title: Using Naturally Occurring Radionuclides To Determine Drinking Water Age in a Community Water System.
abstract: Drinking water quality in a community water system is closely linked to the age of water from initial treatment to time of delivery. However, water age is difficult to measure with conventional chemical tracers; particularly in stagnant water, where the relationship between disinfectant decay, microbial growth, and water age is poorly understood. Using radionuclides that were naturally present in source water, we found that measured activity ratios of (90)Y/(90)Sr and (234)Th/(238)U in discrete drinking water samples of known age accurately estimated water age up to 9 days old (σest: ± 3.8 h, P < 0.0001, r(2) = 0.998, n = 11) and 25 days old (σest: ± 13.3 h, P < 0.0001, r(2) = 0.996, n = 12), respectively. Moreover, (90)Y-derived water ages in a community water system (6.8 × 10(4) m(3) d(-1) capacity) were generally consistent with water ages derived from an extended period simulation model. Radionuclides differ from conventional chemical tracers in that they are ubiquitous in distribution mains and connected premise plumbing. The ability to measure both water age and an analyte (e.g., chemical or microbe) in any water sample at any time allows for new insight into factors that control drinking water quality.
authors.affiliation: †School of Freshwater Sciences, University of Wisconsin-Milwaukee, 600 East Greenfield Avenue, Milwaukee, Wisconsin 53204, United States.
authors.forename: James T
authors.initials: JT
authors.lastname: Waples
authors.affiliation: ‡Stantec, 2335 Highway 36 West, St. Paul, Minnesota 55113, United States.
authors.forename: Jason K
authors.initials: JK
authors.lastname: Bordewyk
authors.affiliation: †School of Freshwater Sciences, University of Wisconsin-Milwaukee, 600 East Greenfield Avenue, Milwaukee, Wisconsin 53204, United States.
authors.forename: Kristina M
authors.initials: KM
authors.lastname: Knesting
authors.affiliation: §Environmental Research Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, United States.
authors.forename: Kent A
authors.initials: KA
authors.lastname: Orlandini
mesh_terms: D060766:Drinking Water / Q000032:analysis*; D005374:Filtration; D008962:Models, Theoretical; D011868:Radioisotopes / Q000032:analysis*; D013997:Time Factors; D060753:Water Quality; D014881:Water Supply; D014922:Wisconsin; D015021:Yttrium Radioisotopes
chemical_list: D060766:Drinking Water; D011868:Radioisotopes; D015021:Yttrium Radioisotopes