Abstrait

Study of the ammoniacal pollution of the M'nasra water table (Morocco)

I.Idrissi Alami, A.Rhidouani, M.Zeraouli, A.Echchelh, M.Addou

We have been interested in the study of the chemical pollution ofMÂ’nasraÂ’s water table. This one is located in the Gharb region inMorocco where 145 000 people live. We have carried out 49 campaigns of measurement in three different periods with a quite important time interval between these periods. This water table constitutes the unique non-available resource of groundwater for this region. Agricultural industries are highly represented in this region where nitrogen fertilizers and pesticides are used at a large scale. The general averages of ammoniumconcentration in 1993, 2007 and 2008 are respectively 1.3mg/L; 2.3mg/L and 3.3mg/L i.e. an increase of 2mg/Lbetween 1993 and 2008. If in 1993, 02wells over 49 prospectedwells (4.08%)were conformed toWHO (Word HealthOrganization) drinkability standards, in 2007 and in 2008 all the wells are polluted.Moreover, the spatial analysis has confirmed an area of 10 000 Ha where MÂ’nasra water table has know an ammoniacal pollution between 1993 and 2008.