LINCOLNTON, N.C. -- As some businesses get ready to reopen in some capacity this weekend, water treatment plants have some advice for the owners.

Robert Pearson, water services director for the City of Lincolnton, says if a business, church, or other building has been closed for more than three weeks then stagnant water has been sitting in the pipes. As a result, the chlorine in it is no longer active.

That means the water is susceptible to bacteria, like legionnaires, but Pearson says it's an easy fix.

Before reopening to the public, you should open the faucets, showers, water fountains, and eye wash stations to let the water run through for about 30 minutes.

Pearson says it's important to clear all of the water out that has been sitting in the pipes, and allow the fresh treated water to come in.

"Identify at what point does the water start coming into your building and start at that point, and start flushing, and step your way through, and work your way through the back," Pearson says.

He also says, if the hot water heater has been turned off during the stay-at-home order then it's best to empty it all out and replace that water, because chlorine dissolves faster in hot water.

For more tips from the CDC on flushing out your water, click here.