title: Climatic, Geographic and Operational Determinants of Trihalomethanes (THMs) in Drinking Water Systems.
abstract: Trihalomethanes (THMs) are conditionally carcinogenic compounds formed during chlorine disinfection in water treatment processes around the world. THMs occur especially when source waters are subject to marine influences, high and-or regular precipitation, and elevated levels of organic matter. THMs formation is then rooted in geographic, operational and climatic factors, the relative importance of which can only be derived from large datasets and may change in the future. Ninety three full-scale Scottish water treatment plants (WTPs) were assessed from Jan 2011 to Jan 2013 to identify factors that promote THMs formation. Correlation analysis showed that ambient temperature was the primary THMs formation predictor in potable water (r2= 0.66, p < 0.05) and water distribution systems (r2= 0.43, p = 0.04), while dissolved organic carbon (r2= 0.55, p < 0.001) and chloride (indicating marine influence; r2= 0.41, p < 0.001) also affected THMs formation. GIS mapping of median THMs levels indicated brominated THMs were most prevalent in coastal areas and on islands. This real-world dataset confirms both geographic and climatic factors are key to THMs formation. If ambient temperatures increase, THMs control will become more challenging, substantiating concerns about the impact of global warming on water quality.
authors.affiliation: School of Civil Engineering and Geosciences, Newcastle University, Newcastle upon Tyne, United Kingdom.|Scottish Water, Castle House, Dunfermline, Edinburgh, United Kingdom.
authors.forename: Maria
authors.initials: M
authors.lastname: Valdivia-Garcia
authors.affiliation: Scottish Water, Castle House, Dunfermline, Edinburgh, United Kingdom.
authors.forename: Paul
authors.initials: P
authors.lastname: Weir
authors.affiliation: Scottish Water, Castle House, Dunfermline, Edinburgh, United Kingdom.
authors.forename: Zoe
authors.initials: Z
authors.lastname: Frogbrook
authors.affiliation: School of Civil Engineering and Geosciences, Newcastle University, Newcastle upon Tyne, United Kingdom.
authors.forename: David W
authors.initials: DW
authors.lastname: Graham
authors.affiliation: School of Civil Engineering and Geosciences, Newcastle University, Newcastle upon Tyne, United Kingdom.
authors.forename: David
authors.initials: D
authors.lastname: Werner
mesh_terms: D002980:Climate; D060766:Drinking Water / Q000032:analysis*; D012606:Scotland; D013696:Temperature; D022882:Trihalomethanes / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis; D018508:Water Purification / Q000379:methods; D060753:Water Quality
chemical_list: D060766:Drinking Water; D022882:Trihalomethanes; D014874:Water Pollutants, Chemical