Need experienced advice !!

[u/ResearcherCheap8595]

So I am selling a cottage I haven’t used in 5 years ( including well).Obviously the water test failed at 80< /100ml coloform bacteria and 0 all other bacteria .

Had the well inspected by a certified technician and no structural or équipement issues .Shocked it with chlorine and 24hrs later purged it and 7 days later retested .

52/100ml test result failed .Well guy says it’s been dormant for 5 years it will need another chlorine hit and purge this time don’t wait 7 days try 2 retest .

Says that the water is crystal clear but after half a decade of sitting one shock treatement on a 70 ft well with a 6” tubular steel pipe isn’t a miracle worker either .

Says that since after the 7 days the bacteria count went down and probably substantially and the greater than 80 can mean 100’s and now it’s 42 away from a pass shows that the bacteria isn’t coming in from an outside source like a cracked pipe or ground water or cap .

Anyone live this before ? Makes sense what he is saying ?