This the article written by Dr Steward Husband from Sheffield University.
Drinking water distribution systems support a diverse microbial community attached to the pipe walls forming biofilms that entrain inorganic and organic components. If the hydraulic conditions in the distribution network increase and overcome biofilm adhesive forces, biofilms can detach from the pipe walls, creating discoloured water plus taste and odour and other water safety issues. A trial from Valencia in November 2019 highlights the predictable patterns in behaviour and highlights how hydraulic network management can be used as a control measure.
A standpipe with incorporated hydraulic (pressure and flow, www.langhamcontrols.com) and water quality (turbidity, http://www.atiuk.com) was connected via fittings (www.greiner.it) to a hydrant linking a 100mm diameter section of AC pipe within Valencia. This was then subjected to controlled flow increases and the impact recorded (flow and pressure 15 second logging, turbidity 1 second logging). The equipment and equipment is shown in Figure 1.
The trial flow, pressure and turbidity results are shown in Figure 2. Five aspects of the results are highlighted with explanations focussing on the turbidity response to the imposed hydraulics;