Use of Isotope and Solute Chemistry to Define the Sources of Pollution in Mawqaq Groundwater, Hail, Saudi Arabia

Groundwater in the area is used for different purposes like domestic, agricultural, industrial and landscaping. More than sixty groundwater samples were collected in an alluvial shallow aquifer in and around Mawqaq Town. The objective was to study groundwater quality and identify the sources of Nitrate (NO3) and bacteriological pollution in groundwater using environmental isotopes (2H, 3H and 18O). The results of the study have revealed the presence of average salinity concentration higher than the permissible limits (500 mg/l) for drinking water. Three groups of water saline boundaries were identified. The presence of high nitrate as nitrogen (NO3-N) was also encountered in the study area. Coliform bacteria have also been identified in some wells. Application of stable isotope has shown the age, origin and the sources of the pollution in the groundwater of Mawqaq area. Appropriate health and municipal authorities of the area have initiated remedial measures and a monitoring program is to be implemented in coordination with these authorities