Years ago, I helped re plumb a 16 unit building with water lines leaking under slab. We moved all lines above under insulation and solved problem. I was told at the time the copper line decayed due to being improperly mated to steel pipe allowing electrolysis to occur and cause the breakdown.
I to carry the XDs 45 IWB using a N82tactical holster at 5 o'clock. I like the fact the XDs has a grip safety but i also carry Glock and Kahr at other times because the holster has good trigger cover.