We have discovered that we have Iron reducing bacteria in our new well.
We have been living in our new house for about 5 months and always had
a funny smell in the cold water. A test from a lab confirmed that it
was iron reducing bacteria and in high concentration 3+ out of 5.

From what I've read on google this is very bad. We did bleach our well
already and that lasted 2 days and the smell came back. We called
Culligan and they stated that the problem could be very serious as the
smell came back so quick after bleaching.

My understanding is that IRB (Iron reducing bacteria) can render a well
system useless very quickly.

Can anyone suggest a course of action to deal with this. The builder
says that its not his problem.

Thanks.