The Department of Environmental Quality is authorized to negotiate loans to political subdivisions and municipal authorities for the construction, reconstruction, and improvement of municipal sewage treatment facilities. All loans shall be made pursuant to rules made by the Water Quality Board and not exceed 25% of the total cost of the facility. The loans shall be authorized by the political subdivision involved pursuant to Title 11, Chapter 14, Local Government Bonding Act, or other applicable law of this state pertaining to indebtedness of political subdivisions.