For the purposes of this act, unless the context clearly requires a different meaning:
a. "Commissioner" means the Commissioner of Environmental Protection;
b. "Department" means the Department of Environmental Protection;
c. "Solid waste" means garbage, refuse, and other discarded materials resulting from industrial, commercial and agricultural operations, and from domestic and community activities, and shall include all other waste materials including liquids disposed of incident thereto;
d. "Person" means and shall include corporations, companies, associations, societies, firms, partnerships and joint stock companies as well as individuals, and shall also include all political subdivisions of this State or any agencies or instrumentalities thereof.