Reengineering our use of water
Water scarcity is a global crisis that is affecting billions around the world in some shape or form. In case you are not familiar with water scarcity, what I mean by the term is threefold. Firstly, water scarcity is the lack of availability of water due to physical shortages. Secondly, a lack of water due to the failure of institutions to ensure a regular supply of water and, thirdly scarcity due to a lack of adequate infrastructure.
The numbers and statistics for water scarcity are staggering when broken down and in many cases largely avoidable if effective action is taken to ensure water security in affected countries and communities.
Of the 7 billion people on planet earth, 30% are currently affected by water scarcity. 2 billion people lack access to water services and face inadequate supply of water on a daily basis. A further four billion people are directly affected by water scarcity in at least one month of the year. About 1.2 billion people currently live in areas of physical scarcity and that number is expected to increase by a further 500 million people in the years to come.
In many countries, it is not a physical scarcity but rather an economic scarcity. Economic scarcity due to a lack of infrastructure currently affects 1.6 billion people. Each year, water-borne diseases kill more people than all forms of violence combined. 43% of these deaths are children under the age of 5. In the developing world, 80% of all illnesses are linked to water. Women in Africa alone spend 40 billion hours a year walking and collecting water. That’s a lot of time wasted that could be used to receive an education, make an income, or grow food.
Water scarcity is expected to increase in the coming decades from the current figures of 30% of the global population to around 50%. That's half the global population who will be affected by 2025. Solving water scarcity is a massive challenge and despite all the immense efforts already being made in this space it seems to have hardly made a dent and the world will face a massive humanitarian crisis by 2040. While many of us around the world look to governments and institutions to solve the crisis, we can start taking steps to mitigate the effects of water scarcity and do our part to ensure that the water security goal is achieved.
In the majority of cities around the world, we are mostly reliant on the government or local authorities to provide us with our water supply. We open the tap and in most cases, we get water. There is no collection, no harvesting, no need for storage, and no real effort required.
However, as water scarcity increases, the ability of institutions to provide for our growing water needs will come under strain and in some cases, they may no longer be able to provide for our water needs. One of the largest places a modern city household consumes water is the bathroom. Almost 50% of all the water used by a household is in the bathroom. While showering and bathing account for a large proportion of this, flushing the toilet equally impacts in the heavyweight division for household water usage.
With the average toilet flush using between 11 and 15 litres of water per flush, and most people doing this activity 3 to 6 times a day, the numbers stack up pretty quickly. A family of four can easily use between 176 and 300 litres of water per day by simply flushing the toilet.
The water used in most cities to flush the toilet is clean drinkable water and water that could be better used for human consumption rather than flushing our waste away. In our efforts to save water and be more water-efficient, we need to look to alternative solutions and think outside the conventional box that we have been operating in.
Now I am not saying we all rip out our toilets and go back to nature or install composting toilets, but rather posing an alternative way of managing and thinking about water usage in our households.
Solution 1: Rainwater harvesting
Rainwater harvesting is an ancient concept and human beings have been collecting water for millennia. However, for the majority of people living in urban areas, rainwater harvesting is a foreign concept and something that we have lost touch with and largely chosen to ignore due to our ever convenient supply.
In most cities, the rain that falls onto buildings, walkways, roads, roofs, and other hard surfaces does not permeate the ground and flows directly into our stormwater sewers and is disposed of into nearby water bodies. This places additional strain on our sewage systems during heavy storms or sustained periods of rainfall and can result in flooding.
A huge amount of water is lost due to run-off in urban areas and this water could have been captured to augment the local supply. In dry months, many areas around the world face water restrictions, and even groundwater supplies can be limited. Rainwater harvesting provides an excellent solution to augment the local water supply and ease the pressure in dry months for communities that face water scarcity.
While most of us living in cities cannot build our own dams to store the captured rainwater, we can install simpler systems that empower us to capture it. The concept is extremely simple and essentially involves capturing and collecting rainwater during periods of rainfall in some form of a collection device for later use. From simple barrels and water storage tanks to complex systems with underground tanks, added pumping as well as water purification capacity, we can all augment our water supply and decrease our demand from local authorities.
If we take an average domestic roof’s surface area of 100m2 situated in a low rainfall area of only 600mm of rainfall per year, and we crunch the numbers, we have the potential to capture 60000 litres of water, per year. That's a significant amount of water that could be harvested and used to help to provide a source of water in drier months.
While the roof of your house or apartment is the most convenient and easiest way to capture rainfall, rainwater can be captured from any area that has significant runoff. Any hard ground surface areas such as pathways and driveways can also be channeled and water collected and stored. Many systems that are commercially available include a mechanism to ensure that the water captured is free from silt, dirt, and unwanted insects and pests. Simple first flush systems, filters, or similar devices are used to achieve this.
Storage tanks can then be properly sealed and isolated so that nothing can enter the tank's post storage. This helps to prevent any degradation of the supply. Storage tanks come in all shapes and forms and it is easier than ever to find a solution to enable you to capture water at home. These systems are also relatively cost-effective and do not require a huge amount of maintenance. From tanks that sit above ground to underground reservoirs, you can easily get started collecting rainwater.
The nonpotable water that is collected from rainfall can be used for irrigation, flushing toilets, washing cars, doing our laundry, and if required purified for our consumption. Earlier we mentioned that toilets consume a huge amount of clean drinkable water each day. One further way that you can save clean water is by redirecting your stored rainwater to your cistern in order to flush your toilet.
Solution 2: Greywater recycling.
Every time you take a shower, wash your clothes, do the dishes or empty the cleaning bucket in the drain, you are flushing water into the local sewage system that could still easily be reused. Greywater is domestic water that is generally generated from sinks, baths, showers, dishwashers, and washing machines.
This water does not contain feacal matter, has a low level of pathogens, and is generally free from heavy chemical pollutants associated with industrial wastewater. While this greywater may contain grease, hair, dirt, and other household cleaning products it is easily reusable within the domestic environment for nonpotable use (unless properly treated).
While the water appears to be dirty and extremely unsuitable for use, the water is generally perfectly safe for irrigation purposes and for flushing your toilets. With greywater accounting for up to 65% of the total wastewater produced by a household, it is definitely an area that one can look at in order to reuse water and augment the local supply. Most households in the city use clean potable water once and dispose of it when in fact it can be reused. Reusing water will decrease your water demands and ultimately your water bill.
The key to an effective greywater system is to ensure source separation and enable your greywater system to collect only water from sinks, showers, baths, dishwashers, and washing machines. It is essential to ensure that toilet wastewater is not included in the greywater system as this contains a large number of pathogens and is difficult to treat at a domestic level. Storage of greywater should be for a very short period of time if it is not treated prior to storage.
The treatment process in the domestic environment uses the same principles used for sewage treatment but on a far smaller scale. There are essentially two main ways we think you can easily deploy for the effective treatment, processing, and cleaning of the greywater.
Firstly, biological systems where you construct small ponds and biodiverse landscapes that naturally purify the water. Admittedly for these, you would need to have a garden or suitable outside area and this may not be possible. So, secondly, you may consider deploying mechanical systems that use sand filtration, UV radiation, or lava filter systems to treat the water.
Whichever method you decide to use for reusing your greywater, you can greatly augment your water demands and decrease your water bills. If you pipe your greywater back into your toilets or use it for irrigation you will save a huge amount of water on an annual basis.
Make sure that you get professional help when setting up a greywater system so that you effectively implement a sustainable solution. It is important to note that if you decide not to treat the water, care should be taken in its use thereafter. It will not be suitable for drinking or use in the irrigation of edible crops.
The harvesting of rainwater, as well as the reuse of greywater, provides you with a fantastic large potential source of water that you can tap into.
With water scarcity increasing around the world and the demand for water increasingly every year, reengineering how we use and dispose of water in our households is essential to long-term sustainability and more effective use of our water resources. By making some small changes, you will not only be helping to save water by effectively reusing water that would otherwise have gone to waste but also reducing your water costs.
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This article is brought to you by H2O Securities. H2O securities are committed to solving the global water crisis and taking an active role in the future of water infrastructure finance. To find out more about H20 securities go to https://h2o-securities.com/
