It means that coliform bacteria was found in the well. Coliform bacteria
are not necessarily harmful, but a safe well should have no bacteria in it.
Coliform bacteria are a group of organisms that belong to a
large family or organisms that are found many places in nature. They are mostly
harmless, and they are found nearly everywhere on the surface of the ground.
Within the family of coliform organisms are a branch called fecal coliforms, or
e. coli organism. These are typically found in the
intestines of warm blooded animals. Most of these are not only harmless, but
they are necessary for digestion. But within this class of e.
coli organisms there are a few bad actors, such as e. coli O157:H7, which can
cause severe diarrhea and even death.
You don_t know. The lab can grow coliforms organisms (if
they are present in the water sample) rather easily and they can also tell of
there are e. coli organisms rather simply. Sickness
depends on a lot of factors, such as pathogenicity of the organism, the
relative health status of the person ingesting the water, and the dose, or
number of organisms consumed. The point here is that bacteria of any type
should not be able to get into your water supply. Here is a parallel story: If
you leave the door to your house unlocked, usually, nothing bad happens. Your
friends come and go and leave your possessions pretty much intact. However, it
could be that a burglar could also walk in with no trouble one day and steal
all of your stuff. Therefore, most people install locks on their doors to keep
everybody out. That_s pretty much the way it is with water wells. A well should
be constructed so that it excludes all bacteria because we
don_t know from one day to the next what kind of harmful biota can sneak in
there.
There are a variety of
reasons. Any or all of the following reasons could apply at the same time.
1.The well could be constructed improperly. The casing could be too short. Well casings must be a minimum of 25 feet deep in order to exclude bacteria, although this is not a magic number. Also, there could be a hole or a poor weld in the joints of the casing.
2.The well may have an
old "sanitary seal" on it. Modern or upgraded well casings stick
above the ground. Water is brought from the well into the house by a water line
that connects to a pitless adapter that is a fitting that is penetrates the
well casing just below the frost depth. If you can’t see you well, the upper
end of it may be buried below ground. If this is the case, it may be either in
a concrete vault or just buried with the upper end of it plugged off with
something called a sanitary seal. This is a misnomer of course, as the seal
doesn’t seal very well and permits water near the ground surface (where all the
coliforms live) to get into the well.
3.The well might be
drilled in a geologic formation that is not conducive to sealing out surface
bacteria. Poor geologic formations come mostly in the form of fractured
bedrock. Soil and glacial till are very good filters and bacteria killers.
Fractured bedrock offers very little, if any, resistance to the movement and
transport of pathogenic organisms. Septic systems that leach sewage effluent
into fractured bedrock can easily contaminate wells. And not just the owners
well. Sewage traveling in bedrock does not respect property boundaries.
4.The well may not have
been grouted during installation. Grout is a slurry material that is deposited
around the well casing. When it dries, it makes a seal between the well casing
and the surrounding soil. This affects mainly newer wells. Older wells will
seal themselves over time by the surrounding soil.
No. You may continue to use your private supply as long as
it safe. If it tests unsafe, the state private water systems rules state that
the health district can require you to make your water safe. If this happens,
the homeowner has a choice of spending more money on the well, or going with
the public supply.
It depends. You may keep your old well to use for
irrigation. It may not be connected in any way to the public supply. If you
chose to maintain your old well for irrigation purposes, it must be brought up
to current physical code, which means that it must have a pitless adapter
installed on it, if it doesn_t already have one. If you choose to
"deactivate" your old well, it must be properly abandon.
In order to properly abandon and old well, it must be
completely filled from bottom to top with cement, grout, or bentonite. A well
abandonment log form must be sent to the health department and to the Ohio Dept
of Natural Resources. A professional well driller best accomplishes this job.
No. Since an irrigation well is not
intended to be used for human consumption, it does not have to be safe.
There are several ways. If
you want to do a one-time disinfection, you can chlorinate your well with
common household bleach. Please see the chlorination instructions.<
There are two way to add permanent and continuous disinfection devices to your well. The first is adding an ultraviolet device, and the second is a continuous feed chlorination device. Both have their advantages and disadvantages. UV is less expensive, takes up little space and has low maintenance. The disadvantage is that it does not leave a residual chemical in the water so that you can test it. Continuous chlorination devices involve holding/mixing tanks, chemical crocks and a chorine feeder pump. It is relatively expensive, it takes up a considerable amount of space, and it is a high maintenance apparatus. These are jobs that best involve a registered water systems contractor.
We don_t have a real good
answer for this one. Wells that are modern and up to code and are drilled in
good geologic formations might be tested annually. If your well is old and
continuously tests unsafe, you will probably shock chlorinate until you get a
safe sample. This may lead one to a false sense of security, as the
contaminating influence might have been killed in the short run, but will be
re-introduced next week.
Public water supplies, depending on the size of the system, are tested every day at multiple points in the system. There would be no reason for a homeowner to test a public water supply. All many of tested parameters are available from your public water supplier. If it is bacteriologically unsafe, they must notify you, and issue the famous "boil order."
The health district takes
water samples on Monday Afternoons. Contact the Environmental Division at
740-333-3590 for details.
Many other tests are also available and the prices for each parameter vary. Sometimes we can refer you to a private lab for the more exotic tests. We can advise you on the advisability of taking certain tests, such as for nitrates or volatile organic compounds.