4. Conclusion
The current very limited interest and understanding of water environment control as reflected in wastewater
treatment is far from acceptable. It is remarkable that we still use such an indirect and imprecise model to characterize
both loading and effluent quality as the BOD. Apart from the already quite well understood needs for
an improved control of nutrients, we will need additional and better reflecting variables to meet our forthcoming needs of a better wastewater control. In this context, it may be sufficient to point out the number of complex
polluting agents, for example, the variation of pharmaceutics found in the municipal wastewaters. A first stage
towards an improved measurement status and more reliable control would be to install on-line meters on the effluent,
as illustrated in Figure 5. In the future, there will very likely become needs for additional control systems
and refined legal frameworks.