It is illegal to allow anything other than rainwater to be discharged to a storm drain.

Never allow pool maintenance chemicals to be transported to a street, gutter, or storm drain. A general rule of thumb is “only rain down the storm drain”. If over applied, spilled, or disposed of improperly, materials such chlorine, bromine, algaecide, biocides, water conditioners, stabilizers, diatomaceous earth (DE), cellulose fiber, and sand particles can be harmful to water quality and creek habitats.

Individuals and businesses that improperly handle and dispose of non-stormwater materials down the storm drain are both subject to civil and criminal prosecution

Best Practices:

Swimming Pools, Hot Tubs, and Spas

  • Pool or spa water must be drained to the sanitary sewer.
  • When cleaning filters, all collected materials must be disposed of into the garbage.

Draining Procedures

  • To drain a pool or spa, first locate the sanitary sewer cleanout or an indoor drain (sink, toilet, or tub) that you can discharge to at the property where the pool is located.
  • Use a siphon or a sump pump that pumps 20 gallons or less per minute to the cleanout or indoor drain.
  • If draining more than 100,000 gallons, check your local jurisdiction for discharge requirements, if you are in Santa Rosa,
  • Rohnert Park, Sebastopol, or Cotati contact Environmental Compliance at (707) 543-3369 at least 24 hours in advance.
  • Do not drain pool or spa water into septic systems, as it may cause system failure:
    • If the sewer system is not available, discharge only onto a landscaped area or onto the ground where the water can soak into the soil.
    • Take care that there is no flow off your property. Use sandbags or berms, if necessary.
    • Do not discharge onto saturated soils or areas where there has been a recent application of herbicides, pesticides, or fertilizers.
    • Make sure the water is clear (not cloudy), the pH is neutralized, and the chlorine or other disinfectant residual is below 0.1 milligrams/liter (parts per million)
  • Another option would be to collect the pool water into a tank and transport it to a sanitary sewer treatment plant or allow it to slowly discharge to landscaped area.
  • Cleaning and emptying the pool as a result of any pool repair (including resurfacing, sand-blasting, painting, etc.), all water must be filtered to remove solids and discharged to the sanitary sewer.

Filter Cleaning

  • Backwash water must be collected, contained, and discharged to the sanitary sewer.
  • Cartridge filters should be rinsed in a sink, bathtub, or over a lawn or other vegetated area ensuring no rinse water leaves the property or enters an outside drain.
  • Use a separation tank for Diatomaceous Earth (DE) and Cellulose Fiber filters to capture the DE or fibers.
  • DE or other filter material can be disposed of in the garbage.
  • To conserve water, direct clean water back into the pool.

Chemical Storage and Handling

  • Properly store and handle all chemicals (chlorine, bromine, algaecide, biocides, water conditioners, stabilizers, etc.) to prevent any spills or discharges onto the ground or into a storm drain.
  • Maintain all hazardous materials in accordance with the Safety Data Sheet (SDS) and all applicable laws and regulations.
  • Immediately clean up spills and leaks when they occur.

Are You Ready to Respond to a Spill?

  • Have a written plan.
  • Train employees annually on storm water regulations, spill response, personal safety, and hazardous waste handling and disposal.
  • Have spill cleanup materials onsite.
  • Have Safety Data Sheets for all products used.

How are the Storm Drain and Sanitary Sewer Systems Different?

Throughout urban communities, the storm drain system transports rainwater to local creeks, rivers, and the ocean. This system was created to prevent flooding within communities and homes.

All water and materials that enter the storm drain system are untreated.

The sanitary sewer is a plumbed system that transports used water from buildings to a wastewater collection and treatment facility, where the water and sewage is treated.

If you see an outdoor drain and are unsure of its use, assume it is a storm drain and do not discharge wash water to it.

Report Spills Here

Cloverdale: (707) 894-2150
Cotati: (707) 665-3605
Healdsburg: (707) 431-7000
Rohnert Park: (707) 588-3300
Santa Rosa: (707) 543-3800,
After Hours: (707) 543-3805
Sebastopol: (707) 823-5331,
After Hours: (707) 829-4400
Ukiah: (707) 463-6288
Unincorporated County of Sonoma: (707) 565-1900
Unincorporated Mendocino County: (707) 234-6679
Windsor: (707) 838-1006,
After Hours: (707) 838-1000

Releasing pollutants into the storm drain system or a waterway is prohibited by local ordinance, state, and federal law.

Have you seen this in your neighborhood?