A threat to Lebanon's waters... Climate change exacerbates nutrient pollution crisis

Writer: Salma Arafa - Translator: Amira Gawdat
الاثنين 26 فبراير 2024 | 09:22 مساءً

From eastern Lebanon, specifically north of the “Bekaa” Valley area, the "Litani" River, which makes its way up to 170 km, stems to its final destination; it pours into Mediterranean waters.

The “Litani” River, whose basin extends over 2,000 km, that was seen as a factor in Lebanon's development, has suffered for a long time from a high level of pollution, as has the “Qaraoun” Lake, which was created simultaneously at the end of the 1950s.

What is meant by nutrient contamination?

Nutrient water pollution has joined the list of threats to Lebanon, which is experiencing infrastructure crises, and the unjust exploitation of its resources has had an impact on the availability of drinking water, although it is relatively rich in water sources compared to the surrounding countries.

Nutrient water contamination refers to excessive amounts of nutrients, such as phosphorus and nitrogen, reaching water because of several factors, such as their leakage from chemical fertilizers used in agriculture, from livestock waste, the arrival of untreated wastewater, or the mixing of rainwater with surfaces carrying such agents, and then their movement into water, according to the EPA website.

Global warming exacerbates the crisis

Climate change has increased the concentration of these pollutants in different ways. Speaking to “Green in Arabic”, Dr. Milad Al-Khatib, lecturer at the School of Environmental and Engineering Studies at the University of Balmand, Lebanon say that climate change, accompanied by a decrease in rainfall, high evaporation rates, increasing water demand and increasing numbers of displaced persons from neighboring countries, has exacerbated the problem.

Al-Khatib pointed out the increased use of pesticides containing such elements during the COVID-19 pandemic, which pushed larger numbers of people to take up home farming for fear of crowding in the markets, coinciding with the spread of the wrong idea that these pesticides may contribute to eliminating the virus itself. This led to an increase in the levels of nutrients in the water, such as phosphorus, besides the arrival of untreated household waste into the water, in addition to factories pouring their waste into the waters of the rivers that feed the Litani River.

Qaraoun Lake... Waste tank

As for Lake Qaraoun, it has also turned, according to the opinion of the Lebanese expert, into a waste tank due to factories dumping their waste into its waters. This led to the emergence of many types of bacteria and a change in the color of the water, which leads to the death of tons of fish and their floating on the surface of the water.

Some have resorted to alternatives such as the creation of artificial fish farms, but eventually the farm has a small area other than the lake, which led to a low level of fish trade, and its high price in the ocean of the basin.

Repeated instructions not to use lake water also reduced the number of tourists visiting the Lake District, decreasing the economic return, and impacted the lives of the residents of the area, according to Al-Khatib.

Nutrient Pollution is one of fish Death reasons- ReutersNutrient Pollution is one of fish Death reasons- Reuters

Another crisis mentioned by the lecturer at the School of Environmental and Engineering Studies at the University of Balmand, Lebanon, is the indiscriminate exploitation of Lebanon's groundwater; Any person can now drill and exploit water, so the frequent presence of underground wells around the Litani Basin has drained the river and led to a high concentration of nutrients as pollution persists.

Scientific attempts

In July 2023, “Heliyon” published the results of an idea proposed by a group of researchers to confront the nutrient pollution crisis in the region's waters, through an artificial wetland.

Wetlands are characterized by the proximity of the water's surface level to the land, and the growth of plants that contribute to the capture of many contaminated elements when they cross water.

Speaking to “Green in Arabic”, Dr. Mohamed Reda Suleiman, Associate Professor of Civil and Environmental Engineering at the Arab University of Beirut, says that the idea is to pass nutrient-laden water at a plant treatment station through which nitrogen and phosphate are absorbed, so that the water comes out free of most impurities.

The professor at the Arab University of Beirut points to the success of many such models in Europe, and in China with more than 400 plant processing units, but the problem is the need for large areas of land.

According to Suleiman, nutrients provide the right environment for the growth and proliferation of bacteria, and algae consumed by microorganisms, which in turn are food for fish, but what happens when the nutrient ratio becomes greater than the consumption rate, is an increase in the growth of algae we often see on the water surface, preventing the passage of sunlight and consuming oxygen which leads to fish deaths; This occurs in closed lakes, but the situation is better in rejuvenated seas.

But there is another aspect that Suleiman referred to, when talking about implementation of the idea, which is that the basic is to prevent contaminants from accessing water. And, that's the point where Dr. Milad al-Khatib, who also participated in the study, also agreed. The suspension of all sources of pollution of all kinds is a condition for achieving the study's results. The lake cannot be cleaned up, and there are tons of other wastes coming into it.

"Al-Khatib" points out that this area can be exploited for water purification, because water slows down its speed, then it deposits nutrients at the bottom and benefits plants. He added that wetlands have a greater impact with biological waste.

Al-Khatib continues that their data from the Litani River Service indicated that the phosphorus rate was 37 times higher than the U.S. EPA's average.

نهر الليطاني- مصدر الصورة: EJAtlasLitani River, EJAtlas

According to the results of the published study, wetlands can reduce the Litani River phosphorus by 43.7%, while ammonia and nitrate will decline by 56% and 57% respectively.

Dr. Jalal Halwani, Director of the Environmental and Water Sciences Laboratory at the Lebanese University, believes that before the nutrient treatment process begins, the flow of non-biodegradable industrial pollutants must be stopped; because relying on wetlands technology can reduce the size of organic nutrients, but - in his view - it cannot affect chemical pollutants coming from riverside plants.

Export crisis

"Halwani" describes the Litani River as one of the most "distinct contaminated rivers", citing the economic effects of this, including the prevention of entry of Lebanese agricultural products into many countries of the world due to crops microbial and chemical contamination.

The Director of the Environmental and Water Sciences Laboratory at the University of Lebanon, speaking to “Green in Arabic”, noted the relationship between the worsening phenomena of climate change and nutrient contamination, stressing that because of high temperatures farmers resort to increased use of water and fertilizers, then the phenomenon of "hyper-nutrition" occurs because the soil take only what it needs.

According to Halwani, this phenomenon not only extends to Lebanon, but also to many countries in the Arab world whose farmers are trying to overcome climate variability, such as the halt of winter rainfall, or rising temperatures during the spring.

On the impact of that phenomenon on Lebanon's marine environments, the Director of the Environmental and Water Sciences Laboratory said that Lebanese shore is affected by nutrients only in rare cases when waves, that play a significant role in pumping oxygen gas, stops.