Water quality index and its variation among aflaj water resources in nizwa area-a case study

In Oman the annual average rain fall is 100mm. Falaj is an open water channel developed some 2000 years back. It originates from a mother well and flows under gravity. Two or more Falaj water streams are called Aflaj. In Oman, more than 3000 falajs water streams are flowing to cater drinking and irrigation need. The aim of this article is to estimate water quality in three falajs water streams in Nizwa area and to calculate water quality index for each stream. Three samples were collected from each falaj and analyzed for total dissolved solids, calcium, total alkalinity, chloride, sulphate, nitrate and total hardness. Water quality index was calculated for each sample and average of three samples taken for assessment. It was observed that the average WQI for Falaj Daris is 57, Falaj Al-Khatmayn is 47 and Falaj Al-Muyassar is 78. It was observed that the water quality for Falaj Al-Khatmayn is excellent and water quality for Falaj Daris and Falaj Al-Muyassar are good and acceptable for drinking purpose after proper disinfection.