These plants save lives.”
That’s how the Boulderbased company Agua Inc describes its rich collection of macrophytes, a class of plants that dominate wetlands, streams and shallow lake ecosystems in the wild. Macrophytes are also the key to Agua’s vision: helping to make clean, safe water attainable in the poorest and least developed corners of the globe. They’re the cornerstone of Agua’s newest of 175 projects, more than 5,000 miles away in The Gambia; a project Agua is calling the largest ecological wastewater treatment facility in the world.
Agua’s newest facility sits near the northwestern tip of The Gambia, the smallest mainland country in Africa. The Gambia has the appearance of wriggling into Senegal’s southern coast, its borders closely mirroring the Gambia River’s winding path inland from the Atlantic Ocean. Located near the coast in a relatively developed area of the country, Agua’s macrophytebased Aquatic Biological Integrated System for wastewater treatment — or ABIS — stands out as one of the largest wastewater treatment plants of any kind, “ecological” or not, in any developing country. ABIS requires no chemicals, uses far less energy than traditional wastewater treatment facilities and boasts dramatically lower costs. Agua says the facility will provide clean water for more than 200,000 consumers, or about 10 percent of the country’s roughly 1.9 million people.
Bianca Griffith, Boulder native and founder of Agua, had been in Senegal organizing sustainable water projects through her nonprofit, Santé Natural, when Gambian officials first contacted her for help. Without a regular supply of chemicals and electricity, a traditional wastewater treatment facility in The Gambia’s Kotu region was leaking polluted runoff into neighboring farms and the nearby coastline, causing serious health concerns for the surrounding population. It’s taken a few years, lengthy negotiations with the Gambian government and the formal founding of Agua in early 2013, but finally in early 2014, Griffith and Agua’s chief operating officer Pedro Delgado, social entrepreneur and native of Spain, moved from Boulder to The Gambia to implement their company’s newest project.
“Maybe I’m a naïve optimist,” Griffith says. “I believe that we can really find a balance between doing something environmentally sustainable that is just as economical as the traditional alternatives.”
Despite its small size, The Gambia still has room for improvement in the realm of water and sanitation. Much of the country, less developed than the touristy coast, lacks wastewater treatment entirely. According to the 2013 United Nations Water Country Brief on The Gambia, 15 percent of the rural and 8 percent of the urban population lacked an “improved” drinking water source in 2010. Trends in improved sanitation facilities lag further: in the same year, 32 percent of the population did not use improved sanitation. (For comparison, around 90 percent of the developing world does not treat its wastewater.) The European Commission gives The Gambia a score of 48.6 out of 100 on its water quality index, and water and sanitation trends in the country remain “of concern.”
“It’s just not right that 900 million people don’t have access to potable water,” says Delgado, who brings to Agua more than 10 years’ experience in helping developing communities implement sustainable wastewater and drinking water treatment. “As much as we’re able, we offer a water solution that’s sustainable, global and one that’s totally based on respect for the environment.”
When Delgado spoke at an Unreasonable Institute event in Boulder, Griffith fell in love with his technology and their shared passion for sustainable development. Eventually they fell in love themselves: the two were engaged a month before incorporating Agua.
Wastewater treatment using floating plants isn’t new; the Environmental Protection Agency even published a design manual on the technique in the late 1980s. And ABIS wastewater treatment has much in common with traditional systems. Both start by using screening to remove large solids, followed by grit chambers and decanters. But Agua says the key distinction is in the next phases, where macrophyte “lagoons,” supported by its patented “BioMatrix” system, take the place of aeration and a secondary clarifier.
Macrophytes are characterized by their ability to grow fully submerged or partially above water, with roots either attached to the bottom or floating freely. In the wild, they help keep the aquatic ecosystems they occupy clean and act as “bio-indicators” of ecosystem health. In The Gambia, Agua’s macrophytes are locally grown, free-floating typha plants (think cattails or bulrushes). To put the typha to work, Agua lays its BioMatrix — a flexible, buoyant, interlocking plastic honeycomb — on the surface of the wastewater treatment lagoon and places a typha plant in each hub of the matrix. The Biomatrix stabilizes the young macrophyte plants, helping create a floating ecosystem and ecological water purification system. The macrophytes’ roots, dangling in the water, become a home to helpful bacteria. These bacteria break down harmful contaminants in the wastewater. The water filters directly through the plants for a minimum of five days. The bacteria living on the plants’ roots, and the macrophytes themselves, purify the water as it flows through. As the macrophytes grow, they stay buoyant because they’re less dense than water. Their root structure becomes more complex, better at aerating and filtering wastewater, and more hospitable to good microorganisms.
University of Colorado Boulder professor of engineering JoAnn Silverstein points out that “ecological” may be a confusing label for the Agua system, since virtually all wastewater treatment uses microbial ecosystems, engineered to provide specific types of treatment.
“This is not to downplay Agua’s achievement in The Gambia,” Silverstein says. “Just to put it into context.”
And even this type of system can have its challenges, she says. For example, macrophytes may create excess bio mass that needs to be removed regularly. If the lagoons receive too much organic matter in the form of untreated sewage, there may not be enough oxygen present for the plants to breakdown wastes. A sediment layer of wastewater solids may accumulate, requiring removal. And in at least one other wastewater treatment facility using floating plants, seeds from the nonnative macrophytes escaped, transported by wind and birds, and the project was abandoned.
Agua emphasizes the system’s strengths, particular for developing nations. Compared with traditional wastewater treatment facilities, the system costs millions less — up to 50 percent less, the founders say — requires no chemicals and uses about 40 percent less energy than a traditional U.S. system.
“Statistics say around 30 to 35 percent of energy costs (in the U.S.) go to water treatment and water distribution,” Griffith says. “We’re looking for energy savings — we’re looking for sustainability.”
Operating as a quasi-utility in partnership with the Gambian government, the new wastewater treatment facility will charge the same rates to its users as the former system charged, putting no additional financial strain on consumers and requiring vastly less energy to power it. And in a developing country where chemical engineers are in short supply, the system requires little technology: Agua says the same person who takes care of the plants can also oversee the wastewater filtration system.
Passionate about sustainable solutions for problems in developing nations, Griffith and Delgado are also empowering the next generation of engineers and entrepreneurs in Africa through their “Agua Campus” in The Gambia. A facility that sounds Boulder-inspired, they call it “an international innovation, education and collaboration hub in West Africa,” with classrooms, co-working spaces and laboratories for visiting researchers and future leaders.
The wastewater treatment facility will be fully operational by mid- 2015.
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