Well, I had no idea my little post would create any controversy. A few observations about the responses I have received, and this is from someone who has no knowledge or affinity for plumbing/science (that's why I went to law school -- please do not insert lawyer joke here).
The main thing I have learned from my personal experience and from reading all the great information on these boards is this: if you have a drilled well, get your water tested every year or two.
Here are some specific responses to your posts, and let me say that I am grateful to have heard from all of you with comments - whether I agree or disagree, I am glad to have your input....
Speedbump: I do not know what kind of sediment filter it was - your first post threw me off and I am afraid to admit what it was lest you mock me (~:
rshackelford: thanks for the tip to check out the other posts. Again, I know nothing about this, but I fear chlorine and I don't think I agree with the concept of shocking the well once or twice a year just in case. When we shocked our well, it was quite a project. A full day with no water, then WEEKS of running the well pump out to the backyard to clear the chlorine, and so weeks of drinking bottled water, us and the animals. It was not easy. Again, I think the main thing well owners need to understand is that many things might compromise a well and well water should be tested frequently. If the test shows a problem, figure out how to solve that problem.
BobNH: thanks for your input - I live in NH too, and so far I have never had a second positive test after shocking the well. If I do, I now am better educated.
Gary: your first post was helpful, but your second basically accused me of failing to notify the buyers of my home that we had a serious problem with our water. I am sure there are people out there who would do this. With all due respect, I am not one of them. I cannot think of a more important issue than clean drinking water and would never fail to disclose such information. Anyone who would lie about this deserves something nasty coming back at them. The issue was fully disclosed and the buyers knew that they should be vigilant in follow-up testing. We did not try to "explain away the contamination by guessing and spreading gossip." I did a lot of research on the internet, had many conversations with my state department of environmental services, and tried my best to determine what might have caused the contamination. Please understand, I had been drinking that coliform-tainted water, so I was not as disinterested as you might think. Finally, I am sure you are correct that some people have follow-up tests that show further contamination because they have a problem with their septic. We had a reputable septic company come in and test the septic system as well. I'm not sure what else we could have done. As far as your question about what problems we had with shocking our well, see my response above to rshackleford. I don't like bleach, and I don't like having to pour a ton of it into the water that I intend to then run through my fixtures and my septic system, and that I eventually hope to DRINK.
This is a wonderful website, and I am glad you all are here helping people like me to better understand plumbing.
Cheers.
Alleycat