Water Solutions for the Khumbu Valley, Nepal
The mission of this design team is to develop a multipurpose freshwater treatment system for the villages of Khumung and Kunde in the Khumbu Valley to complement the water distribution systems in place. In addition, an analysis of the current water delivery system and fire suppression system was done to identify areas for improvements. The water treatment technology chosen shall be easily implemented by the Sherpa and to consider the limitations and needs of the Sherpa community. In order to fully understand the community needs, several team members conducted a site visit in December 2019.
Site location map for Kunde and Khumjung Villages
Three different technologies were analyzed to determine which water filtration option best fits the communities of Kunde and Khumjung. The first option is a centralized, large-scale gravity sand filter that would filter all of the water for both villages. The second option is a small-scale biosand filter, which would be placed in each household. The final option for filtration is a clay pot filter, another small scale household system. In relation to cost effectiveness and availability in the region, it is suggested the clay pot filter should be used by individuals in Khumjung and Kunde. An engineering report produced by a Nepali engineer for a fire suppression system was reviewed by the team and City of Golden engineers. Suggestions on improvement of this report were made to the head engineer of the two villages in Nepal.
Pictured (left to right): Abigail, Kelsey, Anthony, Lhakpa Sherpa, Olivia, Julia, Kayla, and John Spear
- Kelsey Buechler
- Abigail Hasenstab
- Olivia Holt
- Kayla Hubbard
- Anthony Kaiser
- Julia Siegmund
- Dr. John Spear
Project Advisors: Elizabeth Reddy, Alina Handorean
Technical Advisors: Chris Bellona, Jeff Holley, City of Golden Engineers
Clients: John Spear, Laxman, Lahkpa Sherpa
A sincere thank you to all who donated. We greatly appreciate it!
Design Concepts and Decision
Three main filter design concepts were considered; centralized slow sand filtration, decentralized biosand filtration, and decentralized clay pot filtration. Pilot testing for the sand filtration options was planned to go underway at the Colorado School of Mines this spring and is still a possibility for the next team to take on in the fall. The clay pot filter was planned to be tested in Nepal in March, this can also be performed next fall at Mines or in Nepal depending on the future of the project.
A decision matrix analyzing the three water treatment methods was utilized in our design approach. Due to the lower materials cost, ease of implementation and maintenance, and projected removal of turbidity and bacteria, clay pot filters achieved the highest score of the three technologies. This should be future discussed with the engineering contact in Nepal, and the treatment technology of choice should be decided based on future testing.
The scope of the fire suppression design has repeatedly changed over the course of the project; it was initially the goal of the design team to design the entire system. However, following conversations with the engineer in Nepal, the scope changed to analyze and critique a submitted fire suppression design, created by a design team from Nepal. The group has worked with City of Golden engineers to determine what is needed to further the design, and critiques and suggestions will be submitted to the engineer in Nepal.
The main concern with this design is that the water quality of the raw water contains a suspended solid too fine to be picked up by the sand, no matter the media size. It has been assumed that the sediment in the water is glacial till, which is more fine than any available sand media for slow sand filters. Additionally, the development of the bio-layer could be limited due to the extremely cold water temperatures the biosand and slow-sand filters would experience; this would decrease the entire system’s effectiveness greatly. Pilot testing would be a beneficial addition to the design process in order to adjust the system for these possibilities. The village may also not have access to the material or the proper funding required to build the system. Humanitarian aid requests from a non-profit may be a possible option to make this project possible. The filter would have to be properly maintained throughout its life span or the rate of return of the investment of the system would be drastically decreased.
December Site Visit and Crowdfunding
The team was able to raise enough money for travel to Nepal to gather data and information for the project. Four of the six members of the group were able to travel to Nepal over winter break for two weeks in order to visit the villages related to our project, along with experiencing the amazing culture of Nepal and the Khumbu Valley. The team partnered with a Colorado School of Mines student Hike for Help group for the duration of the trip, which allowed us to observe all of the great service they perform in the valley! The following was performed during the site visit:
- Residents of the villages were interviewed to gather important information regarding the project and experiences with water availability.
- Village officials/engineers were interviewed to determine operation of water system, goals for project
- Existing water infrastructure was surveyed and tested
Using the information, data, and knowledge gained from the trip, the group coordinated with the clients and contacts from Nepal to update the final design plans.
Overview of Options
Three options for water treatment and filtration were assessed as possible solutions to water quality concerns (particularly glacial till turbidity). An example of the turbid water is shown to the right, compared to non-turbid water. Design options included centralized slow sand filtration, decentralized in-home biosand filtration, and decentralized in-home ceramic (clay pot) filtration. A decision matrix valuing affordability, ease of use, and safety determined that clay pot filtration was the most effective option. The team selected clay pot filtration as the recommended design solution.
Ceramic filtration systems provide a simple solution for removal of pathogens and turbidity from drinking water. Clay pots are commonly made from terra cotta clay mixed with a combustible material (such as sawdust or finely shredded rice husks). Upon firing in a kiln, the combustible material burns away and leaves fine pores in the ceramic for water to pass through. For further purification, clay pots are often coated with colloidal silver, an antibacterial that inactivates pathogens and prevents bacterial growth on the filter. Clay pot filtration systems have been shown to remove 99% of bacteria and protozoa, approximately 80% of viruses, and 83-99% of turbidity. It is recommended that turbidity of source water is less than 50 NTU. During a future site visit, total suspended solids and turbidity must be measured for the source water in Khumjung and Khunde to determine if this technology is a viable solution for removing turbidity due to glacial till.
Clay pot filters are used in each household, and filter at a rate of 1.5-2.5 L/hour. If a family runs the filter continuously, the system can passively filter about 20 L/day. The clay filter drains into a plastic or ceramic storage container with a spigot, to ensure that the clean water is properly contained so as not to contact any contaminated water. The clay filter also often has a lid to prevent debris from entering the filter. Water is carried from the contaminated source and poured into the clay pot filter (about two times per day), where it is left to drain into the storage container before use for drinking and cooking. Communities using clay pot filtration systems must be supported by a production facility located in country. The organization Potters for Peace works with communities to set up pottery production facilities, where an average facility with three to four workers can produce about 50 clay filters per day. Producing filters in country supports the local economy, decreases transportation costs, and allows for sustainable continuation of water treatment, as filters will be readily available for replacement. Potters for Peace is currently working with a ceramic water filter producer in Godavari, Nepal, that has been contacted by the team. Clay pot filtration is a promising household water treatment solution for Khumjung and Khunde that is low cost, low maintenance, and low risk.
Design Drawing of Clay Pot Filtration System
The figure to the right shows the standard orientation and size of the clay pot filter.
The price of a clay pot filtration system is dependent on local production costs at each facility. The production facility located in Godavari, Nepal (south of Kathmandu) produces clay pot filtration systems that cost $26.00 USD to the user. Replacement clay filters, recommended every 1-2 years, cost about $4-6.
As presented in the decision matrix below, clay pot filtration was selected as the most effective design solution for improving water quality in Khumjung and Khunde. Clay pot filtration systems provide an affordable method for filtering water for drinking and cooking, with low risk and minimal maintenance.
Diagram of standard clay pot filter, with approximate dimensions
Decision matrix for the three water filtration technologies
Due to the multiple changes of direction that this project experienced over its course, to fully develop a comprehensive design that meets the needs of the villages, it is recommended that this project continues to a following senior design team at Colorado School of Mines. This group was able to collect as much data/information from the Nepalese contacts as possible; the subsequent group should use this information, along with the feedback provided to the villages, to further the design.
To finalize the water treatment design, water quality data should be acquired by either the following group, or client contacts located in the villages; the water quality aspect of the project came into importance in the second semester of the design, and the cancellation of the March site visit prevented any data acquisition during this design. Using the clay pot filter contacts, biosand filter contacts, and feedback from the Nepal contacts, the next team should test different filter types to determine the most cost effective and feasible solution. At the minimum, the following water quality parameters should be acquired:
- Total Dissolved Solids (TDS) and Total Suspended Solids (TSS)
The next design team should also use feedback given from the current team, along with the Nepal contacts, to ensure the provided water suppression report is of sufficient quality. Communication should be maintained to determine the methods of construction, correct calculations, etc.
If this project is not continued by another design team, the clients should utilize all the resources and information contained in the final design report to finalize plans for the water treatment and fire suppression systems. The clients are more than welcome to contact the group post-project end to ask any related questions. The design team has leftover monetary funds and physical supplies that should be passed along to the next design team for their travel to the villages.
Meet the Team
Julia is graduating from Mines in May 2020 with a B.S. in Environmental Engineering and a minor in Biology. She is from Austin, Texas and will be moving back after graduation to work as a Water Resources EIT for HDR. She is interested in hydrology, ecology, and sustainable design, and hopes to pursue all of these interests throughout her career. Julia loves hiking, everything outdoors, yoga, travelling, reading (especially memoirs), and swimming in lakes.
Olivia is from Bethlehem, Pennsylvania and is majoring in Environmental Engineering. After graduation, Olivia is continuing at Mines in the Hydrology program in Fall 2020. She enjoys running and climbing with her dog Homer. Olivia does not know what she wants to do but would like to spend most of her time working outside/in the field.
Kayla is originally from Western Massachusetts and will be graduating in May 2020 with her B.S. in Environmental Engineering. After graduation Kayla plans to continue her studies at Mines by pursuing a M.S in Hydrologic Science and Engineering. Her dream job is to either work as a field hydrologist for the National Park Service or to conduct glaciology studies at a research base in Antarctica. Kayla really loves house plants and dreams of visiting Nepal some day.
Anthony is originally from Westminster, Colorado and is graduating in May 2020 with his B.S. in Environmental Engineering. After graduation, Anthony plans on working full time as a full-time engineer in the water/wastewater engineering field. He enjoys snowboarding, water polo, swimming, hiking, and sports in his free time.
Kelsey is originally from Tucson, Arizona and will be graduating in May 2020 with a B.S. in Environmental Engineering. She is a member of the Mines Softball team and enjoys hiking, skiing, and reading in her free time. After graduation she plans to either continue her studies at Mines in a graduate program or start her career as an engineer. Her interests include hydrology, sustainable design, and humanitarian work.
Abby Hasenstab will be graduating in May 2020 with a B.S. in Environmental Engineering. She is originally from Red Bud, Illinois. She has been involved with the Mines club soccer team, leading as president in the 2018-2019 season. She also is a part of the Mines acroyoga club and enjoys slacklining, gaming, and painting in her free time. After graduation, she hopes to work for a consulting firm with a focus in stormwater management. Her dream job is to focus on humanitarian engineering projects on an international basis or to work for the U.S. Corps of Engineers.