WATER QUALITY VULNERABILITY ASSESSMENT ON MAGSUNGAY RIVER: INDUSTRIAL AND HOUSEHOLD WASTEWATER MANAGEMENT IN BACOLOD CITY, NEGROS OCCIDENTAL

Abstract

Freshwater is essential for both natural and human systems to survive. Clean water is a vital determinant of environmental health as well as a need for humans in terms of hygiene and health (Kim, J.-S., et al, 2019). According to Brook, N., (2005), Shift and variability in flow, emissions, population growth, competition for water, data availability and quality, and information gaps all contribute to the vulnerability of water management systems. This case study aims on assessing the vulnerability of Magsungay River as one of the main rivers of the city and cope it with the anthropologic situation of fragmentation in Bacolod City. The records show the trend of population growth in Bacolod City with 429,076 in 2000, 561,900 in 2015, and 624,783 in 2021. Also, expected population would take around in 2022 would be around 636,500 people, which indicates a linear growth towards population in the past two decades. According to the present LULC classifications of Bacolod City, the Built-up matrix covered 4846.86 hectares or 65%. Patches of Built-up settlements followed at 2115.18 hectares or 28% and patches of Bare soil at 267.75 hectares or 3% which is the same with clouds was 193.14 hectares or 3%. The water body areas were measured at 45 hectares or covering 1% of the land mass is the least area covered in Bacolod City. On Water Quality on Upstream area of Magsungay River, the result shows that the pH has a neutral state with 8.2 versus the range of 6.5-9.0. Temperature was ambient as required by standard. True color does not reach to maximum requirement with 15 CU. Dissolve Oxygen with 5 mg/L or ppm and Total Suspended Solids (TSS) is 13mg/L. Unfortunately, Biochemical Oxygen Demand (BOD) has an off-standard result with 16mg/L or ppm versus 7mg/L specification from DAO 2016-08, while downstream result shows that the pH has a neutral state with 7.1 versus the range of 6.5-9.0. Temperature was ambient as required by standard. True color does not reach to maximum requirement with 15 CU. Dissolve Oxygen with 5 mg/L or ppm and Total Suspended Solids (TSS) is 73mg/L. In downstream result on BOD is contrast with the upstream with 5mg/L versus 7mg/L standard. Based on the results, the waters of Magsungay river are greatly polluted due high density of population in Bacolod City with 624,783 numbers in 2021 covering 65% of Bacolod City’s land use and land cover to residential or built-ups. This signifies how dense the city’s population creating a devastating result on the water quality of Magsungay river. Even though, other quality parameters met the DAO-2016- 08 standards, unfortunately, the upstream area of the river contains high concentration of BOD which creates unvaried results towards ecological stability and sustainability.