Comparative Study of Water Quality at Different Peat Swamp Forest of Batang Igan, Sibu Sarawak

Problem statement: It is important to find the status of water quality at converted peat swamp forest into oil palm plantation. This study was conducted to find and determine the water quality at peat swamp forest of Batang Igan, Sibu Sarawak. This study presents a status on the water quality of peat swamp forest at the area. Approach: In-situ data and a total of 72 water samples were collected at four sampling stations (S1, S2, S3 and S4) in three different months of July, August and November 2009. In-situ data included temperature, conductivity, Dissolved Oxygen (DO), pH and Turbidity. Analysis for ammoniacal nitrogen (NH₃-N), Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD) and Total Suspended Solids (TSS) were conducted in the laboratory. Results for water quality parameters are as follows, temperature range (26.85-32.90 °C), pH range (3.03-3.84), DO range (1.99-8.05 mg/L), conductivity (42.07-98.72 µS cm^-1), TSS range (1-54 mg L^-1), turbidity (0.39-9.80 NTU), BOD range (0.5-9.8 mg L^-1), COD (0-17) and ammoniacal nitrogen (0.2-0.42 mg L^-1). The Water Quality Index (WQI) which was calculated based on six water quality parameters namely dissolved oxygen, biological oxygen demand, chemical oxygen demand, pH, ammoniacal nitrogen and total suspended solids, was representative of the state of water quality in Batang Igan peat swamp forest. Results: Based on WQI, S1 was categorized under Class III while S2, S3 and S4 were categorized under Class II. Conclusion: The physical-chemical parameters of water in Batang Igan peat swamp forest were in normal range or in class I and class II that is in good water status except for pH and dissolved oxygen for the water; however it is normal condition for peat water.