 Drinking Water Sources:
| The geographic region where people live
is an important contributing factor to both the quality and availability
of fresh water. You might be interested in viewing
Globalis, a fascinating interactive
world map on the web which highlights the similarities and
differences between the countries of this world and, in addition to many
other comparisons, provides a map of water quality in different regions of the
world (on the left select Category 'Water' and the
indicator, 'Access to safe water' - the map can be zoomed to region and
the 'show ranking' option lists countries by access to safe water).
Another interesting article from The
Why Files takes a look at water availability in different regions of the
world. Every
one who is able to turn on a faucet and expect to fill their glass with
clean, safe water should visit the Peace Corps'
Water
in Africa site. |
 |
Detour to a brief discussion about
fresh water abundance, surface
water, and ground water. |
If you are provided with municipal water, the responsibility
for your safe drinking water lies with the water provider.
 |
Although water companies in the
US and many other countries are strictly regulated and the treated water must
meet certain minimum purity and safety standards, all water companies are not
created equal. You can reasonably assume that most are doing the best they
can with the resources available to them - if for no other reason than to keep their
name out of the evening news.
|
|
|
In general, though, the larger water
companies (in the US anyway) have greater resources available to treat and distribute the
water and maintain the distribution infrastructure. And,
because they serve more people, they are required to meet stricter regulations. |
|
|
Do you
receive and read water quality reports sent out by your water provider?
|
|
The EPA has a site, Water
Where You Live, that enables you to obtain information about specific water
treatment companies in the U.S. After you click on your state, click on
the "Drinking Water" link about 5 down from the top. If your
water company has an on-line quality report, you can read it. You can also
locate information about water companies by county.
|
|
|
The Safe Drinking Water Act of 1996 mandated that public
water companies were to prepare annual water quality reports and make them
available to all customers. |
|
|
The Campaign for Safe and
Affordable Drinking Water (CSADW)
maintains a site that describes water
quality reports and discusses how to interpret them. The National
Environmental Education & Training Foundation (NEETF) also maintains a site
that describes how to interpret
water quality reports. A PDF file, Drinking
Water Quality Reports also has valuable information.
|
|
Some information for well
owners or people who use surface water for drinking. People with
private water supplies are responsible for the safety of their own drinking
water. While all wells, springs, and surface water should be tested
regularly, there are some situations where it is critical to know what is in
your water:
|
|
If you use surface water or water
from an unconfined aquifer and have any sources of pollution nearby, you are at
risk for contaminated water. |
|
|
If you or members of your
family are at higher risk of health problems from contaminants, you should
know what is in your water. |
|
|
If the quality of your
water suddenly changes - new taste |
 |
The depth of a well is
not usually as important as the type of aquifer from which the well draws.
In general,
well water from an unconfined aquifer is much more prone to contamination than
water from a confined
aquifer. Click here to
learn more about aquifers and the contaminant risks associated with each
type. For the teachers who are visiting: I discovered what
appears to be a very interesting groundwater
model that demonstrates confined and unconfined aquifers, how water and contaminants move through
aquifers, various soil structures, and watersheds.
|
Poorly designed or maintained
septic systems are a
potential source
of contamination for wells or springs mostly in unconfined aquifers. The most common contaminants from septic systems tend to be
E.
coli and nitrates, but if other chemicals are flushed into the septic
system by you or your neighbors,
they can become part of the ground or surface water pollutants as well.
The site, Well Water
& Drinking Water Help Links, contains a number of links to other sites
with information for the well owner.
Water
Testing:
If you
use municipal water you should be able to obtain a water quality report yearly
and, except for special circumstances, would probably not need to test your
water. If you use well, spring, or surface water, it is important to test your
water periodically for contaminants liable to be present in your water.
As discussed above, water quality from a water source can change over time -
particularly in surface water or shallow, unconfined aquifers. The University of Tennessee Agricultural
Extension Service article, Safety
of Private Water Supplies, has important suggestions and information about
testing for the safety of your well water. |
Where
You Live:
Home
Located in an Agricultural Area:
Farms can have many potential
sources of pollution for the underlying water, including: manure lagoon, feedlot
/ barn, septic system, earthen silage pit, fuel storage tank, chemical storage
area, chemical mixing area, dump or landfill, and fields on which fertilizers or
pesticides have been applied. For more information on farm wells, go to: Well
Water Location & Condition on the Farm. In
addition to the health effects of nitrates on children, discussed above,
nitrates in drinking water have also been associated with an increased
risk for Non-Hodgkin lymphoma. |
Chlorinated Water and the Risk of Disinfection Byproducts:
Is
your water Chlorinated?
|
|
Most municipal water treatment plants use chlorine
to disinfect the water before it leaves the treatment plant and/or keep
the water biologically safe during the distribution process. Many well
users also use chlorine to disinfect their water.
|
|
|
Chlorine, while an excellent disinfectant, reacts with
organic material in the source water to produce a group of chlorinated
organic compounds collectively known as Disinfection Byproduct (DBPs).
According to several EPA
articles: |
"While
disinfectants are effective in controlling many microorganisms, they react with
natural organic and inorganic matter in source water and distribution systems to
form DBPs. Results from toxicology studies have shown several DBPs to be
carcinogenic in laboratory animals. Other DBPs have also been shown to cause
adverse reproductive or developmental effects in laboratory animals. Several
epidemiology studies have suggested a weak association between certain cancers
(e.g., bladder) or reproductive and developmental effects, and exposure to
chlorinated surface water. More than 200 million people consume water that has
been disinfected. Because of the large population exposed, health risks
associated with DBPs, even if small, need to be taken seriously."
|
In general, the levels of DBPs are
highest in treated water from sources with high organic matter content, such
as rivers and lakes, and lowest when the source is groundwater. Within a
single water supply, however, DBP levels can vary greatly, depending on both
water quality and treatment conditions (this is an informative article on Chlorinated
Disinfection By-Products).
The DBPs include Total Trihalomethanes (TTHMs)
(including chloroform, bromodichloromethane, dibromochloromethane, and
bromoform), and Haloacetic Acids (HAAs) (dichloroacetic acid
and trichloroacetic acid)
|
|
In 1979, the EPA set an interim Maximum
Contaminant Level (MCL) for TTHMs of 0.10 mg/l (or 100 microgram/l) as an
annual average. This applies to any community water system serving at least
10,000 people that adds a disinfectant to the drinking water during any part
of the treatment process. By 2002 the MCL for TTHMS will be lowered to
0.08mg/l (or 80 ug/l) and a MCL for HAAs will be set at 0.06mg/l
|
|
|
In epidemiological studies, investigators
compare health effects in a population of people who drink water containing
higher levels of DBS with a similar group of people who drink water with
lower levels of DPS. According to some
estimates, anywhere between two and seventeen percent of all bladder
cancer cases in the U.S. may be due to DBPs. It is a tough
balancing act between adding too little chlorine (resulting in more
microbial contaminants and fewer DBPs), and too much chlorine (resulting in
dead microbes and higher levels of DBPs).
|
|
|
A 1996
study by King and Marrett concluded "that the risk of bladder
cancer increases with both duration and concentration of exposure to
chlorination by-products". They found that those exposed to
chlorinated surface water for 35 or more years had a 1.4 times increased
risk of bladder cancer compared with those exposed for less than 10 years,
and those exposed to an estimated THM level greater than 49
micrograms/liter for 35 or more years had 1.63 times the risk of those
exposed for less than 10 years.
|
|
Populations At Greater Risk from Water Contaminants:
Pregnant
Women, Children, Elderly, Immunocompromised
|
Any person who requires water of a specific
microbiological purity should follow the advice of their doctor or
local health officials regarding the use and consumption of tap
water treated by ANY purification system.
|
Home
Age and the Risk of Lead Contamination:
The
age of your home can be an important indicator of
whether lead might be a
contaminant in your drinking water.
Lead is a serious threat to human health and can adversely
affect almost every
organ in the human body.
Lead contamination usually occurs in
the home as water dissolves lead from
household plumbing made with lead
containing materials. Even many "lead-free
fixtures still contain
some lead.
More likely than not, water in buildings less than five years old or that were
built
before about 1987 have some levels of lead contamination (In the US,
anyway - I
suspect risks are similar in other countries, but check).
Boiling the water will not
reduce the amount of lead.
Young children and
pregnant women have the greatest risk from even short term
lead exposure.
An adequate calcium intake can help protect
against lead poisoning - but that is
NOT a substitute for lead reducing methods
discussed below.
|
|
Indicators for high lead content in your drinking
water
Lead levels in your drinking
water are likely to be highest if:
your home has faucets or fittings of brass which
contains some lead, or
your home or water system has lead pipes, or
your home has copper pipes with lead solder, and
the
house is less than five years old, or
you
have naturally soft water, or
your water is acidic,
(pH below 7), or
water
often sits in the pipes for several hours, or
you
use hot water from the tap to make formula or drinks
you
regularly notice blue/green stains on sinks, tubs, and fixtures (this
is probably copper, but it is an indication of corrosive water which will
also dissolve lead).
|
|
Check for lead water pipes
Inside your home - Locate
the pipe leading to the kitchen tap, and follow it
as far as possible until it
exits your home.
Unpainted lead pipes are dull
gray
and
soft.
If you scrape the surface gently with a knife, you will see
the shiny, silver-colored
metal beneath.
If possible, the supply line
from the water main to your home - Try to find
a place where the supply
line is accessible (water meter for example) and
check for indications of
lead pipe.
Other types of pipe in use
Copper - bright copper-brown
color may have silver colored metal around
the
soldered joints - the solder may contain lead.
Iron/Steel - black, may be
rusty, and is quite hard. The
pipe may have a
shinny
galvanized coating.
Plastic - may be white, blue,
gray, black, etc. Lead compounds may
also be
present in some plastic plumbing components. Lead may be
used in
the manufacture of the plastic plumbing products as a
plasticizer. Plastic plumbing components that are certified by the NSF
International do not contain lead. Plastic materials certified by NSF are
recommended for potable water plumbing applications.
Plumbing
components made of bronze and brass contain 3% to 8% lead.
Ace
Hardware Guide to Water Pipes
|
|
If your drinking water has
not been tested for lead, or if it does
contain lead, seriously consider taking
the following precautions.
|
|
Install one of the several treatment methods that are effective at
removing lead. |
|
|
If the water has not been used in a particular faucet for six
hours or longer, run the cold water tap until the water is
noticeably colder, about a minute, to "flush" the pipes. |
|
|
Use only cold water
from the tap for drinking, cooking, and especially
making
baby formula. Hot water dissolves materials better than cold water
and thus may contain higher levels of lead. |
|
|
Frequently clean the screens and aerators in faucets to remove
captured lead particles. |
|
|
If building or remodeling, only use "lead free" piping
and materials for plumbing. Still, as noted above, even "lead free"
brass fixtures probably have traces of lead in them. |
|
|
If you are served by a public water system contact your supplier
and ask whether or not the supply system contains lead piping, and
whether your water is corrosive. If either answer is yes, ask what
steps the supplier is taking to deal with the problem of lead
contamination.
|
One indication that your water is corrosive (if you have copper
pipes) is that you may notice blue/green
stains in tubs, sinks, and
around faucets. If your water is dissolving copper, and if
there is
lead in the pipes, solder, or fixtures, there is a good chance your
water
is also dissolving lead!
Click
here to view more information about lead contamination in
drinking water.
Note:
Drinking water is estimated to contribute only 10 to 20 percent of the total
lead exposure in young children. Make certain you are informed about all of
the risks for lead exposure. You can obtain more information about lead
exposure from drinking water or other sources at this EPA
document. Lead
In Your Home: Parent's Reference Guide is a comprehensive, 67 page EPA
document (in PDF format) for parents who already know their children are at
risk of lead exposure.
|
Contaminants and
Sensory Clues:
Great looking, smelling, and tasting water is no guarantee that you have
safe water!
Many contaminants, lead, mercury, E. coli, disinfection
byproducts - in fact
the majority of the harmful contaminants listed
below - have no taste
or smell, nor would they be visible in harmful
quantities.
Click
here to view more information about water safety and well testing.
|
|
If your water normally looks, tastes, and smells
good and then suddenly becomes cloudy (turbid) or acquires a bad smell or taste it
may be an indicator that the purification process has failed. Immediately
begin using water filtered with a high quality filter, bottled water, or otherwise purified water until you have determined that your water is safe.
That would also be a very good time to consider looking for a permanent
water treatment solution.
|
|
|
Color
Blue to Blue-green
Cloudy, or Milky
Reddish - orange
Dark brown to Black
Yellow
Deposits,
Spots, & Sediment
Soap scum
Bathtub rings
Scaly, whitish
deposit
Spots on clothing
Spots on dishes
Spotting, mottling, of
teeth
Red - brown slime
Black - brown slime
Reddish - brown
sediment
Grittiness,
abrasiveness |
Staining
Blue-green stains
Brown-red stains
Black stains
Blackening and
pitting of metal
sinks and fixtures
Gray stains
Yellow stains
Taste
Alkaline
Metallic
Salty, brackish
Sharp chemical Alkaline
Metallic
Salty, brackish
Sharp chemical |
Odor
Chlorine
Detergent
Sweet, perfume
Fishy
Rotten eggs
Oil or gas
Sewage
Musty, earthy |
Have you ever been told that your household water is unsafe and to
either boil your water before drinking it or to drink bottled water until the
problem has been corrected?
Have you or a member of your family ever become ill from your home
drinking water?
|
If you
answer "yes" to either question, it would probably be a good
idea to invest in a high quality water treatment system. According to
the National Primary Drinking Water Regulations: Public
Notification Rule; Final Rule, Section 1414(c)(2)(C),
The EPA regulations "require Public Water
Services to distribute a notice within 24 hours to persons served for
violations with potential to have serious adverse effects on human
health from short-term exposure". Considerable exposure to the contaminant
can occur during that period. |
Table of
Contaminants and Treatment Methods
|
Comparison of Drinking Water
Treatment Methods
I developed a Comparison
Table listing different drinking water treatment technologies and
the contaminants they remove to make it easier for you to determine
which process, or combination of processes will be best for your
particular drinking water situation.
If
this table is too large for your screen, I have
broken it into two separate tables, one
covering the biological
and organic
contaminants,
and the other covering the
inorganic contaminants.
They should be
easier to read on monitors set at 800 X 600.
I also developed another
table that shows similar water treatment information in a somewhat
different format that you might want to take a look at. This
table is geared mostly to point of use water treatment methods.
The Water
Quality Association (WQA) also has a Table
of Water Contaminants, their health effects, and removal methods
|
| Please be
advised that the information on this page and on this site is for
general educational information only and is NOT intended to make any
specific health claims or recommend any specific treatment method or
preventative advice for any health issue or problem. Consult
your physician or a health specialist for specific steps to take for
your specific health requirements! |
      
 
Copyright © 2005 Randy Johnson. All rights reserved.
|
Introduction
