Safe Drinking Water Act Phase II & V Sampling Procedures: Volatile Organic Compounds (VOCs)

The purpose of these slides is to demonstrate recommended sampling techniques. This presentation includes: supplies needed supplies needed sample tap selection sample tap selection collection; and collection; and shipping. shipping. Volatile Organic Compounds Sampling Procedures

We know and recognize that there are numerous techniques and methods for collecting drinking water samples. The idea of this presentation is to demonstrate the general method used while providing some helpful suggestions for sample collection, whether you are an owner, operator, or trainee. This presentation is in no way to be considered a substitute for the federal Safe Drinking Water Act and amendments. Volatile Organic Compounds Sampling Procedures

What are VOCs and why do we sample for them? The US Environmental Protection Agency has established Maximum Contaminant Levels (MCL) for 21 different VOCs.

What are VOCs and why do we sample for them? These organic compounds can occur in both untreated and treated drinking water. They are generally found at higher concentrations in ground water than in surface water. This is because evaporation is restricted in ground water. Because these organic chemicals are volatile, they require special sampling procedures.

What are VOCs and why do we sample for them? As a result, EPA has established maximum safe levels for each of these contaminants, called "maximum contaminant levels" or "MCLs."

State Guidelines – Rules – Sample Requirements Be sure to check with your state or tribal drinking water program office for additional guidelines, rules and/or sample requirements since they may be more stringent than those required by the federal Safe Drinking Water Act.

VOC Sampling Supplies Before you begin sampling, it is important to have all of your supplies on hand. Here is a list of the suggested supplies you may need:

Cooler for shipping and storage of your sample while in transit between collection point and lab. VOC Sampling Supplies

Bagged Ice for your shipping cooler. VOC Sampling Supplies

PVC or unsupported Neoprene gloves which are necessary to keep your hands safe from sample container preservative chemicals. VOC Sampling Supplies

Safety Goggles which are necessary to keep your hands and eyes safe from sample container preservative chemicals. VOC Sampling Supplies

Sample Containers VOC Sampling Supplies

Lab slips, labels, and markers for sample container identification VOC Sampling Supplies

Additional Recommended Items are: Paper towels for drying off the outside of your sample container after sampling. VOC Sampling Supplies

Plastic storage baggies for ice and sample container VOC Sampling Supplies

Sample preparation instructions Although different sizes and types of sampling containers may be used for collecting VOC samples, most laboratories supply 40mL to 120mL glass vials. The laboratory will normally add the proper preservative in advance to each vile.

Sample preparation instructions For chlorinated waters, a powdered dechlorinating agent (ascorbic acid) will be added, and the sampler must subsequently add hydrochloric acid to the filled vials. Therefore, a small container of 1:1 hydrochloric acid, disposable pipets and small eye-dropper bulbs for chlorinated systems. For unchlorinated waters, the laboratory will add the acid to the empty vials.

Sample preparation instructions Samplers should obtain specific instructions from the laboratory at the time the empty vials are received.

Sampling Preparation Instructions IMPORTANT: The laboratory supplying the sample containers may send trip blanks, sometimes called field reagent blanks, along with the sample containers. Trip blanks consist of sample containers filled at the laboratory, that must remain sealed and must be shipped back to the lab. This is done to check if samples were contaminated during shipment.

Sampling Preparation Instructions If the laboratory has not included trip blanks, contact the laboratory before taking any samples.

As a general rule, proper washing of hands is highly recommended for the sample collector. Sample preparation instructions

Also, food, drink, and even 2nd hand cigarette smoke should never come into contact with the sample or its containers. These foreign objects have been suspected of causing false results in samples, so be sure to practice good clean sample collection procedures. Sample preparation instructions

Do not sample with any containers that appear to have been tampered with since this may cause an undesirable sample result. Sample preparation instructions

Sampling Procedures The laboratory that supplies the sampling containers may provide instruction with the kit for the type of monitoring being performed. Be sure to refer to those instructions when provided.

Important Safety Precautions Safety goggles and gloves must be worn.

Wash hands before and after sampling. Important Safety Precautions

Caution-Hazard Sample containers may contain liquid preservatives. Liquid preservatives will cause burns. If it comes into contact with the skin or eyes, flush with liberal amounts of water and seek immediate medical attention.

Select a state approved sampling location if any have been designated. If not, select a representative sampling location. For a surface water system, the plant effluent tap might be an appropriate sampling location. For a well discharging directly into a distribution system (entry point to the distribution system or EPTDS), a tap on the well’s discharge piping after any treatment would be appropriate. Sampling Procedures

If possible, use a non-swivel faucet and remove all attachments, including any aerators, strainers and hoses. It is normally recommended not to take a sample at that location if all attachments cannot be removed because they may alter the sample results. Sampling Procedures

Turn on the water tap and run the water for 2- 3 minutes then reduce the flow so that the stream is approximately ¼ inch in diameter. Do not change the flow rate until after sampling is completed. Sampling Procedures

While the water is running for those 2-3 minutes, completely fill out the 2-3 minutes, completely fill out the labels and lab slip. Be sure to clearly labels and lab slip. Be sure to clearly identify the system information, like identify the system information, like the public water system identification the public water system identification number, exact sample location, date and time of collection, and the sampler’s name. number, exact sample location, date and time of collection, and the sampler’s name. If the sample collection point has a specific coded identification, include it on the label and sample submission form. Be sure to attach the label prior to sampling. A wet sample container may not allow the label to properly adhere. Sampling Procedures

For Chlorinated Water: If the water has been chlorinated, select vials to which powdered ascorbic acid has been added. If the water has not been chlorinated, select vials to which liquid hydrochloric acid has been added. Fill at least two vials for each sample that is taken.

Remove the cap from the vial, keeping the vial upright to prevent spilling any preservatives. Do not put the cap face down or put it in your pocket. Do not allow the inside of the cap or the bottle threads to be touched by any object Sampling Procedures

Hold the vial at an angle pointing away from your face and carefully fill it until it is full. Be careful not to rinse out the preservatives. If acid has been added to the vial by the laboratory, it will mix rapidly with the water and may splatter a bit. If ascorbic acid powder (dechlorinating agent) has been added to the vial by the laboratory, it will rapidly dissolve. Sampling Procedures

For Chlorinated Water: If the water has been chlorinated, use the vials with a 1:1 (one part acid to one part water) hydrochloric acid (HCl) for each 20 mL of sample volume. This should have been supplied by the lab for you. Sampling Procedures

Carefully complete filling the vial by putting water inside the cap and transferring it one drop at a time to the vial Sampling Procedures

Screw the cap on the bottle being sure not to overtighten the cap Sampling Procedures

Invert the bottle, tap against your other hand, and check for air bubbles. If any are present, add additional water- just a drop or 2, seal and check again. Sampling Procedures

Remember that each “sample” consists of 2 to 3 filled vials. Repeat the sampling procedures to fill additional vials for each sample. Sampling Procedures

Complete all necessary forms supplied by the laboratory with the appropriate information. In many states, the same form that is filled out here will be used to report the analytical results. Also, you may need to complete a chain of custody form, if required.

Place the samples in a cooler. The trip blanks should still be in the cooler. Keep the samples at 2 degrees to 6 degrees Celsius (36 degrees to 43 degrees Fahrenheit) and keep them away form direct light or gasoline and solvent vapors. Pack the samples in a cooler with Ice. As a tip, it might be a good idea to bag up the sample and the ice separately in the cooler. This will help prevent leakage or contamination of the sample from the ice. Sampling Procedures

Deliver the samples to the laboratory or ship the samples by an overnight courier This will ensure prompt testing for the most accurate results. It is recommended that all samples be received by the laboratory within 7days. Sampling Procedures

If the laboratory has any additional recommendations or requirements, they should be read and followed closely. Sampling Procedures

If you have any additional questions, please contact your state or tribal drinking water program office for assistance. Following the proper drinking water sample collection procedures can lead to peace of mind, knowing that the test results truly represent the quality of water your customers are drinking. After all, isn’t our goal to ensure... Following the proper drinking water sample collection procedures can lead to peace of mind, knowing that the test results truly represent the quality of water your customers are drinking. After all, isn’t our goal to ensure... Sampling Procedures

Volatile Organic Compounds (VOCs) Sampling Procedures “Water Safe to Drink”