Legionella & Water Sampling
Verifying Your Water Is Safe
Temperature monitoring shows whether your controls are working. Sampling shows whether bacteria are present. Legionella and water sampling gives you independent laboratory evidence of the microbiological quality of your water, so you can make confident decisions about its safety. Stravica delivers sampling to recognised British Standards, analysed by UKAS-accredited laboratories, with results explained clearly and acted on quickly.
When Sampling Is Needed
Sampling is a check on your control measures, not a replacement for them. In line with HSE guidance HSG274, we recommend Legionella sampling:
- Where temperatures or biocide levels are not being consistently achieved.
- In systems treated with biocides.
- In healthcare premises and other settings with vulnerable occupants.
- After disinfection or remedial works.
- Before buildings are reoccupied after long closures.
- Where an outbreak is suspected.
We will always explain why sampling is or is not needed, and will not recommend routine sampling that serves no clear purpose.
Sampling Done Properly
A result is only as reliable as the sample behind it. Our samplers are trained to BS 7592, the British Standard for Legionella sampling. They use sterile bottles containing a neutralising agent, take care not to contaminate the sample, and minimise aerosols. Each sample is taken as either pre-flush or post-flush, according to what needs to be understood. Pre-flush shows the condition of the outlet, and post-flush shows the condition of the system behind it. Pairing the two tells you whether to replace a fitting or treat the whole system.
Choosing The Right Sample Points
Every sampling exercise follows a written plan that sets out its purpose and justifies each sample point. Points may include incoming mains, cold water storage tanks, calorifiers, sentinel outlets, showers and outlets serving vulnerable people, as well as any outlet that has failed temperature checks. Each point has a unique reference linked to your asset register and schematic, so results can be tracked and compared over time.
Full Chain Of Custody
Every sample is labelled at the point of collection with its reference, location, date, time, temperature and sample type. Residents' names are never used. Samples are kept protected and delivered to the laboratory within the time limits of the analytical method, normally within 24 hours, under a documented chain of custody. If a sample is compromised in any way, it is discarded and retaken, never sent for analysis.
UKAS-Accredited Laboratory Analysis
All analysis is carried out by laboratories accredited by UKAS to ISO/IEC 17025, whose accreditation covers the specific test methods used. We test for:
- Legionella, identified to species and serogroup.
- Pseudomonas aeruginosa.
- Total viable counts.
- E. coli and coliforms.
- Disinfectant residuals.
Our laboratories take part in external proficiency testing, notify positive results promptly, and send results directly to Stravica so they are never delayed or filtered.
Results Explained, Not Just Reported
A number on a certificate is not enough. We interpret every result against the action levels in HSG274, or against your Water Safety Plan in healthcare. We consider the bacteria type found, how many samples were positive, the temperatures recorded at the time, the condition of the system and the people at risk. You receive a clear explanation of what the result means and exactly what we recommend you do next.
Positive Results Escalated Immediately
Results are always reported exactly as received from the laboratory, never delayed or withheld:
- Legionella above 1,000 cfu/l: we phone you the same day and confirm in writing within 24 hours, with recommended actions such as resampling, disinfection, outlet restriction or point-of-use filtration.
- Legionella between 100 and 1,000 cfu/l: notified in writing within 24 hours.
- Any detection in augmented care: reported the same day.
Healthcare And Augmented Care
In hospitals and other healthcare premises, sampling follows HTM 04-01 and your Water Safety Plan. In augmented care units, such as intensive care and neonatal wards, we carry out Pseudomonas aeruginosa sampling at the frequency your Water Safety Group sets, typically every six months. Our samplers follow your infection prevention and control requirements and work around clinical routines.
Verification And Outbreak Support
After disinfection or remedial works, we take verification samples once the system has stabilised, to confirm the work has been effective before outlets return to use. If a case of Legionnaires' disease is linked to your premises, we support you and the investigating authorities with investigative sampling under strict chain of custody, and provide all the records they need, promptly.
Accountable Delivery You Can Trust
Sampling is delivered by trained samplers from Legionella Control Association member organisations, analysed by UKAS-accredited laboratories, and managed and quality-assured by Stravica. Every sample taken is reconciled with a laboratory result each month. You get one point of contact and complete confidence in your results.