Application of Tunnel-Based Salt House Technology to Support Local Salt Industrialization in the Sangihe Islands, Indonesia

Abstract

Indonesia’s reliance on imported salt, particularly for industrial needs, underscores the urgent need for technological innovation in local salt production. This study investigates the application of tunnel-based salt house technology as a strategic solution to develop local salt industrialization in the Sangihe Islands, a maritime region with 93.8% ocean coverage and pristine seawater quality. The research aimed to evaluate the efficiency and effectiveness of tunnel salt houses in increasing production and improving product quality. The experiment was conducted from July to August at the Fisheries Handling Workshop, Politeknik Negeri Nusa Utara, using seawater, UV-transparent plastic, geomembrane tarpaulin, and PVC frameworks. Quantitative descriptive analysis was applied to assess salt yield, NaCl purity, moisture content, and contaminant levels (Mg, Ca, Hg). The results showed that tunnel systems increased evaporation rates and salt yield up to 1.5–2 times compared to traditional methods, with crystallization periods reduced from 10–14 days to 4–6 days. The produced salt contained 79% NaCl, magnesium levels between 1.56–2.78 mg/kg, calcium levels between 289–305 mg/kg, and mercury concentrations below the national limit of 0.1 mg/kg. Although the NaCl concentration remains below the Indonesian National Standard (SNI 3556:2016), the tunnel design demonstrated significant potential to enhance salt quality and ensure production continuity even during high rainfall. The study concludes that tunnel-based salt house technology is technically and economically feasible for the Sangihe Islands, contributing to local salt industrialization and national self-sufficiency efforts.

Keywords: Geomembrane, Salt, Sangihe, Tunnel

Abstrak. Ketergantungan Indonesia terhadap impor garam, terutama untuk kebutuhan industri, menunjukkan urgensi inovasi teknologi dalam produksi garam lokal. Penelitian ini mengkaji penerapan teknologi rumah garam berbasis tunnel sebagai solusi strategis untuk mendorong industrialisasi garam lokal di Kepulauan Sangihe, wilayah maritim dengan luas perairan mencapai 93,8% dan kualitas air laut yang masih alami. Tujuan penelitian ini adalah mengevaluasi efisiensi dan efektivitas teknologi rumah garam tunnel dalam meningkatkan produksi dan mutu garam yang dihasilkan. Penelitian dilakukan pada bulan Juli hingga Agustus di Workshop Penanganan Hasil Perikanan, Politeknik Negeri Nusa Utara, menggunakan bahan air laut, plastik UV transparan, terpal geomembran, dan rangka PVC. Analisis data dilakukan secara deskriptif kuantitatif untuk menilai hasil produksi garam, kadar NaCl, kadar air, serta kandungan pengotor seperti Mg, Ca, dan Hg. Hasil penelitian menunjukkan bahwa sistem tunnel mampu meningkatkan laju evaporasi dan hasil produksi hingga 1,5–2 kali lipat dibandingkan dengan metode tradisional, dengan waktu kristalisasi yang lebih singkat (4–6 hari dibandingkan dengan 10–14 hari). Garam yang dihasilkan memiliki kadar NaCl sebesar 79%, kandungan magnesium 1,56–2,78 mg/kg, kalsium 289–305 mg/kg, dan merkuri di bawah batas aman SNI (0,1 mg/kg). Meskipun kadar NaCl belum memenuhi Standar Nasional Indonesia (SNI 3556:2016), desain rumah garam tunnel terbukti efektif meningkatkan kualitas dan memungkinkan produksi berkelanjutan meskipun pada musim hujan. Penelitian ini menyimpulkan bahwa teknologi rumah garam berbasis tunnel layak diterapkan secara teknis dan ekonomis di Kepulauan Sangihe untuk mendukung industrialisasi garam lokal dan kemandirian garam nasional.

Kata Kunci: Garam, Geomembran, Sangihe, Tunnel