I recently finished my basement and about two weeks ago started noticing a string kitty litter or cat urine odor coming from my water (both hot and cold) the smell will not go away, and is worse in closed in areas, like the bathroom, the laundry room. I tested the water with some over the counter kits and everything is fine, the county came out and tested the water and said it is fine. (I have city water.) I was told by the county chemist that chlorine dioxide dissolved in the water (used to treat the water) reacts to the gases (smells) from the new paint and carpet to produce the odor which is harmless. Everyone but the county that I talk to tells me this is not true. Searching the internet has turned up nothing, I spoke with consultants at the over-the-counter water testing company and they too were baffled. I came up with a few possibilities but still do not know enough 1.) back flow or back pressure which was caused by the plumber branching off my main water line in the basement to install a basement bathroom, and 2.) residual plumbers glue let inside the line or not completely dried by the plumber. Has anyone had a similar problem, have any idea as to what is going on or how I might resolve this? Thanks in advance.