to be accessible for any interested person. Hence it has to be designed such that a lay person is also able to use and understand it. The user can retrieve information on single or combination of techniques, their respective sustainability in terms of the three sustainability criteria and design considerations. Examples of existing techniques help as an illustration for the prospective developer or give planners the opportunity to examine alternatives. A possibility of how sustainability can be numerically expressed is shown in Figure 4:
Figure 4: Example Sustainability Assessment
  Please note that the above Figure is only an example. The decision support tool is intended as a decision help only and is not intended to present absolute solutions. This is especially important when social considerations are taken into account. It still needs the collaboration of the responsible stakeholders to reach the best possible compromise.

Finally, the decision support tool has to be tested. Ideally, a real project serves as a test facility, but mock up projects will have to be sufficient to do initial tests.
 

WORK TO DATE

To date data has been gathered on ecological and conventional water and wastewater systems regarding the discharge of water. An application to EPSRC under the WITE program was made and was unsuccessful. One paper was presented at the SANHYGA99 conference in Piest'any, Slovak Republic and a paper is pending publication in the Journal "Urban Water".

OUTLOOK

Although there is strong support from the water utilities and others, EPSRC has not funded the project (EPSRC is the governmental funding body of the UK that sponsors research projects at UK Universities). If the project is going to develop any further from here is all but sure at the moment since there are no more funds available.

COLLABORATORS

Main investigators in the project are Ms Ana Deletic from Aberdeen University, Professor Enda O'Connell from Newcastle University, Professor Paul Jowitt from Heriot-Watt University and Dr Martin Edge from Robert Gordon University. Research to day was carried out by Anthony Craig (Environmental Psychologist) and Roland Burkhard (Rural/Civil Engineer) at Robert Gordon University of Aberdeen.

Collaborators in industry include West of Scotland Water, North West Water, Thames Water, Essex and Suffolk Water, Lyonnaise des Eaux. Other supporting institutions are CIRIA, Environment Agency, Living Water, The Earth Centre and Findhorn Foundation.
 

PUBLICATIONS

  • Burkhard R, Deletic A, Craig A, Slaven G; TECHNIQUES FOR WATER AND WASTEWATER MANAGEMENT: A REVIEW OF TECHNIQUES AND THEIR INTEGRATION IN PLANNING; Publication pending in "Urban Water"
  • Burkhard R, Deletic A, Craig A (1999); EVALUATION OF HOLISTIC WATER AND WASTEWATER MANAGEMENT STRATEGIES FOR NEW HOUSING DEVELOPMENTS - A REVIEW; 4th International Conference SANHYGA'99; Piest'any, Slovak Republic
 
© 2000, International Ecological Engineering Society, Wolhusen, Switzerland