Environmental analysis has developed similar to analytical chemistry on the basis of scientific disciplines chemistry, physics, statistics, biology. The specialized conditions which characterize environmental determinations have resulted in rapid development of a discipline with a specific profile. These special conditions are caused by requirements of trace analysis (matrix inferences), the use of biological methods and the problem of evaluation. By environmental measurements the compliance of emissions with legal standards are controlled and emissions caused by technical malfunctions are identified at very early stage so that the reasons can be eliminated. During the last years there has been the tendency to substitute discontinuous measurements by continuous ones. This is demonstrated by an concrete example (Monitoring of an waste water sewerage system, comparison 1981/1993). The environmental analysis generates data in the field of chemical and biological systems, the effect monitoring of products (ecotoxicology) which are necessary for the hazard assessment of chemicals in the environmental compartments. An integrated part of all investigations is the evaluation of the results which consists of the data validation and the evaluation step itself.