Pools, Spas, and Fountains


Countywide Stormwater Pollution Prevention Program

Foam Pollution (Stormwater)

Pools, Spas, and Fountains

Your swimming pool, spa, or fountain maintenance practices can make a significant difference in the water quality of our creeks, the Napa River, and the San Francisco Bay.  Many chemicals used in pool maintenance (e.g., chlorine, bromine, copper, and silver) are extremely toxic to aquatic life.  For example, the California Department of Fish and Game has determined that levels of chlorine in water higher than 0.01 parts per million (ppm) are dangerous to the environment.  The typical chlorine level maintained in a pool is 2-4 ppm; that is, 200-400 times the harmful level.  By doing a few simple things, you can protect the fish and critters that live in our creeks and comply with local, State, and federal regulations.  Remember that you are also responsible for the actions of your contractors.  Be sure you know how your contractor will be disposing of the pool, spa, or fountain water and the filter cleaning rinsewater and backwash.

BMPs for Pools, Spas, and Fountains Maintenance

The following maintenance practices for swimming pools, spas, and fountains are approved by the NCSWMP agencies to reduce pollutants discharged to waterways.  By following these practices, you can help protect water quality and comply with local, State, and federal regulations.  Note:  There are additional requirements for commercial swimming pool facilities under the State’s Health and Safety Code. Contact the Napa County Department of Environmental Management if you have questions about commercial swimming pool facilities.

1.  Disposing of Swimming Pool, Spa, or Fountain Water 

  • The preferred method is to discharge pool, spa, or fountain water onto the land surface provided the water is dechlorinated/debrominated, the pH is between 6.5 and 8.5,AND the land area is sufficient to prevent erosion and runoff into a ditch, creek, or other stormwater conveyance.
  • If landscaping is not a viable option, the next best choice is to discharge pool, spa, or fountain water to the sanitary sewer system. Contact your local  sanitation agency  to make sure the discharge will not create a problem in the sewer system or wastewater treatment plant downstream of your property.
  • All local agencies in Napa County have adopted laws that allow swimming pool, spa, and fountain water to be discharged to storm drains only after all of the following conditions are met:
  • Other disposal methods (e.g., sanitary sewer, landscaping) are not possible.
  • The pool, spa, or fountain water is completely dechlorinated/debrominated.
  • Concentrations of copper and silver are not harmful to fish or other aquatic life.
  • The pH is between 6.5 and 8.5.
  • The water is free of any unusual coloration, dirt, suds, or algae.
  • There is no discharge of filter media.
  • There is no discharge of acid cleaning wastes.
  • The water is at ambient temperature.  (Heated water should be allowed to cool.)

Note:  All local jurisdictions require an encroachment permit before draining pool, spa, or fountain water to a public right of way (e.g., street, road, drainage easement).  Lab analysis of the water may be required before an encroachment permit can be issued.  Contact your local  stormwater agency  for more information.

2.  Disposing of Filter Rinsewater and Backwash

  • It is illegal to discharge filter rinsewater and backwash water to streets, storm drains or creeks.
  • Rinse cartridge filters onto a dirt area and spade the filter residue into the soil.
  • Backwash sand and diatomaceous earth filters onto a dirt or rocked area.
  • Keep backwash discharges out of the street and storm drain.  Temporary wash areas must be adequate to contain all washwaters.  The temporary wash area is inadequate if washwater reaches creeks, butters, or storm drains.
  • If you don't have a suitable dirt area, contact your wastewater treatment authority for instructions on discharging to the sanitary sewer.  Pretreatment may be required to remove the diatomaceous earth from the backwash water and prevent blockages to your sewer line.

3.  General Maintenance Tips

  • Clean your pool, fountain, or spa regularly, maintain proper chlorine levels and maintain water filtration and circulation.  If you do so, you will not have to drain your pool as often.
  • Manage pH and water hardness to reduce copper pipe corrosion that can stain your pool and end up in our creeks.
  • Before using copper algaecides, try less toxic alternatives.  Only use the copper if the others really do not help.  Ask your pool maintenance service or store for help resolving persistent algae problems without using copper algaecides.
  • Make sure your pool maintenance service follows all discharge requirements.
  • Dispose of unwanted pool chemicals properly.  Many of them are hazardous wastes when discarded.  Household hazardous wastes may be legally disposed of at the Napa-Vallejo Hazardous Waste Collection Facility.  Go to www.naparecycling.com for more information on hazardous waste disposal in Napa County.
  • Commercial operations, including maintenance companies, may dispose of hazardous pool chemicals for a fee through the Conditionally Exempt Small Quantity Generator Program.  For an appointment, call the Hazardous Waste Collection Facility at 1 (800) 984-9661.  For more information, contact the Napa County Department of Environmental Management.