Phase two
Realising the potential of the PODDS model

Introduction

The PODDS model, developed by the Pennine Water Group at the University of Sheffield has been shown capable of predicting the discolouration response of distribution networks to changes in hydraulic conditions. Results highlighting the capabilities of the full model are presented in figure 1 (below).

The model is based on the novel application of cohesive transport theory and its development has led to a step change in philosophy and perception relating to discolouration. The initial PODDS research project however did not include development of the model into a tool suitable to be readily utilised by the water industry. Practical application is limited by the scope of the parameter dataset and the time required to apply the full model to complex networks.

This project is therefore a way for the project collaborators to lead the industry in developing and producing a practical tool for planning discolouration related operational and maintenance strategies.

Project objectives

Overall this project is aimed at the development of tools and knowledge to facilitate the maintenance of asset performance using proactive, forward looking approaches.

1. Undertake additional fieldwork, using well established methodologies, to develop a robust dataset of parameter values to populate the PODDS model and its derivatives.

2. Develop a simplified discolouration risk (potential) scoring methodology. This will be built into an EPAnet compatible tool and tested.

3. Undertake repeat field investigations (as in objective 1) to establish material regeneration rates to inform maintenance return intervals.

Project deliverables

1. Dataset of model parameter values to populate the PODDS model. This will allow assignment of parameters values at pipe level, on the basis of GIS asset data and other available information.

2. Methodology and EPAnet based software tool for the evaluation of discolouration risk (potential) based on the PODDS modelling approach and parameter database.

3. Quantification of discolouration material regeneration (or accumulation) rates occurring within real systems, and interpretation with respect to the contributing factors.

4. Reports on fieldwork monitoring at each site to provide details of operations undertaken, data plots and model fitting.

5. A final project report with executive summary.

Journal and conference papers

Husband, S, Boxall, J B (2007)
Repeat DMA flushing operations: discolouration comparison, modelling and management – abstract. Proceedings of the EPSRC Developments in Water Treatment and Supply, 4–5 July 2007, Bath, UK.

Boxall, J B and Prince, R A (2006)
Modelling discolouration in a Melbourne (Australia) potable water distribution system. Journal of Water Supply: Research and Technology – AQUA, IWA. 55.3, pp. 207–219.

Husband, S, Boxall, J B (2005)
Material accumulation and mobilisation in a pipe loop system. Proceedings of the EPSRC Developments in Water Treatment and Supply, 5–6 July 2005, York, UK.

Boxall, J B and Saul, A J (2005)
Modelling discolouration in potable water distribution systems. Journal Environmental Engineering ASCE, vol. 131, no. 5.

Boxall, J B, Saul, A J and Skipworth, P J (2004)
Modelling for hydraulic capacity. Journal of the American Water Works Association, vol. 96, no. 4, pp. 161–169.

Boxall, J B, Skipworth, P J and Saul, A J (2003)
Aggressive flushing for discolouration event mitigation in water distribution networks. Water Science and Technology – Water Supply, vol. 3, part 1/2, pp. 179–186.

Boxall, J B, Unwin, D M, Husband, P S, Saul, A J, Dewis, N and Gunstead, J D (2003)
Water quality in distribution systems: rehabilitation and maintenance strategies. Proceedings of the International CCWI conference, Advances in Water Supply Management, 15–17 September 2003, Imperial College London, UK.

Boxall, J B, Saul, A J, Gunstead, J D and Dewis, N (2003)
Regeneration of discolouration in distribution systems. Proceedings of the ASCE, EWRI, World Water and Environmental Resources conference, 23–26 June 2003, Philadelphia, USA.

Seth, A, Bachmann, R T, Boxall, J B, Saul, A J and Edyvean, R (2003)
Characterisation of materials causing discolouration in potable water systems. Water Science and Technology, vol. 49, no. 2, pp. 27–32.

Boxall, J B, Skipworth, P J and Saul, A J (2001)
A novel approach to describing sediment movement in distribution mains, based on measured particle characteristics. Proceedings of the International CCWI conference, 3–5 September 2001, De Montfort University, UK.

Project base

• University of Sheffield

• Department of Civil Engineering

• Pennine Water Group

Project collaborators

All of the project sponsors below provided operational experience, field sites and assistance.

• Anglian Water

• Northumbrian Water

• Seven Trent Water

• Southern Water

• United Utilities

• Veolia Water

• Yorkshire Water