Stormwater Pollution Prevention regulations require the use of best management practices (BMPs) for any project involving site disturbance of over an acre. Usually for geotechnical drilling and well drilling, the sites are much smaller, so we frequently don’t worry about it. I am very fuzzy on the details, but as I understand it, you can still be assessed fines if you don’t implement BMPs, even for smaller jobs, particularly if some kind of pollution event occurs. (Photofrom Earth-Savers.com)
Sheetflow.com has a nice article on Erosion Control Plans for Geotechnical Drilling, and it appears to be equally relevant for well drilling. It is really a boilerplate ECP for a project in Washington, but I think the language can be tweaked for most other jurisdictions as well. It might be worth looking at to get some ideas for how to implement it on your next geotechnical investigation.