Fiberglass Reinforced Plastic (FRP) Septic Tank as a Modern Alternative: A Comparative Study with Conventional Septic Tank

Abstract

Domestic wastewater management in densely populated areas remains challenging because conventional concrete/steel septic tanks can crack or corrode, increasing leakage risk and potentially degrading groundwater quality. This study aims to compare conventional septic tanks with Fiberglass Reinforced Plastic (FRP) septic tanks and to develop an FRP septic tank concept that improves durability, installation practicality, and treatment performance for residential use. A qualitative comparative approach was applied through purposive selection of households/public facilities, in-depth interviews (users, technicians, manufacturers), direct observations of tank conditions and maintenance, and documentation; findings were reduced, categorized (material, efficiency, cost, environmental impact), and thematically interpreted. The study produced an FRP septic tank design concept developed using an Objective Tree, Function Structure, and Morphology Chart, resulting in planning criteria and conceptual drawings. The FRP concept emphasizes lightweight strength, corrosion/chemical resistance, and shape stability under soil loads, while incorporating multi-partition internal processing and media (bioballs) to support staged treatment using gravity flow. The proposed design can reduce leakage risk, simplify installation and maintenance, extend service life, and support more sustainable domestic waste management in space-limited urban neighborhoods. The novelty lies in a residential FRP septic tank concept that integrates three partitions, bioballs, and gravity-based flow without relying on pumps/motors, supported by a structured product-engineering design framework.