quattroworld

I bought three of the self-test kits from Lowe's a few weeks ago.
I put one in my 1st floor office, one in my mom's 1st floor office and one in the basement. I let them stand for 96 hours as specified.
I then send the sample bottles into a lab.

The results came back from those:

My office: below action level of 4pci/L (3pci/L)

Mom's office: 2x the action level (8pci/L)

Basement: 2x+ the action level (10pci/L)

It was recommended to do a second test.
I just got the results back.

Mom's office is at 5.5pci/L

The basement however is almost at a whopping 10x the action level 39pci/L)

I know that weather (specifically "storms") can affect the results which we have had a lot of.

The footprint for the house as some will recall is rather large 30' x 80'. The radon "tube" that the builders plumber installed was installed at one far-end corner of the house.
The tube goes through the basement cement floor, straight up through the roof.
I was curious (now that can be read as concerned) as to how well this tube was going to cover removing the Radon gas from just that one corner.

In my other (smaller) mountain house I installed a single Radon evacuation "system", which consists of the same PVC tube through the basement floor and then a vacuum-fan to suck the gas out and through the wall (not the roof).

I need to figure out what is going to be the best way to rectify and lower the levels so I can request the builder to take care of it (they obviously have no clue and figured just throw a tube in there, that will take care of it).

Some of my ideas so far:

1) Additional tube, basement-to-roof at the opposing end of the house
(probably the least effective solution)

2) Additional 3 tubes, basement-to-roof at the remaining 3 corners of the house.

3) Additional tube, basement-to-roof at the opposing end of the house PLUS the vacuum-fan installed on EACH tube.

4) (Probably too much, and energy-cost nightmare) 3 additional tubes and 4 vacuum-fans.

Thoughts & any BTDT's??