J. Electrical Systems 20-5s (2024): 1463-1466 1463 1 Khristine L. Sandoval 2 Maria Concessa J. Arceo 3 Junjun A. Villanueva Assessment of Physicochemical Parameters in Selected Water Bodies in Laguna, Philippines Abstract: - This study was aimed to examine the frequent variations in four selected physico-chemical parameters of surface water of two lakes in Laguna: Laguna de Bay in Calamba City and Sampaloc Lake in San Pablo City. Parameters such as conductivity, dissolved oxygen (DO), pH, and temperature were determined using in-situ water quality tester. The two lakes are both freshwater body, different data are collected and observed throughout the sampling. Due to various anthropogenic activities, the lakes are biotically affected. The water quality of the two important lakes in Laguna have been compared in different parameters like pH, DO, conductivity, water temperature and color. The result indicates that both lakes are within the standard (25-31°C) of DENR Administrative Order (DAO 2016-08 for Class C), but except for water temperature which exceeds the standard value (36.37°C mean values). The results support insights about the future effects of increased water temperature on fish management and the lake ecosystem for numerous aquatic purposes. This is also for the management and call on action for the residents and local government unit in said municipalities of Laguna especially after pandemic season. Keywords: conductivity, DO, lakes, pH, water temperature I. INTRODUCTION Geographically, world is composed of water that takes up more space with about 75% than the land. In that 75%, only three percent is considered as a freshwater while 97% is saltwater or marine water. Water pollution has become a significant and increasing threat to both freshwater and marine ecosystem as well as in public health. Water is one of the most essential things in life; it is needed by all living things for them to survive. According to [1], the quality of water is depreciated due to pollution, and it is one major concern of environmentalists [2]. Also, water quality mainly affected by geological processes such as weathering and erosion; and anthropogenetic inputs caused by human activities from municipal, households and industrial waste. Aside from natural processes and anthropogenic inputs, there are also waterborne organisms which are bacterial pathogens (Vibrio cholera, Salmonella typhi, Pseudomonas and others) and aquatic parasites (Giardia, Amoeba, Cryptosporidium and the like). These pollutants can be associated to human diseases such as leptospirosis, typhoid, diarrhea, amoebiasis, and the like. Human population suffers from different diseases due to use of contaminated water It is therefore necessary to check the water quality. According to [3], a good quality of water is vital not only to avoid any kind of diseases but also to improve and protect the quality of life. Lake ecosystems are made up of physical, chemical, and biological properties contained within these water bodies. It is also an inland body of water that lacks any direct exchange with the ocean [4]. It has long been at the center of human attention. Toxic wastewater, surface water runoffs from municipal, industrial, and agricultural sources from the increasing population growth and industrial activities at the same time have increase pollution load and freshwater is affected [1,5,6]. Since increasing water pollution can be a threat to aquatic ecosystem, monitoring and evaluation of water quality are needed. A serious world problem because of the different pollutants (physical, chemical, and biological) water sources have been contaminated which become the reason of water [7]. The paucity of information on the water quality of some freshwater lakes in the country encouraged the authors of this study to undertake this kind of investigation. It is, therefore, crucial to thoroughly observe the quality of water and its numerous uses. The present study was aimed at assessing the values of physicochemical selected parameters natural freshwater bodies in two essential lakes of Laguna. II. MATERIALS AND METHODS A. Sampling locations The study was conducted at the two lakes in Laguna which are in the Laguna de Bay-Calamba, Laguna and Sampaloc Lake in San Pablo, Laguna. Laguna De Bay is one of the most significant inland bodies of water and the biggest lake in the Philippines. South Bay part with an average depth of only 2.5 meters where Calamba City, Laguna is located. It was also estimated that the lake’s water holding capacity is 2.19 billion cubic meters and lastly is its watershed area which straddles the whole provinces of Rizal and Laguna with 3,820 square kilometers. 1 University, Philippines Manila, Philippines klsandoval@nu-laguna.edu.ph 2 College of Arts and Sciences NU Lipa Lipa City, Batangas, Philippines 3 College of Education, Arts, and Sciences National University, Philippines Manila, Philippines Copyright © JES 2024 on-line : journal.esrgroups.org National