How to safely buy a lagoon

I found a solid park in a great area, under market rent that has a lagoon.

I know that lagoons are frowned on here, but they are legal in my state and I am wondering how to get it examined to determine the life left with a long term goal to eventually replace it with a tie into the city sewer.

In the mean time I could buy it low, operate it safely and then replace the lagoon and sell at a good profit.

How would I find someone to examine the lagoon for me and tell me how to operate it safely until it needs to be replaced?

What state are you in? We have one in a MS park and it has been no issue at all as long as you have testing and an manager that understands the system.