TWISS ANALYTICAL LABORATORIES, INC
SYNTHETIC ORGANIC CHEMICALS (SOC’s)
Sampling Instructions for Tribal Compliance
COLLECTION POINT
Samples must be collected in the proper number, at the appropriate time and location, and of the proper volume in
order to satisfy the requirements of the Compliance Monitoring.





Groundwater and surface water systems should be representative of the source water following treatment
Samples must be collected at entry points to the distribution system (EPTDSs) representing each nonemergency water source in routine use over the 12-month period of monitoring. Generally, samples should
be taken at the tap on the pipeline before the treated water is sent to the distribution system. Sometimes
sampling taps (faucets) are available in the plant laboratory for the water entering the distribution system.
Systems that draw water from more than one source and that combine (blended sample) prior to
distribution must sample during periods of normal operating conditions.
Samples must be collected at the same sampling point each cycle, unless conditions make another sampling
point more representative.
If the water system is treating for any organic compounds (i.e. packed tower aeration,, granular activated
carbon, oxidation, etc.) contact your regional Drinking Water Specialist to locate the proper collection
point.
Bottles must NOT be filled near gasoline cans, gasoline powered motors, paint cans, lighter fluid, paint
strippers, pesticide bottles or exhaust fumes from running engines. Fumes may contaminate the samples.
SAMPLE COLLECTION
I.
If water taps are to be used for sampling, all aerators, strainers and hose attachments need to be removed.
Open the tap and allow the system to flush for about ten minutes or until the water temperature has
stabilized. Adjust the flow to about the thickness of a pencil. Collect the sample directly from a tap and not
through any plastic or rubber hoses or tubing. Position the container under the tap and collect the sample
from the flowing stream.
2.
Collect 2 one-liter bottles at each collection point for method 525.2 Pesticides
The 1L bottles contain dry preservative (sodium sulfite) as a dechlorinating agent. After the
bottle is filled cap and invert to dissolve the sodium sulfite. Next add 5 mls (complete contents
of vial labeled “CAUTION! Hydrochloric Acid” to reduce the pH to less than 2. Gloves are
provided. Cap and return the acid vial to the plastic bag and place in the cooler for return.
Collect 1 500 ml bottle at each collection point for method 515.4 Herbicides
Collect 1 40 ml bottle at each collection point for method 531 Carbamates
Collect 1 250 ml bottle at each collection point for method 547 Glyphosate
Collect 1 50 ml bottle at each collection point for method 548 Endothall
Collect 2 250 ml Amber PVC at each collection point for method 549 Diquat
Collect 2 one-liter bottles at each collection point for method 1613 Dioxins
Collect 2 40 ml bottles at each collection point for method 504 EDB/DBCP (see additional instructions
on back of this sheet)
IMPORTANT: Be careful not to touch or otherwise contaminate the inside of the lid or the lip of the bottle
during sampling.
All samples must be kept cold. If the samples are to be held prior to shipping, place the bottles in a refrigerator.
Once samples are ready to be shipped, add a bag of ice to the cooler to keep samples stored at 4oC. Samples MUST
be kept at 4o C until they reach the laboratory. If they become warm or freeze they will be rejected.
Twiss only accepts these samples prior to 2:00 PM ON Mon, Tues OR Wed.
Samples must be received at the laboratory on the same day as sampled.
26276 Twelve Trees Lane, Suite C
D:\687307647.doc

Poulsbo, WA 98370 
www.Twisslabs.com
Revision Date: 03/15/13
(360) 779-5141 
Fax: (360) 779-5150
TWISS ANALYTICAL LABORATORIES, INC
EDB/DBCP Sampling Instructions
Please read the following instructions carefully before sampling. Improperly collecting samples may
result in increased cost due to re-sampling.
SAMPLE KIT CONTENTS:
 1 - 40mL vial labeled Field Blank and dated (The field blank serves as an indicator of contamination
which may occur during sample transport or storage. Therefore, this vial must not be opened and
must always travel with the samples).
 2 - 40mL vials for each source to be sampled.
 Drinking Water Sample Information form for each source to be collected.
SAMPLE COLLECTION
I. All samples should be collected after treatment and before the distribution system (representative of
the overall source).
2. Use the same collection point each time you sample.
3. Remove any potentially contaminating devices such as filters, screens, aerators, etc., from sampling
points..
4. Open the tap and allow water to run (at least 3 minutes) until it reaches a constant temperature.
5. Reduce flow to a thin steady stream (thickness of pencil).
Fill 2 40mL vials from each source at the same time and under the same conditions. Avoid agitation
of the sample while filling. Allow the stream of water to gently flow into the vial just to overflowing.
TO AVOID CONTAMINATION, DO NOT TOUCH THE INSIDE OF THE CONTAINERS
WITH THE FAUCET OR YOUR FINGERS.
7. Carefully place the cap onto the 40mL vial. The shiny side of the Teflon cap liner should be face
down in contact with the water sample. Tighten down the cap securely.
8. IMPORTANT: CHECK FOR TRAPPED AIR BY INVERTING THE VIAL AND LOOKING FOR
AIR BUBBLES. IF ANY AIR BUBBLES ARE PRESENT, GENTLY ADD MORE WATER AND
REPEAT STEP 7. THE LAB WILL REJECT EDB/DBCP SAMPLES IF THERE ARE AIR
BUBBLES IN THE EDB/DBCP VIAL. THIS WILL RESULT IN RESAMPLING.
9. Label each 40mL vial with DOH source number and your name for that source. EXAMPLE: SO1,
Well #1.
AFTER SAMPLE COLLECTION
1. IMPORTANT: place vials in a container with double bagged ice. Make sure there is plenty of ice to
keep the samples at 4o C. Place insulating material between the vials and the double bagged ice. If
you are not going to bring the samples immediately to the laboratory, place samples in the
refrigerator.
2. Complete the Drinking Water Sample Information form for each source collected. Indicate exact
time, date and location where the sample was collected.
3. Write the correct DOH source number in the space provided in Item #12 of the Drinking Water
Sample Information form.
TWISS ONLY ACCEPTS THESE SAMPLES PRIOR TO 2:00 PM ON MON, TUES OR WED.
SAMPLES MUST BE RECEIVED AT THE LABORATORY ON THE SAME DAY AS SAMPLED.
26276 Twelve Trees Lane, Suite C
D:\687307647.doc

Poulsbo, WA 98370 
www.Twisslabs.com
Revision Date: 03/15/13
(360) 779-5141 
Fax: (360) 779-5150