FEATURE
29
Rainwater harvesting and treatment of rainwater
By
Rory Macnamara
Rainwater Harvesting is an old practice , and before the first-world countries polluted the world , rain was the cleanest and softest form of water . That said , rainwater has more advantages than disadvantages .
All photos by © Plumbing Africa | Rory Macnamara
A commercial RWH installation .
For the plumber , rainwater harvesting offers an excellent growth opportunity from the simple gutter to tank installation , to the more sophisticated conversion to potable water – thus enabling the customer to go off the water grid , fully or partially .
Sadly , no standard exists for rainwater harvesting per se , but basic plumbing principles apply . The role of the plumber is to guide the customer as to the best installation suited for immediate needs and create openings to ‘ grow ’ the system as required .
Notwithstanding the lack of a standard specifying SANS approved product , it is essential to work with the components currently under SANS 10252-1 & 2 and SANS 10106 . Polyethylene tanks , capacity 2 000l ³ upwards , must abide by the SANS 1731-2019 standard which also calls up SANS 10252-1 & 2 as a normative reference regarding fixtures and fittings .
It is also for this reason that the plumber should discourage DIY as a consumer would be clueless as to the standards required for piping , fittings , and general installation that a plumber is trained in .
For commercial and industrial installation , an engineer will be involved with design , and this is where the sophisticated water collection systems come into play . This is still installed by the plumber , who would have acquired specialist training . What is important is the treatment of water in a tank even if used only for gardening . The further one goes with this type of installation the more critical the treatment and processing of rainwater becomes , especially if one uses such water as potable water . This would have to be done according to SANS 241 Drinking Water standard .
A basic RWH installation for garden use only .
February 2022 Volume 27 I Number 12 www . plumbingafrica . co . za