Jeff Karoub

Associated Press

Flint officials said Tuesday they are a year ahead of schedule in tackling a court-mandated order to deal with lead service lines as the Michigan city recovers from its contaminated water crisis, but an environmental group that sued to make changes disputes the accomplishment.

The city said it's checked more than 18,000 service lines, and replaced 7,700. Mayor Karen Weaver said at a news conference there are between 10,000 and 12,000 more to check and officials have dealt with those deemed the highest priority.

Weaver said "this is a huge step toward" Flint's efforts to move "from crisis to recovery," though she cautioned residents to keep drinking bottled or filtered water until all construction work is done and tests have been completed.

"Getting the poison out — that was my first priority," Weaver said.

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The Natural Resources Defense Council, which is part of a lawsuit over the lead issue, says the city hasn't prioritized homes most likely to have lead and galvanized steel pipes. It adds thousands of the excavated pipes have been copper. A landmark legal settlement reached early last year calls for fully removing the lead pipes by the end of next year.

"The city has announced it has dug 18,000 holes in the city of Flint, but it has not replaced all the lead and galvanized pipes," NRDC attorney Sarah Tallman told The Associated Press. "The city is in violation of the ... settlement."

The environmental group and others who sued have previously accused Flint of ignoring requirements that allow monitoring of whether the court-ordered deal is being followed.

Flint ran into extraordinary trouble when emergency managers appointed by Gov. Rick Snyder put the city on water from the Flint River in 2014 while a pipeline was being built to Lake Huron. The corrosive water was not properly treated due to an incorrect reading of federal regulations by state regulators, and lead leached from old plumbing into homes and led to elevated levels of the toxin in children.