Toxics Standards and Criteria

Toxics standards are different than conventional water quality standards such as pH, temperature, and dissolved oxygen. The toxics standards contain criteria on compounds such as metals, pesticides, and other organic compounds found in the environment. Toxics criteria have been developed to directly address aquatic life protection and human health protection from consuming water and fish/shellfish.

The criteria for toxics can be found in two separate locations:

Although most toxics criteria are discrete values that do not vary with water conditions, many freshwater metals and the freshwater ammonia criteria must be calculated for each specific sample taken, and are dependent on other water quality parameters, such as temperature, pH, or hardness. Ecology has developed a spreadsheet that will make these calculations for you. This spreadsheet also contains a full list of the toxics criteria for aquatic life and human health protection, so is a useful general reference for toxics criteria in Washington.


The state water quality standards:


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Last updated January 2015