Note about the causes of the deterioration of groundwater quality in aquifer of Sanaa -Yemen [Note sur les causes de la dégradation de qualité des eaux souterraines de l'aquifère de sana' a -Yémen]

This study examines the natural and anthropogenic processes that affect the physico-chemical and microbiological quality of sana'a groundwater aquifer. in 2012,fifteen water samples were collected. the physicochemical parameters followed are: t ° c,ph,ec,tds,cl-,no3-,so4-,hco3-,na+,mg+2,k+,ca+2,total hardness (th),fe++,f-,salinity and turbidity and bacteriological (total coliforms and fecal coliforms). these types of groundwater in of sana'a is mainly indicative of the lithology of the aquifer and the influence of evaporation on the composition of the water and consequently a transfer salts from soil to water. the groundwater saturation index are under saturation degrees except for dolomite. the study area is characterized by a high degree of salinity due to high sodium content increased by irrigation activities. the physico-chemical and microbiological parameters exceed the standards of the world health organization (who) regarding the quality of drinking water. all wells are contaminated with coliform. contamination is concentrated in the north of the study area,this probably indicates a migration through the underground waters. parameters were compared with the recommended by who and the national water resources authority (nwra),yemen guidelines.