I own and operate a plumbing shop in Las Vegas. 8 months ago I turned over a project, and the owners started complaining of yellow water after about 3 months.I recently replaced all of the factory installed galvanized nipples with brass. I also replaced all of the die-electric unions. The nipples which were removed had a reddish/brown fungus on the insides, like a scale substance. The owner is convinced that electrolysis is occuring, but I believe that the system may be infested with Iron Bacteria. I’ve had the water analyzed for copper and lead content, and it varies at each sample location. The water coming in has an iron level of .5 parts per million, yet my samples range as high as 7 parts per million. Although this water is metered by the local water district, I believe that it is coming from one of the many wells which serve this area of town. Any suggestions???