The WaterHub at Emory University – Engaging Campus & Community in Water Reclamation
The WaterHub at Emory University is an on-site water recycling system, utilizing biomimicry, or engineered processes that emulate natural ecological systems, to reclaim wastewater for heating and cooling buildings and toilet flushing. Resembling the appearance of a greenhouse, the WaterHub is a living laboratory for research and teaching and for showcasing the capacity of operations to play a major role in water conservation. It is the first system of its kind in the United States and has the capacity to supply nearly 40% of Emory’s total campus water needs. The facility relieves an over-burdened municipal system, saves Emory money over time, and reduces the use of potable water by over 400,000 gallons per day. Through the WaterHub docent program Emory students are trained to lead public tours for campus, community, municipal, and corporate groups from Atlanta, the U.S., and the world. Since its opening, the WaterHub has made Emory a true leader in water conservation and has been the inspiration for individual, institutional, business and municipal behavioral changes and technological innovations.
Metropolitan Atlanta has become emblematic of 21st century water issues as the largest municipality reliant on the smallest watershed in the nation, utilizing mainly surface water to supply the needs of a fast-growing region. Georgia and neighboring states rely on limited water supply for drinking water, industry, agriculture, recreation and more, which has perpetuated the decades-long legal battle between Georgia, Florida and Alabama — the Tri-State Water Wars — over usage of the Apalachicola-Chattahoochee-Flint and Alabama-Coosa-Tallapoosa river basins. Additionally, the Environmental Protection Agency (EPA) issued separate Consent Decrees mandating that the City of Atlanta and the DeKalb County government make improvements to the over-burdened, aging combined and sanitary sewer systems. Emory University is located within both of these municipal boundaries and has become a regional water steward by bringing the WaterHub online to treat water decentrally for non-potable purposes, relieving some of the burden on aging infrastructure and reducing its demand for potable water. Through a partnership with Sustainable Water, a water reclamation and reuse company, the WaterHub at Emory University became a reality in April 2015 and has reclaimed over 168 million gallons of sewer water for utilities purposes to date.
The WaterHub has social justice and environmental health benefits from reducing the load on the municipal water treatment system Over the past several years, Emory University pursued aggressive water conservation strategies to reduced potable water consumption in Emory's buildings. An analysis of the University’s total water footprint led to the decision to reduce potable water use by reclaiming water for uses that do not require drinking water quality. Reclaimed water decreases the need to purchase potable water from the municipal supplier, while also reducing the stress on the municipality’s wastewater infrastructure and extending its lifetime. The City of Atlanta is one of 772 cities in the U.S. that utilize combined sewer systems that collect rainwater runoff, domestic sewage, and industrial wastewater in the same pipe. By reducing the amount of water requiring treatment by the City, the WaterHub’s potential for reducing combined sewer overflows has social justice impacts in a city with heavy rainfall, where overflow events result in flooded homes in historically disadvantaged communities. Furthermore, because the wastewater can be treated closer to the source, the WaterHub reduces the carbon footprint associated with the treatment and distribution of water.
The WaterHub functions as an academic research facility for various disciplines and as a space for community awareness-raising As the first ecological water reclamation treatment facility of its kind in the United States, the WaterHub provides opportunities for teaching and applied research in sustainable water management practices and global public health strategies. Emory University hopes the WaterHub will continue to inspire the academic and broader community to utilize natural systems, decentralized reclamation facilities, and adaptive technology to meet water demands. To realize this goal, the Student Docent Program has trained Emory students to be the public faces of the WaterHub. Student tour guides help engage local, national, and international visitors and offer insight into the facility’s innovative technologies and environmental and educational purposes, as well as offer ways individuals can be water stewards in their own lives.
Research and education is already under way at the WaterHub and led most often by Emory’s Rollins School of Public Health’s Center for Global Safe Water, Sanitation, and Hygiene. The Center uses the WaterHub as a teaching tool for students to have hands-on experience testing treated water at various points in the facility. The Center also conducts research on the quality of treated water in relation to pathogens, while assessing the replicability of the two technologies — a hydroponics system and a reciprocating wetland tidal system — in regions around the world with varying resources.
The WaterHub reduces Emory’s drinking quality water usage from Atlanta’s municipal water supply, while opening up opportunities for more widespread water reclamation and reuse Atlanta is a particularly challenged city in terms of water resources due to its unique geography, geology, and history. Unlike many major cities in the U.S., Atlanta is not built on a major port or waterway. It was founded at the confluence of historic railroad lines and is situated at the headwaters of major watersheds without any significant groundwater resources. In fact, Atlanta is the largest municipality in the U.S. reliant on the smallest single water source for its drinking water. Almost 98% of metro-Atlanta’s drinking water comes from one reservoir and the immediate downstream watershed of the Chattahoochee River.
The WaterHub draws from the wastewater streams of the Centers for Disease Control and Prevention (CDC) headquarters campus and a portion of Emory University and Healthcare facilities, and has reduced Emory’s use of drinking quality water from Atlanta’s municipal water supply by over 168 million gallons since April 2015. Emory’s adoption of the WaterHub technology advances acceptance of reclaimed water for use by institutions, municipalities, and corporations around the country, and Emory’s research on the public health aspects of reclaimed water lends a level of legitimacy to reclaimed water as a substitute for potable water in applications such as heating, cooling and toilet flushing. Already, many other institutions in Atlanta have toured the WaterHub, met with Emory leaders, and contacted the vendor about installing a WaterHub on their campuses and corporate sites. Cumulatively, these efforts could significantly reduce the strain on metro-Atlanta’s water supply.
The WaterHub reduces the complexity and environmental impacts of water treatment Traditional, centralized municipal treatment systems require miles of infrastructure and multiple pumping stations to move wastewater long distances for treatment and redistribution. The complexity of centralized wastewater treatment facilities make them more complicated to operate, expensive, and overly energy consuming in some regions of the world. Unlike these traditional systems, the WaterHub’s treatment processes contain simpler mechanical components and rely mostly on gravity to move water from one level of treatment to another. Water is pumped up a hill for parts of the process, but the energy used by the facility is partially offset by on-site solar panels. Additionally, its proximity to the source of the wastewater means the WaterHub requires less energy to transport waste for processing. In addition, the WaterHub’s ecological treatment processes reduce the environmental impacts of wastewater treatment by minimizing land and chemical usage.
In these ways, the WaterHub reduces the carbon footprint and water footprint of water use at Emory and serves as a model for lower-cost, lower-impact, decentralized water treatment and reuse.
The WaterHub is aesthetically pleasing and odor-free for acceptability in urban areas. Traditional wastewater treatment systems typically require a great deal of land area and are typically large open basins with exposed wastewater, causing an odor nuisance and depressed property values in surrounding areas. The WaterHub is much smaller than traditional municipal systems and requires significantly less land. Designed to be aesthetically pleasing with lush plants and no wastewater exposed in the treatment process, the WaterHub’s odor-free, pleasing, natural aesthetic allows it to be located in densely-populated urban areas. With the urbanization of our global communities, the WaterHub may be a solution to many highly compact urban areas around the globe with significant wastewater challenges and less available land.
The WaterHub docent program trains Emory students to be the tour guides and faces of the facility This program is led through a partnership with the Office of Sustainability Initiatives (OSI), the Campus Services Utilities team, and the vendor, Sustainable Water. The program partners train and pay the docents, who in turn learn about the innovative technologies and their impacts. The students learn presentation skills, advocacy skills related to water stewardship, make connections with individuals and groups interested in water reclamation, and enhance student peer-to-peer education.
In the early phases, project partners took note of minimum design and construction standards, along with operational requirements, for water reclamation plants to ensure public health and safety. Additionally, local municipal agencies may require permits for construction, wastewater pretreatment, or discharge. The WaterHub was designed in compliance with all state and local permitting requirements. This is a critical first step.
The reclamation system was sited based upon the location of the existing sewer structure, available land, and existing chiller and steam plants. Sustainable Water designed the reclamation system to integrate into the existing campus framework using two small parcels of land - 3,000 sq. ft. for the greenhouse and 1,500 sq. ft. for the outdoor lower site.
The WaterHub at Emory University is unique among nontraditional wastewater treatment facilities because it uses both a reciprocating wetland technology (fill and drain wetlands which mimic the ebb and flow of tidal marshes) and a hydroponic technology (containing plants and micro-organisms in specially-engineered, submerged, fixed film textile media). Emory selected this unique approach because having the two systems allows for more filtration of water in addition to opportunities for research comparison of the two technologies.
Wastewater is first sourced from an on-campus sewer pipe and then pumped into the greenhouse portion of the WaterHub. In addition, storm water run-off from the WaterHub greenhouse is captured and directed to the WaterHub for processing. The aesthetically pleasing, compact greenhouse contains a series of interconnected, sequentially operated, cascading hydroponic bio-habitats. Water is circulated through aerobic and anoxic chambers, which contain specially engineered free-moving plastic pellets or engineered fixed-in-place textile material in addition to suspended plant roots, which enhance the surface area upon which microorganisms can live. The pellets, textile and plant roots serve as a natural habitat for 2,000-3,000 different microorganisms and form a unique ecosystem that breaks down waste. Included in the microorganisms are bacteria, protozoa, metazoa and microcrustaceans. Low-maintenance, hardy plants that produce long, dense root systems and thrive in wastewater are an integral part of the WaterHub’s design. These plants were chosen specifically because of their root structure to increase surface area and their hardiness to be long-lasting in wet environments. The tropical plants in the greenhouse include: Angel Trumpet; Ginger; Scarlet Rosemallow; Giant Calla Lilly; Native Water Canna; Longwood; Taro; Umbrella Palm; Mexican Papyrus and Elephant Ear. The hydroponic system is able to process around 400,000 gallons of waste water a day, so it is very efficient, but it requires more maintenance, energy consumption, and capital investment.
From the greenhouse, about 1,200 gallons of the water travels to the outdoor reciprocating wetland tidal system that operates in parallel to the hydroponics system. This system mimics the ebb and flow of tidal marshes and creates an alternate habitat for waste-eating microorganisms. The outdoor treatment area features more native species and includes: Mexican Petunia; Common Rush; Arrow Arum; Lords and Ladies; Duck Potato; Pickerel Weed; Mallow; Water Willow; Golden Club; Acanthus and Iris. The reciprocating wetland technology is well suited for rural and developing areas, which have adequate land resources and seek an ultra-energy efficient process and simplified construction. It was created purposefully at Emory as a research opportunity.
After biological treatment, the wastewater is filtered and disinfected with Ultraviolet (UV) light and light chlorination. The biological processes remove all of the solids, nutrients, and color but disinfection and filtration is required to assure all pathogens are removed as well. The water meets the State of Georgia’s as well as Emory’s specific quality standards. After treatment and disinfection, most of the water is sent directly to campus chiller and steam plants, and any excess treated water is sent to a residence hall for toilet flushing.
The WaterHub has a 50,000 gallon underground storage tank which provides a backup supply of non-potable water. This resource helps Emory maintain heating and cooling functions in the event of water service disruption caused by municipal water main breaks, drought, or other water stresses. It is a critical part of Emory’s resilience planning.
In order to bring students centrally into this living-learning laboratory, the OSI, Campus Services, and Sustainable Water partnered to develop a student docent program. Through this program, top student leaders are identified by the OSI and hired through their intern program. Campus Services funds the program and approves a budget compiled by the OSI. Student docents are trained by the OSI and Sustainable Water staff to lead the tours and to direct visitors to any relevant follow-up information they require. Student docents are responsible for the administration of the program, tracking of tour attendance, directly reaching out to faculty on campus teaching relevant classes that could visit the facility, and assisting campus visitors as needed. These students lead two public tours and often a one-off tour request each week.
Faculty who are interested in conducting research at the facility for their own purposes or for a way to engage their students work directly with the Sustainable Water staff who run the facility to ensure that students learn how to safely and effectively gather and test samples from various parts of the reclamation system.
Project inception: January 2012 Feasibility Study: early 2012 Contract negotiation and pre-planning: late 2012- early 2013 WaterHub Design Development: 2013 Construction Phase: 2014-2015 Official Opening: April 2015 Operational start up: May 2015 Tour and Presentation start up: April/ May 2015 WaterHub Docent program began: January 2016
The WaterHub uses an innovative financing mechanism called a water purchase agreement between Emory University and Sustainable Water, the water reclamation technology provider. Sustainable Water paid all upfront capital costs to build the facilities and dual plumb the buildings with purple (reclaimed water) pipes. Sustainable Water owns the facility, operates it, and sells the reclaimed water the facility produces to Emory at a fixed rate that is less than the projected municipal potable water rates. Emory provides the land for the facility and pays for the student docents who lead the public tours. Because water rates have been rising and are expected to continue to rise, Emory will save money over time paying a fixed rate for the reclaimed water versus the rising rates from the municipality.
This unique project has multiple noteworthy results. The WaterHub at Emory University: (1) consistently, decentrally treats and reuses over 400,000 gallons of water a day; (2) provides relatively inexpensive water for utility purposes; (3) meets the University’s educational and research mission; (4) saves the University money over time that can be reallocated to core-mission teaching and research services; and (5) expands community outreach and education around water conservation.
1) Utility purpose: The WaterHub serves the important purpose of providing a reliable and relatively affordable source of (non-potable) water for use as make-up water for Emory’s boilers and chillers. Since it opened in April 2015, the WaterHub has reduced Emory’s potable water use by more than 168 million. Atlanta’s population boom, consent decrees from the EPA against the City and County, and scarcity due to drought and natural limitations on supply have led to large increases in Emory’s water rates over the past five years. With the forecast of continually rising water rates in the future, Emory’s WaterHub provides an important substitute source of non-potable water that will be less expensive over time than continuing to purchase municipal drinking water. The benefit of an alternate water supply to Emory’s campus also reduces Emory’s draw of drinking-quality water from Atlanta’s municipal water supply.
2) Research and teaching purpose: It was envisioned that the WaterHub would be used for academic purposes. Therefore, the facility is equipped with features not typically found in a wastewater treatment facility. For example, sample ports are located throughout the facility and its piping system to allow student and faculty researchers access to the water as it is being treated. The facility is also designed with a large open floor space in the middle to provide room for classes and tours. Student and faculty research continues at the facility. For example, in Fall 2014, when the plant was still in the construction phase, students from the Rollins School of Public Health conducted a water testing project in Dr. Christine Moe’s "Water and Sanitation in Developing Countries" course. Students analyzed wastewater samples at various stages of treatment, which afforded hands-on exposure to a kind of field work methodology that students are applying during their summer practicums in areas around the world. A research study on pathogen levels in reclaimed water is also underway.
During the feasibility study, it was realized that the WaterHub offers various academic benefits. Therefore, the plant is equipped with sample ports for students and researchers as access points to withdraw water is it is being purified. The first academic research steps started while the WaterHub was still under construction in Fall 2014.
3) Community outreach and education purpose: Since the WaterHub is one of a kind in the United States, Emory’s educational outreach plan includes tours of and presentations about the facility for the general community, national and international visitors, and campus members. Ten student docents have been trained to lead hundreds of campus and community visitors through tours of the facility. There are two tours scheduled each week, and groups can reach out to set up private tours. Each semester, multiple courses of undergraduate and graduate students visit as a part of their curricula, and many more community groups, corporate leaders, municipal representatives, K-12 classrooms, and international visitors come to learn about the facility and water stewardship in general.
1) Before an institution/ organization/ company begins discussing the option of constructing a wastewater treatment and reclamation plant on its property, it is imperative to understand its total water footprint and water demands. The total water footprint includes potable water consumption, wastewater generated, and the recycled water use opportunities. It is advisable to take all of this into account before a project like the WaterHub can be implemented.
2) It is crucial for the success of the project to engage campus and community stakeholders as early and as often as possible. Wastewater reclamation is a very unique undertaking and a relatively unknown initiative, especially on a university campus, and requires municipal permitting. Therefore, it is recommended to practice open and frequent communication because it will affect the project success. For Emory, faculty input played an important role in the design of the WaterHub and led to features such as a lab desk, sampling portals, and room for class tours.
3) In addition, it is suggested to involve and incorporate operations staff in the design phase of a wastewater reclamation facility on a university campus. This collaboration helps to ensure smooth transition of the recycled water to the end-use locations and eliminates the potential of future adjustment procedures.