Assessing the Degree of Water Compliance with Standards

Water chemistry and properties vary within the boundaries of each quality (pollution) class; its rating within a class is best expressed in the domain of nominal values in the appropriate interval and worse expressed near its boundaries. Methods for evaluating such inconstancy were proposed under models of Taguchi (within an allowable interval) and Harrington (in a wider domain). This is shown to enable the assessment of acceptable and maximal admissible risks of the loss of water compliance with a specified quality class for making justified water-management decisions. A method of point estimate is proposed to simplify the expert characteristic of such risks, its application being of greatest use in multidimensional estimation problems.