IC 36-7-4-1103 prohibits action by an area plan commission (the body more or less in charge of zoning regulations) that prevents “the complete use and alienation of any mineral resources or forests by the owner or alienee of them.” The mining companies can argue (and have argued) that this language is incredibly broad. Regulation of any kind at the local level is seen by them as precluded by this statute.
The exception, embedded in the current statute, is that this prohibition is effective only outside of “urban” areas. So people in “rural” areas are (if the mining company interpretation of the statute is to be believed) powerless to implement zoning regulations to keep noise levels down, prevent contamination of water quality, and generally avoid and mitigate the problems that go along with large scale mining operations.
In the statute “urban” is defined as an area with eight or more residences within a quarter mile square area. Rep. Ellington’s legislation would impose a 600% increase in the urban/rural threshold, increasing the number of residences from eight to fifty. My guess is that this would significantly expand the map of places that would lose the ability to regulate mining activity.