Chemical and microbiological composition of groundwaters of decentralized water supply of southern and central districts of Tomsk region

Relevance of the research is caused by the necessity of assessing the quality of drinking water, consumed by the population, in the conditions of decentralized water supply. The aim of research consists in studying chemical and microbiological composition of groundwater which is formed in a natural environment. Methods of research. Chemical and microbiological compositions of water were investigated in the Problem research hydrogeochemical laboratory (TPU), which is registered in the System of analytical laboratories of Gosstandart of Russia. To carry out the full chemical analysis the authors applied the traditional methods. The microbiological analysis was carried out after sampling, as a rule, during the day, while the samples were kept in the cooler bag. To identify the microorganisms the authors used liquid and firm elective nutrient mediums. The trace elements were determined by mass-spectrometer method with inductively coupled plasma (ICP-MS) on the device Elan 6000 (Perkin Elmer) in Geo assets and environment laboratory of Toulouse (CNRS, France). Results. The data of chemical and microbiological compositions of drinking groundwater of Quaternary, Neogene, Paleogene and Cretaceous sediments shown that water is epidemiologically safe (Escherichia coli is not detected), while they often are not suitable for drinking water supply by chemical composition on such components as Fe, Mn, COD, Si, NO2-, NH4+, trace elements - Ba, B and Li. Excess of these elements reflects natural background of the territory and they are typical of the whole region. The microbial flora reflects the geochemical environment, rich in organic matter, but poor in mineral substances