Cooperators wishing to apply chemicals (including pesticides and fertilizer) through an irrigation system are required to obtain a permit from the NRD. Applicator certification is also required, and training/certification sessions are usually held throughout the state each winter/early spring. New permits cost $60, but renewals are just $30 each if submitted prior to June 1. For more details on the program, check out the full text of Chemigation Rules and Regulations.