This is one reason why the Colorado Department of Public Health and Environment is working on new rules to limit phosphorus pollution based on the chemical’s ecological impacts. The state may soon require owners of large facilities, such as wastewater-treatment plants, to make costly upgrades to comply with new limits.
That same agency will have to decide whether to grant the ranch a discharge permit, weighing the possibility of improving trout habitat with the environmental risks. MaryAnn Nason, a spokeswoman for the state’s Water Quality Control Division, said in a statement that the state would evaluate whether the additional phosphorus protects aquatic life, drinking water and recreation, and complies with the state’s regulations on phosphorus.