You only need a permit to apply pesticides if you apply them in or next to a drainage-way, ditch, canal, stream, wetland, creek, or other surface water.
Pesticide general permit
Please note:
The pesticide general permit is currently at public notice and the comment period has been extended to April 14, 2025.
Reporting templates and change of contact form
Maps
- Map of outstanding waters (ArcGIS online map)
- 2018 inventory of outstanding waters (Zip file with ArcGIS shape files)
Sampling
The division conducted sampling to establish a baseline pesticide data set for each major Colorado watershed.
- Guide to interpreting results from aquatic analysis for pesticides
- Summary of all tests by location and test dates
- Includes specific record numbers for designated reports
- Analysis reports for summary
- This is the electronic Colorado Environmental Records Center.
- This link goes directly to the analysis and calculations file for pesticide sampling results.
- Tests are referred to by record number only.
- To determine the specific record numbers for location and test date, see list on page one of the Summary of all tests.
Information
- 2012 Request for Information Report to Colorado General Assembly:
- Compliance assistance:
- Ditches:
- No permit is required for any flow or return flow of irrigation water into state waters unless required by federal regulations (Colorado Water Quality Control Act).
- The state permit for these discharges is consistent with federal permit requirements.
- The EPA Scope Essay has more information about this topic.
- To determine whether an annual report must be submitted:
- Calculate the area of the ditch application, even if it is dry at the time of application.
- Ditch miles treated should be counted once, even if treated more than once in a calendar year. For example, the water in a ditch on a 10-mile stretch has a 10-mile application to your annual treatment area, even if applications are applied to one side of the ditch first and the other side at a later date.
- Flood irrigation
- Waters in a field following flood irrigation are "waters withdrawn for use" and are not"waters of the state." Permit coverage is not needed.
- This water, commingled with irrigation water, is irrigation return flow and/or surface runoff from an agricultural field. Permit coverage is not needed.
- Additional information from Virginia Cooperative Extension:
Pesticide waste disposal information from the Colorado Department of Agriculture
EPA materials
John Nieland
john.nieland@state.co.us | 303-692-3553