A cross connection is a link which allows the
potable (drinking) water supply to be connected to
a line which contains a contaminant. People just
automatically assume the water is safe but that
could be a big mistake.
Contamination occurs through cross connections
where fluids other than water are sucked into the
potable water supply due to a drop in line
pressure. Unavoidable water line breakages,
improper fire hydrant usage, and fire fighting
often result in pressure reversal creating a back
siphonage condition. Here is a true case of what
can happen:
A California homeowner was using an aspirator,
attached to a garden hose, to spray a weed killer
containing arsenic. While he was at the job, the
water pressure reversed. He disconnected the
hose and feeling thirsty, drank from the faucet at
the house. Arsenic in the water line killed him.
A $10 house bibb vacuum breaker, which screws
on the outside connection, would have prevented
this. Hoses should never be submerged but some
farmers still fill tanks with pesticides using a hose
submerged in the tank, which creates a physical
connection between our drinking water and a
deadly substance. Nearly all swimming pool
owners are guilty of filling their pools by this
method. Some other cross connections are supply
lines connected to bottom-fed tanks and supply
lines going to boilers.
The City of South Pittsburg has passed an
ordinance and a policy, for our customers
protection, prohibiting cross connections. We
need the full cooperation of industries, businesses,
and the entire community, so that we don't have a
disaster like the one above.
