What
is a cross connection?
A cross connection is a direct arrangement of a piping line which allows
the potable water supply to be connected to a line which contains a
contaminant. An example is the common garden hose attached to a sill
cock with the end of the hose lying in a cesspool. Other examples are
a garden hose attached to a service sink with the end of the hose submerged
in a tub full of detergent, supply lines connected to bottom-fed tanks,
supply lines to boilers.
What
is the most common form of a cross connection?
Ironically, the ordinary garden hose is the most common offender as
it can be easily connected to the potable water supply and used for
a variety of potentially dangerous applications.
What
is a cross connection control program?
This is a combined cooperative effort between plumbing and health officials,
waterworks companies, property owners and certified testers to establish
and administer guidelines for controlling cross connections and implementing
means to ensure their enforcement so that the public potable water supply
will be protected both in the city main and within buildings. The elements
of a program define the type of protection required and responsibility
for the administration and enforcement. Other elements ensure continuing
education programs.
What
is the difference between pollution and contamination?
Pollution of the water supply does not constitute an actual health hazard,
although the quality of the water is impaired with respect to taste,
odor or utility. Contamination of the water supply, however, does constitute
an actual health hazard in which the consumer is subjected to potentially
lethal water borne disease or illness.
What
is meant by “Degree of Hazard?”
The degree of hazard is a commonly used phrase referring to cross connection
programs, and is simply a determination on whether the substance in
the non-potable system is toxic (health hazard) or non-toxic (non-health
hazard).
What
is the difference between a toxic and a non-toxic substance?
A toxic substance is any liquid, solid or gas which, when introduced
into the water supply, creates or may create a danger to the health
and well being of the consumer. An example is treated boiler water.
A non-toxic substance is any substance that may create a non-health
hazard, is a nuisance or is aesthetically objectionable. Examples of
non-toxic substances are foodstuffs such as sugar, soda pop, etc. Therefore,
you must select the proper device according to the type of connection
and degree of hazard.
Are
there any regulations in OSHA regarding cross connections?
Yes, OSHA requires that no cross connection be allowed in an installation
unless it is properly protected with an approved backflow preventer.
These requirements are also covered in B.O.C.A., Southern Standard Building
Code, Uniform Plumbing Code and City, State and Federal Regulations.
--Excerpt
from Watts Industries, Inc. public service booklet 50 Cross-Connection
Questions, Answers, & Illustrations. © Watts Regulator
Co., 1997 |
