I remember Neillsville from "The Rock" radio station. ;)
So, to answer the question, we need to know where the water is coming from. You mention that it's due to a high water table.
As such, I'd not ever finish the basement. It will always be one power outage or one clogged drain away from being ruined again.
It also means that your dehumidifier will never 'win'. Basements are moist by default simply due to cooler temps, but if you have constant hydrostatic pressure, it will always be an uphill battle.
Your (what I call) interior footer drain will certainly help, but you're at the mercy of the drains always remaining unclogged and the sump pump always having power. You'll also have to make sure it can handle excessive rain during those big midwestern downpours.
If it was merely an occasional rain/snow melt issue, I'd feel OK finishing the basement, but given the high water table, I'd consider rethinking doing a full finish project down there.
If your water problems are primarily at the footer, It may be OK. As that is exactly what the drain system is designed to handle. But if you have actual cracks in the walls and water is coming in there, I'd be definitely be hesitant.
One other note...a bit further west into MN, the clay soil we were on had a lot of radon. So you may want to get a radon test before thinking of finishing the space as well.
Oh, one last comment: note that the systems being proposed are in no way 'waterproofing' systems. They are water abatement systems--in that they are designed specifically to not be waterproof and actually allow the water to come in so it can be moved out. It's a nit-pick, for sure, but actual waterproofing is an entirely different discussion.
Having vapor barriers in most basement environments is a really bad idea. Really these only are a good idea in extremely cold environments or when a basement is truly a "basement" - meaning it is completely below ground level.
It is highly likely that water is saturating your foundation and then not drying quickly because of the vapor barrier. But there are just a ton of reasons:
- Given you have carpet the moisture could be seeping in from the floor and staying in the carpet a bit. You may not even notice this but the carpet becoming constantly a little damp will make it smell.
- It could be just water trapped in the walls because of the vapor barrier or trapped in the insulation itself. This will not be totally fixed unless you tear down all the drywall - or enough to take vapor barrier and bottom insulation out. See people 10 years ago and even now thought that insulating your basement walls top to bottom with batts fiberglass was the best way to do it. Well it traps water and causes mold growth and provides no cost savings in most regions.
- You could have a leak. Basically you will probably need to untack carpet or flooring around the perimeter to see if water is leaking in. I doubt that you have a real leak and not see any moisture at all underneath your walls.
Dehumidifiers are for very small constant humidity problems. When you have a "smell" problem the dehumidifiers are hardly ever going to fix the issue. You either need to seal your basement better from the inside or outside, remove the vapor barrier (that is probably just amplifying a bigger issue), and the easiest and most helpful thing is to increase airflow. If you have windows trying to keep them open a lot. If you have stairs that are near an outside door trying to get the airflow circulating. I have even seen people run fan to their attic to recycle air in basements.
Best Answer
Your primary concern would be with any lead-containing coating beneath the Drylok. Your secondary consideration should be for silica.
According to the CDC, an N95 is NOT adequate for lead dust, you need a P-100 or equivalent rating on your respirator.
For airborne silica dust, an N95 is acceptable.
So if you are relatively confidant that there isn't an old lead-containing coating beneath the Drylok, the N95 would be sufficient.