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Sammamish Town Center (not licensed)

Pool and Spa Care

Public Works

Engineering Technician

Lisa Werre
(425) 295 0573

Chemicals used for pool/hot tub maintenance can harm plants and aquatic life in our lakes, rivers, creeks, and wetlands. Even in extremely small amounts! It's important that you follow the City's requirements for draining your pool or spa to protect our waterways from harm.

Pool and Spa Discharge Requirements

Drain your pool or spa in accordance with City regulations: see Title 21.03.050.F. Permit application information, if required, is available on the Permit Center website here.

Swimming pool cleaning wastewater and filter backwash shall not be discharged to the storm drain system.

Drain your pool or spa where water will soak in

  • Drain to vegetated areas that may infiltrate into the ground.
  • If vegetated areas are not available, reduce chlorine in the pool water to undetectable levels (<(less than) 0.1 mg/L).

How to remove chlorine from pool and spa water

Consider the following options for removing chlorine:

  • Simply stop adding chlorine to your uncovered pool and wait. Sunlight will help to naturally dissipate the chlorine within 10 days. During that time, use a swimming pool test kit to measure chlorine.
  • Chemically dechlorinate the pool water. Chemicals that will quickly remove chlorine are available through pool and spa care vendors. Follow the directions on the product label.

Only drain cool water

Discharges should be cooled to prevent in increase in temperature to receiving water. 

Pool Chemicals Harm Aquatic Wildlife

Chlorine is toxic to fish

Chlorine is used to sanitize swimming pools. It is very toxic to fish, damaging their gills and causing fish to drown.

Bromine harms fish

Bromine is also used to sanitize swimming pools, but it does not break down over time as chlorine does. In high doses, it causes many of the same effects to fish as chlorine.

Copper kills algae

Copper is used to kill algae in the filter system. It is very toxic to fish and can cause reproductive problems as well as tissue damage. Copper may also kill the algae that aquatic life needs to eat.

pH needs to be stable

pH is a measurement of how acidic or basic the water is.  Fish have a pretty narrow range of tolerance before they die.  The ideal pH for aquatic life is between 7 and 8.  Many times the pH in a pool is within this range. However, when you drain your pool, it causes a rapid change in pH. Those small but rapid changes in pH can cause serious health problems or death for aquatic life.

Temperature needs to stay cool

Pool water can be very warm compared to river water.  The sudden shift in temperature caused by draining pool water can affect the health and survival of aquatic life.