Question: What is the best way to eradicate cattails from a small pond that meets Maine DEP regulations? Answer: Jonathan Foster, Home Horticulture Outreach Professional I’m going to recommend that you contact the Board of Pesticide Control directly, as they are the regulatory agency that oversees herbicide use in Maine waters and would be the group you’d read more What is the best way to eradicate cattails from a small pond that meets Maine DEP regulations?