It’s so easy!
The first step to the Legionella water sample testing process is to fill the bottle to the top and ensure the lid is screwed on tight.
(The water sample should be collected immediately the tap is turned on without letting any water run to waste)
Normally you will fill the bottle from a single location unless you are doing “indicative sampling” where you can use up to four locations in the same bottle.
Make a note of the:
- Location
- Time of sampling
- Temperature of the water tested
You write these details on the submission – see Chapter 5 The Submission Sheet
NOTE
Fill the bottle first, then take the temperature of the flowing tap water. Don’t let the thermometer touch any water which goes into the sample bottle. You probably use your thermometer all over your building so there could be legionella on it which could contaminate a sample from a location which is free from the bacteria.
| What size bottle should I use? | AquaCert will provide the correct sterile bottle. To comply with UKAS guidelines it will be a 1 litre bottle. The bottle will contain 0.8ml of 3% of Sodium Thiosulphate to absorb disinfectants such as chlorine. |
| Do I fill it to the top? | Yes, a full 1 litre is used for the analysis. Screw the cap on securely and then invert the bottle several times to ensure the biocide neutralising agent is well mixed within the water. |
| Does the bottle have a shelf-life? | Yes, 14 months. The expiry date is printed on the label. |
| How do I store the bottle after filling it? | Keep the bottle at ambient temperature (not in the fridge) and out of the sun. Once you place the sample in our courier bag, it will prevent sunlight affecting any bacteria which are present. |
| How long can I store the sample filled bottle? | UKAS states that the sample must reach the lab within 48 hours and be stored between 6°C – 20°C during transport. This is the reason we can’t use the normal Royal Mail postal service. Samples which reach the laboratory more than 48 hours after being taken are deemed non-compliant and won’t get tested (because their results wouldn’t be accepted in a UK court of law). |
| How fast should the tap be flowing when I take the sample? | Adjust the flow so it is at a similar rate as when people use it. |
| Do I sterilise my hands before taking the sample? | Good hygiene when sampling should always be a priority. Luckily legionella water sample testing is more forgiving compared to sampling for other bacteria such as TVC, E.coli or Pseudomonas. |
| Do I sterilise the tap before taking the sample? | Sometimes you do and sometimes you don’t. We know that sounds confusing so read Chapter 6 (Pre or Post flush sampling) for more information. |