Kajian Beban Pencemaran dan Kualitas Air Sungai Batang Arau di Kota Padang
Development activities in the area of the watershed of a Batang Arau were very intensively with the increase of population that high as the impact of high dynamic of development in the town of the field. Padang has the development of population growth rate 1,09 % according to data from the central bureau of statistics Padang City in 2010. It is in line with the course of economic Padang City. Economic activities of micro agriculture, industry (industry small to large industries) or mining was the backbone of the economy padang. However, with increasing population, development and the economy in padang thought to have an undesired effect negative into the environment are increasing the loads of pollution in the watershed of a Batang Arau in particular the Batang Arau River. The accumulation of the burden of contaminant on the upstream to downstream will make the level of pollution Batang Arau River more tainted. The purpose of this research is a) identify sources contaminant the waters of the Batang arau River at Padang City, b) evaluate developments water quality of the Batang Arau River from upstream to downstream during the period 2008-2012 and c) knowing pollution load any sources contaminant and a capacity of the burden of pollution Batang Arau River. The technique of adoption of the data used in this research is by means of observations, inventorying sources of pollution on the Batang Arau River and an interview with the methods purpossive of sampling. In addition, was also performed by collecting data secondary through the study of literature and examine documents. The condition of the quality of the water of the Batang Arau River analysis based on government regulation of the republic of Indonesia number 82 in 2001. The status of the quality of the water of the uses index the quality of water national sanitation foundation (IKA-NSF). Calculation the pollution loads from various sources contaminant carried out through the approach of rapid assessment of sources of water, polution, water and land while calculation capacity of the burden of pollution according to the decision of the state minister of environment No.110 in 2003. Contaminant sources in Batang Arau River at Padang city is waste from domestic/household, industry, agriculture and mining. Water quality of Batang Arau Rivers was decresing from upstream to downstream. The development of the water quality of Batang Arau River showed that on the upper and middle of the River, the river water quality meets quality raw rods or class II PP 82/2001, while in the downstream river water quality meets quality raw rods or class IV PP 82/2001. Based on the water quality index value, The Batang Or Padang city in 2008-2012 in moderate to good conditions that are in the range of 53-72 in the rainy season and 56-74 during the dry season. The burden of the most heavily contributed to pollution into the Batang Arau River is industrial waste (tons/month 152.905, 9 of BOD, 139.456, 3 ton/month of COD, 124.858 ton/month of TSS and 10.885.106 ton/month of TDS) followed by mining wastes (0 ton/month of BOD, 316.480 ton/month of COD, 316.754 ton/month of TSS and 2.532.920 ton/month of TDS), domestic waste (tons/month 100,115 of BOD, 223,60 ton/month of COD, 101,64 ton/month of TSS and 185,49 tons/month of TDS) and waste agriculture (7,52 tons/month of BOD, 9,94 ton/month of COD, 2,98 ton/month of TSS and 121 ton/month of TDS). The pollution load that entered into the river has exceeded the capacity of good ability on the upstream (26,438 tons/month of BOD, 220 ton/month of COD, 440,64 ton/month of TSS and 8812,8 ton/month of TDS), the middle part (31,88 ton/month of BOD, 265,68 ton/month of COD, 531,36 ton/month of TSS and 10627,2 ton/month of TDS) and downstream (41,21 ton/month of BOD, 343,44 ton/month of COD, 686,88 ton/month of TSS and 13737,6 ton/month of TDS).