This document on municipal waste water treatment plants has been published within the WESP cooperation project: the Working group Emissions of Service industries and Product use. In this project information has been collected on processes in the target groups of consumers, construction, service industries, environmental firms and recreation to get agreement about the data used bij different institutes and to afford support to governmental policy on emission reduction. This document contains information on the processes, emission sources, emissions to air and water, waste, emission factors, use of energy and energy factors, emission reduction, energy conservation, research on clean technology and standards and licences.