Wis. Admin. Code NR § 812.28
NR 812.28 Pump installation equipment and supply pipe. Pump installation products and equipment may not be used unless they are approved for use under s. NR 812.091. Pump discharge and supply piping shall conform to the requirements specified in s. NR 812.11 for steel pipe or shall conform to the requirements in the "Pipe and Tubing for water services and private water mains" table in s. SPS 384.30, except that Type M copper pipe may not be installed underground. Pipe used for year-round installations shall be protected from freezing. Lead-based solder for pipe connections may not be used. Limitations on the use of plastic pipe are found in s. SPS 384.30. Plastic pipe may not be used for buried pipe in soils known to be contaminated with volatile organic chemicals. Plastic pipe may be used as drop pipe installed within a well or for discharge piping between the well and the building served, provided it meets standards specified in s. SPS 384.30 and has a minimum pressure rating of 150 pounds per square inch. When plastic pipe extends through the seal of a well with an above-ground discharge, the portion of the plastic pipe extending above-ground from the well shall be protected from sunlight or the plastic pipe used shall be of the type with inhibitors recommended for use in direct sunlight.
Wis. Admin. Code Department of Natural Resources § NR 812.28
The department recommends the installation of torque arresters on the drop pipe for submersible pumps. The department recommends that galvanized pipe not be used when the water quality is known to be corrosive.