WATER SYSTEMS
Taking the optimal steps to maintain water quality
Karina Jones, an IHEEM-registered Authorising Engineer (Water) at Eta Projects, and a member of the Institute’s Water Technical Platform, considers some of the most prevalent hazardous waterborne bacteria found in healthcare premises, and the key steps to keep their growth and transmission in check, and thus safeguard patients, staff, and visitors, against infection.
In England and Wales, the Drinking Water Inspectorate (DWI) provides independent reassurance that water supplies are safe, and that drinking water quality is acceptable, while the World Health Organization produces international norms on water quality and human health via guidelines for regulation and standard setting worldwide. Water quality is determined by its origin, and can often be altered or compromised by the way water is managed – especially in large buildings, where complex domestic hot and cold water systems can provide a suitable environment for water quality to diminish – due to factors including incorrect temperature management, water stagnation, exposure to incorrect components, non-Water Regulations Advisory Scheme (WRAS)-approved installations, or the addition of biocides.
Regular testing To implement appropriate water management within buildings (especially in healthcare environments), incoming mains water should be tested to drinking water parameters1
to obtain an understanding
of its quality. This is often overlooked at the start of building projects, potentially resulting in unnecessary expense, and delaying occupation. In nature, water is mineralised when it filters through different rock layers from origin to source, which influence the degree of mineralisation. Natural mineral water thus contains a different mineral concentration. For infants, athletes, or pregnant women, the concentration of certain minerals is key. Minerals such as sodium may present at too high a quantity, and others, like magnesium, at too low a level.
Sodium levels The appropriate sodium level is also essential to the human body, with Public Health England (PHE) recommending a daily UK adult allowance (RDA) of 2.4 g. Together with chloride and potassium, sodium is among the most important
Strict adherence to hand hygiene is vital in preventing the transmission of hazardous waterborne microorganisms in healthcare settings.
electrolytes for the body – regulating water balance, influencing blood pressure, kidney function, and acid-base balance, and controlling cell function and our immune systems. In fact, many cellular processes are only possible through sodium, which contributes to the normal functioning and health of skin, bones, muscles, and connective tissue. Sodium levels in drinking water vary significantly depending on location. In healthcare environments, infants and young children, and those with high blood pressure or impaired renal function, should only be exposed to low sodium levels in drinking water, and where water is undergoing softening, it must not enter the healthcare facility’s potable water distribution system.
Key testing parameters Testing of incoming water quality will include microbial level, mineral, sodium load, and pH value. The pH standpoint water values may vary between 6.5 and 9.5. pH levels are determined by water’s
acidity or alkalinity, identified by the number and activity of free hydrogen ions dissolved in it. The ideal level for drinking and consumption (tap water) is 7-8.5 pH. Acidic drinking water damages cement- lined pipes, while galvanised steel is prone to corrosion from a pH below 7.5. Copper lines must not be used if the pH is below 7, as acidic water washes copper from the pipes. Too much of this trace element is especially dangerous for babies and children. Knowing the pH level of drinking and tap water is key to both good water quality and waterborne pathogen control.
Water hardness Water hardness levels play a huge part in water system maintenance due to scale build-up. Scale or limescale is a hard, rock- like deposit of calcium or magnesium salts that forms in heat exchangers, cooling tower packing, and other water-fed equipment, due to heat. Scale formation impairs heat transfer and flow, and can be a breeding ground for Legionella. To
February 2023 Health Estate Journal 33
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