Diagnosis of the ageing of water pipe systems by water quality and structure of iron corrosion in supplied water

To develop a method for screening ageing of water supply systems by analysing the supplied water's quality, water samples were collected from a water treatment plant, a delivery pump station, two distribution reservoirs and two feed pipes along a water pipe system. Principal component analysis of the water was conducted. In the first principal component, many elements exhibited high factor loadings, whereas the major contributor for the second principal component was iron (Fe). The unlined steel pipe, which was beyond its working lifetime, had a significantly high Fe content in suspended solids. X-ray absorption fine structure (XAFS) analysis showed differences in the abundance ratios of Fe₃O₄ and α-FeOOH among the sampling points. It was concluded that the concentration and speciation of Fe in supplied water can be a useful index for detecting the ageing of pipes.