Advice and Opinion Residential

‘Green’ plumbing systems: helping property owners conserve water and reduce utility bills

Brendan Reynolds, Executive Director of IOPSA.

South African property developers are increasingly exploring ways of using water more efficiently, a trend that has seen an increase in demand for qualified plumbers with the necessary skills and experience to assist with and implement water-efficient designs.

This understanding transcends only the installation of water efficient taps and appliances, as well as ensuring that plumbing systems are installed, maintained, and repaired correctly so that they do not waste water. The skills and experience of qualified plumbers are also being harnessed in the next step of water management hierarchy which entails reusing available water on a property as part of a more holistic ‘green’ plumbing solution.

Many of our members have been appointed to work on innovative greywater and rainwater harvesting projects alongside consulting and wet services engineers. This is considering the extensive knowledge that Institute of Plumbing South Africa (IOPSA) members bring to these projects. It spans the correct installation of these systems through to the selection of appropriate materials that have been approved by standards authorities, as well as ensuring compliance with municipal bylaws. A further benefit of working with our members is that they are held accountable by IOPSA and, thus, provide follow-up should any problems arise with the installation of these systems,” says Brendan Reynolds, Executive Director of IOPSA.

There are many examples of how these systems are helping property owners to conserve water and reduce their utility bills. A large industrial premises in the East Rand, for instance, only uses municipal water in the dry winter months. This is to top up rainwater supplies that it harvests and purifies to a drinking quality. Meanwhile, two commercial developments in Sandton have reduced potable water consumption by as much as 90% by harnessing rainwater harvesting technology and other efficient systems, such as air-cooled chillers.

There has also been growing interest in rainwater harvesting in the residential property market. In response to this demand, a large property developer intends implementing rainwater and greywater harvesting systems at all its lifestyle centres. The company has already achieved significant savings in water through effective demand-side management practices, and this development will enable it to further reduce reliance on municipal supplies. This focus on water efficiency is also demonstrated by the many International Excellence in Design for Greater Efficiency EDGE Advanced certifications that the company has received for its developments. EDGE Advanced certified developments reduce energy and water consumption by at least 40%.

Meanwhile, many private homeowners are also working with qualified plumbers to help them design and install rainwater-harvesting systems, with the rising cost of water also a major motivator for them pursuing “green” plumbing.

Qualified plumbers know how to correctly install downpipes from roofs to rainwater-storage tanks. This is in addition to the proper way in which to connect the tank overflow to a stormwater system and a pressure pump. Moreover, their knowledge has helped to avoid typical mistakes in the installation of rainwater tanks. These include locating tanks on a base that can erode in the rain or wind; using piping material that reacts with acidity in the rainwater; and specifying the incorrect-sized pump and pipes for an application. Another common mistake is installing pumps at a low outlet because they draw in sediment from the bottom of tanks into the system. Tanks also need to be of water-tight construction; covered with materials that are weather, insect and vermin proof; ventilated; and provide access for regular inspection and cleaning.

Certainly, significant strides have also been made in the country in the field of greywater reuse systems. A case in point is an automated greywater system at one the country’s universities. It collects shower water at campus residences, treats it and sends it back into the system for flushing toilets. This is a significant saving considering that flushing of toilets accounts for about 30% of all indoor water use.

It is often incorrectly assumed that these systems are simple to install. Meanwhile, substandard installations can also sometimes be a legal liability placing homeowners at risk.

Qualified plumbers will know how to correctly isolate the shower and bath greywater in the system for recycling and then route it to bathrooms to flush toilets. The installation will include a plumbed portion of the pipe from the unit as a riser branching off to the toilets. This is in addition to an overflow line that leads from the inflow pipe to the main building drain as a bypass in case the system is overloaded. Moreover, the installation will include a vent pipe overflow outlet that connects to the same drainage line to also prevent excess greywater from backing up into the system. A qualified plumber will also be required to install a vent line and, as this water is non-potable, all lines also need to be marked accordingly. Preventing backflow into the potable water system is also a crucial legal requirement that must be considered to prevent contamination. Certainly, correct maintenance of the system by a qualified plumber is also an important consideration.

It is encouraging to see the growing interest in ‘green’ plumbing in a country where water is a very scarce resource. However, to realise the full benefits of these systems, which includes a smaller water footprint and savings in utility bills, it is imperative that qualified plumbers are involved in their installation, repair, and maintenance,” Reynolds concludes.