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A Rapid Drawdown Event Related to Quarry Operations in a Dolomite Aquifer |
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| Authors: | John J Onsen Wayne P. Fassbender Patrick Jurcek Laura L. Barreto Larry F. Boyer |
| Affiliation: | John Jansen, E.G., is the senior geoscientist for Aquifer Science and Technology, a division of Ruekert &Mielke, Waukesha, Wisconsin. He has a B.S. in geology, and an M.S. and Ph.D. in geological sciences, all from the University of Wisconsin-Mil-waukee.;Wayne P. Fassbender, P.G., is a senior hydrogeologist with Graef Anhalt, and Schloemer in Milwaukee, Wisconsin. He has a B.S. in geology from the University of Wisconsin-Milwaukee.;Patrick Jurcek, P.G., is a senior hydrogeologist with Layne Christensen Co. in Pewaukee, Wisconsin. He has a B.S. in geology, and an M.S. in geological sciences, both from the University of Wisconsin-Milwaukee.;Laura L. Barreto, P.G., is a senior hydrogeologist with Graef, Anhalt, and Schloemer in Milwaukee, Wisconsin. She has a B.S. in geology, and an M.S. in geological sciences, both from the University of Wisconsin-Milwaukee.;Larry Boyer, E.G., is a principal and senior geologist with Graef, Anhalt, and Schloemer in Milwaukee, Wisconsin. He has a B.A. in geology and environmental geology and an M.A. in geology, both from the University of California-Santa Barbara, and a Ph.D. in geophysical sciences from the University of Chicago. |
| Abstract: | Two active quarries are mining stone from the Silurian dolomite aquifer in Waukesha County in southeastern Wisconsin. The village in which the quarries are located uses local zoning to control the depth of mining and to institute a long-term water level monitoring program and well guarantee/one with the quarry owners. Water levels dropped as much as 40 feet in at least 24 residential wells surrounding the quarries over a period of a few hours to days. The rapid decline in head was caused by a single boring drilled lo a depth of 75 feel he low the floor of one quarry. The borehole penetrated a localized fracture zone under confined artesian head. Water levels recovered to previous static levels within nine days after grouting the borehole. The rapid drawdown event demonstrates the potential impact of mining in fractured aquifers. The apparent complete recovery of the aquifer demonstrates that quick response can sometimes restore an aquifer. However, the potential for blasting into a similar zone illustrates the need for a well-thought-out aquifer monitoring program and emergency response plan. The experience of the village is a good example of managing conflicting uses of a finite resource and collecting baseline data needed to make informed decisions. |
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