Water, Sewage & Effluent November December 2018 | Page 13

www.waterafrica.co.za Water Sewage & Effluent November/December 2018 11 contamination from ‘faucets’ (which we call a tap), sink surfaces, and patients. This brought me to the realisation that the sanitary drainage system from the ‘fixtures’ (WC, bidet, shower, bath, washbasin, sink, sluice, slop hopper, floor drains, and grease trap) all become contaminated and contribute to — and exacerbate — the problem. It is vital to note that each of the above-mentioned fixtures are connected to the sanitary drain, which is connected to a sewer network from the building down to the sewage treatment plant. All along the building, the drainage system is connected to the bathrooms, sluice rooms, slop hoppers, kitchens, floor drains, grease traps, mortuary, and all the other hospital drainage. This building drainage is connected to the municipal sewer and this sewer is connected to the sewage reticulation and eventually connected to the sewage treatment works. All along this sewage network, other buildings are connected, such as mortuaries, abattoirs, butcheries, factories, restaurants, and even the undertaker. innovations important to note that a SANS standard is not compulsory unless it has been specifically promulgated as such. There is a hospital design document called R108, but it only states that the water and drainage must be designed by ‘an experienced engineer’. The design of a hospital drainage system and water system requires specialised competence and experience as well as high-quality materials, fixtures, equipment, and systems, since health and safety is a high priority and the preservation of a ‘clean environment’ is crucial. It is a startling fact that many hospitals are struggling with contamination and the so-called ‘hospital bug’ or ‘super bug’. And this seems to be pandemic. In a research report published by the US National Library of Medicine – National Institute of Health, titled, Hospital Drains as Reservoirs of Pseudomonas aeruginosa: Multiple-Locus Variable- Number of Tandem Repeats Analysis Genotypes Recovered from Faucets, Sink Surfaces and Patients (and, interestingly, filed under ‘Pathogens’), the researchers indicate that they found the above-mentioned Let’s have a look at the vulnerable environment that is a hospital, and some examples of how easily contamination and pathogens can spread: • There are washbasins in the ICU right next to the bed of an ill person. If the plumber has to work on the washbasin and remove the trap, then all the air in the pipeline will escape into the ICU. • When a nurse or nursing assistant empties a bedpan in the sluice room, the air in the sluice room is contaminated. The same happens when a patient or a visitor uses a toilet. People complain about ‘bad smells’, when in essence, bad smells are germs and it is the reason someone invented the so-called ‘toilet friend’ — an extractor to extract the foul-smelling air directly from the WC. • When a cleaner opens a floor drain outlet to clean it, then the foul air from the piping escapes into the kitchen, perhaps without even being noticed. It is essential that the internal and external systems are designed by one engineer, with one responsibility, and based on one set of design criteria and assumptions. Hospitals — by nature a contaminated environment The building drainage is connected to the municipal sewer, which is connected to the sewage reticulation and eventually connected to the sewage treatment works. Any drainage system requires access to allow for maintenance and to remove blockages — and this is by means of ‘inspection eyes’ that are situated on all fittings such as bends, tees, and junctions. In fact, from any fixture in any building down to the sewage treatment works, the only barrier between the user of the fixture and the total sanitation system, is a thin layer of water, called a trap. This trap of water is about 75mm thick. In any drainage system, there is a need for access to allow for maintenance and to remove blockages. The access is by means of inspection eyes that are situated on all fittings such as bends, tees, and junctions on the above-ground piping, and externally underground, there are manholes, inspection chambers, rodding eyes, and cleaning eyes, placed at a required distance of at least 25m apart. In wet areas, such as kitchens and food preparation areas, floor drains are required. Now, when any of the access points inside the building, including floor drains, is opened for maintenance or to unblock a blockage, then the highly