Silica (frac) sand mining

Sand mining has occurred in Wisconsin for hundreds of years; however, recently there has been a dramatic increase in the number of mining proposals. This increase is attributed to a surge in hydrofracking, a technique used by the petroleum industry to extract natural gas and/or crude oil from rock formations, which requires a certain quality of sand in the process. Wisconsin has high-quality sand resources and therefore is seeing a substantial rise in mining permit requests to mine for frac sand. The extracted sand is then shipped out of state to be used at gas and oil fields for hydrofracking. Consequently, the topic of sand mining in Wisconsin has generated interest from regulators, legislators, local governments and the general public.

Regulations

DNR report

DNR silica sand mining report

The rapid expansion of sand mining in Wisconsin has created a high level of interest about this activity from members of the public, reporters, local government officials, state legislators and others. In response, DNR released the following report in January 2012 that summarizes the best current information on silica sand mining, its possible environmental impacts and local, state and federal regulations that address sand mining and processing. The report will be updated periodically as any significant new information becomes available.

Boreholes/Drillholes

Abandonment of boreholes/drillholes

State law requires the proper abandonment of all boreholes or drillholes exceeding 10 feet in depth or which intersect groundwater.

Borehole definition

State law defines a borehole as "a circular hole deeper than it is wide, constructed in earth material for the purpose of either installing a well or obtaining geologic or groundwater related data." Boreholes are also referred to as drillholes.

With the rapid expansion of frac-sand mining operations in the state, there is an increased amount of soil-exploration drilling as landowners and others seek to identify large sand deposits. The resulting boreholes, unless properly sealed, present a risk to groundwater resources because they can create a pathway for surface runoff to contaminate underground aquifers.

NR 141 requirements

Chapter NR 141, Wis. Adm. Code [exit DNR], addresses sealing requirements for boreholes and groundwater monitoring wells. It states, among other requirements, that "boreholes and groundwater monitoring wells shall be abandoned by complete filling with neat cement grout, bentonite-cement grout, sand-cement grout, concrete or bentonite-sand slurry." Failure to properly abandon a borehole can result in liability for water contamination.

While the code specifies that a bore hole be properly abandoned within three days of its use being discontinued, the DNR encourages drillers to close boreholes drilled for the purpose of soils exploration immediately as the hole is completed in order to avoid the potential for soils collapse and bridging to occur in the hole.

Take action

Fill out the Well/Drillhole/Borehole Filling & Sealing (Form 3300-005) [PDF] after borehole abandonment. Submit the completed form to your local DNR office to the attention of the "private water supply specialist."

Contact

For further information about proper abandonment of boreholes and drillholes, contact:

Dave Johnson
Drinking Water & Groundwater Program
608-261-6421

Maps

Location of mines and processing plants in Wisconsin

location of frac sand mines and/or processing facilities in Wisconsin location of frac sand mines and/or processing facilities in northern and west central Wisconsin

Resources

Silica sand mining studies and resources

Endangered species resources

Last revised: Tuesday January 22 2013