Indice degli argomenti

  • Introduzione

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  • Beni Hassen

    The Beni Hassen Municipality is located 18 km southward of Monastir city, house of the ONAS directorate premises. Located in the flat rural area of the arid Tunisian Sahel, the main economic resource is the cultivation of the olive trees. Due to the lack of surface water resources and the high level of salinity of the groundwater, it is a rainfed area that is suffering nowadays for the severe rainfall reduction caused by the climate change effects.

    The WWTP managed by ONAS is located 2.6 km NNW from the centre of the town of Beni Hassen.


    Nearby the Beni Hassen's WWTP, the CRDA of Monastir realized, in 2017, a piped irrigation network serving a command area of 60 hectares. Within this area, only a part of farmers, owning 30 ha (50%), accepted to irrigate their plots with Treated Waste water.

    The existing tertiary treatment plant was out of order since the beginning of the MENAWARA project, because of the clogging of the sand filters and of the burning of the 8 UV lamps. Despite it, facing the 2021-2023 drought, with an emergency decree, ONAS was authorized to distribute the secondary treated water to the farmers only for the olive cultivation, by-passing the out-off order tertiary treatment. 

    The MENAWARA project has foreseen the rehabilitation of this tertiary plant

    👉 The Beni Hassen intervention site has been chosen by the MENAWARA project as the area showed a great potential in terms of re-use of Treated Waste Water. About 30 ha of olive trees belonging to 10 farmers will benefit from the rehabilitation of the tertiary treatment plant and the creation of a storage basin. Thanks to the intervention, better water quality will be provided to farmers increasing the amount of TWW used in agriculture thus decreasing the pressure on fresh water in the semi arid region.


  • MENAWARA rehabilitation of the Waste Water Treatment Plant

    An emergency affected the Beni Hassen area due to the rainfall reduction in the last years, especially in the 2022-23 winter seasons, with zero rain in 2023, and more than 50% of reduction in 2022. This was the main reason why the MENAWARA project decided to rehabilitate the tertiary system (Sand filter +UV disinfection) and to build, in addition, a RCC tank of 100 m3 for improving the functioning of the CRDA pumping station at the outlet of the WWTP feeding the d/s piped irrigation network.


    Concerning the rehabilitation of the tertiary treatment system, the two sand filter vessels were properly painted and the sand, inside both, replaced 



    Regarding the UV disinfection system, 8 UV lamps have been replaced.

    This intervention allowed us to give an initial response to farmers in the Beni Hassen area who, in recent years, have been suffering the effects of climate change in terms of increasingly intense drought periods which make their activity more and more complex. The rehabilitation of the tertiary treatment of the Beni Hassen WWTP will allow irrigating with better quality TWW on approximately 30 hectares owned by farmers, which represent 50% of the irrigation area, who asked to use this non-conventional water. This intervention paves the way for further actions that could very shortly satisfy the needs of all 60 hectares of the Beni Hassen district.