Sediments provide habitat for many benthic organisms. They also influence the environmental fate of many chemical substances in aquatic ecosystems by acting as both sinks and subsequently sources of substances that have entered the aquatic environment. Many aquatic organisms may be exposed to chemical substances throught their immediate interactions with bed sediments; therefore, benchmarks of environmental quality (such as sediment quality guidelines) are required to support protection and mangement strategies for freshwater, estuarine, and marine ecosystems. Sediment quality quidelines can be used to assess sediment quality, to help set targets for sediment quality that will sustain aquatic ecosystem health for long term, and to develop site-specific objectives. This paper outlines the importance of environmental sedimantology and gives details of some sediment quality criteria studies, especially in Canada with certain assessment approaches. Therefore, this will provide a way how to work with sediments and develop their quality quidelines, initially at the national base.