Walter M. Grayman, [*] Rolf A. Deininger, [ ] Richard M. Males, [ ] and Richard W. Gullick [ ]
[*]W.M. Grayman Consulting Engineer, Cincinnati, Ohio.
[ ] The University of Michigan, Ann Arbor, Michigan
[ ]RMM Technical Services, Inc., Cincinnati, Ohio
[ ]American Water, Voorhees, New Jersey
Public water systems using surface water sources are vulnerable to a variety of disruptions in water quality as a result of accidental, intentional, or natural contamination of supplies. Surface water sources, particularly rivers, can be subjected to a variety of contaminants which can change rapidly both in nature and concentration. The frequency, magnitude, and type and location of contamination are highly variable and stochastic, and thus cannot be predicted in a deterministic manner.
Protecting the water that is used as a supply source for a potable water treatment plant is of utmost importance. This is the first stage of the multiple-barrier approach to water treatment and supply, which includes selection and maintenance of high-quality source water, its treatment and disinfection, maintenance of distribution system water quality, and water quality monitoring.
Many utilities practice some degree of monitoring of their source water. These data, however, are often limited in the number of parameters measured, and are collected at a frequency that is not conducive to detecting sudden changes in water quality (e.g., weekly, monthly, or quarterly sampling). Early warning systems are designed to address these limitations and to improve on the information available, and to utilize...
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