How often should a Pool test be completed?
Swimming and spa pool waters should be subjected to at least monthly and Hydrotherapy pools should be tested weekly.
Any other times that a pool should be tested?
Additional testing may be needed in other circumstances e.g. before a pool is first used or re-opened after a shut-down period, or when there is contamination. Should your pool fail a UKAS test we recommend immediate shutdown until the pool has been shock treated. After any pool test failure, we recommend a retest which we can complete ASAP ( normally within 48 hours). Note retests are subject to an additional charge above your monthly contract price.
What Microbiological checks are completed on Pool water?
HSS Microbiological tests your Pool water for,
- Aerobic colony count cfu/ml ( @37c for 24 hours)
- Total Coliforms cfu in 100ml
- E coli ( Esherichia Coli) cfu in 100ml
- Pseudomonas aeruginosa cfu in 100ml
How is the water sample taken ?
HSS and our UKAS lab will provide sterile sample containers. Sampling is undertaken in accordance with the laboratory recommended procedure. Sampling procedures are covered in PWTAG Technical Note 27.
In order to neutralise the chlorine in the water sample, the sterile bacteriological sample bottle provided by the laboratory will contain sodium thiosulphate pentahydrate. This ensures that any microorganisms in the pool water are preserved for lab analysis, and the sample is representative of the water at the time of sampling
It is recommended that the sample is kept chilled (at 5 ±3 ºC) and transported to the laboratory so that it can be analysed within 24 hours of sampling. Our normal transport time is less than two hours and average time is an hour or less from sampling to Lab for items that we collect in Surrey and Sussex. Our mail order samples are processed same day as they arrive back with us and not subject to the same controlled temperature conditions but do offer a cheaper alternative.
HSS are an external ‘microbiological testing contractor’ that collect your sample and deliver it to our chosen accredited laboratory.
Why is HSS microbiological sampling so important?
Although the look of the pool water provides a reasonable guide to how well treated the water is, microorganisms may still be existent. The presence of disinfectants in the form of oxidising biocides is significant: a pool which has insufficient chlorine residual will eventually become turbid and cloudy due the failure to oxidise bather pollutants (eg. nitrogenous compounds like ammonia and urea) and an increasing bacterial load. Bacteria will multiply rapidly in the absence of an oxidising biocide, further reducing the clarity of the water.
Clear, sparkling pool water is one indication that disinfection reserves are being maintained and that the filtration system is working effectively. But pool operators cannot be confident that the water treatment system is operating effectively without regular independent microbiological testing.
If the investigation of a disease outbreak focuses on a pool, a good record of microbiological testing can contribute reassurance to both operator and enforcing authority that the pool may not be contributing to the problem. Seasonal pools, and pools that have been closed for any length of time, must have a satisfactory microbiological test report before re-opening
When will I get my results back ?
Full results are normally returned within 96 hours of testing. Some of the tests require samples to be placed on a petri dish at 37 degrees for 24 hours so its not instant results.
Whist we say the written email confirming of your result is normally back in 96 hours, should you fail the Aerobic Colony count we will not wait for the full results we will telephone and email you recommending urgent action this is normally 30 to 48 hours after testing.
How do I book a retest ?
The booking of a re test is subject to an additional charge and can be arranged via email. Should your pool fail a test we recommend a re test as soon as cleaning and shock treatment has been completed.
