FARMINGTON HILLS, Mich. — Crews have installed new sections of a broken 48-inch (122-centimeter) line that prompted a boil water advisory to about a dozen suburban Detroit communities.

The Great Lakes Water Authority says Thursday that work is continuing to restore service to thousands of customers who have had little to no water pressure since the break Monday in Farmington Hills.

Officials have said that more than 300,000 people have been affected by the break.

The water main was expected to go back into service Thursday. The authority says the timeline for lifting the boil water advisory for the communities in Oakland County “has shifted” and that the “revised timeframe is dependent on pressure and water quality testing” that was to begin Thursday and continue into the weekend.