-
The water report that I received from UHL indicates that
total coliform bacteria are at unsafe levels in my
water. Now what do I do?
- What
should I test my water for?
-
How do you convert mg/L (milligrams per liter) to ppm
(parts per million)?
-
What is the infant health advisory limit for nitrate? Is
it safe for adults?
- Are iron
bacteria harmful?
-
How do I convert gpg (grains per gallon) into mg/L (milligrams per
liter)?
-
What's that white stuff in my collection
bottle?
-
What is the unsafe level of nitrate for adults?
-
Where should I collect the water sample?
-
My sample has total coliform bacteria. Will I get
sick?
-
How long does it take to get water test results
back?
-
My water smells and looks funny. Does that make it
harmful?
-
I want to test for everything bad in my water. Can you
do that and how much will it cost?
-
I think my water is making my livestock sick. Can you
test the water for this?
-
My water has a very bad odor - like rotten eggs. Is
it safe to drink? How can I get rid
of the odor?
-
If I add chlorine to my water, will it be safe to
drink?
-
I have a family member with giardia; can you test for
this?
-
What's a "chloroform?"
-
I know I shouldn't drink bacterially unsafe water, but
can I wash my dishes, take a shower, and brush my teeth
with this water?
Q : The water report that I
received from UHL indicates that total coliform bacteria are at
unsafe levels in my water. Now what do I do?
A :
Simple mistakes can often mean the difference between
an accurate sample and an inaccurate one. For example, inadvertently
touching the rim of the collection bottle with your hand or not properly
flushing the water line can result in an "unsafe" reading, even though
your water may be perfectly safe.
If you think that you made a sampling mistake that compromised the
accuracy of your test results, review the
sampling instructions,
and resubmit a sample of your water.
If you are sure that you took the sample correctly and the sample is
truly representative of the health of your water, it is important to
determine how and where the total coliform bacteria got in the water
system. Usually such contamination results from a structural defect
either at the well or someplace in the distribution system.
At this point, you have two choices: take additional samples at
strategic locations (i.e. at the well head; before and after water
treatment devices) or contact your
county sanitarian to complete
a sanitary survey on your well and distribution system.
Work with a reliable, competent water treatment dealer to select the
treatment method best for your situation. Shock chlorinating your well
is also recommended.
Two or three days after completing treatment, take another sample and
submit it to UHL to ensure that the treatment is effective and your
water is safe.
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Q : What should I test my water for?
A :
If you are concerned about the general health and
safety of your water, then UHL recommends testing for total coliform
bacteria and nitrate - the two most common contaminants that Iowans are
likely to find in their water.
However, if there was a nearby
pesticide spill or other event that may have caused a contaminant to get
into your water, then request a test for that specific contaminant.
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Q : How do you
convert mg/L (milligrams per liter) to ppm (parts per million)?
A :
We can use them interchangeably for well water measurements: 1mg/L = 1ppm.
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Q : What is the
infant health advisory limit for nitrate? Is it safe for adults?
A :
The infant health advisory or MCL (maximum contaminant
level) established by the Environmental Protection Agency is 10mg/L (as
N) or 45mg/L (as NO3). An infant consuming high levels of nitrate may
develop methemoglobinemia, also referred to as blue baby syndrome.
Ingesting high levels of nitrates will not cause methemoglobinemia in
adults.
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Q : Are iron bacteria harmful?
A :
Iron bacteria are common organisms found in groundwater. These
organisms do not pose a health threat, but they are considered nuisance
organisms because they can cause taste, odor, and/or staining.
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Q : How do I convert gpg (grains per gallon) into mg/L (milligrams per liter)?
A :
Generally, mg/L is used by the scientific community and gpg is used
by the water treatment industry. The conversion formula is: 1 gpg = 17.1
mg/L.
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Q : What's that white stuff in my collection bottle?
A :
The "white stuff" found in some coliform sampling bottles is sodium
thiosulfate, a chlorine neutralizing chemical that inactivates chlorine
so that a valid total coliform bacteria test can be obtained. The sodium
thiosulfate should NOT be rinsed from the bottle even if there is no
chlorine residual in the system.
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Q : What is the unsafe level of nitrate for adults?
A :
The effect of nitrate on adults is unclear and no unsafe level has been
established. However, high levels of nitrates have been linked to
certain types of cancer in adults although there has been no definitive
cause and effect established.
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Q : Where should I collect the water sample?
A :
Where you collect your water sample depends on your purpose for testing.
Generally speaking, the sample should be taken from the faucet that is
most frequently used for drinking purposes.
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Q : My sample has total coliform bacteria. Will I get sick?
A :
Not necessarily.
By themselves, total coliform bacteria are not a health problem.
However, the presence of coliform implies that the system has been
compromised and harmful organisms may already be present or have the
opportunity to enter the system.
Since it is impossible to test for the presence of all possible harmful
microorganisms, if coliforms are found in the drinking water, the water
should be considered unsafe for human consumption and corrective
measures taken.
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Q : How long does it take to get water test results back?
A :
Your results should be back within a week after you submit your water
sample.
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Q : My water smells and looks funny. Does that make it harmful?
A :
Just because water has an off taste or is discolored does not always
mean that the water is unsafe for human consumption. There are naturally
occurring bacteria and chemicals that can cause taste and odors that
aren't harmful to you.
However, if you are concerned about the safety of your water, test
for total coliform bacteria and nitrate to determine if the supply is
contaminated.
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Q : I want to test for everything
bad in my water. Can you do that and how much will it cost?
A :
Testing for EVERY possible contaminant in water is not only
cost-prohibitive but also usually unnecessary. If you are concerned
about the safety of your water, the best approach to take is to limit
the testing to reasonable contaminants. UHL recommends testing for total
coliform bacteria and nitrate, which are good indicators of water
quality. However, if you are aware of a nearby chemical spill or that a
chemical was accidentally back-siphoned into your well, be sure to
request a test for the specific contaminant.
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Q : I think my water is making my
livestock sick. Can you test the water for this?
A :
If you are concerned that your livestock's health is at-risk, consult
your veterinarian. S/he can determine if the illness is linked to the
water or some other source. If it is determined that the cause for your
animal's illness is linked to the water supply, then UHL will test for
the specific contaminant recommended by your veterinarian.
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Q : My water has a very bad
odor - like rotten eggs. Is it safe to drink? How can I get rid of the
odor?
A :
Rotten egg odor is usually due to the presence of
hydrogen sulfide . This contaminant can
cause taste and odor problems in water, but the presence of hydrogen
sulfide are not a health threat.
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Q :
If I add chlorine to my water, will it be safe to
drink?
A :
Prior to chlorination, any defects that allow total coliform bacteria to
enter your water distribution system should be fixed.
To treat a total coliform bacteria problem with shock
chlorination, you must have both an adequate amount of chlorine and an
adequate amount of contact time (between the water and the chlorine) to
destroy the microorganisms.
If that is accomplished, then the well water should be
safe for human consumption. However, those who shock chlorinate need to
be sure to purge their water faucets until there is no detectable taste
or smell of chlorine. Any residual chlorine or chlorine by-products can
be removed by using an activated carbon filter.
Chlorination may eliminate bacteria, but will not
eliminate other contaminants that may be present.
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Q :
I have a family member with giardia; can you test for this?
A :
Collecting and testing specifically for giardia is difficult and
therefore drinking water is screened for the possible presence of
giardia (or other parasites) by first testing for total coliform
bacteria.
If the drinking water is free of total coliform
bacteria, then it is extremely unlikely that giardia is present and no
further testing is necessary. However, if total coliform bacteria are
detected, consult UHL for additional
guidance.
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Q : What's a "chloroform?"
A :
"Chloroform" is a common way that coliform is incorrectly pronounced. It
is also a chemical that can be found in drinking water as a byproduct of
the chlorination process.
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Q : I know I shouldn't drink
bacterially unsafe water, but can I wash my dishes, take a shower, and
brush my teeth with this water?
A :
There is some risk in using bacterially unsafe water for any of these
activities. To ensure your safety, use water that falls within the
limits of the MCLs (maximum contaminant levels).
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