Proper Discharge of Swimming Pool Water
Improperly discharged pool water can have a negative effect on the overall environmental health of streams, and often results in fish kills, harm to aquatic plants and animals, stream bank erosion and flooding of personal property.
In a typical spring, county officials respond to several localized fish kills that are the result of pools being drained for cleaning and maintenance. This pool water is oxygen-deficient, and discharging it directly into a stream or into a storm drain may result in dead fish and the loss of aquatic insects that inhabit the stream system.
In addition, when swimming season is over in the fall, pool operators and maintenance personnel should be careful of how and where they discharge pool water when they lower the level of the pool. Rapidly discharged water from pools can cause erosion of the stream bed and banks, especially in smaller receiving streams.
Here are seven things that should be done prior to discharging swimming
pool water on the ground, into a stream or into a storm drain:
- De-chlorinate the water by allowing it to stand untreated for at least seven days.
- Ensure that the pH of the pool water is close to the pH of the receiving stream (usually close to pH 7, but should be tested first).
- Remove excess sediment and leaves from the water.
- Make sure you know where the discharged water will flow so that it does not flood your basement or affect your neighbor's property.
- Discharge the water so that it does not enter a storm drain or a stream directly.
- Discharge the water over a grassy area to slow it down and aerate it.
- Discharge the water at a slow rate (over 24 hours is best) so it does not erode stream banks downstream of the pool.
For additional information, review the Proper Discharge of Swimming Pool Water brochure or contact the Stormwater Planning Division, 703-324-5500, TTY 711. Commercial swimming pool operators should contact the Health Department at 703-246-2300, TTY 711.