Everything you need to know about water resources

Water is becoming more and more scarce as a resource, due to factors including global warming, poor water management and water-intensive commercial practices. But although there is a need for water sustainability strategies at all levels, water scarcity hasn't yet received the same attention as renewable energy when it comes to thinking of environmentally-friendly solutions.


However, there are a variety of water sourcing and management options that can be beneficial to both the environment and financial savings. Has your business ever considered where its water supply comes from and whether there may be better alternatives? Here, we give an overview of the options available.

Tap water

Also known as potable water, this is the most common source of water in many countries. According to the World Health Organization (WHO), around 71% of people worldwide have access to safe, potable drinking water. Many countries have a centralized water supply that provides clean tap water. Some developing countries provide a decentralized system.

The advantage of tap water is that it's convenient and readily available throughout the developed world. It is also mostly safe to drink. However, water quality can vary across countries and also regions within countries. Tests have also revealed that tap water does suffer from some contamination, with one study revealing that 83% of samples contained microplastics.

There's also the issue of leaks in centralized systems, with an estimated 46 billion litres lost globally every day. Maintenance costs of these systems increase the cost of the water supply for consumers. In Flanders, the annual water bill can be as much as €535 in some regions.

Tap water is an often-used source of water in industry, which doesn’t need treatment for many applications. For some, water softening or reverse osmosis is applied, but in general, it is ready to use source. It does, however, come with a significant cost.

Rain water

Rain and snow are key to the earth's water cycle. However, rain water has never been fully utilized as a water resource. Trillions of gallons of rain falls across the world every year. Capturing rainfall through rainwater harvesting systems and using it to provide water for your business or household is relatively easy, environmentally-friendly and cost-effective. One study has shown that collecting and using rainwater in Atlanta, the USA, could supply the needs of over 2.5 million residents each year.

Collection systems start at around €40-50, but the cost rises when significant storage volumes are required or when groundworks are involved (€2000-€4000 for placement of a 20 m³ buffer tank underground). Of course, water needs to be purified if you want to use it for drinking, greywater use (toilets, showers, dishwashers, etc.) or process water. Investing in a purification system involves an initial outlay but you then have access to a free supply of water through precipitation. Rainwater is a relatively clean source of water, which is soft in nature and requires little treatment. For example, a simple filter for suspended solids, perhaps upgraded with activated carbon to prevent potential colour or odour suffices for non-potable applications.


Groundwater supplies come from beneath the earth's surface, located below soil and rocks and in underground aquifers. It is these resources that provide much of the world's freshwater supply – holding around 98% of the global freshwater not stored in glaciers and ice-caps. Naturally pure and partially replenished through rainfall which seeps through rocks and soil, groundwater can be accessed through various providers – centralized or decentralized, public or private, depending on where you live – but its main problem is that there is a finite supply. In Belgium, for example, legislation is more and more protecting our groundwater supplies by restricting the volume that companies can extract from their wells or even prohibiting groundwater abstraction. We cannot rely solely on exploiting groundwater reserves.

Additional problems associated with groundwater is the vast expense associated with extracting it and knock-on problems such as flooding and sinkholes caused by over-exploitation of the resource. Depending on the source of groundwater, iron or manganese removal might be required. Water softening can be necessary when a calcareous soil type is present. In some cases, microbial contamination or organic compounds can be present. Groundwater sources nearby brackish or saltwater bodies might even experience issues with increasing salinity.

Surface water

Surface water is the supply that comes from rivers, lakes and other fresh waterways. This supply has been much exploited for public and commercial use. Around 63% of the public water supply is drawn from surface water reserves.

Surface water has the advantage of being continuously replenished by rainfall. However, it has the disadvantage of becoming heavily polluted in recent times. Around 80% of the world's wastewater is dumped largely untreated back into the environment.

Surface water needs to be treated to remove pollutants and contaminants from its content. This is generally done at large-scale treatment plants for drinking water production or in smaller-scale installations for process water in companies. One drawback of surface water is the variability of its composition. Dry or wet periods can change the quality and the treatment plant must be designed for such fluctuations.

Saltwater and brackish water

Around 98% of the world's water is saltwater and brackish water contained in oceans and other waterways. This means that the vast majority of the planet's water supply is unsuitable for drinking and daily use in its current state. However, this water can be treated using desalination techniques to make it safe to drink. Because of this, saltwater and brackish water offers great potential as a supplementary water supply and could help avert a water crisis.

Today, desalinated water is used in many places, mostly for industrial and agricultural use but also in some household supplies. Around 300 million people across the globe access water treated at desalination plants. Economic and energy costs of large-scale production are currently high, but these are likely to be reduced as larger parts of the world come to rely on it.


Wastewater is another underused water source. Treated sewage water is often used for irrigation and non-drinkable purposes, but the UN has identified it as a potentially valuable drinking water resource as we move towards a more sustainable future.

Wastewater can be treated biologically and/or by using filtration, for example, reverse osmosis, to remove even the tiniest particles, creating pure drinking water. Some cities – such as Perth, Australia - have begun incorporating treated wastewater into drinking water supplies, greatly reducing how much water is used from other sources.

Many companies consider and even apply wastewater reuse in their organisation, saving costs and limiting their abstraction of our precious freshwater sources. Even in real estate, wastewater reuse is more and more feasible. For example, treating wastewater with a helophyte filter or membrane bioreactor for toilet flushing, or even further upgrading the water for potable use. Technologically, everything is possible, the question remains in which cases it is economically feasible as well.

The great news is you don't have to wait for the authorities to make the move to sustainable water supplies. Treatment systems are available for organizations and households. You invest in a treatment installation and then have access to cheap, renewable water.

Water Experts can help you make the best use of your water resources in a cost-effective way. Our experts scan the possible water sources on your site, determine the need for treatment and the economic viability to propose the best possible solution for your water source management.

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