The procedure of arbitration water control

Summary

Measurement errors cause unavoidable differences between the actual and measured values of the investigated water parameters; from whence it is not possible to guarantee different laboratories, e.g. industrial and public water control, getting identical results. The procedure of evaluating and comparing the risks of getting false water quality reports by the two independent parties is suggested. On the basis of the procedure a method of resolving arbitration cases was developed provided the measurement results being compatible. Possible accounting for non-compatible results is considered including the use of reserve samples of the investigated water, standard samples or reference laboratories. Complete elimination of arbitration cases requires carrying out quality control by a single party concerned. It is shown that in this case the proper control is ensured on condition that «the principle of distributed priorities» is applied.

Key words

potable water quality , measurement inaccuracy , water control , environmental protection , laboratory analysis , arbitration

Establishment of Periodicity of Water Quality Monitoring with Due Regard for Measurement Inaccuracy

Summary

The periodical monitoring of quality of water with changeable characteristics is connected with sampling errors. Methods of accounting of these errors together with characteristics of measurement inaccuracy of polluting substances concentration for assessment of the risk of false conclusions about water compliance (or non-compliance) with specified requirements are offered. It is reasonable to establish the periodicity of measurements from the calculation of proportionality of sampling errors and meteorological inaccuracy specified by the certified measuring technique. The table of optimal periodicity of measurements depending on maximum permissible concentration of a polluting substance and changeability of its concentration in a water body as well as the scheme of prediction of water quality with a specified confidence level are offered for practical application.

Key words

water supply , reliability , pollution , water disposal , standard , quality control , periodicity , selection , samples , measurement inaccuracy , concentration