We recently went through an "odd smell in the water" situation that
came back as both TC and E Coli in the water.

We shocked the well and re-tested a week after the chlorine was gone.
E Coli was gone - but Coliform still present.

Shocked the well again and installed a Sterilight UV filter (SQ8-PA
with a UPS) post sediment filter and softener so we wouldn't have to
worry about the water in the house.

Re-tested the water again after a week and raw water (sample from
storage tank) was still negative for E Coli but still positive for
Coliform. Treated water was fine.

I had previously suspected earwigs - as the old well cap was not very
good and not tightly sealed and upon opening it - there were dozens of
earwigs running around inside the well pipe. The new sealed cap has
kept the earwigs out - but I still have the bacteria issue.

What should I be doing to investigate the source of the bacteria? I
would rather fix the problem as this well was bacteria free for years
before this outbreak and my father who visits frequently has a
compromised immune system so althought the UV works fine - I would
rather consider it a safety net rather than the only thing keeping the
water safe.

Also - any ideas on why the E Coli was there, then gone while the
Coliform stayed? The smell has been consistently gone since the first
shocking.

thanks!