The organic pollution levels of Buhisan, Bulac ao and Lahug Rivers were assessed using temperature, pH, dissolved oxygen (DO), biochemical oxygen demand (BOD 5) as test parameters. Samples were taken monthly for a period of six months from three established sites in each river designated as upstream, midstream and downstream. Results were c ompared with the DENR A dministrativ e Order 90-34 criteria for surface waters. The mean values of all the parameters observed at Bulacao River except for % O 2 saturation (30.45 %) at the downstream site were within the acc eptable limits. For Buhisan and Lahug Rivers, the mean values for DO and BOD did not c omply with the Class D standard set by the DENR. Among the three rivers, Bulacao River appeared to have the lowest lev els of pollution whic h could be due to better implementation of solid waste management observ ed in Bulacao compared to Buhisan and Lahug. Moreov er, the river banks of Bulacao River were observed to be less populated thus, lesser amount of wastes discharged in the area. Apparently, there is a need for a collaborativ e effort among the community, the ac ademe, the NGOs as well as the LGUs for the protection, restoration and rehabilitation of these rivers.

WALIA journal 31(S3): 61-64, 2015