[QUOTE=Serendipity;8834342]
^ Respectfully, this is not correct. I’m an environmental scientist and regularly test wells as a part of my job. I am in Canada, so the testing practices/terminology may be different, but there’s 3 types of coliform that we test for here:
E.coli, which is very very harmful (not 99% harmless) and caused some big problems in the town of Walkerton a few years ago: http://www.cbc.ca/news/canada/inside-walkerton-canada-s-worst-ever-e-coli-contamination-1.887200
Faecal coliform, which can be present when surface (rain) water can get into a well and brings animal waste with it. Also bad.
And total coliform, which is basically all bacteria, bad or harmless. When we take a water sample we have to be careful not to touch the inside of the bottle or the cap because just a touch can result in a high total coliform result from general bacteria on our hands, not harmful.
To the OP, I see that you will be getting the water tested, so I just wanted to let you know that there are different types of coliform. Once you know what type you are dealing with you will be able to make a better decision. And as others have said already, it’s really simple to shock the well with bleach to fix it.[/QUOTE]
Escherichia coli:
"Escherichia coli (E. coli) bacteria normally live in the intestines of people and animals. Most E. coli are harmless and actually are an important part of a healthy human intestinal tract. However, some E. coli are pathogenic, meaning they can cause illness, either diarrhea or illness outside of the intestinal tract. The types of E. coli that can cause diarrhea can be transmitted through contaminated water or food, or through contact with animals or persons.
E. coli consists of a diverse group of bacteria. Pathogenic E. coli strains are categorized into pathotypes. Six pathotypes are associated with diarrhea and collectively are referred to as diarrheagenic E. coli." (Pathotypes being STEC, ETEC, EPEC, EAEC, EIEC, and DAEC.) And frankly, I think it’s irresponsible and potentially dangerous to insinuate that all E. coli is harmful. It has a very important and generally symbiotic role in the gut, even conveying resistance to pathogens by outcompeting them for resources. (Obviously, as with many bacteria, there are pathogenic strains, ranging from a nuisance to truly dangerous, but it’s important to realize that these truly are the minority of the species.)
http://www.cdc.gov/ecoli/general/index.html
And again, coliform presence is an indicator used to determine contamination with generally fecal matter. You can get coliform plates or Petrifilms, on which a variety of harmless bacteria can grow, the only qualifying positive result is a colony with attached air bubble. There are other media selective for E. coli coliforms, as well as a variety of selective and differential media to determine the pathogenicity, or lack there of, of an E. coli cultured.
Coliforms are defined by the FDA-BAM as Gram-negative rods which produce acid and gas from lactose during metabolic fermentation. There are innumerable environmental bacteria which do not remotely fit these characteristics.
And finally, as you’ll note from my previous post, I advised the OP to treat her well, as even though the presence of coliforms does not guarantee presence of pathogens, it does indicate fecal contamination, and without more testing, there is no way to know of what type. They are often referred to as “indicator organisms.”
