In that case, the WHPA was not utilized for this study (Figure 1).
Some more current WPHA plans and maps were on file; the author located others by contacting WHPA plan engineers, hydrogeologists, the Washington State Department of Health, Evergreen Rural Water of Washington, the Nooksack Indian Tribe, and related agencies.
In developing WHPA policies it is important to consider the "sensitivity" of the groundwater to contamination as well as the time-of-travel (TOT).
Based on the above factors, the sensitivity of each WHPA to potential impacts from urban point sources of contamination has been ranked by the Region.
For three UWNY wellfields that tap unconsolidated aquifers, modeled WHPAs were combined with mapped aquifer boundaries to delineate groundwater protection areas.
Then, LBG hydrogeologists familiarized the volunteers with basic hydrogeologic concepts and how the WHPAs and groundwater protection areas were defined.
For a description of WHPA delineation for large wells in bedrock and small wells, see (Bradley and Bobiak 1993).
As discussed later in this paper, the UFE is solved with the USEPA WHPA model (Blandford and Huyakorn 1991).
comparison research indicates that it is important to see how well more complex delineation methods compare with the numerical-modeling method since the latter method is generally considered the most accurate way of delineating groundwater flow (Bogue, 1994).