This memorandum summarizes major state and federal water quality control policies pertaining to nutrients; describes the major provisions of the new Section 17 of Regulation 31 that establishes interim numeric values for phosphorus, nitrogen and chlorophyll; describes the new Regulation 85 that establishes numerical effluent limitations for domestic wastewater treatment plants and other wastewater dischargers; summarizes the rule review process of the Colorado General Assembly; and describes the U.S. Environmental Protection Agency's (EPA) review process for new water quality standards.
Approximately 80 percent of the rain and snow that falls in the state falls west of the Continental Divide; however, most of the state's population and irrigated agriculture is on the eastern side. Consequently, water users have been diverting water from west of the continental divide to the eastern plains. There are 39 transbasin diversions in Colorado including 25 diversions that move water from the Colorado River Basin to eastern plains of Colorado.
