We've just purchased a beautiful house in the country. This is a brand new 120 foot drilled well with 10gpm. the water coming out is clear and odor free. This well has never been used and has been sitting there for a while. The construction is not complete and the plumbing isn't done. We had to take the water test from the pressure tank. Well, my real estate agent put a hose on the tap and let the water run for 30 minutes outside. He then took the test right off the hose ( I wasn't there!) and sent it off. The test came back 12 coliform and 0 e-coli I got nervous about buying the house. We are going to take another test today with NO hose! we'll dissinfect the tap with bleach after letting the water flow for a while then re-take the test. Do you think this will clear it???
When I had the coliform test performed (required by the county to get certificate of occupancy, and performed by the same county folks that issue septic permits), I was required to pour bleach into the well, let it sit overnight, run the water until no bleach could be detected by smell (seemed like forever - was better part of a day) and then contact the folks to do the test.
Coliform can get into the well when it is drilled, when the pump is put in and any time before it is capped (or if the cap is removed for some type of service) - no biggie unless you continue to have them turn up after putting bleach into the well.
It's recommended to treat a well any time the cap is removed - particularly if the pump is pulled as all the pipe and pump is exposed to the outdoors and can pick up bacteria.
If your county folks can't help you with how to treat the well prior to testing, I'm sure you can find the needed info online.
In my case, the county required that a gallon be put in - I think that quantity was not really needed, but that's their requirement.
Make sure to get plain bleach, no additives or colorsafe stuff.
Later, Mike (substitute strickland in the obvious location to reply directly)
FYI, Dunno what part of the country you're in, but I'll bet that some county person will have to perform the coliform test that counts. No sense in wasting money testing if the county is gonna have to do it anyway for no charge (at least there was no charge when mine was done).
Don't put too much stock in a test done without shocking as the coliform was probably introduced when the pump was put in - it's common throughout the surface environment, you've got all sorts of animal life spreading it around. Once the well is closed and shocked, you should not get any more as long as the well stays closed - usual causes if well isn't opened (from info I've found) is surface water entering the well and insufficient distance from or malfunctioning septic drainfield.
After you put in the bleach and wait overnight, you MUST run the water until the bleach is removed. If you test with the bleach in there, the test will not necessarily be valid. You want to know if NEW coliform bacteria (including e. coli) are getting into the well. The bleach will kill everything in the well while it is in there. After shocking and flushing, the odds of future coliform contamination without opening the well is very slim.
A few things I think are important...
Having the Extension Service check the quality of your water - this test has nothing to do with coliform test. It will tell you if there are minerals that can cause staining of fixtures or affecting odor/taste, how hard the water is, the pH (cpvc pipe recommended in my area because of acidity from CO2), and lead content. The test was $25 when I had it done in '97 and I figure the cost is probably similar now. Contact your Extension office and they will provide you with the test kit and tell you the procedure and cost.
The GA Extension Service recommends concrete a minimum of 2' all the way around the well casing and the casing extending a minimum of 6 inches above any high water that can be expected to insure that no surface water enters the well. Well driller should seal the casing in the ground and make sure that the casing extends to the proper depth - it's up to you to pour the pad. The builder *may* pour the pad in your case. I built my house and poured a big pad. I have a storage building over the well where I keep the generator - handy for outages when they (rarely) occur. I have the pressure tank and a whole house filter in there and it's well insulated to prevent freezing :-)
Put a filter before or where the water enters the house - nothing fancy, just a plain old fiber filter unless you have other issues from the Extension Service test mentioned above. You never know when you're gonna have a piece of sand come through the system and it can cause leaking if it lodges in a valve - don't want any drips, particularly in the ice maker. Filters are cheap and cartridge replacement is easy. In my case, my well was drilled during drought conditions, when the water table rose with regular rainfall, there was a good bit of sand (left over from drilling process) washed out of the cracks in the rock which would have played havoc with the valves in the house if the filter weren't in place - the filter clogged completely twice in one month. Never had anything like that before or since - 3 months is the time frame recommended by the filter docs and that has worked fine with that one exception.
Later, Mike (substitute strickland in the obvious location to reply directly)
When mine was drilled (240'), the driller went to the local swamp to get water to keep the drill head cool. Of course the swamp water contaminated the well water. The pipes & well pump were dragged across the ground as they went into the casing. A gallon of bleach was poured in the well, let set 3 days, then flushed. Required testing showed the well passed all tests and I have never had any problems with it.
Wow! Thank you very much for the info...you've been very helpful. We ended up buying the house after all and not worrying too much about the water. We'll shock it and it should take care of it. If not, there's always the uv light which we'll probably install anyways. Thanks again.
too funny! I think that well was shocked back after they drilled it but not flushed or tested. I'm not so worried anymore, I 'll follow the shocking instructions, flush and retest later after I move in. Beside, if this test doesn't turn out (we didn't shock), they are getting me a uv light anyways.
You know what always amazes me: There are these people who are about to make an extremely important and expensive decision. Major maintenance on the well could cost thousands, adding a UV system afterwards would at least be hundreds if not thousands, and the cost of house itself is probably 1/2 million or so. And then they go for advice to ... a whole bunch of clueless people on the net, which they have never met, and who may have no clue whatsover.
That having been said, we were in the same situation (except long after purchase, at the time of building inspection). No big deal. A well that has not been used for a long time usually grows something organic, in particular shortly after being drilled (at which time lots of surface crap falls in, all containing organic materials which will support coliform bacteria). Easy to fix: shock the well with chlorine.
The exact question of what form and how much to use depends on the depth of the well, the diameter of the casing, and the exact materials used for pump and pipe. I hear that for shallow wells, a gallon or two of bleach are sufficient. We asked the county safety & health department for advice on how to shock the well (they are the people who administer the test, and declare the water suitable to drink). They warned us away from swimming pool chlorine. We were told to put about 2 lbs of well shocking chlorine tablets into the well (our well is 750 feet deep), then let it sit for a few hours for them to dissolve. Then start pumping it, and make sure there is a very strong chlorine smell (it was overwhelming). Then pump it for a few hours (at 12 gpm), running the output of the well pump back into the well housing through the inspection port; this rinses the casing, removing an dirt stuck in there. Then flush about 3000 or 5000 gallons out of the well, until there is no more chlorine smell. Then draw the sample for the water test. I would guess that the procedure for a shallow well would be radically different.
Our well had been drilled, then left unused for a decade or more, then it failed the coliform test. No surprise here. We shocked it before house construction began, then it was used intermittently for two years, during construction. We did another water test before we moved in; we've been doing a yearly test in the eight years since. We've never seen E.coli or coliform since.
One more bit of advice. In a follow-up post you mentioned that you might install a UV sterilization system. We also considered it. problem 1: The bulbs don't last long, a year or so. Meaning you'll be checking and replacing them regularly. Problem 2: If you seriously have E.coli in your water, one trip through the UV doesn't give enough safety margin, and you need to fix the fundamenta. We were told that the UV filters only work at industrial strength systems; the ones you can buy for home systems are placebos for people with more money than sense. Also, if your well is anything like ours, you won't see coliform once the colony that's in there is shocked away, and you use water (flush the well) regularly. We were also told by the county S&H people that they never have problems with coliform, except for wells were the surface seals (the concrete pad at the top, and where the casing goes through that concrete pad, and the plumbing stuff at the top) are in disrepair and stuff can get it. For example: if your water has short grey hairs in it, a rat fell into the well casing, and you'll find coliform in the water (we heard the story from one of the county guys; people who work with wells and septic systems all day long have a weird sense of humor). Getting back to the UV system : I would test regularly, maybe add a cup of bleach to the holding tank regularly, and see how the coliform develops.
Thanks for your response, very helpful. I realize that the net is NOT a reliable source of info for such an important purchase. I did contact the ministry of health for instruction. I was curious as to what other thought and did in their situation. I appreciated you imput, especially the bit about the short grey hair. We lived in the country 15 years ago when the rules where not so strict. We hardly never tested the well, and when we did, did not worry much about the colliform, just the e-coli. That well was like a dug well, but only with a drilled well inside of it. Surface water could get into it, I even saw a frog in there once. Having that said, I know we can clean this 120 feet drilled well, I just wondered if the number 12 for coliform was not all that high for an usused well in which the water test was taken straight from a hose.
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