What are Guidelines and Objectives?
When we analyze water quality, we test and determine the concentration of many substances. These concentrations or numbers alone do not mean very much. What levels are normal? What levels are natural? What levels are safe?
To make our water quality data meaningful it is necessary to use a set of science-based benchmarks that provide a point for comparison; for each substance, they tell us how much is too much. The Canadian Council of Ministers of the Environment (CCME) has developed a set of national water quality guidelines to serve this purpose.
Guidelines are specific concentrations (or narrative statements, when appropriate) for specific substances that are recommended as either the upper or the lower limit to protect a given water use. Some guidelines protect human health, such as Health Canada's guidelines for drinking water quality and the CCME water guidelines for recreational use. There are also guidelines for agricultural uses, to help protect crops and livestock from contaminants. Other guidelines are meant to minimize the effects of human activities on the environment. Plants and animals that live in our waters are protected by the guidelines for aquatic life. The animals that hunt in rivers and streams, such as bears and eagles, are protected by guidelines for wildlife consumers of aquatic biota.
The Canada-wide CCME guidelines are considered our national guidelines. In British Columbia, the Ministry of Environment (BCMoE) has developed regional guidelines along with watershed-based or site specific guidelines referred to as water quality objectives. The development of these objectives takes into account the natural water quality conditions (background levels) and local water uses in a given watershed or at a specific location within the province. The CCME national guidelines, BCMoE provincial guidelines and site-specific objectives provide us with answers to our questions: What levels are normal? What levels are natural? What levels are safe?