For more than 30 years, irrigators and dam operators in New Mexico have enjoyed the break from water-pollution controls. The EPA had not complained until this year. Ironically, state regulators are proposing this year to limit the exemption to water-pollution rules on temperature, sediment, dissolved oxygen and the degree of cloudiness in water. State lawmakers wrote the exemption into the state's Water Quality Act. Both the New Mexico Environment Department and the state Water Quality Control Commission say they are powerless to go against the very state law that grants them authority to regulate water quality.
Federal scientists say irrigation farming can pose significant harm to the environment.
Removal of water from rivers for irrigation tends to make rivers warmer and decrease the oxygen needed by fish and other aquatic life. The result, says the EPA, is shrinkage in aquatic habitat. The task of satisfying the EPA probably will fall to the Legislature. The final decision would fall to EPA administrator Carol M. Browner. If she chose to reject the rules and New Mexico continued to refuse to change them, the EPA could draft its own water-quality rules for the state.