(8)5 179(-) (7). If at any time it is determined that application of best available control technology by 1983 will not assure protection of public water supplies, agricultural and industrial uses, and the protection and propagation of fish, shellfish, and wildlife, and allow recreational activities in and on the water, additional effluent limitations must be established to assure attainment or maintenance of water quality. In setting such limitations, the Environmental Protection Agency must consider the relationship of the economic and social costs of their achievement, including any economic or social dislocation in the affected community or communities, the social and economic benefits to be obtained, and determine whether or not such effluent limitations can be implemented with available technology or other alternative control strategies