The deposits into the lake mainly stem from indigenous and non-indigenous sources which are causing water pollution as well as climate disorder, research found.
Indigenous [autochtones] sediments group a large organic and a mineral component whose organic tenure average 3% that is a production of 20 to 60 tons per hectare comprising 2% algae and 1% organisms with carbonate.
While deposits of non-indigenous [allochtone] origin come from the disintegration and erosion of the various geological formations that border the lake basin plus proxy solid and liquid wastes.
They are from households, crafts and industries in different places in the economical city of Bujumbura.
This waste mainly includes plastics, polluted water from industrial processes, wastewater (from toilets), as well as gray or domestic water (from sinks, showers, kitchens and washing machines, etc.).
They queue into rivers that end up in the lake to influence the water’s physico-chemistry conditions (temperature and oxygen tenue).
“Any factor that affects the physico-chemical conditions of lake water has an impact on organic sedimentation and hence on the animal species that depend on it”, said Jean Marie Sabushimike, Environmentalist, Lecturer at University of Burundi in the Geography Department.
For the past decades, the lake’s temperature rose up to 26oC (26 degree Celsius that is +1oC) while hydrogen potential (pH).
Over the last 40 years, an increase in air temperature has been observed in the Lake Tanganyika region. An average increase of 0.40°C during the dry season against 0.28°C during the rainy season in the upper layers (0-100m). An increase of 0.14°C was also noted at a depth of 300m.
Healthy aquatic ecosystem depends on the physico-chemical and biological characteristics.
Research shows that indiscriminate disposal of waste effluents, population growth, the rise of industrialization and the increasing use of phytosanitary products (fertilizers and pesticides) in agriculture have caused the degradation of aquatic environments.
“Which changes the physiology and ecology of aquatic biota, threatening the balance of aquatic ecosystems. Consequently, an intensification of eutrophication resulting in undesirable effects such as a decrease in biodiversity and an increase in species tolerant to pollution”, said Lambert Niyoyitungira, contributor to the research.
Nevertheless, freshwater fish are one of the most threatened taxonomic groups because of their high sensitivity to the quantitative and qualitative alteration of aquatic habits, fish richness and diversity are rapidly declining and some species have become extinct, he added.
Christian Nimubona, Director General of Environment, Water Resources and Sanitation within the Ministry of Environment, said last week when visiting affluents of lake tanganyika in Muha commune that it is essential that the entire population assumes its responsibilities to protect the environment.
He added that rivers and streams whose waters flow into Lake Tanganyika should not be used as dumping grounds.
Wastewater, a threat to human health
In some localities in Bujumbura, residents use water fetched directly from lake Tanganyika or its affluents where sediments crowd.
The situation has resulted in unhygienic diseases such as Cholera, dysentery and diarrhea. In Buterere zone located in the north of Bujumbura city up to 30 cases were recorded in two health centers. Most of them are children under five years old.
Christa Mwajuma, a nurse met at Tunza health center, told me that every day they receive at least 15 patients seeking medical treatment, a half of them exposing symptoms of Cholera and Dysentery.
Since water shriveled from taps, residents use unclean water for basic needs. Therefore, some of them use it immediately without cooking them to kill bacteria which leads them to contaminate unhygienic diseases, said Christa.
Jacqueline Kanyana met fetching water from ditches indicates that they have been running out of clean water supplied by Regideso, a water state-owned company for two years.
“We have been using water from ditches and rivers for two years as an alternative way to survive. We wash our clothes, dishes and wash our kids by using this water”, said Jacqueline.
Buterere zone has been a hub of all trash collected from Bujumbura. Almost the whole drainage channels in Buterere are filled with dumps which make the whole area reek and the citizens breathe bad oxygen.
The director general of Regideso said that the problem of water scarcity is not going to be solved soon.
Albert Manigomba told the media press in July that a lack of sufficient materials and the continuation of the expansion of the city are a major problem.
Impunity a root cause of wastewater and water pollution
A large number of factories, companies and drugstore houses are owned by the pro government or ruling party chiefs, a journey to combating water pollution is still rocket science, said Gabriel Rufyiri corruption watchdog in April.
Owners throw the used materials in ditches instead of keeping them in trash.
To address it, said Rufyiri, it is essential to adopt good practices by industries, households and users of aquatic environments.
Gabriel Rufyiri said that the violation of public policies, in particular the failure to comply with the Water Code, which stipulates that construction must take place 150 m from the shore of Lake Tanganyika and 25 m on either side of the banks of its tributaries that flow through the city of Bujumbura.
The practices also include, in particular, the establishment of water treatment systems before discharge, the regulation of soil fertilization, the prevention of wastewater transfers to aquatic environments, the supervision or prohibition of the use of hazardous substances and the protection of water catchments.
Sanctions are being considered
Christian Nimubona announced that the ongoing raids by the Ministry of the Environment to assess the situation of wastewater discharges into the rivers crossing the city of Bujumbura would be followed by the application of the sanctions provided for by the water code.
According to Article 142 of Law No. 1/02 of March 26, 2012 on the Water Code in Burundi, any person who, in violation of Articles 52 and 53, introduces materials harmful to the health of surface or groundwater is liable to a sentence of penal servitude of two months to five years, a fine of fifty thousand to eight hundred thousand Burundian francs or one of these penalties.
