Appropriate Technology Design Team
(R&D group)

The ATDT group was formed in 2005 within the San Francisco Professional Chapter and known for almost a decade as the Appropriate Technology Design Team (ATDT). In 2014, the team evolved into a national EWB-USA group and it changed its name to the Research and Development (R&D) group.

EWB-USA’s new Engineering Service Corps mode includes the R&D group. The SFP ATDT Composing Latrines in Nicaragua was approved as the first national R&D group project. Future SFP Appropriate Technology projects will be done through the EWB-USA R&D Group.

To find out more about R&D group projects or to volunteer, contact the R&D group through the Engineering Service Corps or e-mail your contact info and
background to

The Research and Development (R&D) group develops solutions for community-identified needs that require researching technologies and/or developing new devices. Project teams are recruited from the EWB-USA’s 16,900+ volunteers and are led by experienced professionals. With a broad range of services, these projects apply both practical experience and creative approaches to address community problems.

Composting Toilets

one of 14 units from August 2014 build

one of 14 units from August 2014 build



The residents of several communities in Nicaragua have a sanitation problem caused by inadequate pit latrines. Based on two successful composting toilet deployments, the SFP Appropriate Technology Design Team (ATDT) has partnered with Rotary clubs of Livermore, CA and Masaya, Nicaragua and NGO, Alcance Nicaragua (AN) for an approved Rotary Global Grant (GG) for $37.5k, enough to do about 80 more urine-diverting-dual-vault composting toilets in four communities: El Llanito and Los Alvarez, near Santa Lucia; and El Tunel, and La Prusia near Masaya.

Community workshop with El Llanito, 2014

Community workshop with El Llanito, 2014


The Rotary Foundation, Rotary clubs of Livermore and Castro Valley CA, andSFP ATDT have funded the approved Rotary Global Grant (GG) for $37.5k. SFP ATDT has provided the engineering design and construction oversight.


The composting toilets are working well. With the approved Rotary Global Grant (GG)  we are ready to deliver more composting toilets in Nicaragua to improve health, protect water and provide valuable organic compost.

Before the first phase EWB-SFP Appropriate Technology Design Team (ATDT) composting latrines project, 95% of the Los Alvarez, Nicaragua community's latrines were in poor condition. These conventional pit latrines flood with water during the winter and overflow sewage which contaminates wells and water supplies. The latrines fail in the summer due to a weakened internal structure. Because of this, inhabitants experience a high rate of illnesses due to exposure to fecal matter and water contamination. The environment is polluted and inhabitants are exposed to physical harm due to latrine collapse.

Our partner organization, Outreach International (OI)/Alcance Nicaragua (AN) has worked with the communities around Santa Lucia and El Tunel and La Prusia to identify these problems and the need to improve their sanitation. Through use of the Participatory Human Development Process, community members identified the problems poor sanitation caused and participated in research to find the best solution: the composting toilet.

Based on the experience of a local leader, a two-vault above-ground system was selected. Since 2010 when EWB-SFP ATDT visited Los Alvarez and built ten units and fourteen more in El Llanito in 2014, families have had successful results with composting latrines as a sustainable solution to their health and sanitation problems which also provides valuable organic fertilizer.

 AN has monitored these toilets since 2011. They are working great and have high user acceptance. Families are able to harvest organic fertilizer worth about $80/cycle.  The design has been refined to be cost effective compared with conventional latrines and the EWB team has developed inexpensive structural upgrades to improve the integrity of the structure.

SFP ATDT Completed or Closed Projects

Fog Harvester

The Appropriate Technology Design Team (ATDT) is working with Themba Develoment Project to collect and distribute clean water through the design and implementation of a fog harvester or alternative method. Themba works at the community level to empower the residents to take charge of their own development to address hunger and food security, water/agriculture, skills development, and education. The ATDT fog harvesting device will improve the accessibility of drinking water in the community and may provide a supplementary source of economic opportunity.


Design, fabricate, test and deploy a fog harvester and affiliated distribution system to the community with local adoption of manufacture, operation, and maintenance.

Design Details

  • Leverage design of existing devices with specific changes to meet local geography

  • Affordable, durable, reliable and simple design

  • Minimal operation and maintenance needs

The Need

A community of roughly 900 people located an hour outside of Queenstown, South Africa has a shortage of clean water for drinking, agriculture and sanitation. The location is very dry, and there is not a sustainable amount of water available or methods to provide it. Currently, residents walk to community tap stations on an as-needed basis for water that runs from a small underground spring. The water quality is uncertain and the quantity available is unreliable throughout the year. The local government used to truck in water, but no longer has the resources to support these villages. The community needs water to sustain life by fighting hunger, dehydration through lack of available water supply, and to maintain a clean and healthy community. Foggy weather conditions common to the area during most of the year can be used to help mitigate this problem through fog harvesting systems, benefiting the community with necessary water resources.

Our Partner The Themba Development Project

Rock Crusher

The Appropriate Technology Design Team (ATDT) is working with A Single Drop to develop and fabricate a device capable of crushing rocks down to a size appropriate for bio sand filters. A Single Drop has helped form local water organizations that implement bio sand filters to communities in need of clean water. The Rock Crusher would enable the local water organizations to expand into communities without access to sand appropriate for bio water filters.


The project aims to create, test and potentially implement a working prototype which will be delivered to A Single Drop with the manufacturing specifications for local production.

Design Details

  • Output to be used to filter water in households of 6 -10 people.

  • Each filter to use approx. 26 liters of 0.19mm to 0.38mm sand.

  • Desired Crusher output: 2 liters/hour.

  • Jagged particles filter better than smooth-round particles.

  • Target cost: $500.

  • 5 to 10 Rock Crusher deployed in the 1st year with more each year.

  • Fabrication and maintenance to be done local to village.

Our Partner: A Single Drop

A Single Drop (ASD) is a non-profit organization working to unite communities by creating and/or strengthening people's water organizations to cultivate peace. Through technological trainings, community development programs and interactive presentations and performances, ASDs goal is to empower communities to proactively and collectively address their own local freshwater issues efficiently and sustainably.

NGO Partner: A Single Drop based in the Philippines and about to expand to Africa.

Cashew Waste

Cashews are one of the favorites of the world’s nuts, but very few people know much about the rest of the story… the tree is closely related to the mango and a cousin of the poison ivy, it produces a fruit which is technically not really a “fruit” but an engorged stem, the “nut” (really a seed) develops outside the fruit, up to 20% of the shell weight is a valuable industrial chemical. The project supporters seek to extract more value for Africa from the cashew crop. Presently raw nuts are shipped abroad for roasting and packaging. These operations could be performed locally, benefiting the communities where the nuts are grown.


A specific goal is to find more uses for by-products – like the fruit and nut shell – so that small farmers can obtain additional income, improving their quality of life.

The Need

The landscape is littered with huge piles of messy shells, while scarce wood resources are consumed to produce energy.

Design Challenges

The oil in the shells (CNSL) is valuable for use in polymers, coatings, and auto brake components it is also noxious (it causes a skin rash much like that from poison ivy) and difficult to extract. Our challenge is to adapt existing technologies to these new circumstances and in a way that is most appropriate for Africa. With or without the oil, the shells have a high energy content, making them suitable for providing process heat for industry or fuel for improved household cooking stoves… except that the simple technologies needed to turn them into charcoal or briquettes don’t exist there yet. When burned in a typical way the oil produces an unacceptable amount of very unpleasant/acrid smoke.

Our Partners

This project is supported by several organizations including the following:

  • Costco

  • African Cashew Initiative

  • The Bill and Melinda Gates Foundationy

Plastic Recycling

The Appropriate Technology Design Team will work with the community in San Juayua/Juan de Dios, El Salvador to utilize discarded waste products, primarily plastic bottles, for non-structural construction materials.


The project aims to design, create, test and deploy a manual recycling system to the community with instructions for local manufacture, operation, and maintenance.

The Need

The community has a shortage of building materials that are effective in insulating the families from common weather conditions. The landscape is littered with plastic soda and water bottles. The community will benefit from both the reduction in the solid waste pollution and by introducing a new source of construction materials to insulate dwellings from rain, wind and heat.



Our Partner: ADESCO

ADESCO is an association formed and regulated by each Municipal government in El Salvador. Each ADESCO works and manages the development of the community in coordination with the local Mayor and his or her office. The specific activities of the San Juan de Dios ADESCO are listed below:

  • Oversee all community and NGO development with a focus on health, water and sanitation projects.

  • Operate, maintain and bill for the community domestic water system that serves approximately 2,000 residents. There are two full-time technicians employed by ADESCO that work on the water system.

  • Interface with EWB and Peace Corps on projects. Recent activities include the construction of 10 new latrines for the most needy families and the design and installation of a new electric pump and the associated infrastructure.

  • Coordinate all activities with the Mayor’s office, including entering into MOU’s, the purchase of materials and the transportation of goods.

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