Well vulnerability: a quantitative approach for source water protection.
The concept of vulnerability of drinking water sources is reviewed, and a quantitative approach for assessing well vulnerability for complex three-dimensional ground water systems is developed. The approach focuses on the relative expected impact of potential contaminant sources at unknown locations within a well capture zone, providing relative measures of intrinsic well vulnerability, including the expected times of arrival of a contaminant, the dispersion-related reduction in concentration, the time taken to breach a certain quality objective, and the corresponding exposure times. Thus, the result of the analysis includes the usual advective travel time information used in conventional wellhead protection analysis, plus a set of selected quantitative measures expressing the expected impact. The technique is based on adjoint theory and combines forward- and backward-in-time transport modeling using a standard numerical flow and transport code. The methodology is demonstrated using the case study of a complex glacial multiaquifer system in Ontario. The new approach will be useful in helping water managers develop more physically based and quantitative wellhead protection strategies.
Frind
E O
EO
Department of Earth Sciences, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1.
Molson
J W
JW
Rudolph
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DL
D003198:Computer Simulation; D003247:Conservation of Natural Resources / Q000379:methods* / Q000706:statistics & numerical data; D004784:Environmental Monitoring / Q000379:methods* / Q000706:statistics & numerical data; D005618:Fresh Water; D008962:Models, Theoretical; D009864:Ontario; D014872:Water Movements; D014874:Water Pollutants, Chemical / Q000032:analysis*; D014881:Water Supply
D014874:Water Pollutants, Chemical