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The Chemigation Program grants permits and inspects closed irrigation systems (such as center pivot irrigation) to protect aquifers and surface water from possible contamination by agricultural chemicals applied through the closed irrigation systems.

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What is Chemigation?

Chemigation is the process whereby agriculture chemicals, (pesticides and fertilizers) are applied to land or crops in or with water through a CLOSED irritation system. (The term "pesticides" includes herbicides and fungicides as well as insecticides.)

Chemigation DOES NOT include the process whereby chemicals are applied to land or crops in or with water pumped from a stock watering well, a domestic well with a diameter of two inches or less, or from a tailwater collection pond.

A CLOSED IRRIGATION SYSTEM includes any device or combination of devices having a hose, pipe, or other conduit, which connects directly to any source of groundwater or surface water, through which water or a mixture of water and chemicals is drawn and applied for agricultural or horticultural purposes.

Under the Act, "irrigation system" does not include any hand-held hose sprayer or other similar device which is constructed so that an interruption in water flow automatically prevents any backflow to the water source and does not include stock waterwells, any domestic well with a diameter of two inches or less, or a system which includes a tailwater collection pond.

An open discharge system is any system in which the water is pumped or diverted directly into a ditch or canal in such a manner that the force of gravity at the point of discharge into the ditch or canal cannot cause water to flow back to the point from which the water was pumped or diverted.

Can I Get an Affidavit in Lieu of Permit?

Each calendar year (beginning January 1, 1990) the owner of an irrigation system who does not intend to practice chemigation during the calendar year must notify the Colorado Department of Agriculture of such intent. Notification must be by an affidavit provided by the department.

Who Must Apply for a Permit?

Beginning January 1, 1990, any person who utilizes chemigation as described above must file with the Colorado Department of Agriculture, an application for a chemigation permit for each irrigation system utilizing chemigation. Permits are not required of persons who apply chemicals to land or crops through open discharge systems.

What Are the Permit Fees?

The annual permit fee is $45.00 for permits issued to permit holders outside of Groundwater Management Districts that have contracted with the Department for enforcement of Section 35-11-113 of the Chemigation Act. The annual permit fee is $45.00 for permit holders within Groundwater Management Districts that have contracted with the Department for enforcement of Section 35-11-113 of the Chemigation Act.

Permits expire on March 31 of the year subsequent to the date the chemigation permit was issued. The reinstatement fee for an expired chemigation permit is double the amount of the fee for a chemigation permit. The reinstatement fee will not be assessed to persons who file an affidavit in lieu of permit for the year prior to the year such persons seek a permit.

Chemigation permits are not assignable. The inspection fee is $50.00 for the inspections conducted by department personnel. The inspection fee for permit holders within groundwater management districts which have contracted with the department for enforcement of the act will set inspection fees independently.

Copies of the Chemigation Act and the Rules and Regulations Pertaining to the Administration and Enforcement of the Colorado Chemigation Act are available from the Department.

When Are Inspections Conducted?

Inspections may be conducted of permitted systems once every two years. Inspections are conducted to assure proper installation and maintenance of equipment that must include:

  • Backflow prevention check valve and vacuum relief valve between the main check valve and the irrigation pump; Inspection port to check the performance of the check valve on the irrigation pipeline;
  • Automatic low-pressure drain placed between the main check valve and the irrigation pump so that a chemical will drain away from the source of the water supply;
  • Check valve in the chemical injection line; and
  • Simultaneous interlock device between the power system of the chemical injection unit and the irrigation pumping plant to protect the water supply from contamination in the event such pumping plant ceases to operate.

Prior to July 1, 1989, existing irrigation distribution systems that were installed and are equipped with a properly located irrigation pipeline check valve shall be considered in compliance if the valve provides a watertight seal against reverse flow.