Page 30 - AL BUHAIRA RAPPORT 2022
P. 30

6          Caring activity of                                                                                                                              Monitoring and following up the lake



                     the lake water surface                                                                                                                          water quality and the environmental

                                                                                                                                                                     situation of the water surface
                                                                                                                                                                                                                                         Monitoring the rainwater network connected
                                                                                                                                                                     Laboratory activity                                                 to the lake

            •  The water surface of the lake is a balanced natural environment that represents one of the main pillars
                                                                                                                                                                     The company’s laboratory monitors the quality of the lake’s water and the rainwater   The quality of rainwater is continuously monitored at the level of the lake’s
               of the bank development process. On this basis, the company attaches great importance to its care and
                                                                                                                                                                     that flows into it, and monitors the environmental situation of the lake’s water   sewage at 20 points, particularly in times of rainfall with the aim of evaluating
               continues to preserve its environmental system, for more than 33 years, by implementing a monitoring
                                                                                                                                                                     surface periodically and continuously as part of an annual programme prepared   possible contamination and taking the necessary measures, in coordination
               and maintenance program that is an example and a point of excellence that contributed to making the lake
                                                                                                                                                                     in advance. The results of monitoring at the reference stations (5 stations) have   with the government departments.
               project a place of attraction and an area for the development of recreational, cultural and sports activities.
                                                                                                                                                                     shown that the lake water quality specifications are very close to sea water and in   Bacteriological analyzes are also being carried out by the Pasteur Institute of
            •  The lake’s waters are characterized by their natural continuous regeneration with seawater, through tidal
                                                                                                                                                                     compliance to the required level and approved standards, indicating the continuity   Tunisia to ascertain the quality of the lake’s water and monitor the arrival of
                                movements at a rate of every 22 days. By maintaining the water quality, we ensure
                                                                                                                                                                     of the regeneration of the lake’s water with the sea in the desired capacity, thereby   water that does not conform to the swimming water specifications, to ensure
                                   the stability of biodiversity involving at least 42 species of algae, approximately
                                                                                                                                                                     ensuring the continuity of the water surface environmental balance.  that the situation is addressed with the concerned structures.
                                      40 species of fish and several other species of animals, which has continued
                                                        for years. (Compared to a few numbers before the                                                             The results during 2022 were identical to the approved standards and the required level
                                                           lake’s cleansing period which did not exceed 10                                                           Lake ratios converge with seawater ratios
                                                              types of algae and some fish species).                                                                                                                                                                                          35
                                                                                                                                                                             1 200
                                                                                                                                                                                                                                                                                              30
                                                                                                                                                                             1 000
                                                                                                                                                                                                                                                                                              25
                                                                                                                                                                              800
                                                                                                                                                                                                                                                                                              20
                                                                                                                                                                              600                                                                                                             15

                                                                                                                                                                             400                                                                                                              10
                                                                                                                                                                              200                                                                                                             5

                                                                                                                                                                               0                                                                                                              0
                                                                                                                                                                                   2010     2011    2012    2013    2014     2015    2016    2017     2018    2019    2020     2021    2022
                                                                                                                                                                                   The percentage of nitrogen in the water               The ratio of phosphorous in the water



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