Screening of protozoans and physicochemical characterization of groundwater in Santa Ignacia, Tarlac, Philippines

• Main Author: Inson, Jessamine Gail M.
• Format: text
• Language: English
• Published: Animo Repository 2019
• Subjects: Groundwater—Microbiology—Philippines—Tarlac; Protozoa; Biology
• Online Access: https://animorepository.dlsu.edu.ph/etd_masteral/6308; https://animorepository.dlsu.edu.ph/context/etd_masteral/article/13366/viewcontent/Thesis_manuscript2_Redacted.pdf
• Institution: De La Salle University

source of water for drinking, domestic, and irrigation purposes; however, consistent monitoring of groundwater quality is lacking in the area. Thus, the present study explored the presence of protozoans in groundwater as a probable source of infection and measured selected groundwater quality parameters to identify possible contamination. A total of 274 groundwater samples used for drinking and/or bathing were collected from 21 sampling sites in the study area during the dry season (January to March). Plotting map was constructed using the geographical coordinates of sampled wells to show the distribution of wells in the study area. Groundwater samples were analyzed for the possible presence of protozoans through modified calcium carbonate flocculation method followed by staining procedures: Lugol's iodine and cold-acid fast, prior to microscopy. Groundwater samples were characterized in terms of selected groundwater quality parameters: pH, conductivity, nitrate, nitrite, iron, and copper contents. Spatial distributions of measured groundwater quality parameters in the study site were mapped using Inverse Distance Weighted (IDW) interpolation technique. Microscopic examination showed that protozoans were absent in all groundwater samples, but plant debris were found to be present. Analysis of selected groundwater quality parameters revealed that the mean values of measured conductivity, nitrate, nitrite, iron, and copper contents of groundwater samples were within the permissible limits set by DENR and WHO. Spatial distribution map showed that the nitrite content of groundwater sources in Padapada exceeded the acceptable limit. In conclusion, the absence of protozoans in the examined groundwater samples does not imply that they do not exist in groundwater sources in the study site. The suitability of water samples for human consumption is not conclusive in the present study due to limited tested parameters. High nitrite content of groundwater samples from Padapada indicates groundwater contamination; hence, further evaluation and monitoring are necessary.