About LET


Water and wastewater technology innovations 


Diane d’Arras
IWA Past President 

The IWA Leading Edge Conference on Water and Wastewater Technologies (LET) has built a world-class reputation as the forum for leading researchers to share and debate the pioneering science, technological innovation and leading practices that will provide solutions to water challenges, old and new. Those challenges are immense. 

Fast growing cities, with rapidly expanding populations and industrial bases, are challenging the traditional model of large-scale centralised technology and infrastructure solutions; wastewater, the majority of which is discharged untreated into nature, presents a significant opportunity for building a circular, green economy; the increased presence of chemical micro-pollutants, including pharmaceuticals, pathogenic microorganisms and antibiotic resistant bacteria, threatens the quality of water around the globe. 

LET, is the window into the potential of the water sector to innovate for a sustainable, water-wise future. LET is the place where individuals who share a passion and commitment to delivering technological innovation come to be inspired. 

Diane d’Arras – Former President, International Water Association (2018-2020) 

 Past Editions 

The 2023 Leading-Edge Conference on Water and Wastewater Technologies concluded its 19th edition in Daegu, South Korea. Gathering industry leaders and experts, the event showcased innovations in water treatment, emphasising resource recovery and novel approaches such as brine mining for critical mineral extraction from reverse osmosis brine. Notably, Hong Kong’s sewage COVID-19 monitoring program demonstrated sewage-based public health insights. The conference spotlighted the environmental engineers’ pivotal role in managing waste carbon and driving a circular carbon economy. Advancements in greenhouse gas accounting and practical applications were highlighted, contributing to a more sustainable industry. The event also signified IWA’s commitment to fostering innovation in the Asia-Pacific region through collaboration with key Korean water organisations and an agreement for future cooperation signed with Daegu Metropolitan City, the host city.

2022: Reno, United States of America

The Leading Edge Conference on Water and Wastewater Technologies, held in Reno, Nevada, in 2022, covered a wide range of critical programme topics, including advances in desalination, emerging contaminants such as microplastics, pharmaceuticals, and personal care products (PPCP), and antibiotic resistance. Furthermore, discussions focused on Wastewater-Based Epidemiology, Energy Efficiency and Resource Recovery in Wastewater Treatment, Novel Disinfection Technologies, Emerging Technologies for Nutrient Removal, Advanced Membrane Applications in Drinking Water, and Comprehensive Sludge Management, which included resource recovery strategies. The scope of the conference was on diverse urban water management systems for different environments, ranging from megacities to smaller towns and rural settings. This emphasis was driven by the intricate interplay of climatic conditions and the interdependence of natural and human environments.

2019: Edinburgh, Scotland

The 16th Leading Edge Conference on Water and Wastewater Treatment, held in Edinburgh, emphasised the global importance of technological advances in water and wastewater technologies. The conference encouraged discussions on developing critical water technology breakthroughs, emphasising the necessity of exchanging cutting-edge research and novel ideas. The conference aimed to address developing water concerns with the active participation of prominent water technology experts. The collaboration with UK water utilities Scottish Water and Thames Water highlighted the need for innovative solutions to concerns such as ageing infrastructure, regulatory compliance, and long-term solutions. The gorgeous setting of Edinburgh added to the attraction of the conference, complimenting its focus on innovation and addressing pressing water sector concerns.

2018: Nanjing, China

The 15th Leading Edge Conference on Water and Wastewater Treatment focused on the transformative power of cutting-edge science, technical innovation, and best practises in water management. LET 2018 focused on eight key programme topics, including direct potable reuse innovations, advances in energy efficiency and resource recovery in wastewater treatment, novel decentralised technologies for both urban and rural settings, and the critical detection and control of emerging contaminants and antibiotic resistance. The conference also included innovative oxidation processes, materials, and membranes for water treatment, sustainable approaches to complex industrial wastewater streams, and new applications of cutting-edge molecular microbiological tools in water and wastewater treatment.

2017: Florianópolis, Brazil

The 14th IWA Leading Edge Conference on Water and Wastewater Technologies (LET 2017) was held in Florianopolis, Santa Catarina, Brazil, with the important topic of influencing water management through advanced science and technology as the central focus. The conference focused on eight key programme issues: Resource recovery, advanced anaerobic technologies, novel treatments for micropollutants and emerging pathogens, multifunctional membranes and advanced treatment materials, applications of advanced microbiology and genetics tools, novel biofilm and granular processes, and the integration of green-blue infrastructure to improve urban water management.

Jerez de la Frontera, Spain (2016)

Hong Kong (2015)

Abu Dhabi, UAE (2014)

Bordeaux, France (2013)

Brisbane, Australia (2012)

More past editions: Amsterdam (2011), Phoenix (2010), Singapore (2009), Zurich (2008), Singapore (2007), Sapporo (2005), Prague (2004), Noordwijk (2003)