It depends on local markets. In Delaware and PA there is nothing special except to comply with the EPA stormwater requirements. Basically make sure nothing you spray, even when rinsing goes into a storm drain. Its usually more of a concern on commercial projects where there is a lot of concrete. All we do is to try and push the water into the landscape or grass and you are fine. There are other things you can do like block a storm drain and use a shop vac to collect water or push broom to push water onto a larger concrete area to dry. Your best bet to take some of the training or go to an event. UAMCC.org is having an event in Baltimore in March that is free.
This is very similar to what we have in Wisconsin. Direct the rinse water and runoff to a "permeable surface," like mulch, rock, dirt, or grass, or to concrete that will not end up in the storm drain system. This is really easy if you are doing single family residential homes, because it all goes in to the landscaping and grass anyway. If you do a commercial project in an urban area, you may need to worry more. It's usually easier than it sounds.
I will dam up or cover drains and put an $80 hardware store sump pump in the lowest spot and pump it out. I usually can use one 12-15 times before it dies, if I Final Wash it afterwards. if I always try to get the site to allow me to put it in their sanitary system through a utility room sink or drain, or I have a sanitary stack cleanout cap with a hose connection and I pump it in to there. Otherwise you can haul it away in a tank on a trailer.
Again, if you're just getting started, I wouldn't worry. On residential homes it's a non-issue. I would probably join that organization they mention, though. Better to be ahead of the game when you do need to do all this stuff.
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Chad A. Eneix, President, Water Dragon Inc. chad@waterdragoncleaning.com