Kajian pencemaran lingkungan akibat penambangan emas tanpa izin terhadap kualitas air Sungai Buladu dan persepsi masyarakat di Kabupaten Gorontalo Utara

OLII, Awaludin, Prof. Dr. H. Sudarmadji, M.Eng., Sc

2010 | Tesis | S2 Ilmu Lingkungan

Penelitian ini bertujuan untuk mengkaji tingkat pencemaran merkuri (Hg) terhadap kualitas air/pH (sifat kimia) dan lingkungan biotik/ plankton (sifat biologi) sungai yang diakibatkan oleh aktivitas PETI, Mengkaji persepsi masyarakat terhadap aktivitas PETI, Menguji konsistensi hasil pengukuran objektif dari pencemaran Sungai Buladu akibat aktivitas PETI dengan persepsi masyarakat. M etode pengambilan sampel yang digunakan adalah purposive. Analisis sampel air dilakukan di laboratorium sedangkan hasil pengukuran pH langsung dilakukan di lapangan, hal tersebut dilakukan untuk mengetahui kadar merkuri yang terkandung di air sungai dan outlet pengolahan bijih emas. Sampel plankton dianalisis di laboratorium untuk mengetahui indeks diversitas plankton. Data persepsi masyarakat diambil langsung dilapangan dengan teknik in depth interview. Hasil analisis laboratorium pada bagian tengah sungai sudah termasuk kategori tercemar berat dan pada bagian hilir sungai termasuk pada kategori tercemar ringan, sedangkan kualitas air pada bagian hulu masih berada dibawah baku mutu air. Analisis kualitas air buangan limbah menunjukkan kadar merkuri pada outlet pengolahan emas tersebut masih dibawah baku mutu limbah yaitu 0,005 mg/L. Hasil analisis laboratorium terhadap plankton pada bagian hulu, tengah dan hilir Sungai Buladu berdasarkan indeks keanekaragaman pada bagian tengah dan hilir sudah temasuk dalam kategori tercemar berat, sedangkan untuk begian hulu Sungai Buladu termasuk dalam kategori tercemar ringan. Dari pendalaman jawaban responden dapat digambarkan apabila menggunakan air Sungai Buladu beresiko terkontaminasi racun merkuri sehingga untuk konsumsi sehari-hari mereka menggunakan air Sungai Kiki dan air sumur gali, akan tetapi hal tersebut tidak menjamin air sungai Kiki dan air sumur gali tidak tercemar oleh merkuri, karena sifatnya merkuri akan merembes ke daratan melalui air tanah dan dapat mencemari air sumur. Hasil uji Laboratorium bahwa pada air sungai dibagian hilir, tengah dan hulu sudah terkontaminasi oleh zat pencemar merkuri tetapi dengan kadar dibawah baku mutu yang sudah disyaratkan dan belum termasuk dalam kategori tercemar berat, hal tersebut didukung dengan hasil wawancara responden yang bermukim di sekitar areal pengolahan emas, sebagian besar responden tidak lagi menggunakan air sungai Buladu untuk dikonsumsi, hal tersebut dikarenakan mereka tahu air sungai Buladu sudah bercampur dengan bahan kimia buangan tambang emas yang berbahaya bagi kesehatan apabila dikonsumsi.

This research aimed to study the pollution levels of mercury (Hg) toward water quality/pH (chemical) and biotic environment/plankton (biological ) of the river caused by PETI activities, studying the community perception toward PETI activities, examining the consistency of objective measurements results of Buladu River pollution from PETI activity with public perception. The sampling methods used is purposive. Analysis of water samples was conducted in the laboratory while the results of pH measurements was done immediately in the field, it is performed to find out the mercury levels contained in the river water and the processing outlet of gold ore. The plankton sample were analyzed in the laboratory to find out the plankton diversity index. Data of public perception taken directly in the field with in depth interviews technique. The results of laboratory analysis the center of river was in heavily polluted category and in downstream of river was including in the light contamination category, while the water quality in the upstream was still under water quality standards. Analysis of waste water quality showed mercury levels at the outlet of the gold processing was still under water quality standards that is 0.005 mg /L. The results of laboratory analysis toward plankton in the upperstream, middle and downstream of Buladu River based on the diversity index in the middle and downstream are including in the heavily polluted category, whereas for upstream of Buladu river was included in the light polluted category. Fom deepening the respondent's answer can be drawn that when using the Buladu river water is at risk contaminated by mercury toxic so that for the daily consumption they use Kiki river water and dug well water, but it does not guarantee that Kiki river water and dug well water is not contaminated by mercury, because the mercury will seep into the ground through the ground water and contaminate the well water. The result of laboratory test indicated that at the downstream, middle and upstream river water have been contaminated by mercury pollution, but at levels under the required quality standards and not included in the heavily contamination category, it is supported by the results of the respondents interview who live around area of the gold processing, the majority of respondents no longer consume the Buladu river water, it is because they know Buladu river water have mixed with chemical of gold mine waste that are harmful to health if consumed.

Kata Kunci : Penambangan emas,Kualitas air,pH,Diversitas plankton,Persepsi masyarakat, gold mining, water quality, pH, diversity plankton and community perceptions