Abstract:
The Lawaye River in San Juan Batangas is an important source of water for local
residents. However, there have been insufficient researches regarding the water
quality of the river. This study was conducted to determine the water quality of
the Lawaye River using coliform count and plankton species composition. Four
sampling sites were setup along the river; boundary, upstream, midstream and
downstream. Fecal coliform count in the river was quantified using the multiple
tube fermentation method while detection of the coliform Escherichia coli
involved the Presumptive, Confirmatory and Completed tests along with the
IMViC profiles. Plankton analysis involved the identification of various plankton
genus found in the river. Nygaard's and Palmer's indices were then used to
determine the river's trophic state and pollution status. The coliform
concentration in all sites was found to be well beyond the normal range. Plankton
analysis showed that sampling areas in the Lawaye River were found to have
different level of organic pollution. The Palmer's and Nygaard7s Indices
demonstrated that the downstream and the midstream sites registered the highest
probability of having organic pollution while the sites found on the boundary and
upsti*eam were comparatively normal and oligotrophic. Factors such as improper
waste disposal, effluents from drainage and agricultural runoffs might have
contributed to the observed results.
