Residents and business owners in parts of upper Northwest Washington are being advised to continue boiling their water through Friday after a pumping station lost power, leaving hundreds in the area with low water pressure.

The water advisory was issued Wednesday evening as a precaution in areas west and southwest of Rock Creek Park after the reservoir in Fort Reno failed to drain and did not pull contamination from the pipes, said D.C. Water’s general manager, George Hawkins.

About 1,000 businesses and homes in an area that runs mostly along Nebraska Avenue, south of Military Road, and extends west past Massachusetts Avenue NW are affected and continue to see low water pressure from their faucets, officials said.

D.C. Water officials advised customers who were experiencing low pressure to boil their water for cooking and drinking because it may be contaminated. Customers who were not experiencing low water pressure and those who do not live in the affected area do not need to boil water.

On Thursday, seven schools in Ward 3 did not serve breakfast, and parents were encouraged to pack lunches for their children because limited food was available in the buildings. Bottled water was delivered to the schools, as well as more than 150 breakfasts and 1,000 lunches. The impacted schools were Hearst, Janney, Lafayette, Mann and Murch elementary schools, Deal Middle and Wilson High.

Blue shaded area in this updated map below represent the areas affected by the boiling water advisory. (D.C. Water and Sewer Authority)

D.C. Public Schools officials said they are advising parents to pack lunch for their children again Friday. But officials said they intend to serve breakfast at the affected schools.

“We knew that if it was a one-day deal, then we should plan for two days,” Deputy Chancellor Lisa Ruda said.

Part of American University’s main campus and residence halls are in the affected area, causing the university to close all but two of its dining facilities, according to AU spokeswoman Camille Lepre. The university ordered more than 830 gallons of bottled water for students. University officials will continue to update students via text messages and Twitter and will distribute more bottled water Friday morning, Lepre said.

AU administrators say they have been in contact with D.C. Water and expect the restriction to be lifted by the afternoon.

Some restaurants in the affected area said they were able to serve customers, but at a slower pace because of the time it took to boil the water used to cook.

Atul Bhola, the owner of Masala Art, said the restaurant will continue normal operation with boiled water into Friday.

D.C. Water crews are waiting for results from two tests conducted Thursday to determine whether coliform bacteria, commonly found in soil, made it into the water. The bacteria do not usually cause illness but are often an indicator of other dangerous pathogens. People with weak immunity may experience gastrointenstinal distress because of the bacteria, officials said.

If the tests show signs of contamination, the advisory could be extended another 24 hours, Hawkins said.

The problem at the Fort Reno pumping station Wednesday was caused by a switch gear failure, D.C. Water said. Water service was restored to the area shortly before 7 p.m. Wednesday.