What is a Hollow Tank Support?
A “Hollow Tank Support” is usually a hollow PVC Upstanding pipe used to support potential weight on top of the Domestic Cold Water Storage Tank and on larger Tanks are used to support the natural and potential weight of the Tank “lids”. Due to their design water can stagnate within the internal area of the support increasing the risk of bacterial contamination with the system. These supports should be safely removed and replaced with a “solid structured” support as seen in image number 2 by competent person/s.
The UK Department of Health Alert (EFA/2013/004) issued on 19th November 2013, an issue with cold water storage tanks which indicates that hollow tank supports are no longer permitted in cold water storage tank installations. This is also supported by the new ACoP L8 legislation provided by the Health and Safety Executive. Hollow internal supports restrict the movement of water, allowing bacteria to form within a cold- water storage tanks. Tanks that contain hollow supports have been identified by the HSE and EFA as providing an environment in which water can stagnate.
What are the Risks?
The presence of stagnant water is likely to encourage the growth of Legionella bacteria above the recommended risk levels. This would then present the risk of the entire domestic water system becoming contaminated. The Hollow Supports should be removed to eliminate possible contamination and replaced with ‘clean’ solid supports, i.e. ones without cavities, crevices or details allowing water to stagnate and harbour micro-organisms.