Pool Water Disposal

Draining your pool in the fall? Here's a stormwater tip.

Proper Disposal of Pool Water

When closing down and winterizing swimming pools, there are many necessary but harmful chemicals that may be inadvertently relayed to the environment. Chlorinated water can have adverse impacts on aquatic life within a body of water when discharged directly to a street, catch basin, or stream.

Recommended disposal options are:

• Discharge into the sanitary sewer system using a pump or surge tank.
• When discharging a pool directly into the environment, water must be tested and comply with the applicable criteria.
• Pool water must sit for at least two days after the last addition of chlorine or until the level of chlorine is below 0.1 milligrams per liter (mg/l).
• The pH must be between 6.5 and 8.5 before it is discharged.
• Algaecides such as copper or silver can interrupt normal algal and plant growth in streams, and should not be used.
• Total suspended solids should be below 60 mg/l. Suspended particles should be allowed to settle out and the water should not appear murky. Settled material should not be discharged to the environment.
• Discharges to the environment should be directed over a vegetated surface so that some level of filtration can occur.
• Discharges shall not be allowed to create any erosion.
• Draining the pool should not coincide with any significant rain event.
• When the pool filter system is cleaned, the sludge material should be disposed of as solid waste. Care should be taken to prevent leaching of the material into the environment.

References

• Environmental Protection Agency (EPA)-Pollution Prevention / Good Housekeeping for Municipal Operation
• Oregon Department Of Environmental Quality (ODEQ). 1997 Environmentally Safe Methods for Draining Swimming Pools.