A pragmatic approach to study the groundwater quality suitability for domestic and agricultural usage, Saq aquifer, northwest of Saudi Arabia.

Abstract

The present study deals with detailed hydrochemical assessment of groundwater within the Saq aquifer. The Saq aquifer which extends through the NW part of Saudi Arabia is one of the major sources of groundwater supply. Groundwater samples were collected from about 295 groundwater wells and analyzed for various physico-chemical parameters such as electrical conductivity (EC), pH, temperature, total dissolved solids (TDS), Na(+), K(+), Ca(2+), Mg(2+), CO3 (-), HCO3 (-), Cl(-), SO4 (2-), and NO3 (-). Groundwater in the area is slightly alkaline and hard in nature. Electrical conductivity (EC) varies between 284 and 9,902 μS/cm with an average value of 1,599.4 μS/cm. The groundwater is highly mineralized with approximately 30 % of the samples having major ion concentrations above the WHO permissible limits. The NO3 (-) concentration varies between 0.4 and 318.2 mg/l. The depth distribution of NO3 (-) concentration shows higher concentration at shallow depths with a gradual decrease at deeper depths. As far as drinking water quality criteria are concerned, study shows that about 33 % of samples are unfit for use. A detailed assessment of groundwater quality in relation to agriculture use reveals that 21 % samples are unsuitable for irrigation. Using Piper's classification, groundwater was classified into five different groups. Majority of the samples show Mix-Cl-SO4- and Na-Cl-types water. The abundances of Ca(2+) and Mg(2+) over alkalis infer mixed type of groundwater facies and reverse exchange reactions. The groundwater has acquired unique chemical characteristics through prolonged rock-water interactions, percolation of irrigation return water, and reactions at vadose zone.

• Authors: Yousef Nazzal, Izrar Ahmed, Nassir S N Al-Arifi, Habes Ghrefat, Faisal K Zaidi, Mahmud M El-Waheidi, Awni Batayneh, Taisser Zumlot
• Journal: Environmental monitoring and assessment (Environ Monit Assess) Vol. 186 Issue 8 Pg. 4655-67 (Aug 2014) ISSN: 1573-2959 [Electronic] Netherlands
• PMID: 24744209 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Water Pollutants, Chemical

Topics

• Agricultural Irrigation (methods)
• Environmental Monitoring (methods)
• Groundwater (chemistry)
• Saudi Arabia
• Water Pollutants, Chemical (analysis)
• Water Quality (standards)
• Water Resources (standards)
• Water Supply (standards)