Ensuring consistent soil moisture content is key in this area. 

If the flooring underneath stinks, how do you think the stink got there?

The major one was the part of the water main running into the house sprain a leak, that ran for some weeks, and caused erosion of the under-soil.  

If there is dog urine, don't be surprised if it seeped through the carpeting, to the carpet pad, or even to the floor underneath.

The issue is to confirm if the soil is contaminated and the extent of the soil contamination.

However, the seller agreed to perform a soil contamination test before closing, which came back clean.

Many would dump the water right next to the house where it would accumulate into large puddles during bad weather and eventually leak into basements OR even worse saturate the soil beneath your homes footer causing it to sink slightly and causing cracks in your foundation which may let in more water.  

Without them you will probably have water intrusion in your basement/crawlspace and a lot of water around your house effecting the foundation and soil among other things.

WI has some poor perk soils so that may shorten the life of the field forcing moving the field which in a park often is difficult.  

I see they got some pretty good wear and floor underneath looks great.