Compliance with the United States Safe Drinking Water Act requires that water
purveyors take water quality samples at entry points to the distribution system as well as
at various points within their water distribution system. These samples must be analyzed
for a variety of constituents and each constituent has its own required sampling
frequency. An individual constituent/location combination may be in one of several
monitoring modes: initial, routine, increased, reduced or waiver. The monitoring mode
depends, in part, on the historical concentrations recorded for the particular water quality
constituent at a particular location. Development of a schedule for monitoring the water
quality of a water system is a complex task that most water systems conduct manually.
Failure to monitor at the proper intervals may result in a violation of the Safe Drinking
Water Act and potentially the receipt of Notices of Violations and fines from the
regulator.
A computer program was developed for a City water purveyor in the state of Arizona to
capture the monitoring rules of the Federal Safe Drinking Water Act along with State and
Maricopa County regulations. This program uses the rules to analyze historical water
quality data and develop the monitoring schedule. The program was also designed to
integrate with the City's existing water quality database. The Water CARS Drinking
Water Compliance database scheduler provides this Arizona utility with an insurance
policy that does not replace human knowledge of regulations, but provides an additional
tool to assess past compliance (e.g., 3rd party audit capabilities) and helps ensure future
compliance. Includes tables, figures.