You probably do have some sort of contamination of rainwater coming from the lines above your house, but I don't think that you need to be concerned about your drinking water, and hereís whyÖ When the rainwater
lands on the line, it spends some time sitting on it before it falls
onto your roof. While itís doing that, it picks up some contaminants.
These contaminants are not likely to be from the power line itself, but
could come from the insulation on the outside of the wires. (The water
is never in direct contact with the wires.) This is especially likely
if the rainwater in your area contains a lot of acid.
But why donít you need to worry about this impacting your drinking water? The reason is that you are actually seeing the stains. This tells you that whatever the water is picking up, itís not staying in
solution very well Ė instead, itís coming out of solution to stick to
your roof. Before rainwater reaches your well, it has to get through a
thick layer of the ground. In this case, the ground itself acts like a
filter. Anything that doesnít stay in solution extremely well is
filtered out. You know that the stuff coming off of the power line
insulation doesnít say in solution well, so it will be filtered out
before the water gets to the well.
Itís hard to say for sure, though, exactly whatís going on without
doing actual tests of your water. If youíre very concerned about this,
you can get in touch with a local water company or your area branch of
the EPA. They can help you to arrange to have your water professionally
tested for contamination.
(republished on 07/17/06)