Clean & Disinfection

Clean and disinfection of cold water storage and systems A key aspect of The Approved Code of Practice (ACOP L8) is to maintain the cleanliness of all water systems. Regular monitoring of cold water storage vessels and their systems (see monitoring and inspecting) is required to identify presence of calcium carbonate scale, sediment, biofilms and signs of corrosion all of which are natural causes from mains water supply. Bacteria (particularly Legionella pneumophila) can survive and multiply under these identified conditions, which potentially could result in serious health implications. A regular, comprehensive physical and chemical clean of these systems will limit the potential for high bacteria counts and followed by regular monitoring will ensure employers comply with codes of practice, whilst protecting their staff, customers and the public.

AES Standards:

Physical clean to impeccable aesthetic standards Chemical cleaning using silver based hydrogen peroxide dosed to recommended standards – the use of this chemical halves the volume of water needed to be ‘dumped’ than using conventional methods Use of alternative chemicals such as chlorine biocide in specialist circumstances Maintain contact time of chemical clean throughout the system to exceed the minimum recommendations Bacteriological samples are collected and transported as per UKAS accredited sample method These samples are independently analysed by a UKAS accredited laboratory to test method no 4 Tests carried out for TVC, e-coli colliforms and Legionella Issue of disinfection certificate and sample results to client Annual reminder of service requirements   Calorifier de-scale In principle this service is similar to the requirements of a clean and disinfection, but due to the nature of a calorifier, greater risk of bacterial growth is apparent. Build up of scale and fluctuating temperatures encourages the growth of bacteria. This not only poses risk to users of the system, but reduces the efficiency of the calorifier resulting in higher running costs and potentially the need of replacement. Access into a calorifier is restricted, so an aggressive approach to cleaning is required by using acid based chemicals. Combined with regular monitoring of the system, will limit the potential of high bacterial counts and will ensure employers comply with codes of practice, whilst protecting their staff, customers and the public. AES Standards: Recommendation of de-scale after any positive identification of excess scale Use of sulphamic acid dosed to recommended standards Neutralise with caustic alkali until original pH levels are achieved Issue of de-scale and cleaning records to client   Mains injection (pre-commission cleaning) A mains injection is the process of disinfecting closed water systems, which are fed directly from the mains supply. British Standards BS6700 requires this process prior to the commissioning of these services and immediately after significant remedial works. Once completed, the regular supply of mains water in efficient systems will maintain a clean environment free from any harmful bacteria, but if delivered below industry standards may result in underperforming water systems or potentially even failure. This will lead to potentially long term financial and health implications. AES standards: Use of silver based hydrogen peroxide dosed to recommended levels pumped throughout the entire system Identification and chemical level testing of nearest and furthest away sentinel points Maintain contact time of chemical clean throughout the system to exceed the minimum recommendations Bacteriological samples are collected and transported as per UKAS accredited sample method These samples are independently analysed by a UKAS accredited laboratory to test method no 4 Tests carried out for TVC and e-coli colliforms Issue of disinfection certificate and sample results to client