Most significant sanitary microbiological parameters of drinking water quality assessment

Summary

Sanitary control of water is a complex and multilevel process. It is associated with every stage of water use, starting from the water supply source selection, monitoring, and water treatment to disinfection and wastewater disposal to collection facilities. Sanitary and microbiological water assessment implies determining sanitary profile, i. e. criteria that reflect compliance or noncompliance of the object under investigation with the regulatory documents requirements. The determined parameters and the frequency of their measurement depend on the assignment of the project under investigation and are strictly regulated by the respective regulatory framework. Sanitary parameters are divided into index parameters
that reflect the level of fecal pollution and indicator parameters that reflect the quality of water treatment. Index parameters include: Escherichia сoli, thermotolerant coliforms and coliphages. Indicator parameters are: total microbial count, total coliforms, sulfite-reducing clostridia spores etc. Determination of some pathogenic and opportunistic pathogenic bacteria like salmonella, pathogenic staphylococcus, blue pus bacillus etc. is an important aspect of water bodies monitoring. EC countries moved from determining groups of sanitary indicator microorganisms (thermotolerant coliforms, fecal staphylococcus, sulfite-reducing clostridia spores) to determining directly sanitary indicator microorganisms (Escherichia coli, Enterococcus faecalis, Clostridium perfringens), which makes water quality assessment more standardized and reliable. Advanced methods and approaches to the assessment of the sanitary state of the water bodies are continuously emerging and introduced in the international practice of sanitary surveys.

Key words

potable water , water quality , total coliform bacteria , sanitary index , index parameter , indicator parameter , Escherichia coli , thermotolerant coliforms , coliphages , total microbial count , salmonella , P. aeruginosa , S. aureus , sanitary microbiological assessment , sanitary indicator microorganism , chromogenic substratum

Sanitary regulation and sanitary control – the basis of ensuring water body safety

Summary

Water safety is provided with two complementary processes: sanitary regulation and sanitary control of water bodies. The task of sanitary regulation is setting safety requirements to biological, chemical and physical indices. Sanitary representative microorganisms include representatives of obligatory microflora of human and homoiotherm organisms that allow estimating the degree of biogeneous pollution. These are Escherichia coli (collibacillus), fecal streptococcus (enterococcus), sulfite-reducing clostridia spores, Proteus, thermophilic microorganisms, coliphages (bacterial viruses) etc. Sanitary index is reflecting the presence and amount of one or another sanitary representative microorganism in a specified sample size taken from the water body under investigation. Qualitative sanitary index reflects and regulates the absence or presence of specified microorganisms in a specified sample size. Quantitative sanitary index is the concentration of specified (unknown) microorganisms in the specified sample size. Index figure reflects the degree of fecal contamination of the water body (Escherichia coli, Enterococcus faecalis, coliphages). Indicator figure reflects the efficiency of disinfection processes and technologies and points at possible presence of pathogens with different tolerance (Clostridium perfringens, coliphages). World Health Organization recommends distinguishing between two types of microbiological monitoring: for estimating water treatment efficiency; for identifying fecal pollution and presence of pathogens.

Key words

potable water , water object , sanitary and epidemiological requirements , pathogens , sanitary index