Colorado River Not The Most Polluted, But Getting There

"Radioactive runoff, toxic rocket-fuel chemicals and human waste threaten the health of the Colorado River as much as the growing number of people who use it, according to a conservation group that today puts the Colorado at the top of a list of rivers at risk."

"This isn't the first time American Rivers has focused on the Colorado. It put the river at the top of the endangered list in 1991, citing the environmental effect of Glen Canyon Dam and has included all or part of the river on the top 10 list three other times since then."