By Christopher Baisley, P.Eng., WaterTrax Inc., Vancouver
Sampling and testing of drinking water has long been the final step in ensuring the quality of drinking water supplied to a community. Despite sometimes-excellent source water quality, and despite the technologies employed to treat water, there are many risks that make it prudent for purveyors and public health officials to ensure that water is safe to consume at the point of use.
As just one of the many levels in the integrated multi-barrier approach to drinking water safety, sampling is a means to an end. The results from each and every test must be screened against applicable standards and appropriate actions taken, if the test of due diligence is to hold. It is not acceptable merely to compile stacks of paper reports; the meaning of incoming test results must be continually assessed.
In the wake of recent drinking water tragedies, the regulatory environment in Canada has been tightened up in some jurisdictions to impose minimum sampling and reporting schedules on waterworks. These enshrine what were previously water quality guidelines as enforceable water quality standards, and strive to improve the accuracy and timeliness of drinking water information. In addition, many organizations with responsibility for delivering water and/or ensuring its safety, are adopting more rigorous sampling and reporting programs, even where regulations may not strictly apply. There is a growing recognition that sampling programs may be a key factor in due diligence for a wide range of organizations that own, operate, or oversee drinking water supply systems.
The impact of stepped-up sampling programs (more samples, more parameters, more often) and new sampling programs on purveyors and agencies can be significant. The industry norm for laboratory reporting is paper-based, and measurements taken by water system operators are most often recorded on paper log sheets. A lot of staff time is required to receive, screen, organize, and archive this information. For example, some very small municipalities in Ontario are considering hiring an additional staff member simply to manage water quality data as a result of O. Reg. 459/00.
An additional outcome of the increased generation of drinking water information is an increased need to report on it. For example, in Ontario, purveyors must produce a quarterly report that summarizes all testing done during the period. In the US, purveyors must produce consumer confidence reports that similarly summarize a year's worth of testing, and identify any violations of drinking water standards. The efforts to compile these reports can be significant, and generally require that every lab test report and a great number of operational logs be entered into word processors, spreadsheets, or database software so that summary analysis and report preparation can be done.
The general trends in regulatory requirements and best practice for water systems include:
To make this happen without unduly taxing the time of water professionals, electronic data management systems are becoming a necessity.
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