Think about radon gas. You can fix for radon for about $400 as you build the house that would cost 4 times that to remediate and be less effective. Radon comes from radium content of granite. You may not have granite around Lake Michigan's ancient lake bottom. The way to check is ask a well driller if they go through granite when drilling for water. One thing about radon is you can't measure for it til the house is finished since it depends on the tightness of the house. Around here house sales are predicated on the radon level &/or its mitigation. Radon in well water is also checked. 4 picocuries/liter or below is the standard for air and for water probably below 100 to 30 ( water standard is somewhat controversial)
Radon leaks in through the basement; there are several things to do as the house goes up. 1) through the foundation footings on each side put a 1 1/2-2'' pvc pipe that extends horizontily 3-4' into the stone that is under the slab. On the outside of the footings run the pvc up the basement wall to above grade and put a gooseneck curve on it so the opening is facing down. Somewhere in the center of the house run a 3-4" PVC pipe from the sub slab stone with some short laterals all the way through the roof, also with an upside down gooseneck to keep the water out. Put 6 mil poly over the stone and under the slab, carefully overlapping and taping the seams. 2) Use a small transfer pit (used to corral toliet water and is all sealed up including the perforation for vent,egress and electric cord) instead of a sump pump pit which is usually open to the basement. Vent this to the outside. 3) Use polypropylene fibers in the slab cement to minimize cracks and gaps and cauk the edge of the slab with silicone in several months when it pulls away from the wall at the edges. 4) after you build the house, check the air for radon (get a Purex kit at a hardware store) If too high, activate the stack by putting a squirrel gage fan in the attic the pulls air through the PVC pipes on the outside of the basement walls through the footings through the sub slab rocks up the 3-4" stack to exhaust above the roof. There will be a natural convection since the 3-4" stack, going through the center of the house heats the air. Make sure you have electricity and access to the attic where this 3-4" central stack is. 5) if there is significant radon in the water consider a charcoal filter that hangs on to the radon gas long enough for the ~2.7 day half-life of radon to reduce the radiation. Do it for water taste as the charcoal filter technically become a radioactive waste and is difficult to dispose of. The use of serious bathroom fans while showering significantly reduces aerosolized radon gas as does exhausting laundry and dishwashing vapor.
Radon has been implicated in lung cancer. Real estate-wise it can effect the salebility of a house. City water is pretty safe because aeration liberates the radon and this is usually part of purification process. This is a serious problem where granite is close to the surface. This was discovered in western NJ and eastern PA where a large geological feature called the Reading prong ( after Reading PA) has the appropiate rock. A nuclear plant worker set off the alarms upon his return to work on a Mon. AM and his house had some astronomical reading of 30,000 that was equivalent to smoking 8-10 packs of cigarettes a day!
RCH<P ID="edit"><FONT SIZE=-1>Edited by Rch on 12/11/01 05:40 PM (server time).</FONT></P>