Those in favour

The critical issue of water shortage is not going away. It has to be dealt with. Many people are critical of the government who, they say, have not acted fast enough to deal with this problem. We know that northern Portugal is not willing to share their water reserves with the Algarve. Rainfall in the Algarve is not sufficient to supply all the water needs, and subterranean water reserves are getting contaminated. The only long-term answer, say many people, is desalination plants. The first one is due to be built in Albufeira.

Those against

The Sustainable Water Platform (PAS) and several environmental organisations are objecting. The 6th April edition of The Portugal News covered many of the objections. Less has been spoken about the fishermen of the area, who believe the desalination plant threatens the fishing in the locality.

What are the facts?

Desalination, the process of removing salt and impurities from seawater to make it suitable for human consumption and agricultural use, has become increasingly prevalent in addressing water scarcity issues around the world. However, there are growing concerns about the potential damage desalination may cause to seawater.

The Madeiran Island of Porto Santo has been entirely dependant on desalinated water since 1980. It marked a significant milestone in the island's efforts to combat water scarcity, a problem that had become increasingly pressing as the local population and tourism sector began to expand.

More interesting is the views of the local fishing industry, one of the groups who are opposing the construction of the plant in Albufeira. The increased availability of fresh water in Porto Santo has indirectly benefited the local fishing industry by supporting the growth of tourism on the island. Tourists attracted by the island's natural beauty and improved facilities, including the reliable water supply, have in turn increased the demand for local seafood, providing a significant boost to the fishing sector.

Reverse Osmosis facts

Reverse Osmosis is a technology that is used to remove a large majority of contaminants from water by pushing the water under pressure through a semi-permeable membrane.

Reverse osmosis is one of the most effective forms of water filtration because unlike chemical or carbon filtration systems, which use certain materials to attract or directly target the contaminants in the water, reverse osmosis works by pushing water through a microscopically small filter material.

This semi-permeable membrane has a pore size of around 0.0001 microns, effectively only allowing the small water molecules through and catching any larger molecules of contaminants, organic materials, or salt. This technology is used to desalinate seawater and reduce high chemical contaminant material such as heavy metals, reverse osmosis is now in use in many governments, commercial, military, and even residential applications.

I have a tabletop unit in our kitchen to treat our drinking water. You can get them from Amazon. It produces superb crystal-clear drinking water, better than water in a plastic bottle. The process of cleaning the water results in about one-third of what you put in being returned to dispose of. In the case of a desalination plant, this ‘rejected’ water is what would be returned to the sea, but there are no chemicals, it’s simply what has been filtered out of the original water. Why should this be a problem?

The problem

According to leading environmental organisations, the desalination processes comes with its own set of environmental challenges that need to be addressed. One significant concern is the production of wastewater, known as "concentrate," during desalination processes. This concentrate is contaminated with chlorine and copper and has a salinity level twice that of ocean water, posing a threat to marine ecosystems. Improper disposal of this concentrate can lead to the creation of a dense plume of toxic brine, which can have detrimental effects on coastal and marine environments.

Furthermore, the rise in salinity and temperature resulting from desalination activities can lead to reduced levels of dissolved oxygen in the water, contributing to the formation of "dead zones" in the ocean.

These dead zones can significantly impact marine animal habitats and disrupt the delicate balance of marine ecosystems. Therefore, it is crucial for desalination plants to implement proper wastewater management strategies to mitigate these environmental impacts and safeguard marine biodiversity. The design of the new desalination plant in Albufeira has the benefit of the latest advances in this technology so should, in theory, be both safe and effective.

Why Albufeira?

One of the most interesting factors is why Albufeira. The initial studies identified Portimão and Monte Gordo. The main selection criteria were the proximity to the ocean, to the water distribution network, and to the power grid, while avoiding national park areas and main recreational beaches. Albufeira has very busy beaches! Power consumption is a major factor.

Albufeira will use alternative ‘green’ power sourced energy, solar being a major energy source, there is no shortage of sunshine in the Algarve.

While desalination plays a crucial role in providing freshwater in water-stressed regions, it is essential to consider its potential damage to seawater. The environmental impacts, health implications, and technological advancements highlight the complex relationship between desalination and seawater quality. By prioritising sustainable practices and continued research into minimising the adverse effects of desalination, we can ensure the long-term health and preservation of our oceans and marine ecosystems.

The problem is that we don’t have any other choices.


Resident in Portugal for 50 years, publishing and writing about Portugal since 1977. Privileged to have seen, firsthand, Portugal progress from a dictatorship (1974) into a stable democracy. 

Paul Luckman