Besides turning the grass brown and drying
up lakes and streams drought conditions can cause other problems. So can heavy
rainfall. Although a well may have had no problems for many years, unusual weather
conditions can cause some wells to be contaminated with bacteria. On the other
hand, wells that have been contaminated by surface water may not show a problem
now, again, due to unusual weather conditions. This emphasizes the need for regular
testing of well water.
The basic test for bacterial contamination
is Total Coliform bacteria. Total Coliform is an indicator of the sanitary condition
of a water supply. Total Coliform includes bacteria that is found in soil, in
water that is on or near the surface of the ground, and in human or animal waste.
When Total Coliform is found in a private well supply, the
first step is usually to check the well for any physical defects. A broken or
missing well cap, or a well casing which is too close to the surface of the ground
or is located beneath the ground, can allow surface water, insects, and debris
to enter the well. If any of these conditions are found, they should be corrected
and the water should be retested.
A well may prove to be inviting
to insects, especially during dry conditions and high temperatures. Sometimes
when checking a well, there is evidence that insects are using the well casing
for a nesting area. When this is found, the problem can be controlled by covering
the top of the well casing with plastic screening and fastening it to the well
casing with a large screw clamp. This covering of screening will also prevent
small rodents such as mice and moles from entering the well. Mice have been known
to squeeze through a space as small as a coin slot. Since one-half inch or more
of space is found around the average well casing, mice and other rodents can easily
enter. Once they fall into the water, they may be disoriented and not be able
to find their way out. Finding rodent hairs in the faucet strainers is one clue
that rodents have entered the well.