The water main break at Centre and South Negley avenues caused either low or no water pressure for residents of the central and eastern parts of Pittsburgh.
(Scroll down for full list of affected neighborhoods.)
"Will it mean that there will be additional inconveniences to people?
But it will also mean that we’re doing everything to make sure that your water is safe," Mayor Bill Peduto told Pittsburgh’s Action News 4.
The boil water advisory is a precaution taken in case bacteria got into the system while the water pressure was low.
"We are going to take every effort to err on the side of caution.
After what happened in Flint and in other areas, the worst thing you can have is a government that doesn’t over-react to these types of situations," Peduto said.
"So although there’s no risk to the public, the boil advisory will stay in effect until we’ve had two consecutive testings for bacteria.
The earliest the final test results will be available is tomorrow evening, Tuesday, December 19, 2017."
The minute starts when the water begins to bubble.