Modeling and Field Work to Investigate the Relationship between Age and Quality of Tap Water

Abstract

Article:Machel, J.M. and Boxall, J.B. (2014) Modelling and field work to investigate the relationship between the age and the quality of drinking water at customer's taps. Journal of Water Resources Planning and Management, 140 (9).1 Modeling and field work to investigate the relationship between the age and the quality of drinking water at customer's taps Abstract: It has been widely theorized that water age may be a useful indicator of the quality of water within drinking water distribution networks. However, there is limited evidence of model simulation results being related to empirical water quality (WQ hereafter) data to substantiate the theory. This paper presents the findings of investigations designed to determine if there was an observable relationship between mean water ages calculated using a WQ simulation model, and measured WQ in two live distribution networks.The age of water in all pipes was calculated using Aquis hydraulic and WQ modeling software. Historic regulatory WQ data was examined to determine if there was a relationship between general WQ and calculated water age within the networks. A more detailed study was then undertaken in one network by translating model locations that were representative of the spread of water age into real world locations.WQ samples were taken intensively from these sites and analyzed for a range of aesthetic, physical, chemical, and bacteriological parameters indicative of general WQ.Some relationship between the calculated mean age of water and the general WQ in the network was demonstrated. Analysis that considered calculated water age and associated WQ along unperturbed flow routes through the network produced a stronger relationship. Given that regulatory WQ within the study networks as reported to the Drinking Water Inspectorate (DWI) was 99.9% compliant, this relationship was deemed noteworthy.

Relating Water Quality and Age in Drinking Water Distribution Systems Using Self-Organising Maps

“…The UK "customer taps" study area (13 sampling locations: 11 at customers' taps, 2 at service reservoirs) is described in Machell and Boxall [13]. The UK "small looped network" study area (5 sampling locations in a compact geographical area) is described in Machell and Boxall [7] and Sekar et al [30].…”

“…The UK "small looped network" study area (5 sampling locations in a compact geographical area) is described in Machell and Boxall [7] and Sekar et al [30]. With earlier approaches it was difficult to find clear relations between water quality data and mean or maximum water age [13]. For the SOM analysis, some data processing steps were taken.…”

“…Average water age for this data set was calculated using a hydraulic model with typical 2012 daily demand patterns. The UK dataset was much smaller, but a more accurate hydraulic model was used and intensive water quality sampling was targeted at areas of the network containing specific water age volumes [7,13].…”

Using the Set Point Concept to Allow Water Distribution System Skeletonization Preserving Water Quality Constraints

“…That is, the longer it takes the water to reach the point of consumption, the worse quality. Machell and Boxall [1] confirm this statement through unperturbed flow routes within a real network.…”

Enabling Efficient and Sustainable Transitions of Water Distribution Systems under Network Structure Uncertainty

“…Furthermore, the water quality of the WDS model is described by the maximum water age, which is a driving factor related to microorganism growth [27].…”