Estimating the leakage contribution of phosphate dosed drinking water to environmental phosphorus pollution at the national‐scale

Ascott, M.J.; Gooddy, D.C.; Lapworth, D.J. ORCID: https://orcid.org/0000-0001-7838-7960; Stuart, M.E.. 2016 Estimating the leakage contribution of phosphate dosed drinking water to environmental phosphorus pollution at the national‐scale. Science of the Total Environment, 572. 1534-1542. https://doi.org/10.1016/j.scitotenv.2015.12.121

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Abstract/Summary

Understanding sources of phosphorus (P) to the environment is critical for the management of freshwater and marine ecosystems. Phosphate is added at water treatment works for a variety of reasons: to reduce pipe corrosion, to lower dissolved lead and copper concentrations at customer’s taps and to reduce the formation of iron and manganese precipitates which can lead to deterioration in the aesthetic quality of water. However, the spatial distribution of leakage into the environment of phosphate added to mains water for plumbosolvency control has not been quantified to date. Using water company leakage rates, leak susceptibility and road network mapping, we quantify the total flux of P from leaking water mains in England and Wales at a 1 km grid scale. This is validated against reported leaks for the UKs largest water utility. For 2014, we estimate the total flux of P from leaking mains to the environment to be c. 1.2 kt P/yr. Spatially, P flux is concentrated in urban areas where pipe density is highest, with major cities acting as a significant source of P (e.g. London into the Thames, with potentially 30% of total flux). The model suggests the majority (69%) of the P flux is likely to be to surface water. This is due to leakage susceptibility being a function of soil corrosivity and shrink‐swell behaviour which are both controlled by presence of low‐permeability clays. The location of major cities such as London close to the coast results in a potentially significant flux of P from mains leakage to estuarine environments. The contribution of leakage of phosphate dosed mains water should be considered in future source apportionment and ecosystem management. The methodology presented is generic and can be applied in other countries where phosphate dosing is undertaken or used prior to dosing during investment planning.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	https://doi.org/10.1016/j.scitotenv.2015.12.121
ISSN:	0048-9697
Additional Keywords:	GroundwaterBGS, Groundwater, Groundwater quality, Surface water interaction
Date made live:	09 Mar 2016 09:32 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/513204

Item Type:

Publication - Article

Digital Object Identifier (DOI):

https://doi.org/10.1016/j.scitotenv.2015.12.121

ISSN:

0048-9697

Additional Keywords:

GroundwaterBGS, Groundwater, Groundwater quality, Surface water interaction

Date made live:

09 Mar 2016 09:32 +0 (UTC)

URI:

https://nora.nerc.ac.uk/id/eprint/513204