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How Does Climate Change Cause Groundwater To Be Unsafe?

As climate change intensifies and reaches a point of no return, a lot of changes have been seen in how people have to live their lives, some of which are more obviously connected than others.

The increase in extreme weather phenomena, droughts, flash flooding and soaring temperatures are more obvious ways in which climate change affects water security, but there are also problems underneath that highlight the need to focus on water recycling now.

One of these is the risks some effects of climate change have on existing potable water supplies, which could make them unsafe to drink without treatment.

As with many climate change effects, this is not a hypothetical, as an island in the middle of the Pacific Ocean has proven to be a canary in the coalmine for many concerns surrounding safe water access.

The Seeping Threat

One of the islands that make up the nation of Vanuatu, Malekula has a population of just 25,000 people, but this community has already seen the water supplies that make living on the island possible start to face serious issues, and it is just one of many islands to have this issue.

The island cluster of Vanuatu is known for its diversity of different communities that historically led self-sufficient, separate lives, but it has also proven to be particularly vulnerable to the dangers of climate change.

Whilst a significant proportion of the people living on the 83 islands that make up Vanuatu have a modern plumbing and drainage system designed to be relatively robust, some islands rely on wells and ground pump aquifers for some or all of their water needs.

Due to the cumulative effects of erosion and the rising of sea levels, wells that were away from the seawater are being drawn ever closer, leading to a dangerous phenomenon known as saltwater intrusion.

This is the movement of salty seawater into coastal aquifers, which increases the salt level of the water pumped from the waters, making it increasingly unpleasant and potentially dangerous.

High salt content over time increases the risk of kidney disease and high blood pressure, but most studies on these effects focus on the effects of relatively minor but constant intake of salt over a long time.

Drinking high amounts of seawater risks causing hypernatremia, an abnormal level of salt in the blood, which is commonly a symptom of dehydration and causes an increase in thirst, loss of appetite and nausea. At extreme levels, salt poisoning can be fatal.

More water is removed from the body to get rid of the sale than is gained from the saltwater, meaning that it is effectively undrinkable.

The cause of this intrusion of saltwater into aquifers is partly the result of rising tides in a part of the Pacific Ocean where sea levels are rising higher than any other on Earth, but it is also caused by population growth.

The more people who live in an area, the more water is needed to be pumped out of the ground, and the more the pump is used, the greater the risk of intrusion of saltwater.

When this happens it can be devastating, as there are few realistic alternatives to help their situation.

The first suggestion would be the use of desalination machinery to filter the salt from the water, but given the expense of both these machines and the energy needed to power them, it has proven to be too expensive for many island authorities.

The alternative is rainwater capture, but in areas like Malekula, many of the villages have houses made with traditional thatched roofs, which are not suitable for the installation of the tanks and piping needed to make rainwater capture plausible.

Rainwater is also potentially contaminated with bacteria such as E coli, which can cause food poisoning, stomach pain and potential kidney failure.

The biggest issue for many on the islands is that whilst rainwater capture works for the most part to fill the majority of their water needs, droughts force the use of wells and pumps, and if

they have saltwater intrusion, they effectively have no water unless they boil it first.

These issues combined with an increase in droughts, cyclones and flash flooding to cause serious issues for water security and a need to think about ways to consume less freshwater from non-renewable sources now rather than later.

It is already significantly affecting communities and this will intensify as sea levels increase and global temperatures rise, putting lives at serious risk in the process.