Are there any laws/regulations impacting what can be done with this. Each state/county is different. I wouldn't want to say that you can do something, and get you in trouble.
If there is sand, I doubt you would be happy with the results of an ordinary trash pump. Sure, it picks up muck that is stirred up with water, but sand is heavy and settles fast. There are pumps that can handle it, but from what I have seen, they are pricy.
Keep trying to get some quotes. It may start answering a lot of the questions you have, and probably will also bring up a lot more.
Is your soil sand, clay or other? If you got a nice spring coming out, and with deepening that spot a bit, you might have yourself a nice year-round trout pond!
