Draining swimming pools and spas to storm drains can pollute streams and lakes with copper, chlorine and other chemicals. Water from a pool or spa is routinely treated with chlorine to prevent bacterial growth that can be hazardous to humans. However, chlorinated water can have a major impact if it is drained into our streams and lakes without treatment. Chlorine and copper are toxic at low levels to aquatic life.
Chlorine burns the gills and fins of fish, destroys sensory organs, interferes with fish’s ability to find food, and causes internal organ damage.
Copper is found in pipes and used as an algaecide in swimming pools. It is a pollutant that directly threatens aquatic life. Excess copper in water causes the formation of acid pH levels, burns the gills of fish, interferes with respiration, and causes internal organ damage.
How should you drain your pool or spa?
Before draining your pool or spa completely, discontinue the addition of salt and chlorine. Test to ensure the chlorine is below 0.1 mg/L and the pH is between 6.5 and 8.5 before draining. There are two options for non-salt water discharges. First, discharge directly to the sanitary sewer via a drain in the home. All saltwater discharges should be directed to the sanitary sewer. Contact Johnston’s water division at 515-278-0822 for any questions. Or, discharge the pool and spa water across a flat vegetated area (not directly onto paved surfaces). Drain water over at least 15 feet of grassy landscape first to allow the remaining chemicals to dissipate before reaching the storm drain. Keep the water flow low, about 12 gallons per minute, to prevent erosion of soil and vegetation. Wastewater from backwash filter systems should be directed to the sanitary sewer through a drain in the home.
What is an illicit discharge?
“Illicit discharge” is defined as any discharge that is not entirely composed of stormwater (EPA) and can include effluent from septic tanks, car wash wastewaters, laundry wastewaters, improper disposal of auto and household toxins and water from pools and spas. In these discharges, pollutants significantly degrade water quality in receiving waters and threaten aquatic, wildlife, and human health. Failure to follow the guidelines noted above could result in a fine under City code (97.03).
For more information on how you can protect Iowa’s streams and lakes, contact the City of Johnston Community Development Department at 515-278-2344.
Learn more (PDF) from the Iowa Stormwater Education Partnership.