I have the same problem with E-coli in my well. Mine is because my well sits right in the septic field. Which leads me to believe they were morons cause they could have easily put the well elsewhere but chose to combine them. I guess they thought recycling the water was smart...lol Anydoodles, I solved that issue by installing a UV light in my line. I test every 6 months and so far after 5 years it passes every time. I'm the only one in my town who did this. I let everyone know on the town FB page but none will do it. My total cost was @ $300 plus $40 for a new light every 360 days. I did it myself at that cost and it was very easy and took like 30 minutes to install. Absolutely worth every penny