ANALISIS KUALITAS AIR DAERAH ALIRAN SUNGAI (DAS) BOAL KABUPATEN SUMBAWA

Abstract

River water is one of the sources of clean water that is commonly used by the community so it is necessary to maintain its quality and quantity. This research aims to determine the water quality of the Boal Watershed from the aspect of discharge, temperature, pH, hardness and E.Colli. Sampling was carried out in August 2021 in the Boal Watershed, Sumbawa Regency at 3 research points representing upstream, middle and downstream. Measurement and sampling of water was carried out 3 times (3 days) at 12.00-13.00 wita. The discharge is calculated by multiplying the wet cross-sectional area of ​​the river and the flow velocity. Temperature and pH were determined in the field using a thermometer and pH meter, while hardness and E.Colli were tested in the laboratory. The results showed that the average discharge upstream, middle and downstream was 0.155 m3/second, 0.13 m3/second and 0.125 m3/second, respectively. The average temperature at the three measurement locations was 25.73 C, 25.37 C and 29.73 C, respectively. The average pH in the upstream is 7.1, while the middle and downstream are 8.4 and 8.6. The average hardness upstream is 142.33 mg/l, middle is 119.77 mg/l and downstream is 138.67 mg/l. For E.Colli, the average values ​​were 7.3 CFU/100ml, 32.3 CFU/100ml and 37 CFU/100ml upstream, middle and downstream. The water quality of the watershed Boal in Sumbawa regency is moderately polluted. This is caused by e.coli.that exceed water quaity standars.