BS 7592-2022 pdf free download.Sampling for Legionella bacteria in water systems — Code of practice.
This British Standard gives recommendations and guidance on the sampling of water and related materials for the investigation of the presence of organisms of the genus Legionella. It is applicable to sampling constructed water systems but also gives methods for sampling of biofilms and sediments that might be present. Some of the same sampling principles can be applied to natural water systems.
This British Standard is applicable to the selection of sampling sites and the methods of sampling for the purposes of routine monitoring, validation, commissioning, investigating a problem, or outbreak investigation. Recommendations and guidance on the selection of sampling points are given. The rationale for the selection of sampling points for particular situations is also covered.
This British Standard is intended for use by all those involved in water sampling for legionellae, including those collecting samples on site and those developing water sampling plans and/or directing where samples are taken from, irrespective of the method of analysis adopted.
It is not applicable to the sampling of soils and horticultural potting mixtures.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this British Standard, the following terms and definitions apply.
3.1 aerosol
suspension in a gaseous medium of solid particles, liquid particles or solid and liquid particles invisible to the human eye and having negligible falling velocity
3.2 biocide
substance used to disinfect water systems and components
3.3 biofilm
community of bacteria and other microorganisms and entrained debris embedded in a protective layer at interfaces in water systems
3.4 blind end
length of pipe closed at one end through which no water can pass
NOTE Also known as “dead end”.
3.5 calorigier
apparatus used for the transfer of heat to water in a vessel by indirect means and incorporating a source of heat
NOTE 1 See also plate heat exchanger (3.27).
NOTE 2 A “storage calorigier” also stores some of the heated water in the same vessel.
3.6 cistern
tank for storage of water
NOTE This includes all cisterns, not just WC cisterns.
3.7 cold-water system
installation of plant, pipes and fittings in which cold water is stored, distributed and subsequently discharged
3.8 commercial spa pool
spa pool usually of bespoke design constructed onsite and incorporating a balance tank in the water circulation system to accommodate the water displaced by bathers entering the pool
NOTE Commercial spa pools have been associated with outbreaks of Legionnaires’ disease in hotels, leisure facilities and cruise liners.
3.9 competence
combination of training, skills, experience and knowledge that a person has and their ability to apply them to perform a task safely
[SOURCE: What is competence [9]]
3.10 constructed water system
water system that has been constructed and does not occur naturally, e.g. a hot-water system
3.11 cooling tower
device for cooling water that, in turn, is used for cooling in a process
NOTE The water is passed over the tower against an air stream. Water evaporates which causes the water to be cooled. The cooler water is then usually pumped to a heat exchanger to remove heat from the heat exchanger and recycled through the tower.
3.12 dead leg
length of water system pipework leading to a fitting through which water only passes infrequently when there is draw off from the fitting, providing the potential for stagnation
3.13 disinfection
process which removes, reduces or renders inactive microorganisms or parasites [SOURCE: BS 8551:2015, 3.11, modified]
NOTE Disinfection here relates to the outlets and systems. Disinfection is not the same as sterilization (see 3.31).
3.14 distribution system
pipework which distributes water from hot/cold/cooling water plant to one or more fittings/appliances/processes
3.15 domestic water supply
hot and cold water intended for personal hygiene, cooking, drinking water or other domestic purposes
NOTE This applies to all such systems and not just those in dwellings.
3.16 evaporative condenser
device similar to a cooling tower, through which water passes against an air stream but as the water falls it also passes over a heat exchanger which contains a fluid that is cooled by the water passing over it
NOTE The fluid could be a gas to be condensed, in which case it could be called an evaporative condenser, or water or other liquid, in which case it is a fluid cooler.
3.17 evaporative cooling
process by which a small portion of circulating water is caused to evaporate, thereby taking the required latent heat of vaporization from the remainder of the water and causing it to cool
3.18 hot tub
self-contained factory-produced spa pool not having a balance tank, designed primarily for domestic use
NOTE Although primarily designed for domestic use, hot tubs are increasingly installed in hotel rooms and holiday chalets and can be offered for hire for parties. They have frequently been associated with outbreaks of Legionnaires’ disease even when only on display in sales situations.
3.19 hot-water system
installation of plant, pipes and fittings in which water is heated, distributed and subsequently discharged (not including cold-water feed cistern or cistern).BS 7592 pdf download.