PHYSICAL AND CHEMICAL PROPERTIES OF WATER: CASE OF TAAL LAKE, PHILIPPINES

Abstract

Water quality can affect the ecosystem at several trophic levels. It is very important for an ecosystem to have healthy water bodies as lives of aquatic species depend upon them. Taal, with a small lake located in the southern part of Luzon in the Philippines is teeming with aquatic resources, yet it is observed that its water quality is deteriorating. The lake is surrounded by several municipalities with tributaries contributing to its quality. This study evaluated Taal lake ecosystem in six sample sites in terms of physical and chemical attributes utilizing secondary data obtained from the Department of Environment and Natural Resources (DENR). Mean values of pH, temperature and Total Soluble Solids (TSS) were within the standards set by the agency. However, there was a slight increase in Dissolved Oxygen (DO) and a low Biological Oxygen Demand (BOD). There is high nitrogen and heavy metal contamination with one highly contaminated site. This was attributed to high municipal and kitchen waste disposal and high amounts of fertilizers used in fields. Taal lake aquatic ecosystem can be classified as severely polluted based on the chemical parameters. Nitrate, phosphate, oil and grease, pH, temperature and DO levels vary significantly from site to site. Levels of arsenic, chromium, TSS and BOD do not show any significant difference among the sites.