Residents of Alexandria, Va., who have been shouldering the cost of replacing 200-year-old sewer lines in Old Town appear poised to get relief from Richmond as the General Assembly signaled it wants to award the city $25 million for a big, disruptive construction project.

The legislature’s conference committee included the money in its final budget recommendation, which was expected to be voted on Saturday before going to Gov. Ralph Northam (D) for his signature. Northam included the project in his budget recommendation this year, as did the Senate.

The $350 million project became politically necessary after decades of neglect. Residents and legislators expressed outrage in 2016 when it was revealed that even as the city planned to overhaul three sewer outlets, it was delaying work on the biggest outlet, at Oronoco Bay, until the mid-2030s or later.

One legislator, who represents a downstream area, suggested stripping Alexandria of all state funds if it didn’t replace the sewers by 2019, which city engineers said was impossible. Others legislators suggested Alexandria, which is relatively prosperous compared to the rest of Virginia, should tax itself to cover the entire cost.

In the end, the state ordered that the sewer lines be replaced by 2025, a schedule the city still called “not feasible.” The governor at the time, Terry McAuliffe (D), signed the requirement nearly two years ago.

But the sewer outlets were then transferred to Alexandria Renew, the city’s independent sanitation authority, which said it could meet the deadline.

“It’s very important to Alexandria because this project is going to be a huge expense,” said state Sen. Adam P. Ebbin (D-Alexandria), who credited Sen. Richard L. Saslaw (D-Fairfax), a conference committee member, for shepherding the funding through. “I’ve been working on this for a few years, but Senator Saslaw closed the deal.”

Saslaw, a veteran legislator from the minority party, noted that the money was not in the House budget at all, but “I stayed on top of it from start to finish, and we got it,” he said.

The sewer replacement is already costing taxpayers, whose average yearly residential sewer bill is $550 per household. Ratepayers are likely to see an increase by 2025, with an average sewer bill of $838 to $1,030 per residence, Ebbin said in a letter to the chair of the conference committee.

The project will replace existing pipes with storage tunnels that will hold and funnel sewage to the city’s wastewater plant, where the sewage will be treated before being released into the Potomac River through its tributaries.

Alexandria is not the only city to have problems with combined sewers. More than 800 U.S. cities built a single sewer — with much of the construction in the 1800s — for rainwater runoff and for waste from toilets, sinks and tubs. The sewer led straight to the river.

Over the years, many cities, including Alexandria, separated sewage and rainwater runoff as they built sewers and sent the sewage to a treatment plant that processes and cleans it to ensure it meets federal water quality standards before heading to the river. The combined sewers are gradually being phased out under the federal Clean Water Act.

“We’re obviously thrilled to see the support of the budget conference committee and hope both houses and the governor agrees,” Alexandria Mayor Justin Wilson (D) said. “It shows a vote of confidence in the city and Alexandria Renew’s process toward getting moving.”

Laura Vozzella contributed to this report.