Application of Water Quality Index for Loktak Lake

Water quality is a significant contributor to all spheres of life. It is vital to test the water before it is used for drinking, domestic, agricultural or industrial purposes. Loktak lake is the major freshwater wetland of Manipur (India) and was declared a Ramsar site in 1990. The study aimed to check the water quality status of Loktak lake. The results showed that the maximum pH was7.58 recorded at Sendra, and the minimum pH was 7.10 at Phubala. The maximum EC was 173 recorded at Komlakhong and the minimum was 99 recorded at Phubala. The DO was recorded maximum at Ningthoukhong at 7.9 mg/ l and minimum was 6.2 mg/l recorded at Mayang Imphal. The maximum BOD was 2.7 mg/l recorded at Mayang Imphal and the minimum was 1.9 mg/l recorded at Ningthoukhong. The maximum Total Hardness was 50 mg/l recorded at Komlakhong and the minimum 30 mg/l recorded at Phubala. The maximum total alkalinity was 78 mg/l recorded at Komlakhong, and the minimum was 50 mg/l recorded at Phubala. The maximum acidity was 20.1 mg/l recorded at Komlakhong and the minimum was 12.5 mg/l recorded at Phubala. The maximum chloride was 11.36 mg/l recorded at Mayang Imphal and the minimum was 6.10 mg/l at Phubala. The maximum TDS was 68 mg/l at Mayang Imphal and the minimum was 33 mg/l at Phubala. The maximum sulphate was 31 mg/l recorded at Sendra and the minimum was 18 mg/l recorded at Phubala. The maximum COD was 26 mg/l recorded at Mayang Imphal and the minimum was 7mg/l recorded at Ningthoukhong and Mayang Imphal. The present study revealed that most parameters are within the permissible limit when compared with BIS/WHO/ICMR. The value of the water quality index were good as per the National Sanitation Foundation Water Quality Index.