32 FEATURE
Greywater reuse systems – SANS 1732:2019
ByRory Macnamara
South Africa is a semi-arid country , and a huge business opportunity exists for plumbers to encourage their customers to take responsibility for saving water .
with potable water in any form of manner . SANS references to these points are 6.2.3.1 and 6.2.3.2 . Both installation and repairs must be done by a qualified plumber as outlined in the standard which includes the issuing of a CoC in both cases .
A copy of the complete standard is obtainable from www . sabs . co . za .
Index Water
Any grey water system must be designed by a qualified engineer registered with the Engineering Council of SA ( ECSA ) and installed by a qualified plumber who must issue a Certificate of Compliance ( CoC ) issued by the Professional Body for Plumbing which is Plumbing Industry Registration Board ( PIRB ).
The benefit to plumbers While the Department of Water & Sanitation is the legislator and custodian of our water , it falls to local authorities to ensure that water is used in a manner that conserves this resource . Grey water provides an additional method of conserving water as well as using recycled water and rainwater for the consumer to reduce water bills as well as using ‘ free water ’ for irrigation and toilet flushing .
The plumber can be part of the customer saving water and cutting costs . As plumbers are qualified in matters of piping , pressure , hydraulics and the like , it makes sense for them to be the drivers of such systems .
Grey water is defined as water drawn from baths , showers , and hand wash basins only . Any other wastewater is excluded from this standard . Grey water is used for irrigation and toilet flushing only and may not cross or interfere with the potable water supply . Both exposed pipes and taps must be clearly identified by a colour code of purple to avoid any confusion . ( 6.2.2.2 . in Standard )
For the design , the following must be considered :
• The immediate capture and use of untreated grey water for irrigation
• Drawings must be prepared , one for irrigation and toilets
• The collection , treatment , and storage of greywater for flushing toilets
The general requirements for design and manufacturer of the system must be in accordance with SANS 10252-2 : Water Supply and Drainage for Buildings – Part 2 Drainage Installations for Buildings . This refers to pipes , drainpipes , and valves . Cisterns supplied with grey water may not be supplied
We provide a few suggestions to assist with the ‘ selling ’ of such systems to customers .
Rather than keeping collected water in buckets and basins , which has a lifespan of 24 hours maximum , collect it sensibly for a longer period with the proper and correct treatment .
Untreated water can have a negative effect on humans anyhow even if boiled after contamination . It may impact of the groundwater and cause contamination .
Soil degradation , especially when using washing machine , washing up water in kitchen sinks and dishwasher with harmful detergents on plants , grass , and the like . Whilst the thought is good and to be encouraged , it is doing the wrong thing for the wrong reason . Customers need to be encouraged to do the right thing for the right reason .
By ‘ selling ’ the greywater concept you are engaging with your customer to offer to throw in a free inspection after
www . plumbingafrica . co . za @ plumbingonline @ plumbingonline @ PlumbingAfricaOnline January 2021 Volume 26 I Number 11