Many of the U.S. sewer systems are more than 60 years old. Some are much older, reports the Environmental Protection Agency (EPA). So when heavy rains and large snowmelts overwhelm the systems’ capacity -- producing sewer runoff into lakes and rivers -- a city can find itself in violation of the Clean Water Act.

To fix the problem, the EPA issues “consent decrees” requiring cities to modify their utility systems, sometimes at a cost of more than $1 billion. These demands, mayors and utility officials say, come when there’s little to no money for upgrades (lest they enact unpopular rate hikes) and no federal grants attached.

But federal officials are taking a new approach to enforcing clean water regulations and want to work more closely with municipalities to find more cost-effective solutions. This summer, the EPA released a new framework that it says will offer more flexibility and possibly more savings to cities as they pursue compliance. Nancy Stoner, the EPA’s acting assistant administrator for water, says the policy was developed with input from utility managers, mayors and other local officials. The goal is to let local leaders prioritize improvements to address the most pressing problems fastest. Historically, Stoner says, a community facing sewer overflows would have to craft a long-term plan to address what investments are needed to stop them. If other issues came up -- like discharges at the water treatment plant or leaking pipes -- they’d also need to be addressed, but separately.

The voluntary policy would let cities develop comprehensive plans that address multiple environmental issues at once. The move comes as federal officials estimate that the cost to all levels of government of improving clean water infrastructure over the next 20 years could exceed $400 billion.

The policy doesn’t give mayors a pass, and the EPA isn’t abandoning issuing consent decrees either. Some city officials argue that by not pledging to cut back on enforcement, the EPA is undermining the collaboration and flexibility it says it’s promoting. “Cities are not criminals or criminal enterprises, and should not be treated as such,” said Mayor David Berger of Lima, Ohio, at a recent congressional hearing on the subject.

Overall, groups representing localities have expressed cautious optimism about the plan. The U.S. Conference of Mayors praised the EPA for recognizing that cities have limited resources. Carolyn Berndt, who leads the National League of Cities’ federal relations efforts on infrastructure issues, says that framework may signal a shift at the EPA from a top-down approach to a more collaborative one. And Lawrence Levine, senior attorney with the Natural Resources Defense Council, adds that while the EPA’s framework is short on specifics, it shows a strong desire for collaboration. “We’re hopeful it will lead to positive results,” Levine says. “At the same time, I think it’s also clear there are a lot of important things that are yet to be known or understood about how this will work in practice until it’s actually applied to some early adopter cities.”