A belated reply from me just to say how much I have appreciated your incredible work over the past decade plus and how much we will miss you! You have been a great model across the foundation on both the “what” and the “how” – which is why you were such a worthy Bill Sr award winner – and will leave a very strong legacy with both us internally and the many partners and communities you have helped externally.
I am unfortunately traveling today so can’t attend your celebration but did want to take the opportunity to send my deep personal thanks for your contribution — and please do stay an engaged member of our alumni community going forward.
Warm regards,
Mark Suzman
CEO, Gates Foundation
Dear Roshan, I am out of town today so will not be able to see you in person. You have accomplished so much at the foundation and have been a source of vision and encouragement to me and many others. I will miss working with you, but I am excited for this next chapter.
It has been a huge honor to know and work with you.
Rodger Voorhies
President, Global Growth & Opportunity,
Gates Foundation
Dear Roshan,
So sad to hear that you have decided to step back but totally understand that families are much more important.
I am with you and let’s keep in touch….!
Best wishes,
Mihoko
Dear Roshan,
It’s been such a joy getting to know you—especially through your well-deserved recognition as the 2023 Bill Gates Sr. Award recipient. You’ve always carried such warmth and humility, and your smile reflects the compassion and dedication that have defined your incredible impact both within the foundation and far beyond it.
I’m so sorry I wasn’t able to attend your farewell the other day, but I didn’t want to miss the chance to share how deeply admired and appreciated you are. The thing about legacies is that they extend beyond any period of time. While this may mark the end of an era, the legacy of you—your leadership, kindness, and unwavering commitment to equitable solutions—will continue to influence our foundation’s culture for years to come.
Wishing you all the best as you begin this next chapter in Nepal. You leave behind not just accomplishments, but a lasting sense of purpose and community that will continue to inspire us all.
With gratitude,
Lindsey Grays
Congratulations!
You have been an amazing leader on the WSH team and have had a huge worldwide impact on people and sanitation for those who can least afford access.
I look forward to seeing you soon!
Warmest regards,
Sun Kim
Dear Roshan,
This is the most complete and most beautiful message I have ever seen emerge from the WSH team! Thank you for including me.
It’s been a special and wonderful 13 years, and you capture it all so well.
I know you will need to sit with this transition for a while and let it sink in; the same was true for me. But you are leaving at the right time, and there is much you can still be a part of and contribute to, and much you can still accomplish through the many people who will come your way…
I am sorry that my own situation doesn’t allow me to be a part of some of the next steps we are planning in the way I had hoped. But I hope to see you before you fly into the sunset; best of luck and
Much love from
Jan Willem (your brother)
Dear Dr Roshan,
Your kind acknowledgement shall continue to inspire as was your demonstrated leadership over years towards improving Sanitation Sector in our region.
Privileged to have known you as a friend and guide ever since FSM-3 at Hanoi, I stand most relieved to note that you shall be associating with and supporting the sector as a mentor….. because a lot more yet needs to be accomplished.
Farewell, Sir. 💐💐 We assure our full support to Sakshi and look forward to deploying transformative sanitation technologies in our towns.
Warm Regards,
Rohit Kakkar
Jt Advisor (CPHEEO),
Ministry of Housing & Urban Affairs,
Govt of India
309 Sankalp Bhawan,
Kasturba Gandhi Marg,
New Delhi-110001
+918750622900
“CLEANLINESS IS NEXT TO GODLINESS”
Dear Roshan,
Thank you for your deeply thoughtful and inspiring message — it captures the essence of what we have all sought to achieve together in India’s sanitation journey. Working with you and the BMGF team has been an immensely rewarding experience. Our joint advocacy for Faecal Sludge and Septage Management (FSSM) across Assam, Jharkhand, Madhya Pradesh, and Chhattisgarh has helped establish strong state policy frameworks and operational guidelines that continue to strengthen India’s pursuit of safely managed sanitation and the SDG 6.2 targets. Your leadership has been pivotal in transforming sanitation from a focus on infrastructure to a systems approach—grounded in inclusivity, sustainability, and service delivery.
For UNICEF India, your partnership has been instrumental in enabling governments to embrace citywide inclusive sanitation, ensuring that the most vulnerable, especially children, benefit from safer, cleaner, and healthier environments.
On a personal note, I am touched and grateful for your kind words and recognition. It has been an honor to collaborate with you and learn from your wisdom, humility, and relentless commitment to the sector. As you retire and return home to spend cherished time with your mother and family, I wish you health, happiness, and continued purpose. Your contribution to India’s sanitation story will continue to inspire all of us.
Regards,
Sujoy Mojumdar
Senior WASH Specialist,
UNICEF India | 73 Lodi Estate, New Delhi, 110003 India
Phone: | Mobile:9717402345 | E-mail: smojumdar@unicef.org
Follow us on Facebook, Twitter, Instagram and at www.unicef.org/india
Dear Sir,
I want to sincerely thank you for your mentorship, guidance, and support throughout my career. I still fondly remember our first interactions during the ENPHO days with all the other team members, and later meeting you in different positions across various organizations — each time an inspiring experience that left a lasting impression.
I remain deeply grateful for the opportunity you gave me to work in Bangladesh on the Sanitation Planning for Coastal Towns Project. That experience greatly contributed to my professional growth and strengthened my confidence in the sanitation sector.
I have always considered you a well-wisher and someone whose guidance I could rely on whenever needed. Your leadership and vision have been instrumental in shaping progress across the WASH sector, and it has been a privilege to learn from your example.
As you step into this new phase of life, I wish you all the very best. May this next chapter bring you joy, good health, and fulfillment of all your dreams. I am sure our paths will cross again somewhere in this small world.
Warm regards,
Rajesh Pai H
Mobile: +919900050800
Dear Dr. Roshan,
Your message was both moving and inspiring. You have brought exceptional clarity, courage, and collaboration to the water and sanitation space, and it has been a privilege to witness your leadership. The way you built networks, catalysed change, and created capacities that continue to sustain interventions is truly remarkable.
You didn’t just fund programs, you shaped a FSM movement, nurtured institutions, and mentored individuals who will carry forward shared vision. Few leaders combine strategic thinking with such humility and generosity of spirit. Other development and philanthropic organizations can learn from your unique approach to partnership and impact.
Thank you for being a mentor, cheerleader, and catalyst for so many of us in the WSH sector. Your interventions will continue to guide the work in India. Wishing you joy, peace, and meaningful new beginnings (R 2.0) as you return home to Nepal. Let’s stay connected.
Warm regards,
Prof Chary
Dear Roshan,
Thank you for your mail and your kind words about our work together. It was a real privilege to work with you and we very much look forward to staying in touch.
Warmest and hope to catch up soon.
Sunita Narain, CSE
Dear Roshan Ji,
Thank you for your deeply moving message and for sharing your incredible journey with all of us. At the very outset I want to express my sincerest appreciation for your leadership and mentorship over the years.
It has been an honour and privilege to collaborate with you and the Foundation under your guidance. Your vision and commitment have not only advanced the sanitation sector in India but have also transformed the way we think about inclusivity, sustainability, and systems change. The progress we’ve collectively made in Tamil Nadu—from the early challenges in Trichy to the breakthroughs in Perinaickenpalayam and beyond—stands as a testament to your belief in local institutions, partnerships, and perseverance.
Your ability to bring together diverse actors across governments, academia, civil society, and the private sector has created a powerful and enduring ecosystem. Many of us have learned immensely from your humility, technical insight, and unwavering optimism. You have inspired a generation of practitioners and researchers who will continue to carry forward your legacy.
As you step into this next phase, I wish you the very best in your well-deserved retirement. May this time in Nepal bring you rest, joy, and cherished moments with your family—especially your mother. I also take comfort in knowing that your wisdom and energy will continue to guide the sector through your mentoring and advisory roles.
Please know that you will always have friends and collaborators here at IIHS. We look forward to staying in touch and to seeing you again soon.
Best,
Niladri Chakroborti
IIHS
Hi Roshan,
Thank you for your support, your contribution and your leadership. We will miss your warm and open enthusiastic manner of engagement. That I was witness to from my days with NIUA and CSE.
Your retiring/leaving without a blemish on your professional and personal dealings – is an example for others in todays time.
Wish you all the best and we will look forward to meeting again and again,
Regards,
Depinder S Kapur
Head,
Climate Centre for Cities (C Cube),
National Institute of Urban Affairs (NIUA)
1-2 Floor Core 4B,
India Habitat Centre, Delhi
T: 011-24643284, 24617517
M: 9711178181
Dear Roshan ji,
I join Meeraben and our CWAS and GSGS team at CEPT to thank you for bringing this unique and resourceful platform of academia-industry partnership through GSGS. Reading such a wonderful note was truly humbling — what a remarkable journey it has been, shared with so many incredible partners. It has truly been a joy working with you. Being part of GSGS since its inception and watching GSGS flourish under your inspiring leadership has been both humbling and rewarding. I still remember our first meeting for GSGS at CEPT in 2019 and we have come a long way, always supported by your positive and encouraging outlook. We look forward to your continued mentorship. Thank you for introducing us to Anindita in round 2 of GSGS. She has been a wonderful support and has been providing valuable inputs from time to time.
You are passing on the baton to very capable hands. In our limited interactions with Sakshi — through GSGS in Sri Lanka and a few meetings with CWAS — she came across as an approachable and energetic leader. We look forward to advancing GSGS’s vision and impact with her guidance and support.
We will stay connected. See you soon in December.
Regards,
Prof Mona Iyer
CEPT University
Congratulations on completing 13 years at the Foundation and on your retirement!
Wishing you happiness, good health, and wonderful moments in the new phase of life.
Warm Regards,
Neelima Thota
+91-9731700663
Dear Dr. Roshan,
Thank you for your kind words and such a comprehensive acknowledgement!
You have been an inspiration to all of us working in the sector, and I can’t think of anyone else who brings in your level of enthusiasm and energy. While you always put your heart and soul into each initiative, you also ensured that all the partners walked alongside and had the freedom to think out of the box to find solutions, which is the reason so many wonderful milestones could be achieved by all the sector partners.
While we will miss meeting you at key events, I do hope that our paths cross again and I get to learn a lot more from you.
Thank you so much for being our North Star, and lots of best wishes for all the good things that lie ahead!
Hope to meet soon, either in India or even better in Nepal! Lots of best wishes from the CDD family!
Regards,
Sandhya Haribal
CDD
Dear Roshan-
It was great working with you during my SCI-FI and SCI-AI days.
Your gesture of affection and trust on my abilities as a team member working towards inclusive sanitation will always be remembered fondly. You were like a guru to me.
Thanks for your support. I wish you loads of best wishes for your future endeavours.
Best regards,
Anju Dwivedi
Dear Roshan,
You have been an amazing professional and a team player for the WASH sector. Many enriching discussion we have had and your un-waiveing support for the very basic cause for better, healthier cities has been phenomenal.
We at UMC value your partnership, mentorship and above all your friendship. I and Meghna and all my colleagues join here with me to wish you all the very best in all your future endeavours.
Let’s be in touch. Best wishes and thanks very much for all that you have done for us.
Regards,
Manvita Baradi
Founder and Director, Urban Management Centre, Ahmedabad, India
Dear Roshan Ji,
Thank you for sharing your heartfelt message. While sad to hear that you would be retiring soon, I want to acknowledge how your leadership and vision have truly shaped the way this part of the world understands and advances inclusive and sustainable sanitation.
Your work with the Gates Foundation has left an enduring legacy — and I’m so grateful to have been a small part of this over the past 10 years. In India, Nepal, Bangladesh as well as Africa.
As you begin this new chapter, I wish you the very best in your retirement. May you have good health and happiness always.
With warm regards,
Dorai Narayana
Dear Roshan,
When I visited India 15 years ago, I was told that there was no FSTP in India. Now, there are more than 1,000 FSTPs already built and operating, and another 1,000 FSTPs are under construction. This is the story I always mention whenever I discuss with my Japanese colleagues on sanitation in India.
I suppose that such transformation would not have happened without you and your Indian partners’ vigorous efforts.
I truly appreciate your leadership and friendship. I hope that our roads will cross again in the future. I am expecting to meet and work together with Sakshi.
With Best Regards,
Kazushi Hashimoto
ADBI Consultant and Advisor to Japan Sanitation Consortium (JSC)
+81-80-1021-8096
Dear Roshan,
Greetings and belated Diwali wishes!
Thank you for including me in your farewell message. First and foremost, my heartfelt wishes for this new chapter with your family. I’m sure your mother and loved ones are overjoyed with your decision.
At the same time, I believe the world of sustainable sanitation will deeply miss your visionary leadership and the courage with which you inspired a movement in this region. Personally, I feel fortunate to have learned so much from you, not only about leadership but also about compassion, humility, and the art of building strong, motivated teams. I’ve always admired how you uplift your colleagues, leading them to achieve even the impossible with grace and confidence.
Wishing you peace, happiness, and all the wonderful surprises that life has in store for you ahead.
Hope to keep in touch.
Regards,
Dr. Sunitha K Nayar
Dear Roshan,
No words can truly express how I feel upon hearing about your retirement. It has indeed been a great experience working with you. I deeply value your guidance, friendship, support, and mentorship in shaping GSCOE’s vision and mission.
What I can assure you is that the legacy you’ve built, to advance the sanitation revolution in India, we will carry forward with the same dedication and spirit.
Wishing you a happy and healthy retirement filled with peace and joy.
Regards,
Praveena Gangadharan, Ph.D.
Associate Professor,
Department of Civil Engineering / Environmental Sciences and Sustainable Engineering Centre
Indian Institute of Technology Palakkad,
Palakkad – 678623, Kerala, India
Telephone: 0491-209-1112
Homepage: https://iitpkd.ac.in/people/praveena
Website: https://www.praveenag.in/
Dear Roshan,
Thank you so much for your thoughtful message. It truly means a lot to all of us at GSCOE, IIT Palakkad. Your guidance and support during the formative years of GSCOE were invaluable. Truly appreciate the opportunities and networks you created for us. We continue to draw inspiration from your vision and are delighted to work with Sakshi as we move forward. We look forward to welcoming you to ICNSS 2026 | 2nd International Conference on Non-Sewered Sanitation Systems which will be held at IIT Palakkad between 09-12 July 2026.
Warm regards,
Dr. Devasena M
Chief Technical Officer,
Global Sanitation Center of Excellence (GSCOE)
Indian Institute of Technology Palakkad, Sahyadri Campus, Kanjikode,
Palakkad, Kerala – 678623, INDIA. (Time zone: UTC +5.30)
Web: https://gscoe.iitpkd.ac.in/ | https://devasena.my.canva.site/
Phone:91-9600004594
Dear Roashan ji,
Wishing you all the best for your post retirement life.
We had indeed good time in setting up GSCOE at IIT Pallakkad with help of Director IIT Pallakkad, Dr Devasena, Dr. Praveena and others.
Thank you for your support during my period at PSA Office.
Now, I am always available for you and can take your call at anytime.
Best wishes again.
Regards,
Dr M Mohnaty
Director, ICAR-IISS Bhopal
Dear Roshan,
Reading your message filled us with warmth and gratitude. It reminded us how much your vision and catalytic support have shaped the course of so much good work in India. For us at UMC, your trust and encouragement were truly transformative. It was only because you first showed belief in our approach that we were able to receive the Foundation’s direct support – to first strengthen NULM’s work on urban livelihoods, and then to focus on the safety and dignity of sanitation workers.
Your confidence in us, right from the time we were taking our first steps in this space, urged us to go further and do better. Beyond all the professional milestones, what we are going to cherish most is you, your warmth, humility, and infectious optimism.
Your absence will be vividly felt, but we know that your spirit and guidance will continue to shape this sector and all of us who have been privileged to work with you. Of course, it is not a goodbye, for we will always be friends, and India is never too far.
With warm regards and deep appreciation,
Manvita & Meghna, on behalf of the UMC team
Dear Roshanji,
Thank you for sharing with us this significant milestone in your professional journey.
All of us at CWAS and CEPT University extend our heartfelt thanks to you for your unstinting support to CWAS-CEPT over the years. Our belated greetings to you for Diwali. In Gujarat, the day after Diwali is the beginning of a new year. We wish you and your family our warmest wishes for the new year, which also marks the beginning of a new chapter for you.
We echo all the partners in acknowledging your key and important role in India’s transformative sanitation journey. Your vision and stewardship have been key to scaling up FSM infrastructure and a comprehensive Citywide Inclusive Sanitation (CWIS) approach across Asia and Africa.
Your constant encouragement and support have helped CWAS to grow from its early days of PAS, and later to the pioneering efforts in innovative sanitation in Wai and Sinnar. Your support has enabled us to continue the PAS support to states and cities for over 15 years now, and to scale up CWIS and integrate it in academic programs through GSGS. We are really very grateful to have been part of this learning journey alongside you.
Our team was also inspired by your reflections on your professional journey shared during one of our CWAS annual retreats. We cherish your visits to CEPT and our interactions at various meetings and seminars over the years. We are sure that we will have many opportunities to stay connected in future.
We will continue working closely with Sakshi to carry forward the ongoing initiatives and benefitting from her continued guidance and support.
With our very best wishes,
Dhruv, Aasim, Meera, Dinesh, Mona and the entire CWAS family
CWAS-CEPT University
Dear Dr Roshan,
Thank you so much for everything you have given to this sector – and to all of us who have had the joy of working with you.
I still remember meeting you in Rajasthan back in 2016 – your energy and optimism were infectious. You made me genuinely excited about the work we were doing, and since then, you have always been someone I could reach out to anytime for guidance and encouragement. Whatever little I have been able to do in this sector has been shaped by your constant support and belief in me.
What makes you truly special is how humble and grounded you have always been. There is a warmth you bring into any room – and that loud, happy laugh of yours instantly makes everyone feel at ease! Maybe that is why you have built such strong connections all over the world; people open up to you because you listen with empathy and see things as they truly are.
You are, and will always remain, my hero – someone I truly look up to and hope to become a little more like. I have said this before and will say it again: please always stay the way you are. It’s rare and comforting to have someone so genuine and caring in a world that often feels too noisy and fast.
Cheers to your second innings, Dr Roshan – sixty is just the start of another wonderful chapter until you hit the century! 😊
Regards,
Suraj Kumar
Dear Roshan Ji,
Greetings from ASCI
It’s truly difficult to imagine the sanitation sector without your visionary leadership and the deep sense of collaboration you brought to it. You have been a catalyst in transforming sanitation from a construction agenda into a movement for inclusion, dignity, and sustainability. Your humility, wisdom, and ability to connect people and institutions have left an indelible mark on all of us and in the sector.
At ASCI, we are immensely proud of our long partnership with you—from the early days in Warangal that became a national and international model for FSSM, to the many capacity-building programs and the SaniTour that shaped hundreds of sector professionals across South Asia. Your trust and encouragement strengthened our conviction that institutions like ASCI have a vital role in advancing Citywide Inclusive Sanitation.
I also deeply value our shared journey through FANSA, where we worked to bring the voices of the unheard onto sanitation platforms and to uphold the rights and dignity of the most marginalized. Your steadfast belief in inclusion and equity has inspired many of us to pursue this mission with even greater purpose.
As you move into this new chapter, please know that your legacy will continue to guide us. You have built a community of practitioners, policymakers, and advocates who will carry forward your vision of inclusive and sustainable sanitation for all.
Wishing you peace, joy, and many meaningful moments with your family. You will always remain a cherished mentor, collaborator, and friend to all of us at ASCI.
With warm regards and deep appreciation,
Sneha Latha,
ASCI
Dear Roshan,
Greetings!
On behalf of the entire WASHi team, I extend our deepest appreciation for your inspiring note and for the incredible journey we have shared over the years. Your leadership, humility, and unwavering commitment have profoundly shaped the sanitation sector, not just in India, but across South Asia.
We at WASHi feel privileged to have worked alongside you from pioneering ideas like the Mobile Treatment Unit to supporting in advancing transformative sanitation technologies like OP in Kerala. Your mentorship and encouragement have helped us grow stronger and more confident in pursuing inclusive and sustainable sanitation solutions. Your warmth has left a lasting mark on each one of us personally.
As you step into this new chapter of life, we wish you the very best for your well-earned retirement and a joyful time ahead with your family in Nepal. May this new phase bring you fulfilment and continued happiness.
With warmest regards and immense gratitude,
AK, on behalf of the WASHi team
Dear Roshan,
I just got back from the GWOPA Congress and it was amazing to see how many of the seeds you have sown continue to blossom. More sanitation operator partnerships are taking off, more utility leaders and young professionals are receiving training and support through the GSGS network, and the shared frameworks and tools you and the team helped shape are enabling us all to communicate better and think more clearly about where we are and where we want to go.
Your ability to think long-term while bringing people and organizations together to make things happen is deeply inspiring. On a personal note, I remain forever grateful for the faith you placed in us and for the opportunities you created that allowed us to grow both as an organization and within the sector.
Thank you for being such a steady source of guidance and inspiration. I can’t wait to see the next set of ideas that will take root under your continued mentorship. Looking forward to catching up soon in Bangkok!
Deepa Karthykeyan
Co-Founder and Partner
Web: www.athenainfonomics.com
Dear Roshan,
It’s difficult to imagine the sanitation sector without your active presence! But as many have already said, the seeds you’ve sown across different parts of the world will continue to grow and flourish.
I echo others’ words in thanking you for your clarity of vision and ability to set strategic direction. But what also stands out for me are your remarkable insights into how things were likely to pan out on the ground—shaped by decades of experience. When results didn’t add up, you were often the first to suspect that the measurement technique might be flawed—and you were right. When you predicted trouble with a vendor, it usually turned out to be the case. You saved us from many a challenge and guided us on countless issues. And of course, your cheerful disposition and ability to lighten any situation will always be remembered.
Thank you, from all of us at IIHS, for your steady support—from the inception of TNUSSP to its maturity now—and for standing by us, even through the difficult moments on the ground. We’re equally grateful for the mentorship you’ve extended to many of us as we’ve grown into leadership roles.
Wishing you all the very best for this next phase of your journey—and we’re so glad you’ll be that much closer to us again! 😊
Warm regards,
Kavita Wankhade,
IIHS