Sentence:  the magnitude of effort and costs of each of these possible phases of an effective safety program for metal and nonmetallic mines ( excluding coal and lignite mines ) ; and the scope and adequacy of State mine safety laws applicable to such mines and the <WSD>enforcement</WSD> of such laws . 
Meaning of the word marked with <WSD> tags:  the act of enforcing; ensuring observance of or obedience to