I work for a restoration company which means we clean up after fires, floods, broken pipes, and other disasters. In many cases, we have to extract water or sewage from buildings using a truck mounted extraction unit and then dump this water somewhere. The closest place to our shop is a Flying J, and I have a list of RV parks and other locations throughout the city for us to dump as convienently as possible.

If you own or operate a park and you have a dump station, you might want to look in your phone book under "Water Damage Restoration", "Carpet Repair" and "Carpet Cleaning". Write to these companies and let them know you can offer your dump station for a fee (maybe a discount) and your location. Remind them that dumping contaminated water anywhere else could bring stiff EPA fines!

Just a suggestion, hope it helps.

Cant you dump it at your shop?

The companies by us go to a sewage treatment plant. They are allowed to dump there, for a fee.
Just a thought. If the park has a septic field , it might be more than it can handle. Could do more damage than what it is worth to make a few bucks.

Even if you remind those companies of the EPA rules and they dump something illegal you are the one that will receive the fine if they fail to comply. I would prefer not to risk those chemicals being put in our tanks.

No, unfortunately, we don't have any type of dump at our shop (yet. I keep pushing for one).

As far as chemicals, the only chemicals would be ones used during carpet cleaning which can be disposed of in a sanitary sewer.