We had a new well drilled on our farm and the well driller was going to use a cable drill. I told him I wanted him to use chlorinated city water and not his well water. He said he would. Shortly after the well was drilled the water would turn black in the toilets and livestock waterers and stink. I told him about it and he said, yes, we have the same problem with our well at home. That told me right there that he lied to me about not using his well water to drill. He infected our well with his iron bacteria. There was an article about this in Water Well Journal several years ago. Long story shorter, I installed a hydrogen peroxide injection system and the black water and smell was gone instantly. I'm using 50% h2o2 metered into the well water at about 25ppm as it comes from the well on it's way into the pressure tank. My grandson in Shreveport, LA had a new well drilled and the water smelled so bad they had to open the windows. I put in the same system for him and the smell was gone instantly.