County Urges Precaution When Draining Pools

It is coming up on the time of year when homeowners start to drain their pools. The Prince William County Department of Public Works urges pool owners to use proper procedures to protect the environment, preventing chemical contamination, erosion and flooding in yards and surrounding areas.

The Dangers of Chlorine and Cleaning Chemicals

The most harmful result from draining pools improperly is dumping chlorine into the environment. According to Prince William County Environmental Engineer Dave Ungar, “Depending on the level of chlorine, it could kill fish. Chlorine is always harmful to all aquatic life.”

Discharging cleaning chemicals is also destructive to the environment. Ungar states, “We don’t want people to clean their pools with chemicals and then discharge those chemicals into the environment. It can have a bad impact.”

People should let their pools sit untreated for at least 10 days before they drain them to allow any chlorine in the water to evaporate completely. Refrain from using cleaning chemicals until after the pool is drained.

Chlorine in discharged pool water should not exceed 0.01 milligrams per liter of water. The pH should be between 6.0 and 8.0. “Pool owners should test their water right before they discharge it,” Ungar says.

Properly Draining a Pool

People should avoid draining their pools too quickly or onto paved surfaces. According to Ungar, “Drain your pool in a grassy area so that it seeps into the ground. Don’t drain it all at once. Try to break it up. Do it at a slow rate to slow down the amount of water that can cause flooding and erosion downstream.”

Draining pools slowly will help minimize adverse impacts on neighboring and downstream properties. “Releasing that much water at an uncontrolled rate could erode and destroy stream channels. This alone causes pollution, even if the water itself was not contaminated. Eroded stream channels are undesirable, as the problem only gets worse with time, and if not treated, could lower property values,” states Ungar.

While emptying pools into stormwater drains is not prohibited, the Department of Public Works does not encourage the practice. “Many people are unaware that storm sewer systems do not treat anything but stormwater. This means that whatever goes into the sewer goes directly into nearby creeks and streams. Debris, such as leaves and sediment, traveling along with swimming pool water can also cause significant problems to receiving waters,” says Ungar.

If you are a pool owner, please adhere to this guidance as you empty your pool this season, to help ensure no harmful impact on the environment.