Effective porosity of a carbonate aquifer with bacterial contamination: Walkerton, Ontario. Canada.

Link to Full Text

Download Full Text

Publication Date

September 2012

Abstract

Preferential flow through solutionally enlarged fractures can be a significant influence on travel times and source area definition in carbonate aquifers. However, it has proven challenging to step beyond a conceptual model to implementing, parameterizing and testing an appropriate numerical model of preferential flow. Here both porous medium and preferential flow models are developed with respect to a deadly contamination of the municipal groundwater supply at Walkerton, Ontario, Canada. The preferential flow model is based on simple orthogonal fracture aperture and spacing. The models are parameterized from borehole, gamma, flow and video logs resulting in a two order of magnitude lower effective porosity for the preferential flow model. The observed hydraulic conductivity and effective porosity are used to predict groundwater travel times using a porous medium model. These model predictions are compared to a number of independent estimates of effective porosity, including three forced gradient tracer tests.

Keywords

Conceptual Model, Carbonate Aquifer, Bacteria, Water Supply, Tracer Test, Effective Porosity

Document Type

Article

Notes

Journal of Hydrology, Vol. 464-465 (2012-09-25).

Identifier

SFS0055810_00001

Link to Full Text

Share

 
COinS