lawnboyil - In Michigan, if a pond has an overflow or a point of overflow, that goes into a ditch, storm sewer, or another body of water, you need to get a permit from the Department of Environmental Quality (DEQ) before applying any chemical. This means pretty much any pond. You need to apply several months in advance for these permits.
You need to submit a map of the body of water, the legal name and description of property, complete with the areas of infestation, your methods of control, and the chemical(s) that you wish to apply. This has to be submitted in triplicate. Also, ponds need to be posted with approved signage.
After the season, you have to submit a report as to how your chemical treatments worked, fish kills (if any), and type of aquatic plants controlled.
Also, you need an Aquatic license and yes, there is a demand for this kind of work since many of us are giving up on this paperwork nightmare.