PRELIMINARY WATER QUALITY EVALUATION OF THE VAISIGANO RIVER, SAMOA 1PATILA AMOSA, 2FAAINU LATU, 3TAEMA IMO, 4VAREA VAURASI 1,2,3,4ScienceDepartment, National University of Samoa, Samoa Email:
[email protected],
[email protected],
[email protected],
[email protected] Abstract - This study analysed water samples collected from Vaisigano River on Upolu Island, Samoa to evaluate the degree of pollution by nutrients, heavy metals and microorganisms. Samples were collected monthly from December 2016 to April 2017 at 3 sitesalong the river and analysed for dissolved oxygen (DO), biochemical oxygen demand (BOD),total - phosphorous (TP), nitrate (NO3 ), faecal coliform (FC), Enteroccoci (Ent) and the two heavy metals Cu and Pb. The results were used to calculate a water quality index (WQI) for each station with (WQIw) and without bacteria (WQIwt) to estimate the contribution of microbes to water contamination and to determine the overall health of each site. The WQIwvalues for the three stations ranged from (37.48 – 41.05)± 1.91 while WQIwtranged from (41.14– 59.03)± 9.14. All values were below 100 which is the critical value for surface water safety for use for human activities, aquatic life and wildlife survival.Based on the WQI values, water quality at the three sites wasgenerally poor. Keywords - Water quality index, pollution, microbial contamination, nutrients, Samoa I. INTRODUCTION studies conducted in the vicinity of Samoa on the quality of streams [9, 10] have shown only partial The impact of climate change on the quality of water compliance to established drinking water standards. resources and associated health implications has seen For example, of 44 streams analysed by [10] in an influx of research to assess the health of rivers.