Faced with federal mandates to spend billions of dollars fixing sewers, a handful of major U.S. cities are pushing back against federal and state environmental regulators - and starting to see results.

For Omaha, which expects to spend $2 billion for its own sewer overhaul, the emerging movement could lead to big savings down the pipe.

Indianapolis became the first major city to successfully revamp its plans and renegotiate its agreement, a move officials say will shave $740 million off a price tag that was ballooning toward $4 billion.

Atlanta, which has already raised utility rates by more than 250 percent in a decade, seems close to getting a 13-year extension to finish its work.

And in Pittsburgh, an area sewer utility is telling the U.S. Environmental Protection Agency that it needs to scale back its $3.6 billion plan to something more manageable.

Omaha officials say they recognize that renegotiating is a possibility in the future, although they have no current plans to ask for a revised deal.