"Is 'abatement' even possible in a rowhome? " Yes. You can run the exhaust line inside (often a PITA on a multi story house, especially an older one) or on the outside (and then hide it as a downspout for gutters).

The drain should be part of the "sealed" drain plumbing, so it'll be sealed from the ambient environment under the slab. You won't have radon coming up out of the drain if that's what you're asking. Pricklypear pretty much nailed it regarding radon mitigation. It typically involves adding perforated pipe under the slab and bringing that pipe outside the house's envelope and up the side of the house to the roofline. A low CFM fan is added to the pipe, it essentially creates a slight vacuum in the pipe under the slab, drawing and radon out and exhausting it to free air outside the house. If you're going to make the basement into living space that will regularly be used, definitely run more tests. Multiple if possible. Sort of like getting "three bids" to qualify a budget. Radon can change throughout the year. Seasonal, dry versus moist soil, etc. If you have time it's best to test throughout the seasons. Regardless, a long-term test would be more reliable than a short-term test. Long-term active testing (90 days for example) would be more accurate than a short-term (48-96 hour) passive test.

Hey Al, first of all, if you are going to alter a quote, don't provide an easy link to it. I beileve it says 1/2 ppd NOT 12 1/2ppd and it says the 1/2ppd is what the action level for radon in the home provided by the EPA is equivalen to, not exposure from granite countertops. I consider any study you or the SSFA provided samples to, or in any way contributed to, to not be reliable due to your bias. Nor do I believe the MIA should be funding or contributing to a study if it is to be considered unbiased and reliable. WITHIN the scientic community, readings are sometimes taken at face value until proven otherwise, because reputable scientists should adhere to professional standards. You are in no way a part of the scientific community and about as biased as they come. Your readings carry no weight with me. Neither would the MIAs. Even within the scientific community, results must be reproducable before they are give too much weight. Those scientists have said they WILL publish. The thing about peer review journals, though, is that it not just up to the person who does the study. It has to have been conducted in a reliable enough way to pass scrutiny by the peer review board and accepted for publication. Saying you are going to publish doesn't make it so. I hope they do, though. That would mean at lest that others in THEIR scientific field feel that the study was significant enough to share. Then, if others in that field desire, they will conduct their own studies to determine if the results are reproducable. If not, the entire debate starts again. If they are, then we have a starting point. That is a long way from you shouting from the roof tops in forums that Shivakashi should be banned or that one guy with Lung Cancer of unkown type and medical history got it from his countertop. I certainly don't have any reason to believe you would find a single hot stone and submit as many elevated samples as you could get from it that would make it seem like you were right in your calls of the sky falling, any more than I would have reason to believe the MIA or others in the industry would hide hot stones. But it really is better if you guys have no connections to the studies at all. I am sorry Al, this may be your bread and butter, but I don't plan to make it my profession. I left that one and have made NO to attempts to go back. I disliked working with and against biased people who only want to promote their own interests. I do not sell, fabricate, mine or do anything else having to do with rock, granite, solid surface or any other type of countertop. I am a nurse. I refuse to spend my day following links from the SSFA or the MIA. If there were any independent studies from peer reviewed scientific journals linking granite countertops with cancer, I am sure you would have posted to them directly by now. I did do a quick search at one time from Pub Med and could find no studies linking granite countertops to radiation or specifically to radon exposure. I did find articles noting that radon can come from building materials in general, including cement, drywall and granites, but I mentioned that myself at one time. My impression from your reaction then was the same as it is now, that your only interest in radon or radiation exposure and health risks are if it is in granite countertops. Do you also warn your customers that most elevated radon levels come from the soil, not countertops, and that radon can also come from other building materials, and that they should test their homes and act if they find elevated levels even if they purchase solid surface countertops from you? Do you only sell and install "no VOC" cabinets and carpets and adhesives? If you have a direct link to one or more scientific journals that report on radon measurements from granite countertops in buidlings, or exposure to radon or radation from granite countertops, please provide links and I will be happy to look at a couple (not even 10 so please don't provide 50 and expect me to wade through and find a few lines that you can extrapolate into something). These are specifically studies in peer reviewed scientific journals that AT LEAST test granites of the types being used AS COUNTERTOPS. Please don't waste my time by linking to articles in publications by the SSFA or MIA or any other trade journals. In my opinion, relying on studies about granite funded by the SSFA are akin to relying on cancer studies funded by tobacco companies. I have called you strongly biased, I don't recall calling you a liar. I do have some ignorance about radiation reading and testing, it simply isn't my area of expertise any more than it is yours. However, I don't consider you any more of an expert on it and I do tend to be choosy about who I let "teach me" about any subject. No insult intended but I wouldn't consider letting a guy with a kitchen business teach me about the measuring of radon or radiation or the health effects of radon or radiation any more than you would let me teach you about how to install cabinets. I want information without the "spin". I really don't expect to ever get it from you. Sue

Houses near me (Alexandria, VA) have done similar projects, but usually they are basements that have about 80" clearance to the joists, and they want to go up to about 90" so it meets code for habitable space after ceilings and floors are installed (I think the code here requires 84" to finished ceiling). I think the most common issue is that your sewer drain pipe may not be deep enough under the slab, and it may run under the area you want to excavate. I know my 4" cast iron pipe is just below the slab level, and I assume this lines up with the main in the street. I would need some type of evacuation system to raise sewage up if I lowered the drain pipe. Footings for existing walls may be an issue if they extend quite a distance out from the walls. I saw one "This Old House" episode where they excavated the area between the footings to get more height, but left the original footings in place. That created a stepped floor that had full head room in the middle, but had a shelf around the perimeter walls. I never saw how they finished the walls, so I don't know how they dealt with it. Removing a basement cement floor and underlying dirt is going to be expensive if they can't get equipment in and out through a wide walk-out door. With only stair access they will have to jackhammer the cement into relatively small chunks and carry it out in buckets. Dirt will have to come out the same way. This is very labor intensive. When they do the new floor pour they will have similar issues if there isn't a window that provides a good location for the chute into the basement. Bruce