From The Denver Post (Bruce Finley):

This summer, federal Environmental Protection Agency teams began testing at Denver Water’s Dillon Reservoir, and at the South Platte and other rivers. The EPA also launched new studies of effects on fish. “At low levels, we don’t know what the effects (on people) will be,” said Kristen Keteles, a Denver-based EPA toxicologist…

The EPA is making emerging water contaminants a top national research priority, agency spokesman Rich Mylott said. “Obviously, it’s going to keep building up in the environment,” said David Norris, a CU professor of integrative biology who has documented feminization of fish in three rivers. Solving the problem ultimately “is going to take changes in the composition of what we purchase,” Norris said. “This has the potential of feminizing humans.”[…]

Improvements this year at Boulder’s wastewater treatment plant were shown to reduce feminization of fish. USGS and CU scientists are monitoring fish near the plant. “We’ve found antidepressants, like Prozac, accumulating in the brains of fish,” CU’s Norris said. “We’ve found it slows their reactions down, slows their response to a predator.”

Reverse osmosis and ultraviolet treatment systems being installed at some new suburban water plants can remove some contaminants. Researchers haven’t found ways of removing everything. Costs of plant upgrades run into the hundreds of millions of dollars.