PREDIKSI DAMPAK LIMBAH CAIR DOMESTIK AKIBAT PERTUMBUHAN PENDUDUK MENGGUNAKAN QUAL2K (STUDI KASUS DAERAH ALIRAN SUNGAI KAMPUNG BUGIS, KOTA TARAKAN, KALIMANTAN TIMUR) PREDICTION OF DOMESTIC WASTE WATER IMPACT AS THE RESULT OF POPULATION GROWTH USING QUAL2K (A CASE STUDY OF KAMPUNG BUGIS WATERSHED, TARAKAN, EAST BORNEO)

VIVIEN UTAIBAH E., Dr. Eko Sugiharto, DEA.

2014 | Skripsi | KIMIA

Daerah Aliran Sungai (DAS) Kampung Bugis memiliki peranan yang vital bagi masyarakat Karang Anyar, Kota Tarakan Kalimantan Timur yaitu sebagai sumber air baku Perusahaan Daerah Air Minum (PDAM). Namun demikian, Sungai Kampung Bugis juga menerima limbah buangan rumah tangga dari pemukiman sekitar sungai. Sesuai Peraturan Pemerintah Lingkungan Hidup No. 1 Tahun 2010 guna mengawasi kualitas air DAS Kampung Bugis, dilakukan penentuan Beban Pencemar menggunakan pemodelan lingkungan QUAL2K. Dampak pembuangan limbah akibat pertumbuhan penduduk dan rencana pengolahan air limbah agar kualitas air tetap memenuhi Baku Mutu Kelas 1 (Peraturan Pemerintah No. 82 Tahun 2001) telah disimulasikan. Simulasi dilakukan menggunakan data primer berupa hasil analisis kualitas air dan hidrolika DAS Kampung Bugis. Segmentasi sungai dibagi menjadi 19 sesuai jarak dan topografi sungai. Kondisi awal Sungai Kampung Bugis ditentukan melalui Indeks Pencemar dan banyaknya limbah dihitung menggunakan analisis Beban Pencemar. Hasil simulasi dikalibrasi menggunakan metode trial and error kemudian diuji dengan metode Uji Statistik U. Bertambahnya debit limbah cair domestik dihitung sesuai dengan proyeksi penduduk tahun 2014-2018. Perencanaan pengolahan air limbah disimulasikan menggunakan efektifitas Instalansi Pengolahan Air Limbah (IPAL) 20% - 80%. Perhitungan Indeks Pencemar memberikan hasil bahwa sungai ‘tercemar ringan’ dan menerima Beban Pencemar sebesar 0,24 kg/tahun DO, 1,33/tahun NH4, 0,02/tahun NO2 + NO3, 24,91 kg/tahun alkalinitas dan 27,91 kg/tahun CBODs. Pertumbuhan penduduk menyebabkan konsentrasi polutan bertambah dari tahun 2014 hingga 2018. Hasil pemodelan pengolahan air limbah hanya mampu menurunkan parameter NO3-N dan pH agar memenuhi Baku Mutu Air Kelas 1, sedangkan parameter lain masih melebihi baku mutu.

Stream of Kampung Bugis has a vital role for society of Karang Anyar, Tarakan, East Borneo as drinking water resource. However, this river is also as a sink of waste water from households around it. As mentioned in the Government Regulation of Ministry of Environment No. 1 of 2010, to monitor the water quality of the watershed of Kampung Bugis, the determination of Pollutant Load has been conducted by QUAL2K environment modeling. The impact of waste disposal and sewage treatment plan due to population growth in order to keep the water quality meets the Class 1 of Water Quality Standard (Government Regulation No. 82 of 2001) has been simulated. The simulation was performed using water quality and watershed hydraulics data analysis results as the primary data. Segmentation of the river is divided into 19 reach based on the appropriate distance and topography of the river. Present conditions that determined through Pollution Index and the number of waste are calculated using Pollutant Loads analysis. The simulation results are calibrated using trial and error method then being examined by U Statistics Test method. The increase discharge of domestic wastewater is calculated in accordance to the population growth from 2014 to 2018. The scheming of wastewater treatment was simulated with effectiveness from 20% to 80%. Pollutant Index gives the result that the river is 'lightly polluted' and receive Pollutant Load 0.24 kg/year of DO; 1.33 kg/year of NH4; 0.02 kg/year of NO2 + NO3; 24.91 kg/year of alkalinity and 27.91 kg/year of CBODs. Population growth led to the increasing of pollutant concentrations from 2014 to 2018. Wastewater treatment modeling results can only reduce NO3-N parameters and pH to meet Class 1 of Water Quality Standards, while the other parameters still exceeded.

Kata Kunci : QUAL2K, pemodelan lingkungan, kualitas air, Tarakan