A sustainable sanitation chain is essential for clean, healthy, and liveable conditions in developing countries. Under the Swachh Bharat Mission Gramin, the Indian government constructed 180 million toilets with onsite sanitation technologies (OSTs), but these often fall short in managing faecal sludge (FS). This study systematically characterizes FS to assess its resource potential and develop a treatment design in a rural area of Maharashtra, India. The collected FS contains nutrients like nitrogen, phosphorus, and potassium, qualifying it as an organic fertilizer per Indian specifications. However, high pathogenic content requires pathogen elimination and liquid–solid separation. A 1000 m3 drying bed and 20 m3 pathogen elimination chamber are needed for FS treatment in Vadgaon Maval, aiding in establishing FSM regulations for India.