I have been considering adding power washing to my services, as I have a few commercial landscape maintenance accounts that could really use some cleaning of their ashpalt lots, drive thrus, etc. Equipment and prices I can research, but what I'm having trouble with is finding out about the enviromental requirements. I mean, if I blast off an oil spot, its going into the gutter, and down the storm drain. Now, arguably thats where its mostly going to go anyway, but at a much slower pace, but is that really kosher? Is anyone aware of regulations concerning power washing effluent? I can find nothing on my state website.