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The Three Evil Tee's
By David F. Walling
The purpose of this article is to clear up some misconceptions about trihalomethanes,
tetrachloeoethylene and trichloroethylene. My water treatment customers for years have
asked me about potential health risks of these three contaminants. It has always been a
challenge to explain to anyone the problems these contaminants add to point of use and
point of entry water treatment systems. Because two of them sound very similar and all of
them poses a serious threat to the health of this country. I believe that anyone who uses
tap water for drinking should know about the risks that are involved when they are exposed
to these contaminants. The EPA currently tracks some 80 different contaminants that may or
may not be found in the drinking water in the United States. As testing methods improve
than more stringent regulations may follow.
Trihalomethanes (THM)
This poses one of the largest threats to populations of people who reside in
municipalities that use primarily surface water treated with chlorine. Trihalomethanes
(THM's) are the byproducts of chlorine's use in treating drinking water, what is left of
the chlorine after it kills bacteria reacts with the dead organic content in the water.
Portions of the residual become trihalomethanes. Chloroform is the best known example.
THM's cause 10,000 cases of colon and bladder cancer annually. The chlorine industry
strenuously opposes closer regulation of THM's. The detected increases of THM's presence
in numerous large-scale water treatment systems have sparked the use of chlorimine for
disinfecting. Chlorimines residual does not react with the remaining dead organic content
like chlorine. The result is less THM's present in the finished drinking water. One
drawback to the use of chlorimine is that it needs a longer contact time with granular
activated carbon (GAC) filters to be removed from the water. This posed a huge problem to
the kidney dialysis industry that uses treated tap water for process makeup water. Because
many facilities would use water treated with GAC filtration sized for chlorine removal.
The longer contact time for the removal chlorimine required resizing of pretreatment.
Tetrachloroethylene (PCE)
This is used primarily in the textile industry, and as a component of aerosol dry-cleaning
products. Major releases of tetrachloroethylene to air and water are from dry cleaning and
industrial metal cleaning or finishing. Water pollution can occur from tetrachloroethylene
penetrating the walls of some types of pipelines used for water distribution. From 1987 to
1993, according to EPA's Toxic Chemical Release Inventory, tetrachloroethylene releases to
land and water totaled over 1 million lbs. These releases were primarily from the alkali
and chlorine industries that use it to make other chemicals. The largest releases occurred
in Louisiana and South Carolina. PCE released to soil will readily evaporate or may leach
slowly to the groundwater where the break down by soil microbes is slow. PCE released to
water will primarily evaporate and has little potential for accumulating in aquatic life.
Continued exposure over many years could leave you with liver damage and you may have an
increased risk of getting cancer. Granular activated carbon filters will absorb
tetrachloroethylene but you should follow the manufacturer recommended service intervals
for the filter. Follow up with testing to make sure the filter you have is doing a good
job of absorbing the contaminant. The list of trade names given below may help you find
out whether you are using this chemical at home or at work. Here is a list of trade names
and synonyms: Ethylene tetrachloride Perchloroethylene PCE Ankilostin Didakene Fedal-un
Nema Perclene Persec Tetlen Tetracap Tetraleno Tetropil Antisal 1 Dow-per Perawin Perchlor
Percosolv Perk Perklone Tetraguer Tetralex Tetravec
Trichloroethylene (TCE)
The greatest use of trichloroethylene is to remove grease from fabricated metal parts.
Major environmental releases of trichloroethylene are due to air emissions from metal
degreasing plants. Wastewater from metal finishing, paint and ink formulation,
electrical/electronic components, and rubber processing industries also may contain
trichloroethylene. Production of trichloroethylene has increased from just over 260,000
lbs. in 1981 to 320 million lbs. in 1991. From 1987 to 1993, according to the Toxins
Release Inventory, trichloroethylene releases to water and land totaled over 291,000 lbs.
These releases were primarily from the steel pipe and tube manufacturing industries. The
largest releases occurred in Pennsylvania and Illinois. The largest direct releases to
water occurred in West Virginia. Water treatment dealers in several states report few
calls regarding the contaminant. However, TCE has been detected at levels higher than the
US Environmental Protection Agency (EPA) standard of 5 parts per billion (ppb) in 25
states since 1988. If released to water, it will quickly evaporate. It has only a moderate
potential to accumulate in aquatic life. Trichloroethylene released to soil will either
evaporate or leach into ground water. People who drink water containing trichloroethylene
over many years could experience problems with their liver and may have an increased risk
of getting cancer. Granular activated carbon filters will absorb trichloroethylene but you
should follow the manufacturer recommended service intervals for the filter. Follow up
with testing to make sure the filter you have is doing a good job of absorbing the
contaminant. Here is a list of trade names given below may help you find out whether you
are using this chemical at home or work. Here is a list of trade names and synonyms:
1,1,2-Trichloroethylene Acetylene trichloroethylene Algylen Anameth Benzinol Chlorilen
CirCosolv Germalgene Lethurin Perm-a-chlor Petzinol Philex TRI-Plus M Vitran
It is not dificult to find out about contamination in your area just go to your local
library and do an article search of your local newspaper. Use the contaminants in this
article as the keywords. You can also call your city water treatment facility and ask to
see a currant water analysis. If you are concerned that these contaminants are in your
drinking water than I would suggest getting your water at home tested for these
contaminants immediately. One such water testing company can be found on the internet at h2otest.com/index.html after you get your results you can go out and find the best treatment
method that suites your particular water treatment problem. Technology is on your side but
you should educate yourself about the tap water in your area this will help you in your
decision.
For more information, please contact R/O CONN
at (602) 432-5402 or fax (602) 942-1451.
Or you can E-mail us at roinfo@roconn.com.
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Copyright © 1998 R/O CONN. All Rights Reserved
U.S. Patent # 5,660,720
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