Drinking water qualityVending machines and bottled water dispensers are commonplace in many organisations; however, nearly 30% of all the cold water samples taken from vending machines fail to meet the wholesome drinking water criteria stated in the Water Supply 2000 regulations. These regulations stipulate that wholesome drinking water should have no colour, odour, taste, or turbidity nor should it contain certain chemicals or micro-organisms. The 4 main types of micro-organism that can be present in water are Coliforms, Cryptosporidium, Pseudomonas aeruginosa and Escherichia coli (E.coli).
When analysing samples for the TVC analysis, 1ml of the sample is placed into 2 separate Petri dishes, 15ml of Yeast extract agar (YEA) is added to each and left to set. They are then incubated at their relevant temperatures for a set period of time. After incubation, they are read using the Sorcerer system. Each Petri dish is placed in the Petri-viewer and dark-field illumination provides a high contrast image for the system to analyse. Special algorithms are used to detect, separate and count the number of colonies. The Sorcerer system is linked to the ems database, allowing all counts to be automatically entered against each particular sample. Typically, up to 400 plates are counted per day. The system has significantly reduced the time spent in reading these plates, and by linking to the company database, the risk of errors has also been reduced. Furthermore, certain bacteria such as aerobic spore bearing types, which have irregularly shaped colonies can be excluded from the counts using the image editor function. ems is a UKAS accredited laboratory, and any new procedures/equipment must be of a high standard. The accuracy of the Sorcerer colony counter ensures that there is no 'drift' during use and its audit trail facilities guarantee that it conforms to UKAS standards. ems has a broad spectrum of customers ranging from major blue chip corporations and financial institutions to schools and colleges. They provide professional, qualified advice on a broad range of Environmental Auditing, Risk Assessment, Health & Safety, Training needs and specialist consultancy. ems expertise ensures clients receive independent strategic technical advice to achieve practical solutions and help meet legal compliance. This gives reassurance of providing a healthier, safer, and more productive environment. Useful linksContactRebecca Jupp - Lab Supervisor |
Coliforms
are a large collection of various species of bacteria (both faecal and
non-faecal). Contamination from these bacteria, does not pose any threat
to human health, but can indicate that there may be more dangerous bacteria
present in the supply, such as Salmonella.
Health, safety & environmental consultancy, ems has for over 20 years "monitored the health of buildings" through independent workplace audits, especially covering indoor air and water quality. ems's UKAS accredited laboratory, based in Horsham, East Sussex processes around 35,000 samples each year. Rebecca Jupp and her colleagues are regularly look at drinking water quality using general TVC's (Total Viable Counts) at a range of dilutions, E.coli/coliform identification, Pseudomonas aeruginosa identification and Legionella identification from water samples.