(Waste) Water quality sensor requirement and (too) high standards

Today in the water sector there are many methods for generating values in big databases. Everything should be connected in the cloud and everyone should access everything anytime. The data is changing very fast in every level and layer and should be controlled anytime. For better quality more methods in measuring data should be applied in parallel and so improve the quality, but this point is very complicated. You can not always compare different data measured by different methods, there are a lot of other enrivonmental factors  in most cases. Many systems in different countries exists with a lot of methods and values (eg. ph,chlorine,nitrate,germs,pathogens,viruses,micro/nano materials(plastic,metall,glass,wood,...),minerals(salt connections,...).