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How to Take Samples—Water
Remember, analysis is based solely on the sample provided.
Improper sampling will result in misrepresentation of values.
General Sampling Instructions
For most water tests, follow these steps when collecting
a sample. Take the sample close to the pump, before the water
goes through a treatment system (unless testing the treatment
system). Run the pump for approximately 2-3 minutes. Removed
the screen or aerator from the faucet. Allow the water to run
approximately 5 minutes to clear the line. Take the sample midstream
of the sample flow. Do not touch the inside of the collection
bottle, the opening or inside of the cap. Fill the sample bottle
to the neck and cap tightly. Sample bottles not properly filled
will not be analyzed. Samples should be received in the laboratory
with a temperature of 6°C (43°F) or below by Minnesota Department
of Health standards. Samples received above that will have the
temperature on the report flagged as such.
How to Collect a Drinking Water Sample for Bacterial
Analysis
Your sample bottle (height of 4") has been sterilized. For
accurate testing, it is important to keep it free from contamination.
If you accidentally contaminate it, please return it for another
sterile bottle. Do not boil the bottle or put anything inside
it except your sample. Select an outside faucet if testing the
well. If testing household piping, select a faucet from a kitchen
or utility sink. Bathroom faucets are not recommended. Remove
any filter or screen from the tap. Disinfect the faucet with
bleach or a flame before taking the sample. Outside faucets
may also be flamed with a hand-held torch if they are not made
of plastic or rubber. Turn on the cold water and let it run
for at least 5-10 minutes. Adjust the water to produce an even
flow. Remove the cap from the sample bottle. Do not
set the cap down or touch the inside of the cap or bottle.
Fill the sample bottle to the neck only. Do
not let the faucet touch the mouth of the bottle. Carefully
re-cap the bottle and immediately mail or deliver the sample.
Certified samples must be analyzed within 24 hours of the time
you took the sample. Both Colilert and Membrane methods are
certified by the Minnesota Department of Health. The Colilert
coliform method gives results the next day, where the membrane
method will take an extra two days if any growth is found.
Samples must be received by 12:00 noon on Fridays to
be processed. Any "RUSH" samples must use Colilert
method for analysis. Keep your water sample out of the sunlight
and heat. Samples should be received in the laboratory with
a temperature of 6°C (43°F) or below by Minnesota Department
of Health standards. Samples received above that will have the
temperature on the report flagged as such.
Collecting Other Samples
Lead and Arsenic Samples
If testing interior piping, select a faucet from a
kitchen or utility sink. Bathroom faucets are not recommended.
Remove any filters or screens from the tap. The water must not
be used for at least 6 hours, preferably standing in the line
overnight. Place the container under the faucet and slowly turn
on the COLD water. Do not purge the line or use the hot water
side. Catch the first flow from the faucet and fill the container
until just below the neck with allowance for preservation. Do
not overflow the sample bottle. Cap the bottle and record the
sample date and time.
Lakes, Rivers and Reservoirs
Select a spot where a representative sample can be
taken. Remove the cap from the sample bottle from below the
surface to avoid introducing surface scum. Position the mouth
of the bottle into the current, away from the hand of the collector.
Do this in a continuous sweeping motion, extending the mouth
of the bottle into the water and sweeping to a depth of approximately
one-two feet. Continue the sweep to the water surface and above.
Carefully pour off the water above the neck of the bottle, and
then replace the cap without touching the mouth of the bottle.
Cap the bottle and record the sample date and time. Samples
should be received in the laboratory with a temperature of 6°C
(43°F) or below by Minnesota Department of Health standards.
Samples received above that will have the temperature on the
report flagged as such.
Bottle Requirements
Small (Sterilized) 4" Bottle
**Each bullet requires one small bottle
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Coliform (Total, E.coli or Fecal)
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Nitrate and Coliform
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Arsenic
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Lead
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Iron Bacteria
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Sulfate Reducing Bacteria
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Fluoride
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Minerals: Ca, Mg, K, Na, Cu, Fe, Mn, Zn
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Solids
Large 6" Bottle
**Requires one large bottle
Miscellaneous
Stearns DHIA
Laboratories
825 12th Street South, PO Box 227
Sauk Centre, MN 56378-0227
320.352.2028 · 800.369.2697
Fax 320.352.6163 ·
Email
Hours
Monday-Friday: 8AM-4PM
Front Entrance Drop-Off Open 24 Hours
Refrigerator Available for Water, Milk,
and Wet Feed Samples
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