Chlorine produces bacteria-free water and eliminates algae
and slime. It also removes hydrogen sulfide from ground water (wells and
springs) and eliminates iron bacteria (cenothrix), which are associated with
objectionable odor and taste.
Despite these important facts, some people still object to
chlorine in their drinking water. Comments such as “I don’t like the way chlorine makes my water taste” are common.
The bad taste actually is due to an insufficient residual or
the lack of chlorine in their water. If you can smell or taste chlorine in your
drinking water, there isn’t enough chlorine residual in it.1 The proper
dosage of chlorine to maintain the required minimum residual of
“free” chlorine is the important key. If the residual falls below
the “free” minimum, the reforming of chlororganics and chloramines
(the taste and odor producing part of the disinfection process) takes place as
a result of increased contamination (chlorine demand). The increased levels can
be a result of a main break, cross connection, increased bacteria growth from a
dead-end line or a combination of all of these. (There are other possibilities as well.)
There are some who favor switching to bottled water to avoid
drinking chlorinated water. Consumers may be startled to learn that there may
be some brands of bottled water that contain cancer-causing chemicals in
amounts that exceed federal standards. If these chemicals are found in bottled
water, there are no regulations that require the public to be notified. The
Kansas Department of Health and Environment conducted a study of 80 bottled
water samples that were collected from retail stores and manufacturers between
March 21 and May 22 of 1994. In 15 percent of the bottled water, cancer-causing
chemicals were discovered. Nine contaminants were found in amounts that exceed
federal limits. The results weren’t made public until 14 months later.2
When the same type of tests is given to a municipal or rural
water district producing potable drinking water, the public must be informed
immediately of any contaminants found in excess of the U.S. Environmental
Protection Agency’s limits. The water district then would be tested on a
more frequent basis. The customers in the affected district are encouraged to
drink bottled water but the bottled water also may be contaminated.2
Many bottled water brands begin as tap water from a public
water system with the chlorine residual removed. After this, it is given a
two-year or more shelf life. There are little or no restrictions on the
environment in which the water is stored.
The complete elimination of deadly diseases such as cholera,
typhoid and others now is taken for granted. These eliminations can in part be
attributed to the effectiveness of chlorinated water. Some people comment that
they would rather wait until something happens and they are ordered to
disinfect instead of taking preventative measures. The deaths in Walkerton,
Ontario, Canada, in June 2000, were caused by E. coli as a result of run-off
from a cattle ranch. No preventative measures had been taken and several lives
were lost. A good thing to keep in mind is what goes in the ground today is
what you will drink tomorrow. Isn’t that reason enough to see a need for
disinfection?
Chlorine has been available since the early 1900s and has
overwhelmingly proved its effectiveness since that time. Chlorine is as
important to pure water as the polio vaccine has been to the public health.
Chlorination is used for taste and odor control, water main
sterilization, algae and slime control, hydrogen sulfide removal, iron and
manganese, cooling towers, low pressure drip irrigation systems and poultry
drinking/processing water to name a few uses.
Water quality can be obtained by many forms of processes and
alternative means of disinfection. However, a minimum residual level of the
disinfectant has to be provided at the furthest distance from the injection
point. So far chlorine is the only disinfectant approved that provides this
required measurable residual amount. Clean, efficient, pure 100 percent
chlorine is available only in gaseous form, and it has the safest accident
record. Calcium hypochlorite at 65 percent and sodium hypochlorite containing
10 to 15 percent available chlorine are perceived as being safer. However,
their easy-to-use containers allow for accidents and the possibility of
allowing contamination even during the manufacturing process.
Chlorine in drinking water is mandatory in most states. In
those where it is not, it is important to remember the benefits, cost effectiveness and safety record of chlorine gas (the purest form of chlorine) when fed through an all vacuum mounted chlorinator.
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