Buying old MHP lot to build a house

Hello, we are currently in the process of buying a lot that was subdivided from an old mobile home park to build our new home. The lot is clear of any MHs, my concerns are underground utilities and specifically septic tanks. There is an old packaging plant in the back of the lot that was never completed.

Is this common to build on old park land? Is there any safety measures we can take to be sure there are no dangers?