Microbial quality assessment of tap water in Cantilan, Surigao del Sur

88 Mercado et al. Int. J. Biosci. 202 5 RESEARCH PAPER RESEARCH PAPERRESEARCH PAPER RESEARCH PAPER OPEN ACCESS OPEN ACCESSOPEN ACCESS OPEN ACCESS Microbial quality assessment of tap water in Cantilan, Surigao del Sur Kyla Rita A. Mercado * , Jasmine D. Cubillan, John Manuel C. Bunie North Eastern Mindanao State University, Philippines Key words: Microbial water quality, Tap water assessment, Water treatment monitoring http://dx.doi.org/10.12692/ijb/26.3.88-93 Article published on March 07, 2025 Abstract Ensuring access to safe and potable water is a critical public health concern, particularly for communities relying on a single water source. This study evaluates the microbial quality of tap water in Cantilan, Surigao del Sur, a town known as the “Cradle of All Towns.” Water samples were collected from multiple locations over a two-year period (January 2022 – December 2023) and analyzed for compliance with the Philippine National Standards for Drinking Water (PNSDW) 2017. Results indicate that, while the water supply generally met regulatory standards, minor seasonal variations in microbial counts were observed, particularly in May and June 2022, where slight traces of contamination were detected in some areas. However, these fluctuations remained within acceptable limits, suggesting that the water distribution system is well-maintained. The findings underscore the importance of continuous monitoring and improvements in water treatment strategies to ensure long-term water safety. This study provides essential insights into the current state of water quality in Cantilan, serving as a foundation for future water safety initiatives and policy recommendations. * Corresponding Author: Kyla Rita A. Mercado  [email protected] International Journal of Biosciences | IJB | ISSN: 2220-6655 (Print) 2222-5234 (Online) http://www.innspub.net Vol. 26, No. 3, p. 88-93, 2025 89 Mercado et al. Int. J. Biosci. 202 5 Introduction Ensuring the safety and quality of drinking water is a critical public health concern, particularly in regions like the Philippines where access to clean water can be inconsistent. Studies have assessed the physico-chemical and microbiological characteristics of domestic water supplies to determine their potability. For instance, research conducted in Bontoc, Mountain Province, revealed that while physico-chemical parameters generally met acceptable ranges, microbial contamination was prevalent, rendering the water unsafe for direct consumption (Magwilag et al., 2023). Similarly, an assessment of freshwater systems in Mega Manila indicated that, although heavy metals and organic pollutants were undetected, high microbial activity was present in several samples, suggesting potential health risks (Obusan et al., 2023). Bacterial groups have been used as an indicator of water pollution, specifically the total coliform count. WHO (1971) stated that the allowable limit of coliform and E. coli should be 0/100 mL for drinking water and 126 CFU/100 mL for domestic and recreational water. Proper chlorination of the water system together with constant monitoring, proper disposal system to not contaminate the water source and sanitation education for the community should be prioritize by the concerned body to ensure water safety (Sitotaw et al., 2021). These findings underscore the necessity for regular monitoring and implementation of effective water treatment systems to ensure the provision of safe drinking water. The Philippine National Standards for Drinking Water (PNSDW) of 2017 provide guidelines for acceptable levels of various water quality parameters, emphasizing the importance of maintaining both microbiological standards to protect public health (Philippine National Standards for Drinking Water (PNSDW, 2017). Materials and methods The research was conducted in Cantilan, Surigao del Sur, utilizing data sourced from Cantilan Water District. A comprehensive monthly microbial water analysis was performed across various locations within Cantilan. The analysis focused on quantifying total coliforms and fecal coliforms, using the Multiple Tube Fermentation (MTF) technique and Heterotrophic Plate Counts (HPC), where the pour plate method was implemented for enumeration. The temporal scope of this study spans from January 2022 to December 2023. Results and discussion The microbial analysis of waterworks in Cantilan for the year 2023 shows that the heterotrophic plate count (HPC), which measures the concentration of heterotrophic bacteria, was elevated in certain months, particularly September, where Brgy. Linintian recorded 485 CFU/mL. Although HPC does not directly correlate with health risks, higher counts suggest potential regrowth or biofilm formation within the distribution system. The WHO highlights that HPC should ideally remain below 500 CFU/mL to ensure acceptable water quality (Table 1). Some et al. (2021) stated that one of the major problems concerning water quality is the microbial pollution. The presence of pathogenic bacteria, protozoa and viruses is a serious threat to humans as it could lead to enteric outbreaks. Table 1. Water microbial analysis of water works in 2023 Month Location HPC a/ CFU/mL Total coliforms MPN/100mL Thermotolerant (Fecal) coliforms MPN/100mL Remarks Baterial count 14 - Jan - 23 Brgy. Buntalid 15 CFU/mL <1.1 <1.1 Passed Brgy. Magasang 0 CFU/mL <1.1 <1.1 Passed Brgy. Magosilom 0 CFU/mL <1.1 <1.1 Passed Brgy. Linintian 0 CFU/mL <1.1 <1.1 Passed Brgy. Tapi 0 CFU/mL <1.1 <1.1 Passed 12 - Feb - 23 Brgy Buntalid 2 CFU/mL <1.1 <1.1 Passed 90 Mercado et al. Int. J. Biosci. 202 5 Bgry. Linintian 0 CFU/mL <1.1 <1.1 Passed Brgy. Magasang 0 CFU/mL <1.1 <1.1 Passed Brgy. Magosilom 0 CFU/mL <1.1 <1.1 Passed Bgry. Pag - antayan 0 CFU/mL <1.1 <1.1 Passed Bgry. Tapi 0 CFU/mL <1.1 <1.1 Passed 18 - Mar - 23 Brgy. Buntalid 0 CFU/mL <1.1 <1.1 Passed Bagsukan 11 CFU/mL < 1.1 <1.1 Passed Brgy. Linintian 2 CFU/mL <1.1 <1.1 Passed Brgy. Magosilom 0 CFU/mL <1.1 <1.1 Passed Brgy. Pag - antayan 0 CFU/mL <1.1 <1.1 Passed Brgy. San Pedro 0 CFU/mL <1.1 <1.1 Passed 8 - Apr - 23 Brgy Linintian 2 CFU/mL <1.1 <1.1 Passed Brgy Buntalid 1 CFU/mL <1.1 <1.1 Passed Brgy Magasang 1 CFU/mL <1.1 <1.1 Passed Brgy Magosilom 1 CFU/mL <1.1 <1.1 Passed Brgy. Pag - antayan 0 CFU/mL <1.1 <1.1 Passed Brgy. Tapi 4 CFU/mL <1.1 <1.1 Passed 5 - May - 23 Brgy. Busukan 3 CFU/mL < 1.1 <1.1 Passed Brgy. Consuelo <1.0 CFU/mL <1.1 <1.1 Passed Brgy. Magosilom <1.0 CFU/mL <1.1 <1.1 Passed Brgy. Linintian <1.0 CFU/mL <1.1 <1.1 Passed Brgy. Pag - antayan 1 CFU/mL <1.1 <1.1 Passed Brgy. Parang <1.0 CFU/mL <1.1 <1.1 Passed 10 - Jun - 23 Brgy. Busukan 1.0 CFU/mL <1.1 <1.1 Passed Brgy. Consuelo <1.0 CFU/mL <1.1 <1.1 Passed Brgy. Linintian <1.0 CFU/mL <1.1 <1.1 Passed Brgy. Magasang 1.0 CFU/mL <1.1 <1.1 Passed Brgy. Magosilom <1.0 CFU/mL <1.1 <1.1 Passed Brgy. Parang < 1.0 CFU/mL <1.1 <1.1 Passed 8 - Jul - 23 Brgy. Bugsukan <1.0 CFU/mL <1.1 <1.1 Passed Brgy. Buntalid <1.0 CFU/mL <1.1 <1.1 Passed Brgy. Calagda - an <1.0 CFU/mL <1.1 <1.1 Passed Brgy. Linintian <1.0 CFU/mL <1.1 <1.1 Passed Brgy. Pag - antayan <1.0 CFU/mL <1.1 <1.1 Passed 6 - Aug - 23 Brgy. Buntalid <1.0 CFU/mL <1.1 <1.1 Passed Brgy. Calagda - an <1.0 CFU/mL <1.1 <1.1 Passed Brgy. Linintian <1.0 CFU/mL <1.1 <1.1 Passed Brgy. Magosilom <1.0 CFU/mL <1.1 <1.1 Passed Brgy. Pag - antayan <1.0 CFU/mL <1.1 <1.1 Passed Brgy. San Pedro <1.0 CFU/mL <1.1 <1.1 Passed 9 - Sep - 23 Brgy. Linintian 485 CFU/mL <1.1 <1.1 Passed Brgy. Magosilom 29 CFU/mL <1.1 <1.1 Passed Brgy. Pag - antayan 101 CFU/mL <1.1 <1.1 Passed Brgy. Parang 101 CFU/mL <1.1 <1.1 Passed Brgy. Tigabong 1 CFU/mL <1.1 <1.1 Passed 7 - Oct - 23 Brgy. Bugsukan <1.0 CFU/mL <1.1 <1.1 Passed Brgy. Buntalid 4 CFU/mL <1.1 <1.1 Passed Brgy. Consuelo <1.0 CFU/mL <1.1 <1.1 Passed Brgy. Linintian 4 CFU/mL <1.1 <1.1 Passed Brgy. Magosilom 2 CFU/mL <1.1 < 1.1 Passed Brgy. Parang <1.0 CFU/mL <1.1 <1.1 Passed 11 - Nov - 23 Brgy. Magasang 1 CFU/mL <1.1 <1.1 Passed Brgy. San Pedro <1.0 CFU/mL <1.1 <1.1 Passed Brgy. Parang <1.0 CFU/mL <1.1 <1.1 Passed Brgy. Buntalid <1.0 CFU/mL <1.1 <1.1 Passed Brgy. Linintian 1 CFU/mL <1.1 <1.1 Passed Brgy. Magosilom 1 CFU/mL <1.1 <1.1 Passed 10 - Dec - 23 Brgy. Linintian <1.0 CFU/mL <1.1 <1.1 Passed Brgy. Magosilom <1.0 CFU/mL <1.1 <1.1 Passed Brgy. Pag - antayan <1.0 CFU/mL <1.1 <1.1 Passed Brgy. Calagda - an <1.0 CFU/mL <1.1 <1.1 Passed Brgy. Parang 1 CFU/mL <1.1 <1.1 Passed Brgy. Buntalid <1.0 CFU/mL <1.1 <1.1 Passed 91 Mercado et al. Int. J. Biosci. 202 5 Table 2. Water microbial analysis of water works in 2022 Month Location HPC a/ CFU/mL Total coliforms MPN/100mL Thermotolerant (Fecal) coliforms MPN/100mL Remarks Baterial count January 31,2022 Brgy. Magosilom 3800 <1.1 <1.1 Failed Brgy. Linintian 1 <1.1 <1.1 Passed Brgy. Buntalid 10 <1.1 <1.1 Passed Brgy. Parang 2 <1.1 <1.1 Passed Brgy. Magasang 20 <1.1 <1.1 Passed Brgy . Linintian 5 <1.1 <1.1 Passed February 21,2022 Brgy. Linintian <1 <1.1 <1.1 Passed Brgy. Buntalid <1 <1.1 <1.1 Passed Brgy. Parang <1 <1.1 <1.1 Passed Brgy.Pag - antayan <1 <1.1 <1.1 Passed Brgy. Consuelo <1 <1.1 <1.1 Passed Brgy. Magosilom <1 < 1.1 <1.1 Passed March 22, 2022 Brgy. Linintian 23 0 0 Passed Brgy. Magosilom 190 0 0 Passed Brgy. Buntalid 35 0 0 Passed Brgy. Palasao 27 0 0 Passed Brgy. Magasang 25 0 0 Passed Brgy. Pag - antayan 36 0 0 Passed April 19,2022 Brgy. Lininti - an 1 0 0 Passed Brgy. Pag - antayan 5 0 0 Passed Brgy. San Pedro 7 0 0 Passed Brgy. Buntalid 1 0 0 Passed Brgy. Parang 8 0 0 Passed May 4, 2022 Brgy. Linintian 50 0 0 Passed Brgy. Buntalid 10 0 0 Passed Brgy. Parang 150 1.1 0 Passed Brgy. Pag - antayan 10 0 0 Passed Brgy. Magosilom 10 0 0 Passed June 6, 2022 Brgy. Pag - antayan 0 0 0 Passed Brgy. Parang 0 0 0 Passed Brgy. Palasao 0 0 0 Passed Brgy. Tigabong 0 0 0 Passed Brgy. Pag - antayan 0 0 0 Passed July 5, 2022 Brgy. Magosilom 0 0 0 Passed Brgy. Palasao 0 0 0 Passed Brgy. Buntalid 0 0 0 Passed Brgy. Magasang 0 0 0 Passed Brgy. Linintian 1 0 0 Passed Brgy. Magosilom 0 0 0 Passed Brgy. Calagda - an, 0 0 0 Passed August 8, 2022 Brgy. Buntalid 8 0 0 Passed Brgy. Tigabong 25 0 0 Passed Brgy. Parang 32 0 0 Passed Brgy. Pag - antayan 21 0 0 Passed Brgy. Magosilom 17 0 0 Passed Brgy. Linintian 62 0 0 Passed September 10, 2022 Brgy. Parang 0 <1.1 <1.1 Passed Brgy. Consuelo 1 <1.1 <1.1 Passed Brgy. San Pedro 1 <1.1 < 1.1 Passed Brgy. Linintian 1 <1.1 <1.1 Passed Brgy. Bugsukan 0 <1.1 <1.1 Passed Brgy. Magosilom 1 <1.1 <1.1 Passed October 08,2022 Brgy. Palasao 123 <1.1 <1.1 Passed Brgy. Magosilom 65 <1.1 <1.1 Passed Brgy. Linintian 39 <1.1 <1.1 Passed November 13, 2022 Brgy. Magasang 0 <1.1 <1.1 Passed Brgy. Magosilom 0 <1.1 <1.1 Passed Brgy. Linintian 0 <1.1 <1.1 Passed 92 Mercado et al. Int. J. Biosci. 202 5 Brgy. Buntalid 0 <1.1 <1.1 Passed Brgy. Pag - antayan 0 <1.1 <1.1 Passed Brgy. Parang 0 <1.1 <1.1 Passed Decmber 11, 2022 Brgy.Pag - antayan 2 <1.1 <1.1 Passed Brgy. Magosilom 2 <1.1 <1.1 Passed Brgy. Linintian 0 <1.1 <1.1 Passed Brgy. San Pedro 10 <1.1 <1.1 Passed Brgy. Parang 5 <1.1 <1.1 Passed Brgy. Palasao 0 <1.1 <1.1 Passed According to Luvhimbi et al. (2022), although water leaving the treatment plant met bacteriological standards, the detected coliform bacteria could be an indication of contaminated distribution networks. Total and fecal coliforms were consistently below detection limits (<1.1 MPN/100mL) across all sampling locations, confirming the absence of fecal contamination and compliance with PNSDW standards. This suggests that the water is microbiologically safe for consumption and that treatment processes effectively address contamination risks. Seasonal variations in microbial counts, especially during the rainy season, may indicate increased organic matter inflow or reduced chlorination efficacy, necessitating regular monitoring and possible adjustments to treatment protocols. The data in this Table 2 presents microbial water quality results from various locations in Cantilan, Surigao del Sur, between January and December 2022. The primary indicators for water contamination were Total Coliforms and Thermotolerant (Fecal) Coliforms, which are commonly used to assess the safety of water for consumption. These indicators are measured in Most Probable Number (MPN) per 100 milliliters and Colony Forming Units (CFU) per milliliter. High levels of these bacteria suggest contamination, often from fecal matter, and can pose health risks such as waterborne diseases. The results reveal that, generally, the water sources in the tested locations meet the safety standards for drinking water, with most locations consistently showing low or undetectable levels of both Total Coliforms and Thermotolerant Coliforms. Notably, the water in sites such as Buntalid, Magosilom, and Linintian exhibited passing results throughout the year, indicating good water quality with minimal or no contamination. In particular, tests from February to December 2022 mostly reported either zero or less than 1 CFU/mL, demonstrating that the water sources in Cantilan were generally safe to consume. However, an important exception was observed in January 2022, when Barangay Magosilom showed an alarmingly high Total Coliform count of 3800 CFU/mL. This value far exceeds acceptable limits and suggests significant contamination, likely from improper waste disposal or other local environmental factors. The failure in Barangay Magosilom calls for further investigation into potential causes of contamination, such as inadequate sanitation or pollution sources. The high level of contamination in this location is a critical finding, as it could pose a significant public health risk if not addressed. Conclusion The findings of this study indicate that the microbial quality of tap water in Cantilan, Surigao del Sur, remained relatively stable throughout the two-year monitoring period, with only minor variations observed across different locations. Notably, slight traces of microbial contamination were detected in some areas during May and June 2022. However, overall microbial levels remained within the acceptable limits set by the Philippine National Standards for Drinking Water (PNSDW) 2017, demonstrating that the water supply system is generally well-maintained. The absence of significant seasonal fluctuations suggests that existing water treatment and distribution practices are effective in ensuring water safety. Nevertheless, the occasional presence of microbial contaminants highlights the need for continuous monitoring and proactive management 93 Mercado et al. Int. J. Biosci. 202 5 strategies to maintain water quality and prevent potential health risks. Future research could explore factors influencing these variations and recommend further improvements in water treatment processes. Acknowledgments The authors would like to thank the Cantilan Water District for allowing access of the 2022-2023 microbial analysis results. References Luvhimbi N, Tshitangano TG, Mabunda JT, Olaniyi FC, Edokpayi JN. 2022. Water quality assessment and evaluation of human health risk of drinking water from source to point of use at Thulamela Municipality, Limpopo Province. Scientific Reports 12(1), 6059. Magwilang EB, Paredes ALY, Armas FC, Bugnay HGP, Dagupen RD. 2023. Physicochemical and microbiological assessment of domestic water supply in Bontoc, Mountain Province, Philippines. H 2 Open Journal 6(2), 242–255. https://doi.org/10.2166/h2oj.2023.019 Obusan MCM, Castro AE, Villanueva RMD, Isagan MDE, Caras JAA, Simbahan JF. 2023. Physico-chemical quality and physiological profiles of microbial communities in freshwater systems of Mega Manila, Philippines. Data 8(6), 103. Philippine National Standards for Drinking Water (PNSDW) of 2017. 2017. Food and Drug Administration Philippines. Retrieved from https://www.fda.gov.ph/wpcontent/uploads/2021/08/Administrative-OrderNo.-2017-0010.pdf Sitotaw B, Melkie E, Temesgen D. 2021. Bacteriological and physicochemical quality of drinking water in Wegeda Town, Northwest Ethiopia. Journal of Environmental and Public Health 2021(1), 6646269. Some S, Mondal R, Mitra D, Jain D, Verma D, Das S. 2021. Microbial pollution of water with special reference to coliform bacteria and their nexus with environment. Energy Nexus 1, 100008.