Inventarisasi Sumber Pencemar dan Pemetaan Kualitas Air Kali Asem

Abstract

Pencemaran air Kali Asem akibat tingginya aktivitas antropogenik di Kota Bekasi memerlukan penanganan berbasis data spasial. Penelitian ini bertujuan mengidentifikasi sumber pencemar, memetakan sebaran kualitas air, menentukan titik tercemar tertinggi, serta menyusun rekomendasi pengelolaannya. Metode yang digunakan meliputi inventarisasi lapangan, analisis laboratorium pada tujuh titik sampling, pemetaan spasial Inverse Distance Weighting (IDW), dan penentuan status mutu air menggunakan metode STORET serta Indeks Pencemaran (IP). Hasil inventarisasi mengidentifikasi sumber pencemar di hulu didominasi oleh industri dan kawasan TPST Bantargebang, sedangkan bagian tengah dan hilir didominasi oleh limbah domestik serta UMKM. Parameter BOD, COD, dan total coliform tergolong tinggi, sementara DO tergolong rendah. Evaluasi status mutu air menunjukkan Kali Asem mengalami cemar berat di bagian hulu, dan cemar sedang di bagian tengah (titik paling tercemar pada Titik 1, nilai STORET -40, dan Titik 4, nilai IP 7.29). Rekomendasi pengelolaan berfokus pada pengawasan efluen limbah industri/lindi di hulu, perbaikan sanitasi domestik di tengah dan hilir, serta pemantauan kualitas air berkala.

Water pollution in the Asem River, caused by intensive anthropogenic activities in Bekasi City, requires management informed by spatial data. This study aimed to identify pollution sources, map the spatial distribution of water quality, determine the most polluted locations, and formulate management recommendations. The methods included field inventory, laboratory analysis of water quality at seven sampling points, spatial mapping using the Inverse Distance Weighting (IDW) method, and water quality status assessment using the STORET and Pollution Index (PI) methods. The inventory results showed that pollution sources in the upstream section were dominated by industrial activities and the Bantargebang Integrated Waste Processing Site (TPST), while the middle and downstream sections were mainly influenced by domestic wastewater and small and medium enterprises (SMEs). High concentrations of Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD), and Total Coliform, together with low Dissolved Oxygen (DO), indicated deteriorating water quality. Water quality status assessment revealed that the upstream section was classified as heavily polluted, whereas the middle section was moderately polluted, with the highest pollution levels recorded at Sampling Point 1 (STORET score of -40) and Sampling Point 4 (Pollution Index of 7.29). Management recommendations focus on strengthening control of industrial effluents and landfill leachate in the upstream section, improving domestic sanitation in the middle and downstream sections, and implementing regular water quality monitoring.