It went from a 2 ppm yesterday to probably a 5 and now it's at a 3 today. How long should I run the water for? And were trying to speed it up because the county won't retest it for bacteria until all the chlorine is gone. Also in your opinion is 1 gal of bleach to much?
Amount depends on the well. I tend toward overkill. And as I write in my writeup, I think pH is important for killing effect for a given amount of chlorine.
But short answer is I used 3 gallons of bleach and 3 gallons of vinegar, all said and done IIRC. I was doing my well and plumbing, and again, I was into overkill. I started with a gallon. Used chlorine test strips, and then I added more bleach. I read pH after a lot of recirculating, and added more vinegar. Repeat. My well is 4-inch bottom feeding.
I have to think that recirculating into the top of the well while also sending water to the ditch is going to be important to get your chlorine level down. You want to wash out chlorine that is above the pump as well as chlorine below the pump.
With DIY coliform tests, the positive result is due to wrong sampling techniques, and getting the sample contaminated. I presume you did not do your own test.
So short answer is 1 gallon is not too much, but your procedure is too simple. Did you run chlorinated water through the hose bib that they use to sample? In sanitizing, you want all of your faucets to have sanitizing levels. But if you are focused on passing a test, at least make sure you ran treatment levels through the faucet that will be used for sampling.
So to clear the chlorine, run for hours while recirculating. Maybe overnight. Go full blast into the top of the casing and out to the ditch simultaneously for hours. You can use a clamp or two on a step ladder to direct a hose into the top of the casing for recirculation. Go outside every hour or so, and stick a test strip into the recirculating stream to see how you are doing.
If you are worried about running the well dry, the recirculating water will not run the well dry. The water to the ditch could be throttled if running dry is a concern.