It is declared to be the public policy of the State of West Virginia to maintain reasonable standards of purity and quality of the water of the state and a reasonable degree of purity of the air resources of the state. In the exercise of the police power of the state to protect the environment and promote the public health, safety and general welfare, the Legislature has enacted the Water Pollution Control Act as article eleven, chapter twenty-two of this code and the Air Pollution Control Act as article five, chapter twenty-two thereof. It is recognized and declared by the Legislature that pollution control facilities, as hereinafter defined, are required for the protection and benefit of the environment and the general welfare of the people, are nonproductive, do not add to the economic value of a business enterprise and do not have a market value after installation in excess of salvage value.