It has a half-life of 15 years and can collect in fatty tissues of certain animals. EPA banned registration and interstate sale of DDT for virtually all but emergency uses in the United States in 1972 because of its persistence in the environment and accumulation in the food chain. Designated segment Stream or water body with defined uses and assumed numerical criteria intended to protect those uses. Segment name, number, boundaries, defined uses, and numerical criteria appear in the Texas Surface Water Quality Standards. Designated uses Those water uses identified in state water quality standards which must be achieved and maintained as required under the Clean Water Act.
Uses can include cold water fisheries, public water supply, agriculture, etc.
Freshly dead or partially decomposed organic matter. Concern about them arises from their potential toxicity and presence as contaminants in commercial products. Discharge permit A permit issued by the state to discharge effluent into waters of the state. Includes aluminum, barium, cadmium, copper, lead, nickel, mercury, selenium, silver, and zinc. Dissolved minerals Inorganic substances that occur naturally and typically have a crystalline structure when not in solution.