Frank Oesterholt is a senior researcher and project manager on the Industry, Wastewater and Reuse team. His specialties are process water preparation, water reuse and circuit closure. For example, he worked for the sector doing research on ‘critical success factors for circuit closure in the sector’ as part of the sector research programme (OPIW 52). Frank specialises in legionella prevention, mainly targeted towards risk analysis and management plans. He authored publications including the Dutch Health and Safety Executive information page on Legionella (AI-32) published by Sdu and focused on chilled water systems and process water systems. Frank is a member of the Subcommittee on Techniques for Legionella Prevention of the Ministry of Infrastructure and the Environment (under the Committee of Experts, Materials and Chemicals). He is also a member of the Nationwide Consultation Platform for Legionella (LOPL). Frank also specialises in water and energy. In that context, he is the coordinator of the Joint Research Programme theme Climate Neutral Water Cycle. Over the past years, he worked on research focusing on heat and cold recovery from drinking water and more recently he worked on research into the role of drinking water companies in a future hydrogen-based economy.