Plumbing Africa April 2020 | Page 59

HEALTH AND SANITATION 59 “Additional benefits of using the Rainwatch in a rainwater harvesting system include that it reduces the need for separate leaf catchers and first flush devices, and it reduces the maintenance load or replacement frequency of downstream filtration equipment. It can be easily cleaned, and the filter itself is washable and reusable, meaning that maintenance costs are very low.” It’s made from polycarbonate and acrylonitrile butadiene styrene (ABS) plastic combined with a filtration membrane designed to filter contaminants as small as 50 micron. It slows and cleans the water over a large filtration surface, allowing significant flow rates. This means that the filter can capture water without overflow wastage, even in heavy rainfall. Most rainwater catchment systems use large run- off areas to collect rainwater, which then goes through a centrifugal pump. This pump breaks up the contaminants into fine particles, making them difficult to remove even with fine post-tank filters. This Australian product helps to improve the quality and health benefits of rainwater. Doust says its development was inspired after reading reports on the number of contaminants present in rainwater tanks, even those with post-tank filters. “The Rainwatch filter is the first patented filtration device that cleans water and extracts sediment before it’s stored in the tank. This both increases the quality of the rainwater and reduces the hassle of cleaning the tank,” he says. Behold the clarity of the rainwater. “Traditional rainwater systems are pumping contaminated water to the point of use because the particles are too small for the filter to catch. However, because Rainwatch is a gravity-feed pre-tank filter, it’s able to remove most airborne contaminants and microscopic particles. When rainwater is combined with a complete filtration system that includes a Rainwatch, it makes it safer and more viable to drink,” explains Doust. “While the Rainwatch filter has the ability to remove most airborne contaminants and microscopic particles, the product is designed to be an addition to current rainwater filtration and sterilisation systems rather than a replacement. It allows water to be treated for human consumption, but it is not designed to independently eliminate point of use sterilisation for human consumption,” says Doust. “We recommend it be used in conjunction with a UV filter close to the point of use to ensure the healthiest consumption of rainwater possible.” Due to the extraction of contaminants before the storage of rainwater, Rainwatch helps to significantly reduce sediment build-up in rainwater tanks, extending the de-sludge cleaning period from every two to three years to every five to ten years. “This provides huge time and cost savings to tank maintenance, which is the main cause of poor water quality. It also reduces the need to empty the tank and waste the precious rainwater in order to clean it,” says Doust. The filter still needs to be cleaned every three to six months, but the cloth can be replaced every three years depending on the volume and frequency of rainfall and the level of April 2020 Volume 26 I Number 02 The Rainwatch filter has been designed to work as a component of all current rainwater catchment systems, with a polynuclear aromatic hydrocarbon (PAH) removal efficiency of 97%. PAHs are chemicals that can be released into the air, water or soil from burning, industrial processes and the use of some household products. Rainwatch’s certificate of patent. exposure to contaminants. The Rainwatch filter is designed to increase the catchment efficiency of most current rainwater systems, which is particularly important given that South Africa – like Australia – continues to experience a decrease in the availability of water. “Water restrictions and environmental factors have resulted in a scarcity of water resources, so even though municipalities are struggling to supply high-quality water, prices are continuing to rise. Rainwater tank installations and maintenance services consequently represent a huge opportunity for plumbers,” says Doust. PA “Rainwater tank installations and maintenance services consequently represent a huge opportunity for plumbers.” www.plumbingafrica.co.za