We carry out Legionella testing across Hampshire, taking water samples and sending them to a UKAS-accredited laboratory. However, a sample is only one part of the picture. So before we suggest one, we check whether your site actually needs it.
Risk assessment first, sampling second
For most buildings, the starting point is a Legionella risk assessment, not a lab test. That’s because a sample only tells you about one outlet on one day. An assessment, on the other hand, looks at the whole system: where water sits still and how warm it gets. After that, the report tells you whether sampling would add anything useful.
In a typical flat or small house, sampling is rarely needed. Some sites, however, do benefit from it. In those cases, we plan the samples around what the assessment found, so every bottle has a reason behind it.
Legionella testing: Hampshire sites that need it
We usually suggest sampling in these situations:
- Higher-risk sites, where the assessment shows the controls are hard to keep on top of
- After remedial work or a tank disinfection, to check the fix has worked
- Care homes, because residents are more vulnerable to infection
- Pools and spa-type showers, since they create a fine spray that people breathe in
- Sites with a positive result in the past, so you can show levels have stayed down
- HMOs, if the landlord or managing agent asks for it
Across the county, that covers a wide mix of buildings. For example, we see care homes near Winchester, shared houses in Southampton and holiday lets in the New Forest. In each case, we agree the outlets to sample before the visit, so you know the cost up front.
How we take the samples
Good sampling depends on doing the same steps in the same order every time. So our engineers follow a set routine at each outlet.
- First, we take a pre-flush sample. This is the first water out of the tap or shower, and it shows the state of the outlet itself.
- Then we run the water and take a post-flush sample. This shows the water reaching the outlet from the wider system.
- We use sterile bottles and label each one with the outlet, date and time.
- We also note the water temperature at the moment of sampling.
- Finally, we complete a chain of custody form, so the lab can trace every bottle.
After that, the samples go to a UKAS-accredited laboratory. Because Legionella grows slowly in the lab, results usually take 7–10 days to come back.
Reading your results
The lab report shows whether it found Legionella in each sample and, if so, how much. A positive result simply means the lab detected the bacteria. Even so, the count matters as well. HSE guidance in HSG274 sets out the levels at which you should act. We then explain where your results sit in plain words.
Comparing the two samples also helps. For instance, if only the pre-flush sample is positive, the problem is often local to that outlet. If both are positive, it points to the wider system, such as a tank or cylinder.
What happens after a positive result
A positive result is not a reason to panic. Instead, it’s a reason to act quickly and calmly. The people who test your water also fix plumbing and heating. So we can usually start the fix ourselves, rather than wait for another firm. The usual steps are:
- Finding the likely cause, such as a dead leg, a dirty tank or hot water that isn’t hot enough
- Carrying out the remedial works, which may include cleaning and disinfecting the system
- Taking fresh samples once the work is done, to confirm the levels have come down
- Updating your records, so you can show what you found and how you dealt with it
Temperature monitoring between tests
A lab test is a snapshot, so it doesn’t replace regular checks. Temperature monitoring, by contrast, is the everyday way to show your controls are working. Legionella grows most between 20°C and 45°C, therefore the aim is to keep water outside that band.
- Stored hot water should reach 60°C
- Hot outlets should hit 50°C or more within a minute
- Cold outlets should drop below 20°C within two minutes
We can set up a simple monitoring routine for your staff, or carry out the checks ourselves. Then, if a reading slips, you can deal with it before it turns into a positive sample.
Where we sample in Hampshire
We’re based just over the border in Poole, and Southampton and the New Forest are under an hour away. For Legionella testing, Hampshire is well within reach, including Southampton, Eastleigh, Romsey and Fareham.
Landlords with shared houses sometimes add sampling to their assessment. If that’s you, our page for landlords explains how we work with agents and tenants.
What sampling costs
Prices for Legionella testing in Hampshire vary, because they depend on how many outlets need sampling and where your site is. So we give you a fixed quote before the visit, with no call-out fees and no hidden extras. To get a price, send us a few details through our contact page.
Already had a positive? Tell us when you get in touch. We’ll then plan the clean-up and the re-test together, so you aren’t left waiting between two separate jobs.
Common questions about Legionella testing
Do I need Legionella testing if I’ve had a risk assessment?
Not always. For most homes and small premises, the risk assessment and simple temperature checks are enough. However, sampling is worth doing on higher-risk sites and in care homes. It also helps with pools, spa-type showers, and after remedial work or a positive result. Your assessment report will say whether sampling would help, so you only pay for it when it adds something.
How long do Legionella test results take?
Results usually come back within 7–10 days. That’s because the UKAS-accredited lab has to grow the bacteria before it can count them, and that takes time. We then send you the lab report with a short note on what the figures mean.
What happens if a sample comes back positive?
First, we look for the cause, such as a dirty tank, a dead leg or low hot water temperatures. Then we put it right, which may mean cleaning and disinfecting part of the system. After that, we take new samples to check the levels have dropped. Because we’re plumbers too, the fix and the re-test can usually be handled by the same people.
Do the occupants need to be in when you take samples?
No, they don’t need to be there. However, we do need access to each outlet we’re sampling, along with the boiler or cylinder and any loft tank. If a site manager or agent can let us in, that works well. We’ll agree the outlets and the timing with you beforehand, so nobody is caught out on the day.