Core Team

Tate Rogers
Founder and Principal
Chris Wray
Chief of Party - SWAP

Tate Rogers is the founder and Principal at  Triangle Environmental. He completed his M.S. and B.S. degrees from North Carolina State University where he first developed an interest in sanitation. Tate has supported the design, construction, lab and field testing of novel systems spanning the sanitation value chain since 2011. Tate has field tested over a dozen prototypes in countries including South Africa, Malawi, Zambia, Rwanda, Madagascar and India. Tate has worked with several lead teams in the sanitation technology space including NC State University, RTI International, Duke University, NASA, Biomass Controls and Crane Engineering.

In his free time, Tate enjoys music and going to concerts, traveling, and hosting the weekly Toilet Tuesday in Durham, NC.


Chris Wray has been involved in mobile, online and technology solutions in the USA, Europe and Asia for more than 25 years. He’s led a broad range of programs from mobile handset development to environmental monitoring. Chris has worked with many of the worlds mobile networks, handset manufacturers, retailers, e-commerce, banking and insurance organizations, as well as international development agencies, taking on roles of COO, Operations Director and IT Director to bring outstanding program results. Based in Cambodia since 2015, Chris also plays an active role in the startup community and currently mentors the Women in Tech Network. His interests are in the overlap of people and technology and extend to personal productivity, digital marketing and human/technology behavior.

When not embedded in technology you’ll find him outdoors and probably behind a camera.


Aaron Forbis-Stokes
Research and Development Manager
Jenelle Van Eynde
Project Manager - SWAP   
Operations Support
Sarah Hennessy
Implementation and Servicing Manager

Dr. Aaron Forbis-Stokes is a Sanitation Technology Consultant at Triangle Environmental. He received his Ph.D. at Duke University in Civil and Environmental Engineering in 2017. His doctoral work focused on the "Anaerobic Digestion Pasteurization Latrine (ADPL),"  a self-sustainable, off-grid fecal sludge treatment system. His leading efforts with the ADPL progressed the innovation from a lab-scale experiment to 6 full-scale prototypes operating across 3 countries, some of which have operated for over 5 years. Technical fields of work included digester design optimization, biological nutrient removal, and microcontrols for system operation and remote data acquisition.

As a member of Triangle Environmental, Aaron has continued collaboration with ongoing research at Duke University as well as branched out to working with other teams, like Crane Engineering. Aaron’s combined experience in multi-disciplinary research and development, international implementation and operation with multiple partners, and technical communication make him an effective collaborator in multiple stages in the development and market application of sanitation technologies.


Outside of work and being a regular attendee of the Durham Chapter of Toilet Tuesday, Aaron loves spending time in the great outdoors, exploring new territory, and being on a bicycle.


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Caroline Saul
Technical Lead - SWAP
Business Development and Digital Services

Jenelle Van Eynde provides project and operations management support to Triangle Environmental. Her experience in the water, sanitation and hygiene sector spans more than seven years. Jenelle brings over ten years of experience in project management, desk research, strategic support, event management and facilitation, high-level executive support, and pipeline management. And, she has experience working with for-profit companies, non-profit organizations, and large foundations across the world.


When not working in the WaSH sector, Jenelle enjoys volunteering in her local community, trying new restaurants with her husband, visits with her family in the Pacific Northwest, and HIIT workouts.


Sarah Hennessy supported the installation and commissioning of Duke University Center for WASH-AID's toilet prototype, with RTI International in India, and with Triangle Environmental in South Africa. Sarah is currently stationed in Kenya, providing technical engineering support to Sanivation and exploring viable commercialization routes to bring innovative technology to market. Sarah is experienced working on collaborative, multi-disciplinary projects with professionals from academia, industry, government, and non-governmental agencies. Sarah’s work with diverse teams has provided her a widespread network of experts, helping her holistically field test technology prototypes. This integrated approach will aid in the transition from field testing to successful commercial implementation.


Sarah holds a B.S. in Chemistry from Furman University and a M.S. in Environmental Engineering from Clemson University. When not at work, Sarah loves exploring the great outdoors by foot or bike with her husband Jeff, her hammock, and a good book.


Dr. Caroline Saul recently relocated back to North Carolina after spending five years working in the Business Innovation Group at Eawag in Switzerland. At Triangle Environmental, she heads up new business development and service design to complement our technical research.


Caroline’s background in Environmental and Energy Engineering and Economics has motivated her to work towards developing systems for extending basic services to all. She has worked in Indonesia, Uganda, Burkina Faso, Haiti, and Kenya. At Eawag, her research consisted of longitudinal case studies of water and sanitation service providers in low-income countries. The primary focus of her research has been business model innovation in container based sanitation service providers and water kiosk operators, particularly the roles of digital technologies in operational models. 


Outside of the office, Caroline can be found on an Ultimate (frisbee) field, fly fishing, or scuba diving.


Marielle DuToit
Research Scientist
Samras Piseth
Research Manager - SWAP

Dr. Marielle DuToit is a Research Associate at Triangle Environmental. She recently earned her Ph.D. in Civil and Environmental Engineering at Duke University, where she studied water treatment technologies with a multidisciplinary approach. Her work focused on integrating conductive water filtration membranes into novel electrochemical sensing systems. Over the course of her graduate education, Marielle's experience ranged from polymer membrane fabrication to electrical circuit design to membrane modification with nanomaterials to membrane system analysis with electrochemical impedance spectroscopy. She remains interested in exploring the sensing and performance-enhancing possibilities for conductive membranes, especially as they may serve to benefit sanitation processes.


Aside from electrocuting membranes in the lab, Marielle also enjoys playing music with several local bands, reading novels, talking politics, and doing just about anything (but especially biking) outside.


Sensamras (Samras) Piseth is based in Cambodia and recently joined Triangle Environmental as the Research Manager for the Solid Waste Accountability Platform (SWAP) project funded by USAID.

Samras holds a bachelor’s degree in Engineering specializing in Water Resource and Rural Infrastructure from the Institute of Technology of Cambodia and a Master’s Degree in Environmental Geology from Gadjah Mada University, Indonesia. Samras has five years working experience with non-profit organizations in WASH. Growing from socio-economist to project manager, Samras has been responsible for carrying out surveys on piped water supply and household level fecal sludge management, activity planning, group discussions, reporting and grant management. She facilitates communication from the national to local level for smooth project implementation.

Besides work and regular walking and aerobics, Samras loves spending her weekend with her son. She finds going to beach and mountains very relaxing for long holidays.


Nicola Greene
Sanitation Industry Specialist - Emerging Markets

Dr. Nicola Greene has consulted for Triangle Environmental since 2017 and has been based in East and Southern Africa since 2014 with a specific focus on improved fecal sludge management. Nicola is an engineer by training and holds a PhD in Civil Engineering from the Water Engineering and Development Centre (WEDC), Loughborough University. Nicola is focused on the practical aspects of the on-site sanitation market and the industries within it; assessing the needs of the key players and matching these with emerging technology and service design. 


She brings a broad perspective having worked in Rwanda, Kenya, Zambia, Uganda, Ethiopia, Sierra Leone, Malawi and Nepal;  across a range of stakeholders including NGOs, Social Enterprises, Private Sector, Utilities and Local Government. Recently, Nicola founded a small business in Nairobi, Kenya (Opero) which focuses on building sanitation and solid waste systems that scale.


When not focused on fecal sludge, Nicola enjoys mentoring small businesses, making things, and spends most weekends on a mountain bike.


Join Our Team!

We do not currently have any openings, but we would still love to hear from you!

Please Contact Us so we can get to know you for any openings we have in the future!