Sec. 131.006. EXCLUSIONS AND EXEMPTIONS. The provisions of this chapter do not apply to the following:
(1) surface mining operations conducted on public land regulated by the General Land Office if the land is reclaimed in a manner consistent with this chapter; and
(2) land on which the overburden has been removed and minerals have been produced before June 21, 1975.
Acts 1977, 65th Leg., p. 2610, ch. 871, art. I, Sec. 1, eff. Sept. 1, 1977.