Project Number:
DNR-113
Other Project Number:
WR94R015
Funding Year:
1994
Contract Period:
Funding Source:
DNR
Investigator(s) and affiliations:
Todd W. Rayne, Wisconsin Geological and Natural History Survey;
M. A. Muldoon, Wisconsin Geological and Natural History Survey;
P. D. Roffers, Wisconsin Geological and Natural History Survey
Abstract:
Abstract: A wellhead-protection study for the city of Sturgeon Bay, Wisconsin, demonstrates the necessity of combining detailed hydrostratigraphic analysis with groundwater modeling to delineate zones of contribution for municipal wells in a fractured aquifer. We used a three-dimensional numerical model (MODFLOW) combined with a particle tracking codes (MODPATH) to simulate the groundwater system around Sturgeon Bay and to delineate capture zones for five municipal wells.
Detailed hydrostratigraphic characterization involved locating and characterizing vertical and horizontal fractures and high-permeability zones. Correlating stratigraphic interpretations with 7 “hard” hydrogeologic data such as gamma and flowmeter logs, packer tests, and fracture mapping produced a hydrostratigraphic model with 14 gently dipping high-permeability zones related to bedding planes or facies changes. These zones serve as major horizontal conduits for groundwater flow.