EMPOWERING SCHOOL SANITATION POST-DISASTER: WATER FILTER DEVELOPMENT AND THE ECONOMIC VALUE OF LEMONGRASS SOAP PRODUCTION IN MIS BI AL-NAZHAR, LANGKAT REGENCY

Abstract

MIS BI Al-Nazhar, a primary school in Kecamatan Tanjung Pura, Kabupaten Langkat, North Sumatra, faces persistent water and sanitation challenges in the aftermath of local disaster events, as its groundwater source is contaminated by salt intrusion and bacterial contamination originating from brackish soil. This community service program, entitled "Empowering School Sanitation Post-Disaster: Development of Water Filters and Soap Production in MIS BI Al-Nazhar, Langkat Regency," was designed to strengthen the school's sanitation resilience through the development of a simple household-scale water filtration system and training in lemongrass (sereh) soap production. The program was implemented in four stages: introduction and socialization, technology transfer and installation, hands-on training and mentoring, and monitoring and evaluation. A two-tank filtration system equipped with silica sand, manganese greensand, and activated carbon media, supported by a 3-way valve and a bypass line, was installed to reduce turbidity, iron and manganese content, odor, and taste in the school's water supply. In parallel, teachers and students were trained to produce lemongrass soap from palm oil, soybean oil, and citronella extract through the saponification process using NaOH. A production feasibility analysis showed that the cost of goods sold (Harga Pokok Produksi/HPP) of the soap was Rp4,056.89 per bar, generating a profit of Rp943.11 per bar at a selling price of Rp5,000, with a break-even point (BEP) of approximately 559 bars per month. The program is expected to improve access to safe water, strengthen hygiene behavior among students and teachers, and open an economically sustainable micro-enterprise opportunity for the school community.