This act shall be deemed to be an exercise of the police powers of the Commonwealth for the general welfare of the people of the Commonwealth, by providing for the conservation and improvement of areas of land affected in the surface mining of bituminous and anthracite coal and metallic and nonmetallic minerals, to aid thereby in the protection of birds and wild life, to enhance the value of such land for taxation, to decrease soil erosion, to aid in the prevention of the pollution of rivers and streams, to protect and maintain water supply, to protect land and to enhance land use management and planning, to prevent and eliminate hazards to health and safety, to promote and provide incentives for the remining of previously affected areas, to allow for government-financed reclamation contracts authorizing incidental and necessary coal extraction, to authorize a remining and reclamation incentive program, to prevent combustion of unmined coal, and generally to improve the use and enjoyment of said lands, to designate lands unsuitable for mining and to maintain primary jurisdiction over surface coal mining in Pennsylvania. It is also the policy of this act to assure that the coal supply essential to the Nation's and the Commonwealth's energy requirements, and to their economic and social well-being, is provided and to strike a balance between protection of the environment and agricultural productivity and the Nation's and the Commonwealth's need for coal as an essential source of energy.