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

Wash water, irrigation water, and leaks from vehicles or equipment should never be allowed to be transported into a street, gutter, parking lot, or storm drain. Fat, oil and/or grease from the bakery, meat department, or restaurant can cause buildup in city sewer lines and lead to sanitary sewer overflows. If discharged or disposed of improperly, materials such as soapy water, hydrocarbons, oil and grease, nutrients, pathogens, and heavy metals 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:

Keeping Your Property Clean

  • Check and clean outside areas regularly.
  • Use dry cleanup methods (i.e. broom or vacuum). Avoid hosing down or pressure washing.
  • Immediately clean wet or oily spots with rags and absorbent.
  • Process water from a power-washer must be collected. Prior to power washing of any surface, refer to the “Power Washer Guidelines” document and/or your local municipality for requirements and regulatory compliance.
  • Replace damaged or leaking dumpsters by calling your garbage company.
  • Keep dumpster lids closed.
  • Docking areas can act as catch basins for wash water, leaks, and spills. If a spill does occur act quickly to block the storm drain and contain the spill.

Operating Your Business

  • Maintain equipment you own and rent regularly to prevent leaks.
  • Check compactors often for leaks and make sure the drainpipe goes to the sewer only.
  • Minimize the amount of liquid placed in dumpsters or compactors. Place only empty containers in the dumpster or compactor.
  • Clean equipment (floor mats, garbage cans, tray racks, etc.) in a designated wash area that drains to the sanitary sewer.
  • Pour mop wash water into an inside drain only.
  • All wash water from cleaning shopping carts must be collected. It must be discharged to the sanitary sewer.
  • Process water from a power-washer must be collected and discharged to the sanitary sewer. Prior to power washing of any surface or equipment, refer to the “Power Washer Guidelines” document and/or your local municipality for requirements and regulatory compliance.

Even products labeled “biodegradable” or “environmentally safe” contain ingredients which are initially toxic to aquatic life, including fish.

Food Service Cleanup Procedures

  • Check your local jurisdiction for discharge requirements.
  • All food service facilities in Santa Rosa, Rohnert Park, Sebastopol, and Cotati that discharge to the sanitary sewer are required to obtain a Wastewater Discharge Permit. Go to for a Wastewater Discharge Permit Application.
  • Install a properly sized and City approved grease removal device, also commonly referred to as a “grease trap” or “grease interceptor”.
  • Scrape excess grease into a container and dispose of it in the garbage or tallow bin. Place food scraps in waste containers.
  • When cleaning the tallow bin area, use dry cleanup methods only. Sweep up all debris; Grease and oil spots can be cleaned with rags and absorbents (such as kitty litter). Stubborn stains may be cleaned by mopping (wash water must be emptied in a sink, or sanitary sewer).
  • Hazardous waste (such as cleaning with solvents) must be cleaned up and collected for transport to the Household Toxics Facility. Special cleanup equipment and procedures may be necessary.


  • Minimize the use of fertilizers and pesticides.
  • Check irrigation systems regularly for leaks and overspray.
  • Use drip and bubbler irrigation.
  • Reset irrigation controllers as the seasons change the amount of water needed.

Inform Your Customers

  • Label storm drain inlets with simple messaging such as “No Dumping, Drains to Creek” with a clear picture or symbol.
  • Post signs informing people that dumping waste on your property is illegal.
  • Anything dumped at your site becomes your responsibility; make sure everything is disposed of properly to avoid violations.

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.

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?