Method for Locally Adapted Water‐Pollution Abatement in Lake Mjøsa, Norway

In the past, the effects of pollution abatement were measured in terms of the size of reductions achieved. This paper demonstrates a method that can be used to measure effects in relation to the practical significance of the reductions for the people living in the area concerned. The approach used in the project on locally adapted regulatory impact analysis (LARIA) aims to overcome the problem of finding a correct balance between the size and cost of the effort required in relation to the benefit to society for conservation projects. The proposed methodology consists of four parts. First, the user interests in the Lake Mjøsa basin are determined, and relative weights expressing the importance is given to the uses. Then, a water‐quality‐effect model is developed. Focus is placed on developing a phosphorus effect model taking into account the biological availability of phosphorus. The third step is a model to express the benefit to society from improvement in water quality. The fourth step is to identify and rank all available abatement measures using information from the effect model and the cost of implementation of each measure.