# Presentation: 180031

## Bacteriological Sampling

- Ken Morin, P.E.
- (based on slides prepared by:
-  Bob Clement, EPA Region 8)

## Find an outside faucet that is not leaking that you can flame.

##    Thoroughly flame the faucet   for a minute or two or   until any leaking water   dries up.    Do not heat      the faucet too      much because      the valve may      have a rubber      seal in it.

## Open faucet to full flow for 5 minutes or a temperature change in the water before taking the sample.

## Reduce flow to a gentle stream to take the sample.  Hold container well belowits rim.Test for chlorine residual,if the water is disinfected.

## Do not overfill the container.  The splashing could contaminate the sample and wash out the sodium thiosulfate used to remove the chlorine residual.

## Do set sample container or even the lid on the ground.

## Do not sample faucets with attachments on them or remove them.  The constant moisture is a breedingground forbacteria.

## If you sample an inside faucet thoroughly clean the faucet and sink.

## Take the aerator and rubber gasket off and clean the faucet and sink.

## Use a squirt bottle to disinfect the faucet, with its aerator removed, with alcohol.

## Alcohol is a better disinfectant on a faucet than bleach because it evaporates quicker.

## Properly label squirt bottle with name, hazard warning, and target organ effect.

## Open cold water faucet and let run for 5 minutes or a temperature change before taking a sample from the aerator-less faucet.

## Reduce flow from aerator-less faucet and take the sample.

## There should be some space between the cap and water level.  Required sample volume 100-ml.

## Completely fill out the bacteriologic sampling form.

## Required Information on Bacteriologic Sampling Form

- Name of the site
- Site’s PWS ID Number (assigned by the State)
- Sampling location as specified in the Coliform Sample Siting Plan
- Date and time sample was taken
- Type of sample
- routine
- repeat (give date of original positive and location of all four repeat samples)
- special
- Chlorine residual, if system is disinfected
- Name of the sampler

## Mailing the Sample to the Lab

- Label the sample container with the same information as on the form.
- Place the labeled container and completed bacteriologic sampling form in the shipping container.
- Ship the container via overnight mail to ensure delivery to lab within 30 hours.

## Driving the Sample to the Lab

- Label the sample container with the same information as on the bacteriologic sampling form.
- Place the labeled container in a clean cooler.
- Put blue ice in the cooler to keep the sample at 4C, or
- Pack the cooler with ice, but ensure the ice is below the container cap and the container  cannot tip over.
- Bring the completed bacteriologic sampling form.

## Avoiding Sample Contamination

## Clear tallgrass, weeds,and brushat least4 to 5 feetin diameteraround thetap.

## Hold sample container well below the rim.

## Do set sample container or even the lid on the ground.

## Do not overfill the container.  The splashing could contaminate the sample and wash out the sodium thiosulfate used to remove the chlorine residual.

## Avoid faucets with attachments on them or remove them.  The constant moisture is a breeding ground forbacteria.

## Do not sample from a swivel faucet it may harbor bacteria and contaminate the sample.

## Avoiding Sample Contamination

- Wash hands with soap prior to sampling.
- Bring an extra sample container.
- Do not use a sample container or lid that was dropped.
- Run water from tap for at least 5 minutes or until a temperature change is felt.
- Reduce flow from tap to be sampled to a gentle stream after water has flowed for 5 minutes or a temperature change is felt.

## Avoiding Sample Contamination

- Do not sample from:
- a faucet with its aerator still on,
- swivel faucets, or
- taps or hose bibs that have attachments on them.

## Avoiding Sample Contamination

- Keep the sample container closed until:
- the container’s label is filled in,
- water has flowed from tap for 5 minutes or you feel a temperature change in the water, and
- you are ready to take the sample.
- Do not blow into the container.
- Do not touch the inside of the container or lid.

## Avoiding Sample Contamination

- Hold the container well below its rim.
- Hold the container lid with fingers avoiding its edge or inside.
- Keep the lid away from splashing water.
- If water is splashing off your hand or the sink and it could have entered the container, take another sample using the extra container.

## Avoiding Sample Contamination

- Immediately close the container after collecting the sample.
- Leave the faucet or tap running until the sample has been taken and the container is closed.
- Do not stir the sample in the container.
- Clear tall grass, weeds, and brush at least 4 to 5 feet in diameter around the tap.