The article analyses the main features of the construction of regional environmental monitoring systems. New approach to construction of distributed database of these systems is considered, structure and composition of data base of separate nodes of network of observation stations and algorithms of synchroni-zation of data updating in them are proposed. Models and methods of primary processing of measurement information are proposed. Analysis had been car-ried out on how to address the problem of finding sources of pollution on the basis of operational data from monitoring systems.