Standards for Chemical and Physical Monitoring of Drinking Water

Objective:

To help ensure that consumers of water provided by a public drinking water supply have clean and safe drinking water. Chemical and physical guidelines as specified in the Guidelines for Canadian Drinking Water Quality 6^th Edition, 1996, as revised, shall be considered as objectives which are applicable to the Province of Newfoundland and Labrador. The Guidelines note that the maximum acceptable concentration (MAC) can be achieved by available water treatment methods at reasonable cost and it must also be reliably measurable by available analytical methods. If it is determined that water quality criteria are exceeded, priority should be given to meeting the Guideline objectives taking into account costs, the degree of excedence and local factors.

The following standards for routine chemical and physical water quality monitoring are applicable in the Province of Newfoundland and Labrador. The minimum parameters to be monitored are shown in the table below. This table does not include all parameters in the Guidelines rather only those included in standard chemical analysis and metal scan packages. Some parameters are without MAC but are required for normal operational evaluation. The collected samples are to be analysed by accredited laboratories. If there is reason to suspect the presence of certain substances in a water supply system, additional parameters may be added as required by the Department of Environment.

Samples for chemical and physical parameters shall be taken from the source water (lake, pond, river, reservoir, well or spring ) and from the distribution system. The distribution system samples shall be taken at a point significantly beyond the point at which treated water enters the distribution system. Additional sampling locations may be identified if profiling/bench marking data is required for any of the parameters. All sampling shall be done by taking grab samples.

Samples are to be collected semi-annually with the exception of trihalomethane samples which are to be collected for each season of the year. Plant operators may be required to sample for operational parameters (aluminum, pH, fluoride, colour, residual chlorine, temperature and turbidity) on a weekly or bi-weekly basis.

It is essential that results of chemical and physical monitoring are provided to the operator of the water supply system and that the operator make those results available to the consumers. Where results show that the water exceeds the MAC or any aesthetic objectives, the water supply owner / operator shall develop an action plan in consultation with appropriate authorities for addressing non-compliance issues.