Logam Cu di lingkungan perairan sungai bervariasi akibat dari berbagai proses seperti pengenceran, adsorpsi oleh partikel, terakumulasi dalam biota dan mengendap di sedimen. Dalam lingkungan perairan ada tiga media yang dapat dipakai sebagai indikator pencemaran logam berat, yaitu air, sedimen dan organisme hidup. Penelitian ini bertujuan menentukan kadar Cu di sedimen di wilayah perairan sungai pamusian pasar tenguyun Tarakan Tengah Kota Tarakan Kalimantan Utara Penelitian dilakukan pada bulan Juni-Agustus 2020 yang terdiri dari kegiatan lapang dan analisis logam berat di laboratorium. Kegiatan lapang mencakup pengukuran kualitas air, pengambilan sampel sedimen untuk analisis Cu dilakukan pada 3 stasiun yang menyebar pada arah barat, utara dan selatan dari timur perairan Sungai Pamusian Pasar Tenguyun sedimen tersebut di ekstrak kemudian dianalisis menggunakan Atomic Absorption Spectrometry (AAS) untuk mengukur konsentrasi Cu sedimen.
Konsentrasi logam Cu pada sedimen berkisar antara 0,15-0,39 mg/L pada ketiga stasiun penelitian. Presentase fraksi sedimen di semua lokasi stasiun penelitian yang dimana menunjukkan presentase tekstur masing-masing yaitu 89,28%, 91,51%, dan 94,47% pada fraksi Pasir, diikuti dengan sisa presentase tekstur debu yaitu 3,02%, 2,13%, 4,28 dan liat yaitu 7,70%, 6,36%, 1,25%. Nilai kualitas perairan Sungai Pamusian Pasar Tenguyun yaitu suhu perairan: 30,5-33,8°C, salinitas: 32,0-33,0 ‰, pH: 7,31-7,99, kekeruhan: 0,19-1,59 NTU. Penelitian ini menunjukkan bahwa konsentrasi logam berat Cu pada ketiga stasiun masih berada di bawah ambang batas maksimum dari baku mutu yang telah ditetapkan.
Kata Kunci: Cu, logam berat, kualitas air, sedimen

Cu metal concentrations in river water vary due to a variety of processes, including dilution, particle adsorption, biota accumulation, and sedimentation. Water, sediment, and living organisms are three media that can be utilized as indicators of heavy metal pollution in the aquatic environment. This study aimed to determine Cu levels in sediments in the Pamusian River, Tenguyun Market, Central Tarakan, Tarakan City, North Kalimantan. The study was conducted in June-August 2020 and included field activities as well as heavy metal analyses in the lab. Field activities included measuring water quality and collecting silt for Cu analysis at three sites located in the west, north, and south of the Pamusian River Tenguyun Market's east waters. The sediment was extracted and then analyzed using Atomic Absorption Spectrometry (AAS) to measure the sediment Cu concentration. At the three research locations, the concentration ofCu metal in the sediment ranged from 0.15-0.39 mg/L. The percentage of sediment fraction at all locations of the research station which showed the percentage of texture respectively was 89.28%, 91.51%. and 94.47% in the Sand fraction, followed by the remaining percentage of dust texture which was 3.02%, 2, 13%, 4.28 and clay namely 7.70%, 6.36%, 1.259%. Water quality valued of Pamusian River Tenguyun Market were water temperature: 30.5-33.8C, salinity: 5.93-7. 10, pH: 7.31-7.99, turbidity: 0.19-1, 59 NTU. This study showed that the concentration of heavy metal Cu at the three stations was still below the maximum threshold of the established quality standard. Keywords: Cu, heavy metal, water quality, sediment