"Mechanical control issues" within the treatment plant have led to the increased turbidity — or cloudiness — level in water being delivered to parts of central and lower Bucks County, necessitating the boil-water advisory that remains in effect, Pennsylvania American Water said Saturday.

"The team's investigation found that mechanical control issues within the plant led to the situation, which we are now working to resolve," the statement by spokesperson Terry Maenza said. Repair work is happening "around the clock" and in coordination with the Pennsylvania Department of Environmental Protection, Maenza said.

Meanwhile, customers in Yardley Borough, Lower Makefield Township, and parts of  Falls Township should continue to boil water before drinking it (that goes for pets, too), making ice, brushing teeth, washing dishes, or using it to cook, Maenza said.

"Until we complete repairs and stabilize the treatment plant, we cannot provide an estimate of when the boil advisory will be lifted," he said.

Turbidity could be an indication of the presence of bacteria, viruses, or parasites that can cause nausea, diarrhea, or headaches, the utility has said.

Water tankers are available for customers — who are urged to bring their own containers — from 6 a.m. to 10 p.m. at Yardley-Makefield Fire Company locations, Gas Light Village, and Falls Township.

American Water has provided information on boil advisories on its website.

The Pennsbury School District, which canceled classes Friday as a result of the water problem, said it would be monitoring the situation through the weekend before making a decision about classes Monday.