Portable Toilets

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

Never allow overspray from cleaning or debris from portable toilets or hand washing stations to be transported to a street, gutter, parking lot, or storm drain. If over applied, spilled, or disposed of improperly, materials such as bacteria, ammonia, organic matter, surfactants, disinfectants, and suspended solids 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: 

Your Job Done Right

  • Pump-out service for portable toilets and hand washing stations shall be conducted in a manner that prevents the release of sewage and/or wash water to the storm drain system and creeks.
  • Wastewater shall be disposed of to the sanitary sewer at the job site or to a holding tank for later disposal to the sanitary sewer at the business’s office or other approved location.
  • A one-time discharge permit may be required from Environmental Compliance at (707) 543-3369 for disposal to the sanitary sewer.


  • Place units away from storm drains, inlets, waterways, and areas with high vehicle traffic.
  • Place a containment tray under each unit to collect rinse water; Pump any collected liquid to a tank.
  • Post signs with company contact information for reporting the need for cleaning or repair.


  • Prior to cleaning, remove trash and discard into the garbage.
  • Block the unit doorway to contain any rinse water in the unit and pump ponded liquid to a tank.
  • Minimize use of cleaning fluids.
  • Immediately clean up drips or small spills.

Cleaning products labeled “nontoxic” and “biodegradable” can still harm wildlife if they enter the storm drain system. These products are prohibited discharges to the storm drain system.

Vehicle and Equipment Maintenance

  • All chemicals and cleaning agents must be securely stored on trucks.
  • Maintain all hoses, couplings, tanks, etc. on trucks in good condition to prevent leaks and spills.

Storage and Maintenance Facilities

  • Inspect all units regularly.
  • Immediately replace any damaged or leaking units.
  • Washing of vehicles, portable units, or other equipment at a storage facility must be performed in a wash pad that drains to the sanitary sewer to ensure the collection of any generated wastewater.
  • Properly store and handle potential contaminants (portable toilet waste, disinfectants, oils, detergents etc.) to prevent spills or discharges.
  • Hazardous materials and waste shall be stored in a manner that will prevent contact with rain water and run-off.
  • Maintain all hazardous materials in accordance with the Safety Data Sheets (SDS) and all applicable laws and regulations.

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 and in every vehicle.
  • 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?