In the article the methodical and organized problems of toxicological examination of water in field conditions and the ways of there decision are discussed. Is shown, that realization of examination and quality surveillance of water in the field are rather complicated by absence of a uniform service, which would bear in complete volume the responsibility for all parts of field water supply system and for final result of their functioning--quality of water. For radical improvement of means of the control it is offered to the experts of a chemical type to concentrate more attention on traditional and non-traditional methods of indication, detection and definition of potent poisonous substances in water. And under aegis of medical service will be developed and be improved the biological methods of the control of water quality.