From my contact at the Suwanee mgmnt district -
"I greatly appreciate your concern for doing your maintenance in an environmentally responsible manner. Lake Butler in Union County is within the Suwannee River Water Management District, but we have no direct jurisdiction over this type of activity. The Florida Department of Environmental Protection handles a lot of the water quality issues in the state. You can find information on their program at:
Water Programs - FDEP. I gave their site a quick look and other than a permit exemption form for dock reconstruction, I didn’t see anything that applied to your situation. My next suggestion would be to talk to the county code enforcement officer or building inspector. The number I found is (386) 496-2676.
My guess is that your ultimate responsibility is to follow the label instructions for the product you are using. Manufacturers must produce a material safety data sheet (MSDS) for any potentially hazardous product. I’ve enclosed an example. "