PITTSBURGH — About 18,000 Pittsburgh Water and Sewer Authority customers are being told to boil their water before using it because it could be contaminated by animal droppings.

The problem stems from worn covers at the Lanpher Reservoir in nearby Shaler Township, which serves customers in Pittsburgh’s northern neighborhoods and several nearby suburbs, including Shaler and Reserve townships.

Pittsburgh Public Schools and Shaler Area schools will be using bottled water until the advisory is lifted, which the water authority hopes will be a day or two. The city was setting up water buffaloes for residents who can’t boil water.