Bacteriological studies for Kranji catchment

• Main Author: Por, Yu Ling.
• Other Authors: Chua Hock Chye Lloyd
• Format: Final Year Project
• Language: English
• Published: 2009
• Subjects: DRNTU::Engineering::Environmental engineering::Water supply
• Online Access: http://hdl.handle.net/10356/15966
• Institution: Nanyang Technological University

With the introduction of ABC Waters Programme by Singapore’s Public Utilities Board (PUB), Kranji Reservoir and some of its surrounding water bodies will be used for recreational purposes. The purpose of this project is to determine whether the water bodies surrounding Kranji Reservoir are safe for recreational activities. Possible point and non-point sources contributing high levels of bacteria within the Kranji Catchment are identified. Reasons as to why some of these locations are contributing high bacteria concentration are discussed. Any correlations between bacteria levels during dry and wet weather are also examined. Water samples are collected from the surrounding of seven main sampling locations identified. These seven main sampling locations are namely CP01 to CP07. However, this study focuses more on CP02. Other then obtaining water samples from the above mentioned locations, water samples are also collected from potential point sources identified within Kranji Catchment. Some of which includes chicken farms and septic tanks of Sewage Treatment Plant (STP). Water samples are either manually collected or obtained via a Portable Sampler. These water samples are tested for only three parameters. They are total coliform, E. coli and Enterococci. Results have shown that urban land use generates the most amounts of bacteria. This is observed in the results of CP02, which consists of mainly high-rise residential. The bacteria level recorded for this high-rise residential is relatively higher compared to agricultural land use and undeveloped lands. The average total coliform and E. coli concentration for CP02 are greater than 9,855,424 CFU/100 ml and 62,062 CFU/100 ml respectively. A trend is observed from the water samples collected from the surroundings of CP02. As the sampling locations get further away from the latter, the concentration of total coliform increases, with the lowest and highest being 0 CFU/100 ml and 787,833 CFU/100 ml. This study has also shown that bacteria levels are much higher during storm events as compared to during dry weathers. Due to the low number of water samples tested for Enteroccoci, no correlations can be drawn.