(CNN) About 133,000 people in the Greater Detroit area remain under a boil water advisory Sunday, a day after a leak was discovered in a 120-inch water transmission main that distributes water from the Lake Huron Water Treatment Facility to residents, the Great Lakes Water Authority said.
That's down from 935,000 people who were under the advisory at its height Saturday. The water authority said in a statement Sunday it expected the pipeline to return to service within two weeks -- one week for repairs and a second week for quality testing.
Michigan Gov. Gretchen Whitmer declared a state of emergency Sunday for Lapeer, Macomb, Oakland and St. Clair counties following the water main break.
"We're drawing on every resource we have and taking every action necessary to get impacted families the help they need," Whitmer said.
"On Saturday I activated the State Emergency Operations Center to coordinate our response efforts, and with today's state of emergency declaration, we are ensuring that state resources will be available as long as the impacted communities need them," she said.
The leak was discovered early on Saturday, according to the authority. The leak is approximately one mile west of the Lake Huron Water Treatment facility and crews are working to isolate the area so repair work can begin.
The water authority originally issued a precautionary Boil Water Advisory for the following communities impacted by the break: the Village of Almont, City of Auburn Hills, Bruce Township, Burtchville Township, Chesterfield Township, Clinton Township, City of Flint, Flint Township, City of Imlay City, Lenox Township, Macomb Township, Mayfield Township, Village of New Haven, Orion Township, City of Pontiac, City of Rochester, City of Rochester Hills, City of Romeo, Shelby Township, City of Sterling Heights, City of Troy, City of Utica, and Washington Township.
Several communities were removed from the list Saturday afternoon, including the City of Flint, which has battled water issues since the 2014 water crisis in which lead contaminated water was being pumped into residents' homes and businesses.