Preyan Arumugam expertise lies in the design and optimisation of decentralised wastewater treatment systems (DWWTs) and the testing and validation of water-efficient sanitation solutions (WESS), including non-sewered sanitation systems (NSSS), innovative frontends (low-flush and mechanical) and other off-grid technologies. This applied research has directly informed the development of technical standards such as ISO 30500, SANS 24521, SANS 1733, and, most recently, the development of a new South African standard for community-scale WESS. She works closely with national and local government, municipalities, technology providers, commercial partners, certification bodies, and testing institutions. In 2024/2025, she was appointed as a Technical Advisor to the National Department of Water and Sanitation for the development of the National Sanitation Programme of Action (NSPA). Much of her research is funded through the Water Research Commission’s (WRC) South African Sanitation Technology Enterprise Programme (SASTEP).