Diazinon Hazard

Household Drains

The common pesticide diazinon is becoming a problem in Colorado rivers and streams. Homeowners who dump diazinon down their drains could be contributing to that problem. Diazinon dumped down household drains ends up at wastewater treatment plants. Diazinon cannot be removed during the treatment process.

Wheat Ridge's wastewater is treated by several privately operated Sanitary Sewer Districts. The treated water is discharged to the South Platte River, where the combined makes up 90% of the river for nine months of the year. It only takes a single homeowner disposing of four ounces of concentrated diazinon down the drain to affect test organisms at the Wastewater Treatment Plants, meaning it will affect the smaller organisms that live in the river.


Colorado's rivers and streams are a source of drinking water and support fish and other wildlife. We must all do our part to prevent diazinon from entering any river or stream. To keep diazinon and other pesticides out of rivers and streams, please follow these five easy steps:
  • Buy only as much as you need
  • Use as directed and do not over apply
  • Use all of the product, and make sure there are no leftovers
  • Triple-rinse the empty container with a garden hose. Pour the rinse water on the grass and let the container dry out, wrap the container in old newspaper, and dispose of it in the trash.
  • Never dump any leftover pesticide down any drain
If you do have leftover diazinon, pesticides, or other hazardous materials, take advantage of the Rooney Road Recycling Center which allows you to dispose of household hazardous waste easily and safely.