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VOLATILE ORGANIC COMPOUNDS (VOCs)
Contaminant Sources
VOC contamination in drinking water can result from the following:
· Discharge from industrial and commercial areas
· Discharge from dry cleaners, landfills and airports
Monitoring Requirements
Monitoring is required quarterly for the first year and annually for
the second and third years. The results will determine the future monitoring
requirements for the fourth year and beyond.
Sampling Procedures
VOC samples are point-of-entry samples,
taken after treatment and before reaching the first consumer. Prior to
sampling, evaluate the area around the sample tap for possible air contamination.
A loosely sealed or open gas can in a pump house could give off VOCs.
Check for recent use of cleaners, solvents, or degreasers, which could
taint a sample. Some other products that could possibly contaminate a
sample include the following:
- Perfume
- Cosmetics
- Skin-applied pharmaceuticals
- Suntan lotion
- Automotive products
- Crystalline bathroom/urinal deodorizers
- Plumbing compounds
If odors from any of these are present, air out the area prior to sampling.
1. If the sampling faucet has an aerator, it must be removed. Run water
until it is cold. Reduce the flow to a thin stream.
2. Remove the cap ring from the sample vial, making sure not to lose
the Teflon liner. If the liner falls out, replace it in the cap ring,
smooth Teflon side down, and flush under running water for 30 seconds.
3. For wells that are chlorinated, it is necessary to add ascorbic
acid. To add the ascorbic acid powder, give one push of the dispenser/cap
to deliver approximately 30 mg of acid into the sample vial. Ascorbic
acid should be added to each 40-ml VOC vial before a chlorinated sample
is added. NOTE: Each vial contains 2 drops of 50% HCl. This is a strong
acid. Do not remove it from the vial.
4. To minimize the formation of bubbles, fill the vial by allowing
the water stream to strike the inner wall of the vial. Fill the vial
to the brim with a minimum of splashing, forming a positive (convex)
meniscus at the brim. Do not overflow excessively.
5. Replace the cap by gently setting it on the water meniscus, making
sure that the white smooth side of the liner faces down. Tighten firmly,
but do not over tighten. The vial cap or neck can be easily broken.
6. Turn the vial over and check for air bubbles. If there is a bubble
larger than the size of a small pea, then resample or quickly add more
water.
7. Check the appropriate boxes on the vial label to indicate that the
proper preservatives were added.
8. Repeat the steps for the other vials, opening only one at a time.
Add ascorbic acid to the trip blank when it is added to the associated
samples.
9. Fill out the request forms completely. Samples must be shipped on
ice.
Safety glasses and gloves are recommended when taking samples.
Reporting Requirements
Upon receipt of the completed sample form from the laboratory, check
to make sure that all required testing was done (checked items on back).
Sign and date the completed form and submit it to the WDNR within ten
days after completion of tests or within the following timeframes:
- Ten days following the month in which the result is received.
- Ten days following the end of the compliance period.
Report all MCL, monitoring and public notice violations to the WDNR
within 24 hours. It is recommended that you keep a copy of the completed
form for your records (click
here for sample form in PDF format).
Treatment Options
Health Effects
The health effects associated with the presence of Volatile Organic Compounds
in drinking water vary depending on many factors including the type of
contaminant present, the levels found, and the duration of exposure. Generally,
health effects associated with exposure to VOCs include the risk of cancer,
anemia, liver or kidney damage, or damage to the nervous and circulatory
systems.
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