Homeowner ALERT ... !
Certain TOILET BALLCOCKS
may be dangerous to your
Are you UNNECESSARILY exposing your family to potentially harmful
bacteria and viruses?
All too frequently people who use a blue dye toilet tank freshener complain about "blue
their kitchen sink. Where did this "blue water" come from?
Even if you have never had this problem, you may unnecessarily be exposing yourself and
bacteria and viruses that could make you ill. Experts say that each time you flush your toilet, a
bit of sewer gas seeps into your toilet tank. To prevent sewer gas and the germs associated with it
from getting back into your drinking water, it is essential that the toilet ballcock you have installed
in your toilet tank be properly air-gapped from the water contained in your toilet tank.
An air gap is essential to prevent a cross-connection between your drinking water and the sewer!
Air gaps eliminate cross-connections between your drinking water and the contaminated water in
your toilet tank. Unfortunately, not all toilet ballcocks provide this essential air gap. If a cross-
connection exists, a small change in water pressure could allow this contaminated water to
to other water outlets in your house, including your kitchen sink. To prevent this type of backflow
from occurring, be sure to install a "plumbing-code approved" toilet ballcock.
This is a CORRECT Installation!
A "plumbing-code approved" toilet ballcock will prevent hazardous backflows if installed correctly.
The air inlet on the ballcock MUST be located above the water level maintained in the tank by the
float and the overflow pipe. Allowing the refill tube to fall down into the toilet tank creates a cross-connection!
It is important that the refill tube be attached to and properly air gapped above the over-flow pipe.
This installation is INCORRECT!
It creates a CROSS-CONNECTION!.
If you are not sure which toilet ballcock is safe to use, contact your local water utility, call your
plumber, or call the UF/TREEO Center at 352/392-9570.
If you have any additional questions or concerns, contact your local water utility company, call
your plumber, or call the University of Florida, TREEO Center.
The following UF/TREEO instructors can assist you with any question you might have about
backflow prevention and cross-connection control:
The Center for Training, Research and Education for Environmental Occupations, better
known by the acronym "TREEO",
has been conducting courses in cross-connection control and backflow prevention since 1979.
3900 SW 63 Blvd
Gainesville, FL 32608-3848
This document was prepared in 1990 by Robin Ritland and Les O'Brien for the University of
Florida, TREEO Center.
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