Wastewaters from the chemical industry may contain a large number of both known/identified and unknown/not identified chemical substances, and the composition of the effluents may vary greatly from plant to plant. Usually only a minor fraction of the chemicals present are identified and adequate environmental property data may be available only for a small number of these. Effluent characterizations in terms of summary parameters are therefore necessary to complement chemical specific characterizations, but the selection of suitable summary parameters other than traditionally wastewater parameters depends on the particular effluent and the available information. The types of pollution effects to be mitigated depend on the intrinsic properties and volumes of effluent discharged as well as on the initial dilution and the specific characteristics and designated uses of the receiving water. For these reasons management decisions should be based on individual case specific environmental impact or risk assessments and simultaneous individual technical and economical evaluations of potential remedial actions (comprising cleaner technology options, wastewater treatment, and improved dilution in the receiving water). This paper presents a generalized integrated impact assessment and control strategy for marine discharges based upon Danish experiences over a 10 year period.