Covington’s approximately 9,000 residents were advised Friday to boil their drinking water until further notice because a faulty valve allowed water to flow through a new pipe that had not been tested.

Covington issued the notice Friday morning. Because the entire city is affected, the state Department of Health agreed to expedite testing of the water, which normally can take three days, according to Gina Hayes, Covington’s director of administration.

The city’s population swells to about 20,000 people during the workday because the parish courthouse, hospital and School Board offices bring in thousands of workers, Hayes said.

St. Tammany Parish Hospital has a well on its campus to provide access to safe water when the city’s water supply is interrupted, spokeswoman Melissa Hodgson said. “At present, we are drawing on our campus resource, and we anticipate returning to city water as soon as we are notified that it is safe to do so,” she said.

The need for the precautionary step occurred when a section of pipe was replaced as part of an ongoing project, Hayes said. That work was completed Thursday.

The state requires any new section of water line to be tested for water quality, and the test was scheduled for Friday morning.

But city staffers discovered the new line already had been pressurized as a result of a faulty valve. The new section had been treated with chlorine on Thursday, but testing had not occurred, so the city issued the boil-water advisory, which will remain in effect until testing shows the water quality is acceptable.

Water intended for drinking, making ice, brushing teeth, bathing or preparing food should be boiled for a full minute in a clean container after the water has reached a rolling boil.