The high scientific standards maintained by the Journal of Water Supply: Research and Technology - AQUA in its papers owe much to the continuing dedication of the journal's referees, who give freely of their time and expertise. IWA Publishing is pleased to pay tribute to this contribution by recognizing those who have participated in the review process. Thus, the Editors of the Journal of Water Supply: Research and Technology - AQUA acknowledge with particular gratitude the following referees who have reviewed papers during the period January 2019-December 2019.
| Fathy Abdalla | Shakhawat Chowdhury | Yong Han | Mahmoud F. Maghrebi | Anne Schechner |
| Amaal Abdel-Satar | Yi-Hsueh Chuang | Yiming He | Krishnanand Maillacheruvu | Raju Sekar |
| Mahyar Aboutalebi | Gianpaolo Cimellaro | Chihpin Huang | Irena Helena Maliszewska | S. Selvakumar |
| Mostafa AbuKhadra | Charles Cravotta | P.S. Husband | Enrique Cabrera Marcet | Tjandra Setiadi |
| Narsimha Adimalla | Jan Dahlquist | Belal Hussein | Nuno Martins | Omid Seyedashraf |
| Rana Muhammad Adnan | Abdullah Darzi | Maria Ignat | Gagan Matta | Syyed Adnan Raheel Shah |
| Augustine Affam | Lassâad Dassi | Jan Ilavsky | Blaine McCleskey | Saroj Sharma |
| N. Aghazadeh | Johannes Deelstra | Hafiz Zargham Bin Imran | Dena McMartin | Baoyou Shi |
| Mansoor Ahammed | Xitlali Delgado | Munawar Iqbal | Oscar Jose Mesa | Vaclav Sipek |
| Warish Ahmed | Pantelic Dijana | Ivana Ivancev-Tumbas | Omar Magdy Hamed Mohamed Abdeldayem | Arnold Strasser |
| Jae Chan Ahn | Lihua Dong | Anthony Izuagie | Wael Mortada | C. Suribabu |
| John Akudago | Shuying Dong | J Jagadeesh | Aniket Muley | Massoud Tabesh |
| Jorge Alamilla | Enrico Drioli | Vaclav Janda | Baden Myers | Mohammad mehdi Taghizadeh |
| Abid Ali | Huan-Feng Duan | Lordwin Jeyakumar | Jana Naceradska | Morin Takla |
| Imran Ali | Weili Duan | D.C. Jhariya | Remziye Nalcacioglu | Hao Tang |
| Majid Ali | Joel Ducoste | Klaus Johannsen | Olesya Nazarenko | Tiku Tanyimboh |
| Abbas Al-Omari | Bruce Dvorak | Santosh Kaini | Nobuaki Negishi | Vaibhav Thakkar |
| Taha Al-Washali | Mustafa El-Rawy | Vasilis Kanakoudis | Thabo Nkambule | Ali Torabian |
| Ivar Annus | Ahmed El-Zeiny | I.Ethem Karadirek | Mititelu-Ionuş Oana | Stavroula Tsitsifli |
| Francisco Arregui de la Cruz | Miraç Eryiğit | Theodoros Karakasidis | Takehiro Ohta | Mustafa Tuzen |
| Erik Arvin | Balaji Etikala | Bassam Kassab | Adam Olivieri | Taro Urase |
| Gholamreza Asadollahfardi | Emma E. Ezenwaji | Hiromi Kato | Gideon Oron | John van Leeuwen |
| Mari Asami | Luigi Falletti | Konstantinos Katsifarakis | Yaser Ostovari | Petra Vasatova |
| Martijn Bakker | Wei Fan | M.R. Kavianpour | Hitesh Panchal | Vasant Wagh |
| Clarisse Balland-Bolou-Bi | Hafiz Farid | Tasneem Gul Kazi | H.K. Pandey | David Walker |
| Edita Baltrėnaitė | Owais Farooqi | Evangelos Keramaris | Assela Pathirana | Corinne Wallace |
| Magdalena Baresova | Beatriz Felices Rando | Nitasha Khatri | Catherine Paul | Wuyi Wan |
| Lisa Barrott | Marco Ferrante | Sagar Khetwani | Petra Peer | Chen Wang |
| Srikanth Baskar | David Ferras | Joshua Kibet | Guilong Peng | Song Wang |
| Isabelle Baudin | Giuliana Ferrero | Petr Klusoň | Yen-Ping Peng | TsingHai Wang |
| Rolf Baur | Petr Filip | Vladimír Kočí | Radim Petricek | Xuan Wang |
| Stephen Beck | Mohammad Firuz Ram | Ivana Kopecka | B. Petrusevski | Thomas Wintgens |
| William Becker | Marcos Foguel | Ioannis Kougias | Oscar Pozos-Estrada | Chia-chen Wu |
| Belkacem Bekkoussa | Hadi Galavi | Steffen Krause | Ram Prasath | Jianhua Wu |
| Fabrizio Bezzo | Kein Gan | Malgorzata Kutylowska | Thomas Putranto | Shian-chee Wu |
| Omer Bilhan | Jinliang Gao | Anker Lajer Højberg | Jin Qian | Ting-Nien Wu |
| Cristiana Bragalli | Zongjun Gao | Mathieu Laneuville | Zhiming Qiang | Yaoguo Wu |
| Irena Branyikova | Rahul Garg | Pierre Le-Clech | Li Qingzhu | Xinglong Xiao |
| Ines Breda | S Gato-Trinidad | Lai Yoke Lee | Majid Radfard | Yong Xiao |
| Bruno Brunone | Jingye Ge | Mariangela Garcia Leite | Subecha Rai | Jiale Xu |
| Laura Bulgariu | Daniel Gerrity | Cong Li | Marjan Randjelovic | Yunfeng Xu |
| Gary Burchard | Mansour Ghaderpoori | Fulin Li | S. Rangabhashiyam | Sarvin Zaman Zad Ghavidel |
| David Carmena | Farshid Ghanbari | Jiansheng Li | Goutham Rangarajan | Saeed Zeinali Heris |
| Nelson Carriço | Dra Leda Gianuzzi | Kein Li | Badri Narayan Ravikumar | Guangming Zeng |
| Cem Çetinkaya | Jerome Gilbert | Peiyue Li | Harish Ravishankar | Taotao Zeng |
| Panchangam Sri Chandana | Fabio Gonçalves | Yiming Li | Mohammad Rezaie-Balf | H Zhang |
| Dr. Rashmi Chandra | Konstantinos Gonelas | Jr-Lin Lin | Sergio Rodriguez | Junzhi Zhang |
| Kwok-wing Chau | Cheng-bin Gong | Kun-Yi (Andrew) Lin | Lin Ronghua | Yanhao Zhang |
| Saif Ali Chaudhry | Xiaobo Gong | Po-Hsun Lin | Mohammad Reza Safaei | Ying Zhang |
| Bing Chen | Marjan Goodarzi | Yi-Pin Lin | Mehdi Safari | Qin Zhong |
| Kuan-Chung Chen | James Goodrich | Lucija Lipus | Biswajit Saha | Xingding Zhou |
| Ya Cheng | Neil Grigg | Bo Liu | Elad Salomons | Haider Zwain |
| Yong-guang Cheng | Ibrahim Ahmed Hamza | Wanhong Ma | G. Eduardo Sandoval-Romero |