(a) A State regulatory authority may establish additional or more stringent criteria for determining whether lands within the State should be designated as unsuitable for coal mining operations. Such criteria shall be approved pursuant to subchapter C of this chapter.

(b) The Secretary may establish additional criteria for determining whether Federal lands should be designated as unsuitable for surface mining operations.

(c) Additional criteria will be determined to be more stringent on the basis of whether they provide for greater protection of the public health, safety and welfare or the environment, such that areas beyond those specified in the criteria of this part would be designated as unsuitable for surface coal mining operations.