U.S. Environmental Protection Agency
Region 8 Laboratory
16194 W. 45th Dr.
Golden, CO 80403
&EPA
United States
Environmental Protection
Agency
Quick Guide
to Drinking Water
Sample Collection
Second Edition, Update
September 2016
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Disclaimer
This document provides a general summary of techniques used by EPA Region 8 Laboratory staff
for the collection of chemistry samples for drinking water analysis. Other approaches to sample
collection may be acceptable or desirable under given conditions. This document is intended as a
refresher for those already trained in sample collection. The user is urged to check with the
laboratory performing the analysis to ensure that the bottles, preservatives, and holding times which
are to be employed are compatible with the methods used by the laboratory.
The second edition corrects and expands on the guidance for sampling water lines for compliance
with the lead/copper rule. The first edition should not be used. The second edition also updates
sampling techniques for total coliforms and E. coli and provides a reference for the Revised Total
Coliform Rule. In addition, it contains minor editorial corrections and updates.
The second edition update expands on the guidance for sampling water lines for compliance with the
lead/copper rule.
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Contents
Disclaimer 2
GENERAL SAMPLING PROCEDURES 4
SPECIFIC SAMPLING PROCEDURES 6
Asbestos 6
Biological Contaminants 7
Bacteria and Coliphage 7
Total Coliform and E.Coli 8
Cryptosporidium and Giardia 9
Classical Chemistry Constituents and Nutrients (IOCs) 10
Unpreserved Classical Chemistry Constituents Including Nutrients,
Anions and Other Analytes as Listed (IOCs) 10
Classical Chemistry Constituents and Nutrients Requiring Acid
Preservation as Listed 11
Cyanide 12
Colorimetric Analysis for Disinfectant Residuals 13
Haloacetic Acids (HAA5s) 14
Metals (IOCs) 15
Radionuclides 16
Synthetic Organic Compounds (SOCs) 17
Total Organic Carbon 18
Volatile Organic Compounds (VOCs) 19
Common VOCs 19
Total Trihalomethanes (TTHMs) 20
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General Sampling Procedures
This summary document is designed to be used by personnel trained in the collection of drinking
water samples and handling of sample preservatives. Follow the procedures described below to assist
in the collection of an acceptable sample and to maintain the integrity of the sample after collection.
1. Prepare a Sampling and Analysis Plan (SAP) that describes the sampling
locations, numbers and types of samples to be collected, and the quality
control requirements of the project.
2. Check with the laboratory before collecting samples to ensure that
sampling equipment, preservatives, and procedures for sample collection
are acceptable. It is best to obtain sampling supplies directly from the
laboratory performing the analyses. Gather all equipment and supplies
necessary for the project.
3. The acids and bases used in preservation of many types of samples
described in this document are dangerous and must be handled with care.
Always wear gloves and eye protection when handling preservatives. When
opening a preservative bottle, particularly a glass ampoule, break open the
ampoule away from yourself and others. Have acid/base neutralization
supplies (baking soda) on hand in the event of a spill. If acid spills on your
skin or clothing, remove the contaminated clothing and rinse the area with
water. Do not apply baking soda (the heat of reaction can cause burns).
4. Collect samples in an area free of excessive dust, rain, snow or other
sources of contamination.
5. Select a cold water faucet for sampling which is free of contaminating
devices such as screens, aeration devices, hoses, purification devices or
swiveled faucets. Check the faucet to be sure it is clean. If the faucet is in
a state of disrepair, select another sampling location.
6. Collect samples from faucets which are high enough to put a bottle
underneath, generally the bath tub or kitchen sink, without contacting the
mouth of the container with the faucet.
7. Open the faucet and thoroughly flush. Generally 2 to 3 minutes will
suffice, however longer times may be needed, especially in the case of
lead distribution lines. Typically the water temperature will stabilize which
indicates flushing is completed. Once the lines are flushed, adjust the flow
so it does not splash against the walls of the bathtub, sink or other surfaces.
8. Follow the collection instructions provided for the analytes of interest
described on the following pages. Wear eye protection and gloves if you
are handling containers with acidic/basic preservatives and when you are
collecting samples.
£
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General Sampling Procedures
9. Lead and Copper Rule Compliance Samples:
Select a cold water faucet for sampling which is free from devices that are
designed to change the water composition, such as water softeners or point
of use filters. DO NOT remove any screens or aeration devices. If you are
collecting a first-flush sample for lead/copper, allow the water to sit
undisturbed for at least six hours. DO NOT intentionally flush the water
line before the start of the 6 hour period. Place a wide-mouth 1 L bottle
under the faucet. Open the faucet and collect the first water out of the tap.
If you want to test a lead service line then 8 to 10 sequential sample bottles
(the number depends on how far the lead service line is from the tap) would
be needed to see the profile of lead distribution.
For more detailed sampling instructions, refer to the EPA's Clarification of
Recommended Tap Sampling Procedures for Purposes of the Lead and
Copper Rule at: https://www.epa.gov/dwreginfo/memo-clarifying-
recommended-tap-sampling-procedures-lead-and-copper-rule.
10. Fill out the chain of custody form with the sample collection information.
Record the site location, name of the sampler, date and time of collection,
method of collection, type of analysis to be completed, and preservative in
use.
Deliver or ship samples to the laboratory to ensure that holding times are
met. Holding time starts at sample collection and ends at preparation
and/or analysis. Be sure to allow time for the laboratory to process the
samples
11. Return empty preservative containers to the laboratory for proper disposal.
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Specific Sampling Procedures
Asbestos
Bottles to use
Plastic or glass bottles may be used but plastic is preferred.
Preservative to use
Cool to < 4 °C (< 39.2 °F)
Holding times
48 hours
Sampling instructions
Check with the laboratory but generally 1 L is required for analysis. Wear gloves and eye protection
when collecting samples. Rinse the bottle and cap three times with sample water and fill the bottle to
within one to two inches from the top. Place the sample into a cooler with ice for immediate delivery
or shipment to the laboratory.
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Specific Sampling Procedures
Biological Contaminants
Bacteria and Coliphage
Total coliforms; fecal coliforms; E. coir, enterococci; heterotrophic bacteria; or
coliphage
Bottle to use
Sterile 125 or 150 mL plastic bottles must be used.
Preservatives to use
Sodium thiosulfate if sample is chlorinated
and
Cool to < 10 °C (< 50 °F) for source water and groundwater samples (recommended for drinking
water as well) but do not allow samples to freeze
Holding times
Holding times are generally very short - 8 hours for source water compliance samples, 30 hours for
drinking water samples, 48 hours for coliphage samples. Deliver samples to the lab the day of
collection if possible or ship via overnight delivery.
Sampling instructions
Wear gloves when collecting samples. Do not rinse the bottles. The bottles are sterile so care
must be taken not to contaminate the bottle or cap. Once the distribution line is flushed and the
flow reduced, quickly open the bottle (but do not set the cap down), hold the cap by its outside
edges only, and fill the sample bottle to just above the 100 mL line leaving a one inch headspace.
Cap the bottle immediately and place it into a cooler with ice for delivery or overnight shipment
to the laboratory.
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Specific Sampling Procedures
Biological Contaminants
Total Coliform and E. Coli
Tips and guidance for total coliform and E. coli sampling
Some tips on collecting samples
• Remove any attachments on the faucet
• Allow water to flow for 5 or 6 minutes before sampling
• Do not rinse or overfill container
• Always collect cold water; never sample hot water
• Do not touch the inside of the sample bottle or its cap
Avoid these sampling sites for total coliform. if possible
• Outdoor faucets
• Faucets connected to cisterns, softeners, pumps, pressure tanks or hot water heaters
• New plumbing and fixtures or those repaired recently
• Faucets that hot and cold water come through
• Threaded taps
• Swing spouts
• Faucets positioned close to sink or ground
• Leaky faucets
For guidance on sampling related to the Revised Total Coliform Rule (effective April 1, 2016), refer
to the Revised Total Coliform Rule: A Quick Reference Guide under Quick Reference Guides at
Revised Total Coliform Rule And Total Coliform Rule (https://www.epa.gov/dwreginfo/revised-
total-coliform-rule-and-total-coliform-rule).
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Specific Sampling Procedures
Biological Contaminants
Cryptosporidium and Giardia
Giardia and Cryptosporidium sampling using EPA analytical methods 1622, 1623 or
1623,1 without filtration in the field
Bottle to use
Plastic cubitainers or equivalent that can hold 10 L samples are used.
Preservatives to use
Cool to < 10 °C but do not freeze, keep at < 20 °C during shipment.
Holding time
96 hours
Sampling instructions
This method of sample collection is acceptable for EPA analytical methods 1622, 1623 and 1623.1
when sending water samples to the laboratory without filtering in the field. Talk to the lab to
determine if this collection procedure is acceptable for the analytical method they plan to perform.
Wear gloves when collecting samples. Rinse the sample bottle three times and fill the bottle
completely to ensure 10 liters are collected. Chill samples to 1 - 10 °C as soon as possible by storing
in a refrigerator or by pre-icing them in a cooler prior to shipment. Load samples into a cooler with
fresh ice for either immediate delivery or overnight shipment to the laboratory. Complete any
applicable sample collection forms.
Note: An additional 10 L matrix spike sample may be required by the laboratory.
For additional sampling instructions, including those for filtration, refer to EPA's LT2:
Cryptosporidium & E. coli Sample Collection Recommendations Pocket Guide at:
https://www.epa.gov/dwreginfo/long-term-2-enhanced-surface-water-treatment-rule-
documents#! t2crvptosa m pi e
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Specific Sampling Procedures
Classical Chemistry Constituents and Nutrients (IOCs)
Unpreserved Classical Chemistry Constituents Including Nutrients, Anions and
Other Analytes as Listed (IOCs)
Acidity, alkalinity, biological oxygen demand, bromate, chloride, chlorite, color,
conductivity, fluoride, foaming agents, nitrate, nitrite, odor, o-phosphate, residues,
silica, sulfate, surfactants, total dissolved solids, total suspended solids, turbidity
Bottles to use
Plastic or glass bottles may be used but plastic is preferred.
Preservative to use
Cool to < 4 °C (< 39.2 °F)
Holding times
Most of these analytes have short holding times. Deliver samples to the lab the same day if possible
or ship via overnight delivery. Check with the lab regarding the holding times for the specific
analytes of interest.
Sampling Instructions
Check with the laboratory on the sample volume required for analysis. Wear gloves and eye
protection when collecting samples. Rinse the bottle and cap three times with sample water and fill
the bottle to within one to two inches from the top. Place the sample into a cooler with ice for
immediate delivery or shipment to the laboratory.
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Specific Sampling Procedures
Classical Chemistry Constituents and Nutrients (IOCs)
Classical Chemistry Constituents and Nutrients Requiring Acid Preservation as Listed
Ammonia; nitrate + nitrite combined; kjeldahl and organic nitrogen; total phosphorus
Bottles to use
Plastic or glass bottles may be used but plastic is preferred.
Preservative to use
Sulfuric acid (H2SO4) to pH < 2
Holding times
28 days
Sampling instructions
Check with the laboratory on the sample volume required for analysis. Wear gloves and eye
protection when handling acids and while collecting samples. If the bottle contains a preservative, do
not rinse the bottle. If the preservatives are not included in the bottle, rinse the bottle and cap three
times with sample water, fill the bottle, and then carefully add the preservatives following the
instructions provided by the laboratory. The bottle should be filled to within one to two inches from
the top. Deliver or ship the sample to the laboratory.
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Specific Sampling Procedures
Classical Chemistry Constituents and Nutrients (IOCs)
Cyanide
Bottles to use
Plastic or glass bottles may be used but plastic is preferred.
Preservatives to use
0.6 g ascorbic acid if sample is chlorinated
and
sodium hydroxide (NaOH) to pH > 12
and
cool to < 4 °C (< 39.2 °F)
Holding time
14 days
Sampling instructions
Check with the laboratory on the sample volume required for analysis. Wear gloves and eye
protection when handling acids and other preservatives and while collecting samples. If the bottle
contains a preservative, do not rinse the bottle. If the preservatives are not included in the bottle,
rinse the bottle and cap three times with sample water, fill the bottle, and then carefully add the
preservatives following the instructions provided by the laboratory. The bottle should be filled to
within one to two inches from the top. Place the sample into a cooler with ice for delivery or
shipment to the laboratory.
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Specific Sampling Procedures
Colorimetric Analysis for Disinfectant Residuals
Free chlorine, combined chlorine, chloramines, total chlorine
Bottles to use
Glass test tubes are generally used.
Preservative to use
None
Holding times
Analyze immediately on-site
Sampling and analysis instructions for the DPP colorimetric methods
Several methods are approved for analysis of disinfectant residuals. A common method is the DPD
colorimetric method {StandardMethods, 18th edition or later 4500-C1 G). Test kits for the DPD
method are available commercially. The analyst should follow the specific directions provided with
the test kit.
In general, the analyst will need to measure out a known volume of sample using a test tube or flask
provided with the kit and will need to add the DPD reagents in the order described, wait a specific
reaction time, and then measure the pink color that develops in the sample. The intensity of the pink
color that develops after the addition of a reagent is measured using a spectrophotometer or a color
comparator and relates directly to the amount of disinfection residual present in the sample.
Example test kits
1
«»
1
m
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Specific Sampling Procedures
Haloaeetic Acids (HAASs)
Monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, monobromoacetic
acid, dibromoacetic acid
Bottles to use
Glass bottles must be used.
Preservatives to use
Ammonium chloride
and
Cool to < 4 °C (< 39.2 °F) but do not freeze
Keep samples in the dark
Holding times
Holding times are either 14 or 28 days depending upon the laboratory method in use.
Sampling instructions
Check with the laboratory on the sample volume required for analysis. Wear gloves and eye
protection when handling acids and other preservatives and while collecting samples. Do not rinse
the bottle. If the preservatives are not included in the bottle, carefully add the preservatives
following the instructions provided by the laboratory. Fill the bottle to within one to two inches from
the top. Place the sample in a cooler with ice for delivery or shipment to the laboratory.
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Specific Sampling Procedures
Metals (IOCs)
Antimony, arsenic, barium, beryllium, cadmium, calcium, chromium (total),
magnesium, manganese, mercury, nickel, selenium, sodium, silver, thallium, lead,
copper, zinc and other trace metals
Bottles to use
Plastic or glass bottles may be used but plastic is preferred.
Note: 1000 mL wide-mouth bottles are recommended for collection of lead and copper rule
compliance samples.
Preservative to use
Nitric acid (HNO3) to pH < 2
Holding times
28 days for mercury, 6 months for other metals
Sampling instructions
Check with the laboratory on the sample volume required for analysis. Wear gloves and eye
protection when handling acid and while collecting samples. If the bottle contains a preservative, do
not rinse the bottle. If the preservatives are not included in the bottle, rinse the bottle and cap three
times with sample water, fill the bottle, and then carefully add the preservatives following the
instructions provided by the laboratory. The bottle should be filled to within one to two inches from
the top. Deliver or ship the samples to the laboratory.
Lead and Copper Rule Compliance Samples: Refer to item #9 in the General Sampling
Instructions above. Do not remove aerators or rinse bottles. Use the bathroom tap if the kitchen tap
has a water softener or point of use filter on it.
Note: If samples are not acid preserved, they must be received by the laboratory within 14 days of
sampling.
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Specific Sampling Procedures
Radionuclides
Gross alpha, gross beta, strontium-89, strontium-90, radium-226, radium-228, cesium-
134, iodine-131, tritium, uranium, photon emitters
Bottles to use
Plastic or glass bottles may be used but plastic is preferred.
Preservatives to Use
Hydrochloric acid (HC1) or nitric acid (HNO3) preservation for all analytes except iodine-131 and
tritium, which do not require acid preservation. For cesium-134, only HC1 may be used as a
preservative.
Holding times
8 days for Iodine-131, 6 months for all other radionuclides
Sampling instructions
Check with the laboratory on the sample volume required for analysis. Wear gloves and eye
protection when handling acids and other preservatives and while collecting samples. If the bottle
contains a preservative, do not rinse the bottle. If the preservatives are not included in the bottle,
rinse the bottle and cap three times with sample water, fill the bottle, and then carefully add the
preservatives following the instructions provided by the laboratory. The bottle should be filled to
within one to two inches from the top. Deliver or ship samples to the laboratory.
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Specific Sampling Procedures
Synthetic Organic Compounds (SOCs)
Alachlor, Atrazine, Benzo(a)pyrene (PAHs), Carbofuran, Chlordane, 2,4-D, Dalapon,
l,2-Dibromo-3Chloropropane (DBCP), Di(2-ethylhexyl)adipate, Di(2-
ethylhexyl)phthalate, Dinoseb, Endrin, Ethylene Di bromide (EDB), Heptachlor,
Heptachlor Epoxide, Hexachlorobenzene, Hexachlorocyclopentadiene (HEX),
Lindane, Methoxychlor, Oxamyl (Vydate), Pentachlorophenol, Picloram, PCBs,
Simazine, Toxaphene, 2,4,5-TP (Silvex), Diquat, Endothall, Glyphosate, Dioxin
Bottles to use
Glass bottles must be used. The type of cap required will depend upon the analyte and method
the lab is using. Talk to the lab to be sure.
Preservatives to use
Check with the lab to verify the type of preservation required which depends on laboratory
method in use
and
Cool to < 4 °C (< 39.2 °F) but do not freeze
Holding times
Holding times are generally short - call the lab to be sure.
Sampling instructions
Check with the laboratory on the sample volume required for analysis. Wear gloves and eye
protection when handling acids and other preservatives and while collecting samples. Do not
rinse the bottles. Ask the lab how to fill the bottle as this may depend on the bottle in use and the
method used for analysis. Place the sample into a cooler with ice for immediate delivery or
shipment to the laboratory.
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Specific Sampling Procedures
Total Organic Carbon
Bottles to use
Glass bottles are preferred but plastic may be used as well.
Preservatives to Use
Check with the lab to verify the type of preservation required which depends on laboratory method
in use. Generally, preservation includes:
Hydrochloric (HC1) or sulfuric (H2SO4)
or phosphoric acid (H3PO4) to pH <2
and
Cool to < 4 °C (< 39.2 °F) but do not freeze
Holding time
28 days
Sampling instructions
Check with the laboratory on the sample volume required for analysis. Wear gloves when handling
acids and other preservatives and while collecting samples. If the bottle contains a preservative, do
not rinse the bottle. If the preservatives are not included in the bottle, rinse the bottle and cap three
times with sample water, fill the bottle, and then carefully add the preservatives following the
instructions provided by the laboratory. The bottle should be filled to within one to two inches from
the top. Place the sample into a cooler with ice for delivery or shipment to the laboratory.
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Specific Sampling Procedures
Volatile Organic Compounds (VOCs)
Common VOCs
Benzene, Carbon Tetrachloride, o-Dichlorobenzene, p-Dichlorobenzene, 1,2-
Dichloroethane, 1,1-Dichloroethylene, cis-l,2-Dichloroethylene, trans-1,2-
Dichloroethylene, Dichloromethane, 1,2-Dichloropropane, Ethylbenzene,
Monochlorobenzene, Styrene, Tetrachloroethylene, Toluene, 1,2,4-Trichlorobenzene,
1,1,1-Trichloroethane, 1,1,2-Trichloroethane, Trichloroethylene, Vinyl Chloride,
Xylenes (total)
i
Clear or amber volatile organic analysis (VOA) glass bottles with Teflon septum cap must be used.
Preservatives to use
Check with the lab to verify the type of preservation required which depends on laboratory method
in use. Generally, preservation includes:
Sodium thiosulfate or ascorbic acid if sample chlorinated
and hydrochloric acid (HC1) to pH <2 and
Cool to < 4 °C (< 39.2 °F) but do not freeze
Holding time
14 days
Sampling instructions
Check with the laboratory on the sample volume required for analysis. Typically duplicate samples
must be collected (triplicate preferred) at each sampling location. Wear gloves and eye protection
when handling acids and other preservatives and while collecting samples. Do not rinse the bottle as
it should contain the preservatives before it is filled. Check to make sure this is the case and if not
add the preservative. Slowly fill the bottle by allowing the sample to gently flow down the inside of
the bottle. Create a meniscus of water at the mouth so that the bottle is actually overfilled. Cap the
bottle so that no air bubbles are present in the bottle and the excess water spills down the sides of the
bottle. Check to make sure that the bottle does not contain bubbles by inverting the bottle several
times. Place the sample into a cooler with ice for delivery or shipment to the laboratory.
Bottles to use
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Specific Sampling Procedures
Volatile Organic Compounds (VOCs)
Total Trihalomethanes (TTHMs)
Bromodichloromethane, dibromochloromethane, tribromomethane (bromoform),
trichloromethane (chloroform)
i
Clear or amber volatile organic analysis (VOA) glass bottles with Teflon septum cap must be used.
Preservatives to use
Check with the lab to verify the type of preservation required which depends on laboratory method
in use. Generally, preservation includes the following:
Sodium thiosulfate or ascorbic acid if sample chlorinated and hydrochloric acid (HC1) to pH < 2
and Cool to < 4 °C (< 39.2 °F) but do not freeze
Holding time
14 days
Sampling instructions
Check with the laboratory on the sample volume required for analysis. Typically duplicate samples
must be collected (triplicate preferred) at each sampling location. Wear gloves and eye protection
when handling acids and other preservatives and while collecting samples. Do not rinse the bottle as
it should contain the preservatives before it is filled. Check to make sure this is the case and if not
add the preservative. Slowly fill the bottle by allowing the sample to gently flow down the inside of
the bottle. Create a meniscus of water at the mouth so that the bottle is actually overfilled. Cap the
bottle so that no air bubbles are present in the bottle and the excess water spills down the sides of the
bottle. Check to make sure that the bottle does not contain bubbles by inverting the bottle several
times. Place the sample into a cooler with ice for delivery or shipment to the laboratory.
Bottles to use
9
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20
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