NH is the granite state, and granite off gasses radon. I have a radon abatement system on my water system. Well pump to holding tank, radon system pump to radon system tank with a blower to aerate or bubble the water so the radon is released and vented outside. We can bypass it when desired. There are 2 fail closed solenoids on the radon system inlet, that apparently didn't fail closed. It ran all night earlier this week and overfilled flooding my finished basement. All the furniture was up in those furniture moving pads and everything we had on the floor was in rubbermade containers. In some spots we had 2" of water and it destroyed the wood floor. We pulled up the floor and moved everything outside to shop vac up the water and put fans out to dry everything. No Marlins were damaged. The floor is really the only loss so I took the opportunity today to construct a target in the backyard. It's about 25 meters from the back of the house just to right of the old chicken coop. A little closer view. The floor was a click together type made of cork and the sections are 36" long x 12" wide, so my new target is basically 3'x3'. There is about 5" of boards in front of the frame with overlapping seams and about 8" behind the frame with the rest stacked up behind it. Pansy, the Treeing Walker Coon Hound, approves. The cork seems to be self sealing and it should last quite a while with me limiting it to 22LR at 25 meters. CCI MiniMags did not make it through the first 5" layer.