The first section of this volume (E) describes the estimation of the cost functions for influencing water quality and the second section (F) outlines the relation of the participation in outdoor recreation and public attitudes toward water quality. Cost functions for influencing water quality through the following alternatives are developed: external treatment by municipalities, external treatment for pulp and paper mills, joint facilities, and mechanical aeration. While the cost estimates for municipalities are based on regression curves, the estimate for the mills' joint facilities and aeration are engineering cost-estimates. In the case of the municipalities and the mills discrete levels of primary and secondary treatment are considered. In order to estimate the economic efficiency of joint facilities, estimates were made for the cost of pipelines and joint municipal and mill waste treatment. Engineering-cost estimates are made for mechanical aeration through turbine venting and in-stream aeration. Finally regression estimates were made for the reduction in shoreland values of storage reservoirs resulting from releases for flow augmentation. Section F reports the conclusions of a survey which attempts to identify public definitions of water pollution and participation in water-based outdoor recreation in Wisconsin. (WRSIC abstract)