The U.S. Dept. of Justice, the U.S. Environmental Protection Agency and the Maryland Dept. of the Environment have proposed lengthening the current deadline for Baltimore to eliminate wet-weather overflows from its sewer system.

The new plan, announced on June 1, extends the schedule set in a 2002 consent decree to bring the system into Clean Water Act compliance: The 2002 agreement said work had to be done by 2016. But a “significant hydraulic restriction” affecting sewage flow into the Back River wastewater treatment plant will require more time for now- underway structural improvements and pipeline upgrades, officials say. Under the new terms, the city has until 2021 to complete phase one of the work. EPA Regional Administrator Shawn Garvin says that should reduce up to 83% of the overflows over five years. The new program’s work is estimated to cost $1 billion. So far, the program has cost $867.4 million.

Other upgrades will fall into phase two and have to be completed by 2030. The new agreement will require federal court approval.