Drinking water reservoirs are designated differently from areas for public swimming and water bodies intended for fishing are designated differently from water located in wildlife conservation areas. The size of the water body also is taken into consideration when TMDL calculating is undertaken. The larger the body of water, the greater the amounts of contaminants can be present and still maintain a margin of safety.
Different classifications exist for water bodies based on their purpose: drinking water reservoirs, public swimming areas, fishing zones, and wildlife conservation areas. The size of these bodies influences TMDL calculations, which determine the maximum amount of pollutants a body can tolerate while maintaining safety standards.