South Africa is a water-stressed country. Our average rainfall is around half of the global average and many areas have continuous water restrictions. Added to this, our population is growing at a rapid rate, which is putting further pressure on our already limited water supply. Because of this it makes sense to look at ways to reduce, re-use and recycle water.
About 60% of water in South Africa is used in agriculture. In homes, most of our water usage goes to flushing toilets and taking a bath or shower. In households with gardens, over 45% of water usage goes to irrigation.
Greywater systems for re-use
Every day the average household flushes hundreds of litres of reusable grey water down the drain. A simple grey water system can divert this water, and a residential household of four people can save between 200L and 300L of grey water daily. Water that has been used for washing – whether in the bath, shower, basin or the washing machine – is called grey water. This water can be reused for garden irrigation, allowing you to save potable water and money spent on municipal water usage, and let you water your garden all year round – even in times of drought.
“Reusing grey water in the home is just one of the ways you can choose a more sustainable lifestyle. It’s relatively easy to achieve and most systems are cost-effective to install. Your water costs will also decrease, as you are recycling water you would otherwise be dumping down the drain,” says Orlando Luis, CEO of Brights Hardware, a chain of hardware stores which sell a range of water wise solutions and systems.
Luis explains that the easiest way to utilise grey water in your garden is to re-route the pipes that usually carry the water from the bath, shower or washing machine into the sewer system, into a grey water storage tank which is connected to a pump and an irrigation system, and directs water into the garden. “There are a range of options available depending on your needs and budget – systems can be professionally installed or home owners can opt for the DIY route. Just be sure that the system you choose has an overflow pipe or valve, which enables you to divert water back into the sewer during periods of heavy rain, when harmful chemicals have been used in the water or during periods of illness. The system should also include a filter to remove solid waste like soap, lint and hair from the water before it is distributed.”
Guidelines for using grey water safetly:
- Never store grey water for longer than 24 hours.
- Choose biodegradable and environmentally friendly personal hygiene and cleaning products to prevent a build-up of salts in the soil.
- Never reuse water from your kitchen sink or dishwasher.
- If you wash cloth baby nappies in your washing machine, divert the water to the sewer. You should also do this when using chemicals like hair dye or bleach and if someone in the household is sick.
- Allow grey water to cool in the tank before irrigating the garden. Hot water can kill off beneficial organisms in the soil.
- Never allow anyone in your home, including pets, to drink grey water.
- Grey water shouldn’t be allowed to pool on or run off paving – make sure it soaks directly into the soil.
- Don’t overwater plants just because you have the water. If there has been a lot of rain, rather divert the grey water to the sewer.
- Maintain your system properly and clean the filters regularly.
Rainwater harvesting for recycling
Rainwater harvesting is a technique that collects and stores rainwater for irrigation, laundry, toilet flushing, pool top-up, wash bays and as an off-grid/alternative supply of water.
Luis explains that rainwater can be collected from various hard surfaces such as rooftops, and rainwater harvesting is growing in popularity due to an overall interest in reducing the consumption of potable water and the inherent qualities of rainwater. “Unfortunately, urban living, population increase, climate change, failing infrastructure, pollution, and our lifestyles are all contributing to a worldwide water crisis as our demand exceeds our supply. Rainwater is a natural resource and an excellent source of water for irrigation and household water use.”
The benefits of rainwater collection
- Rainwater is a relatively clean and absolutely free source of water.
- You have control over your water supply (ideal for cities with water restrictions).
- It reduces stormwater runoff from homes and businesses.
- It can solve the drainage problems on your property while providing you with free water.
- It uses simple technologies that are inexpensive and easy to maintain.
- It can be used as a main source of water or provide an excellent back-up source for emergencies.
- The system can be easily retrofitted to an existing structure or built during new home construction.
- Systems are very flexible and can be modular in nature, allowing expansion, reconfiguration, or relocation.
Installing a rainwater harvesting system, is relatively simple, according to Luis. “Rain barrels can get you started. This method is the most common and one that many people are familiar with. This involves installing a barrel at a gutter downspout to collect rainwater. There are many readily available commercial options on the market.”
“The benefit of this option is that it is easily installed by anyone at any home, barrels are readily available and affordable, plus they don’t take up much space. However, they have a small capacity so can easily overflow and waste opportunities to be collecting larger volumes of water. A better solution is to install a rain water tank – or several – and to re-route your gutter system on the home to channel the rain water into these tanks,” says Luis. “Tanks come in a wide range of colours, styles and capacities to suite all budgets, spaces and needs.”
Filtering tap water
South Africa’s collapsing water infrastructure has been in the news recently. This follows the release of the Green Drop Certification Programme report which found that South Africa’s wastewater treatment plants were in a state of collapse, which could result in E. coli bacterial infection and dangerous chemicals ending up in our water systems.
The Blue Drop Progress Report 2022 established that tap water from the majority of municipalities posed a potential health risk to people. The drinking water from 60% of our municipalities does not comply with the microbiological limits as required by the drinking water standard, and 81% have no water safety plans. “In light of this it is a good idea to look at water filtration systems for the home,” advises Luis.
“Water filtration is a method used to remove and reduce impurities in the water. A good water filter acts like a sieve to remove all the bad stuff like chlorine, dirt, dust, rust, and cysts such as Giardia and Cryptosporidium but keeps in all those important salts and minerals to keep us healthy.”
Home water filtration systems can range from simple bottle water filters and filter jugs to in-line tap water filtration systems, fridge water filters, and also reverse osmosis systems. “A popular choice is an inline water filter system. These are as simple as one cartridge that you can attach yourself. With an inline water filter system, you have access to fresh, filtered water on tap. It’s attached under your kitchen sink and filters all the water coming through your original tap.,” says Luis. “Reverse osmosis is a water filtration technology that uses a semi-permeable membrane to remove ions, molecules and larger particles from drinking water. This is achieved by passing water at high pressure through a thin membrane. However, this is only one stage of a four-stage process. Where the water passes through a sediment filter first, then a carbon filter, then the reverse osmosis membrane and finally a filter to remove the odour and taste.”
Purifying tap water
“The easiest and most well-known way to ‘clean’ water is to boil it. The extreme temperatures are able to kill off most pathogens and bacteria. Other options to purify water include additives such as Aquatabs which are effervescent tablets that kill microorganisms in the water to prevent water-borne diseases like cholera, typhoid, and dysentery.”