Distribution of organic contamination based on depth stratification in Maninjau Lake, Indonesia

The purpose of this study was to analyze the organic content of Lake Maninjau based on depth stratification and its organics carrying capacity. Sampling was carried out at the location of lake utilization, namely in the lake center, settlement, hydropower, endemic fisheries, and fish cage following Indonesian National Standard SNI 6989.57: 2008. The parameters measured were BOD₅, COD and environmental condition such as pH, DO and temperatures. Lake Maninjau generally is polluted, especially for organic pollutants characterized by the BOD₅ and COD values that did not meet the quality standard of Government regulations the Republic of Indonesia Number 82 the year 2001 class 2 according to its designation namely 21.87-47 mg BOD/L and 35.2-74 mg COD/L. Using one-way analysis of variance (ANOVA) at 0.05% level of significance both BOD₅ and COD has a strong correlation with depth of the lake, at hydropower and endemic fisheries. At the shallow lake depths, water is easy to mix so that the organic matter distributed vertically. Fish cage has the highest contribution to the contamination of organic matter in the lake. (paper)