MADISON, Wis. (AP) — A Republican-backed bill that would protect existing sand mines from new restrictions would tie local government officials’ hands and make it impossible to regulate the industry in the years to come, opponents told the Legislature’s mining committees Monday.

Sen. Tom Tiffany’s measure reflects the growing tension between residents, mining operations and local governments as the sand mine industry continues its dramatic expansion in Wisconsin. The proposal would prohibit local governments from imposing new zoning ordinances that are more restrictive than existing zoning rules on existing operations. The bill also would shield sand mines from any other new ordinance or license requirement if the mines are operating within the year preceding the ordinance or requirement’s adoption.