Grantee Research Project Results

2019 Progress Report: Sanitary Green Space: a Closed-Looped Sanitation System for GrowingGreen Communities

EPA Grant Number: SU839467
Title: Sanitary Green Space: a Closed-Looped Sanitation System for GrowingGreen Communities
Investigators: Russel, Kory C , DeHeer, Adam , Sund, Nick , Young, Summer , Hershey, Emma , Alig, Sam , Ketterer, Hana , Hansberger, Dayna , Brunkhorst, Alissa , Eikani, Mia
Institution: University of Oregon
EPA Project Officer: Page, Angela
Phase: I
Project Period: December 1, 2018 through November 30, 2019 (Extended to December 31, 2021)
Project Period Covered by this Report: December 1, 2018 through November 30,2019
Project Amount: $14,971
RFA: P3 Awards: A National Student Design Competition Focusing on People, Prosperity and the Planet (2018) RFA Text |  Recipients Lists
Research Category: P3 Awards , P3 Challenge Area - Safe and Sustainable Water Resources

Objective:

Many residents in dense urban slums like those of Lima, Peru do not have access to safe sanitation facilities, resulting in contamination of their drinking water and pollution of their local environment. In order to meet basic needs, residents are typically forced to choose between crowded public toilets, open defecation, and private latrines that are expensive to build and maintain. Household-level sanitation services using container--based toilets have the potential to overcome many of the challenges associated with non--networked sanitation options. This sanitation model is particularly well-suited for low-income urban settlements where demand for sanitation services is high and traditional on-site sanitation and sewerage are not feasible or cost-effective (Tilmans et al., 2015; Russel et al., 2015). However, typical container-based sanitation (CBS) does not provide a treatment solution for urine or household graywater.

Our objective in Phase I was to fill an existing gap in container-based sanitation services by developing a sanitation solution for household liquid waste (urine and graywater).

Furthermore, we hypothesized that we could recycle water and reclaim nutrients from human waste to grow plants rather than simply "treating" the water and throwing away valuable resources. Using the neighborhood of Pamplona Alta in Lima, Peru as our pilot location, we worked with customers of an existing CBS service provider, x-runner, to develop a low-cost and sustainable sanitation system that uses principles of biomimicry to create a "circular economy" whereby resources (composted human feces, urine, and graywater) are reused in a closed-loop cycle to provide basic sanitation and create public green space: a Sanitary Green Space system.

Using a human-centered design approach and codesign techniques, we aimed to develop three iterations of the Sanitary Green Space system and test them for fecal indicator bacteria (fecal coliforms and E. coli). We anticipated that our project had the potential to improve human health and well-being, advance the economic competitiveness of sustainable sanitation businesses, protect and preserve the environment by effectively and efficiently using water, materials, and energy, and by minimizing the generation or emission of pollution or hazardous waste.

After field testing versions of the Sanitary Green Space in Lima, Peru, participants in the codesign workshops identified the potential for our system to treat water sufficiently for reuse in household cleaning activities. Prototyping has begun during Phase I to meet this objective and will continue during Phase II as the implementation pilot expands to additional households.

Research objectives of this project include:

• Evaluating the viability of wastewater treatment solutions to be used in combination with a container-based sanitation service
• Evaluating the capacity for household-scale wastewater treatment to contribute to the growth of publicly accessible green space
• Testing the safety to public health of on-site wastewater treatment used to create publicly accessible green space

Progress Summary:

Following initial testing at the University of Oregon and in consultation with x-runner and its customers, three iterations of the Sanitary Green Space system were tested for implementation in Pamplona Alta, and a fourth iteration is already underway. To begin, we tested raw effluent for fecal indicator bacteria (fecal coliforms and E. coli) as a baseline for comparison with the Sanitary Green Space system. We then tested five distinct sand filter designs (v1) for incorporation into the system and selected the best design for the next version (v2). Because the system had to accommodate household graywater such as dishwater, we added a grease trap to remove fats, oils, grease, and other organic solids. We then connected the system to a planting bed amended with composted human feces. This version was tested at the x-runner waste processing facility in Lima, Peru and continues to operate today. User testing revealed that the system needed to accommodate a higher volume of graywater created by home washing machines, so we increased the size of the grease trap and installed the five new prototype (v3) in Lima, Peru in December, 2018. Customers expressed satisfaction with this design.

V1 Sand filter V2 Sand FIlter Grease Trap V3 Sand Filter Grease Trap

The absence of pathogens in the test results of version 1 and version 2 suggest that theSanitary Green Space system is effective in meeting the goal of reducing the spread of pathogens. Pathogen testing for v3, and nutrient level testing of v2 and v3 are being carried out during the remaining project period of Phase I. However, based on the promising test results from v2, we anticipate that v3 should demonstrate similar results.

	Untreated Effluent	Filter Version 1	Filter Version 2	Filter Version 3
Fecal Coliforms	>1600 MPN	Filter 1:4.1 MPN Filter 2: 2 MPN FIlter 3: 35 MPN FIlter 4: < 1MPN Filter 5: 2419 MPN	N/A	Currently undergoing testing
E.coli	>196 MPN	Filter 1: <1 MPN Filter 2:<1 MPN FIlter 3: 5.2 MPN FIlter 4: < 1MPN Filter 5: 206MPN	<1.8 mpn (below detection limit)	Currently undergoing testing

In addition, the flow of water produced by v2 and the vegetative growth it has supported suggest that the system can effectively increase vegetative cover within the community. At a larger scale, we have collected baseline aerial imagery to compare the effects of green space expansion in our test community. From our initial results, our system has outstanding potential to create additional green space in these communities.

 

Future Activities:

Sanitary Green Space removes human waste from the environment, thereby reducing human exposure to deadly pathogens and risk of diarrheal disease. Additionally, by recycling household wastewater, the system reduces household water budgets-returning that money to the local economy-while improving community resilience to water scarcity and drought. Finally, the system grows plants that can improve human health by creating publicly accessible green space. Sanitary Green Space also supports the growth of container-based sanitation (CBS) in Lima and around the world by providing a complete sanitation service that is more desirable to users.

While our v3 prototype met our initial goals for Phase I, a combination of internal and external factors led us to develop a fourth version of the system. First, x-runner began transitioning to a new solid waste management strategy so our new version would need to function without their compost. At the same time, x-runner's customers who participated in our codesign process developed a thorough understanding of the system and helped us design a new version that would allow them to actually recycle the treated wastewater back into their households. This fourth iteration of the Sanitary Green Space system improves upon previous versions by using four distinct green infrastructure technologies: a constructed wetland, slow sand filter, hydroponic planter, and biosand filter. Its primary innovations include the use of plants in the filtration process, substitution of rock aggregate for compost as the growing and filtration medium, and ultimately the production of clean water to be reused in the household. We have already begun prototyping this version in Phase I and it is our chosen version to be tested in Phase II as we explore options for scaling the Sanitary Green Space system.

In addition to our partnership with x-runner, we are partnering with SquareOne Villages, a local housing organization in Eugene, Oregon. Following the 'housing first' approach, SquareOne Villages operates a transitional and affordable housing community called Opportunity Village. Transitional housing communities face many of the same challenges as Pamplona Alta and other urban slums, such as a lack of household plumbing and sanitation, easy access to clean water, and access to green space. Because of these similarities to our initial pilot location, Opportunity Village provides an ideal location for continuing development and testing of a Sanitary Green Space system in the United States. We have already begun collaborative design workshops with the residents of Opportunity Village in order to tailor their own Sanitary Green Space system to best serve them. After sufficient testing of our v4 prototype, our partner Opportunity Village Eugene would like to serve as a second pilot location for future field testing during Phase II.

As part of our goal to research and develop a low-cost and sustainable sanitation system that cleans and recycles household wastewater while creating publicly accessible green space, we have identified a series of objectives. We will develop two additional prototype iterations of the v4 system that uses plants and aggregate to treat household graywater and urine for reuse in household cleaning activities and irrigation. We will pilot and field test these prototypes at Opportunity Village in Eugene, Oregon. One variation will process both graywater and urine while the second will process graywater only. We will evaluate the performance of these two prototypes based on pathogen and nutrient reduction, plant growth, and effluent flow rate. In cooperation with our partner x-runner, 30 of their service users will then participate in an expanded pilot of the highest performing Sanitary Green Space system. Throughout the project period we will monitor the systems with regular lab testing and digital sensors. We will also conduct a baseline survey, midline survey, and concluding survey with user groups to determine impacts, user satisfaction and customer willingness to pay. Furthermore, knowledge gained from the two implementation sites can be shared to grow a larger approach in additional locations. The transferability of the Sanitary Green Space makes it easily adaptable to diverse locations.

This project will be conducted in collaboration with the CBS alliance and one of its founding members, x-runner. The CBS alliance is a partnership between the private sector, NGOs and research institutions focused on solving the global problem of inadequate water and sanitation in low income urban communities. Our partnerships with the CBS alliance, x-runner and SquareOne Villages helps us achieve our objectives, and meet our goal of serving vulnerable communities in need of sanitation and clean water and contribute to the long-term viability of the project.

Design customization will continue to be driven by stakeholder participation. Using a human-centered design approach and codesign techniques, design development will continue to be tailored to the context in which the product will be used. The collaborative design approach has led to significant developments in the Sanitary Green Space technology and its intended use, and has been proven to be a successful strategy.

Journal Articles:

No journal articles submitted with this report: View all 5 publications for this project

Supplemental Keywords:

Sanitation; green infrastructure; green sanitation infrastructure; environmental justice; codesign; human-centered design; resource recovery; recapture-and-reuse; graywater; greywater; irrigation; green space; closed-loop system; sustainability; Peru; slum, informal justice; wastewater; wellbeing; hazardous human wastes; political legitimacy; pollution reduction; microclimate; willingness to pay; container-based sanitation.

Progress and Final Reports:

Original Abstract

2020 Progress Report

2021 Progress Report

Final Report