Swimming Pool Discharge

Swimming pools must be maintained properly to ensure that chemicals do not enter the street or storm drain system where they can be discharged directly into our rivers and lakes. Products such as chlorine and bromine that control pH, bacteria, and algae can also pollute water and harm wildlife.

Here are some tips on properly disposing of water from swimming pools:


All swimming pool water must be dechlorinated to a concentration of chlorine less than 1 mg/L or 1 parts per million (ppm) prior to discharge. Dechlorination may be conducted by the home owner, property manager, or contractor. Options include:  

  • Natural dechlorination will occur over time and chlorine will dissipate when exposed to the air and sunlight. This process can take 5-10 days, depending on a variety of factors, including pool size.  Do not add chlorine and keep pool pump running.
  • Chemical dechlorination using a chlorine neutralizer such as sodium thiosulphate, sulfur dioxide, or sulfite salts. These come in liquid, tablet, or granular form and are available at pool supply stores. Use minimum amount recommended by the manufacturer, and monitor dechlorination with test kits.
  • Environmental friendly option includes use of Vitamin C powder in two forms; ascorbic acid or sodium ascorbate. This is non‐hazardous and more expensive than other chemical methods, and may take longer to reach acceptable discharge levels. May be available locally.


Before discharging pool water, the following requirements must be met:

  1. A chlorine level test must result in less than 1 mg/L (or 1 PPM).
  2. A bromine level test must result in 0 mg/L (or 0 PPM).
  3. pH levels must not be less than 6 and not more than 9 (standard units).
  4. Discharge must be free of visible solids, nutrients, algae, color, odors and floatables.
  5. Discharge to a grassy area will not cause flooding or erosion.

Chemical levels can be determined using a proper pool chemical test kit, which can be found online or at local pool supply stores:

  • Low‐range chlorine strips are easy to use and reasonably priced. The paper strips are dipped approximately 18 inches below the water’s surface and compared to the color standard.
  • PDP test kits  may also be used by collecting pool water about 18 inches below the surface, adding a reagent to the vial, and comparing it to the color standard.


Filter backwash to remove buildup of materials from the pool filter by reversing the water flow. Do not add treatment chemicals until after the backwash process has been completed.

Drain your pool or spa water to your landscape, lawn or rocky areas on your property and allow the water to fully soak into the ground. This allows you to reuse water you already paid for and could reduce your landscape water use.  Be sure to use caution when applying pool water on certain plants since it contains more salt and chlorine than tap water.

  • Salt or saline pool water contains higher concentrations of salts that can be more damaging to plants and soils.
  • Remember to move the drain hose frequently, since water discharges to one location can create stagnant water areas that can attract mosquitoes.
  • Be sure that the pool water does not flow onto your neighbor's property.
  • Notification or a permit is not required by the Town of Brownsburg when draining your pool on your property.

You should not drain pool water into streets, catch basins, curbs, gutters, ditches, channels, storm drains, and retention basins that are owned and operated by the Town. Do not discharge backwash directly to a storm or sanitary sewer without approval from the Town of Brownsburg.