Learning from Island Communities: Greywater and other Sustainable Lessons

Water scarcity is a persistent problem today, and this is (ironically) especially felt by many island communities around the world. A 2019 report by UNESCO states that 71% of Small Island Developing States (SIDS) face water scarcity, and this figure is as much as 91% for SIDS in low altitudes. Saline intrusion, groundwater pollution, tsunamis, hurricanes, floods and drought are some of the major risks to water security that affect these areas. Other challenges include high population density, climate change risks with respect to erratic weather patterns and rising sea levels, and outdated public infrastructure. While these challenges are not peculiar to island communities, as they can be felt globally, these communities largely bear the brunt of it. So, a simple layman’s question would be: how come islands continue to thrive? What is the secret?

These island communities have existed as long as many of the other communities in more freshwater abundant regions, irrespective of their water stress. This underscores the importance of the conservation techniques which they have developed, such as communal utilization of greywater, to cope with this situation. I find their resilience and adaptability fascinating, hailing from a tropical rainforest region myself, and a solid template the rest of the world can ape to survive our current water-scarce predicament. This article aims to examine some of those techniques without boring the reader and aim to shed some light on low-hanging fruits we can all take up.

All of us are Water stressed

A water stressed region is simply one in which the demand for safe, usable water exceeds the available supply. In this case water use is not restricted to potability for drinking or cooking but includes ecological requirements to ensure use does not limit the ability of future generations to use, sanitation, and agriculture. Some factors exist which can impact water stress, such as population density, climate change, inefficient water use, or dearth of public infrastructure. These factors are often more relevant to water scarcity than the physical conditions of the location. The MENA region has often been termed the most water stressed region on the planet because of its aridity. However, the ease of getting clean, safe water in the Rub’ Al-Khali portion of the UAE or the Nevada desert is much greater than getting it in Uromi, Edo state, a water stressed region in an unbelievably muddy tropical rainforest in Nigeria. This is because where the economic realities in Uromi preclude its ability to sustain its water requirements, the political will, financial ability and public infrastructure exist in the United Arab Emirates to literally pull water into the desert.

However, the ease of getting clean, safe water in the Rub’ Al-Khali portion of the UAE or the Nevada desert is much greater than getting it in Uromi, Edo state, a water stressed region in an unbelievably muddy tropical rainforest in Nigeria.

We are all water stressed because a quarter of the world’s population, about 2 billion people do not have access to potable water. During the onset of the COVID19 pandemic, 2.3 billion people could not even access water to wash their hands, not to talk of drink. Lack of quality water results in the spread of communicable diseases which affect us all. Agricultural pursuits are more expensive where water is a challenge, leading to more expensive food, leading to hunger, leading to more illness and it goes on and on.

Island Communities face unique water challenges

This article focuses on island communities because of the unique water challenges they face such as:

Saltwater intrusion into freshwater or groundwater sources.

This can happen naturally when freshwater aquifers flowing towards the shoreline as a result of lower elevation or even osmotic levels, ends up creating a wedge-like interface with denser saltwater exerting greater hydraulic pressure beneath it. Thus we have a layer of freshwater on a saline base at the coastal areas. It can also happen due to ecological impacts such as global warming and rising sea levels which enable the salt water to push inland in both surface and groundwater. It can also be as a result of anthropogenic activities such as excessive extraction of freshwater from the groundwater, thereby disrupting the pressure difference between the freshwater columns and the saltwater leading to intrusion from the sea or ocean.

Reliance on rainwater

The conditions laid out above such as constant saline contamination of the groundwater, coupled with the high cost of importing freshwater across the ocean, can force an island to rely on rainwater, which may not be abundant year-round. Constant saline contamination of groundwater, the huge cost of importing freshwater across oceans, ensures rainwater harvesting becomes the next viable option. ?with the heavily saline With the fickle nature of nature herself in these uncertain times of climate change, rainfall patterns are inconsistent and droughts are more frequent, making the situation very precarious.

Island communities have developed innovative water conservation strategies to combat these challenges, efficient rainwater harvesting, greywater treatment and use etc. Their expertise in this regard offers a trove of knowledge for regions around the world where water stress is fast becoming a huge problem.

Greywater Reclamation and Recycling

Wastewater generated from household activities is classified into two groups: greywater and blackwater, based on their waste and pathogenic load. Greywater is the relatively clean effluent from activities such as bathing, washing dishes and laundry. It is different from the highly contaminated toilet or kitchen drain effluent called blackwater. Unlike blackwater, with only minimal treatment, greywater can be safely reused or disposed into a water body. Island communities have long factored in greywater recycling as a critical component in their water conservation strategy for irrigation, landscape management or even flushing toilets.

Island communities have developed innovative water conservation strategies to combat these challenges, efficient rainwater harvesting, greywater treatment and use etc. Their expertise in this regard offers a trove of knowledge for regions around the world where water stress is fast becoming a huge problem.

In places like the Galapagos Islands and the Canary Islands, greywater recycling has been implemented as a matter of policy to reduce the impact on the scarce freshwater supplies. The greywater is collected and filtered with sand filters before being reused. Private residences looking to cut on costs of freshwater utilization in the Gulf Islands of British Columbia also implement greywater reclamation in the building construction, connecting laundry and bathroom sink water drains to water closet cisterns for flushing toilets. The total demand for freshwater is reduced, and the mineral rich greywater with increased amounts of phosphorus serves as a sustainable solution to agriculture and landscape management. Greywater utilization also reduces the strain on sewage systems, especially when reclamation and recycling occurs on site.

Rainwater harvesting

As earlier communicated, most islands engage in rainwater harvesting as a solution to freshwater scarcity. In Bermuda, the law requires that buildings are constructed with limestone roofs that are designed to collect the rainwater into underground tanks, from where it is utilized for drinking, cooking and other domestic uses. This simple, but effective rainwater harvesting technique makes it easier for these islands to cope with the erratic rainfall patterns.

Water-saving devices

Island communities use several water-saving devices such as low-flow faucets and showerheads with proximity sensors that turn the tap off when there is no one using it, dual-flush toilets that use different volumes of water for liquid and solid waste, wash-down flushing designed toilets as compared to traditional siphoning flush toilets to push the waste down, rather than whirling, etc. The use of these water-saving devices is required by law on these islands, and supported by a cultural mindset of conservation built in through education and community engagement.

Desalination

Many islands in the Bahamas have their groundwater completely saline. In Nassau, New Providence, desalination is the most viable option for treating water intended for drinking and household use. In Malta, where 70% of the drinking water comes from desalination, they take it a step further by incorporating sustainable energy sources such as solar power to treat the salt water.

We need to apply these strategies broadscale

Greywater recycling, rainwater harvesting and use of water-saving devices are strategies that offer hope to all water-stressed communities worldwide. In residential and industrial areas where water consumption is high, greywater recycling can easily be implemented with only basic infrastructural investments. Cities and towns, such as my indigenous home in Uromi, Nigeria, can incentivize citizens to install rooftop catchment systems and provide either tax breaks or financial assistance to those who do. The government can also support (and make it trendy) by building large scale rainwater storage systems where the water can be stored ahead of the dry seasons.

School children, from the primary schools onwards, need to be taught the importance of water conservation and the need to imbibe a water savings mindset. Civic education in the marketplaces, religious gatherings and other outreach centres must also be practiced to show people the tangible benefits and the need to reduce their water demand.

While we wait for policy support for the big steps, we can all take some small steps too:

• Install low flow faucets in your home.
• Collect and reuse greywater in your homes for flushing toilets, washing floors, or even watering your lawns
• Collect rainwater for storage to use in drinking (after boiling), washing your vehicles, kitchenware, laundry etc.
• Teach your children not to leave taps unattended, resolve leaky taps and pipes early etc.

There are many little ways in which we can support our world, and reduce the water demand within our communities.

If you found this article interesting or informative and you would like to engage further, don't hesitate to drop a comment below.??

References

Water Stress: A Global Problem That’s Getting Worse | Council on Foreign Relations (cfr.org)

Small islands: meeting the challenges of freshwater resilience | UNESCO