Interviewed by Nuria Bolaños, Rainforest Alliance
“This project serves as a model because it shows that it is possible to have your own water treatment system, especially if you can’t get this service from your municipality.”
Located in the heart of the “Riviera Maya” between Cancún and Tulum, Mexico, Centro Ecológico Akumal (CEA) works to conserve the coral reef in Akumal Bay, an important tourism destination. This region has high groundwater levels and the rocky composition of its soil means that any discharge released into the ground flows into the ocean, negatively impacting the coral reef. CEA is developing technology to treat wastewater in order to reduce the amount of pathogens and contamination in the coral reef. The work is being carried out in an area that in the past had no system to treat black and gray waters. This technology involves creating artificial wetlands and aquatic gardens to treat the water before it makes its way into the ocean. The low cost of this technology makes it possible for local inhabitants and businesses to use. There is a direct link between water quality and the condition of the coral reef, and public health. CEA believes that it does not take a large-scale study to determine that more water treatment translates into a reduction of the amount of contaminated water being released into the coral reef.
Question: How did a coral reef conservation organization begin working in waste management?
Sánchez Navarro: The former director of CEA, a geologist, and the project team studied the geology and hydrology of the region. They wondered what was happening to the wastewater from the tourism areas. At the same time, they were studying coral diseases in Akumal and were establishing a link between water use and the condition of the coral reef. They noticed rapid algae growth in a nearby cove where the water was dirty and some of the fish were sick. It wasn’t hard to discover that the septic systems that had supposedly been built were only holes in the ground where everything flowed directly into the groundwater.
After studying the local geology and coming to understand the system, they then focused on the issue of water. They studied water samples and when they discovered that the ocean water contained coliforms, they took action. When they discovered a link between the use and discharge of freshwater and coral reef conservation, they decided to research freshwater issues.
Q: How did you decide to apply this technology for water treatment?
Sánchez-Navarro: The Planetary Coral Reef Foundation was the first to experiment with artificial wetlands in the tropics at the CEA. They had previously built two artificial wetlands that needed maintenance and repair. With funds from the National Fish and Wildlife Foundation Coral Reef Conservation Fund, these wetlands were repaired by completely emptying and cleaning them, repairing the pipes, filling them with gravel, putting in new plants, and then monitoring them. This is a type of technology that can be developed anywhere in the world.
Q: How does an artificial wetland treat water? Does it work in the same way as a water treatment plant?
Sánchez-Navarro: Waste discharged from CEA’s restaurant, dormitories, and other areas goes into a septic tank connected to a number of treatment cells that make up the artificial wetland. The septic tank stores the solid waste and the water flows into the artificial wetland, working in the same way as a water treatment plant. These aren’t septic tanks — they are wetlands constructed with gravel and vegetation. The dirty water that moves into the wetland is treated aerobically as it flows through the root systems, turning it into practically clean water that can be used to irrigate the garden.
Artificial wetlands are not water tanks. They are gardens made up of plants and gravel — not soil. The water flows very slowly through the entire system below the gravel and through the roots of the plants. If the system is properly managed, it is easy to use and odor-free. By not using chlorine, the system does not adversely affect marine life.
Sosa Bravo: These wetlands not only treat black and gray waters, but also provide high quality, clean water for the garden itself or others in the vicinity. Since there is a high level of evaporation in this area, very little water is eliminated from an artificial wetland.
Sánchez-Navarro: This serves as a model because it shows that it is possible to have your own water treatment system, especially if you can’t get this service from your municipality. Although the municipality has developed a treatment plant, not everyone has access to this service. We have shown that it is possible to develop a water treatment system. Some people have built artificial wetlands in their properties and there are now 50 in the Akumal region.
We trained 24 people to use this technology, and took advantage of the training to talk about other topics such as renewable energy and other ways to manage resources in the Mexican Caribbean — we also had participants from Honduras and Guatemala.
Q: How much does it cost to build an artificial wetland for water treatment?
Sosa Bravo: It depends on the size, the number of people and bathrooms, and whether it is black or gray water or both. In any case, it is less costly than a water treatment plant. As far as maintenance is concerned, it is much the same as caring for a garden.
Q: What plants can be used for this garden?
Sosa Bravo: Generally, any plants that can survive in wet regions and need a lot of water. We use plants from the area, including some cattails.
Q: Have you been able to note improvements in the water quality?
Sánchez-Navarro: We have only been monitoring for six months, which is not a lot of time. In the past, CEA didn’t coordinate with other programs to develop agreements. Quite a few universities had come to CEA to study coral diseases such as those caused by pathogens or algae growth. The groups would conduct studies and leave with the results, which didn’t help CEA. We are now collecting this information and learning from it — we don’t have yet have the quantitative data to establish relationships and explain what has happened. Qualitatively, we know that more people treating the water means less polluted wastewater discharged into the coral reef.
Akumal is growing much faster than our capacity to collect data and learn from it. It has grown incredibly fast over the past six years, and CEA has not been able to keep up at the same pace. Recycling and waste management are also lagging behind because of this growth. This same situation is occurring throughout the Mexican Caribbean because the government has not invested in waste management in tourism areas. It is estimated that only 50 percent of wastewater in Akumal is treated — the goal is to reach 100 percent.
Q: How do you test for water quality?
Sosa Bravo: Indicators for bacteria — coliforms and pathogens — and chemicals such as dissolved oxygen, ammonia, nitrites, nitrates, and phosphates. The water discharged from artificial wetlands is in better condition than water that comes out of a conventional treatment plant.
Q: Do you have data that shows the relationship between artificial wetlands and the condition of coral reefs?
Sánchez-Navarro: Not yet. We still need to carry out a study that tracks the flow of water by injecting dye in certain spots to determine where the water is discharged. We have little information on the flow of water. We need to provide evidence that 2,000 inhabitants are discharging their wastewater into the groundwater layer, which then works its way to the coral reef in order for the municipality to pay attention. We are working with a Canadian university to carry out the logistics of this study.
Although CEA has done a lot of research on the coral reef, very little has been related to reef conservation because we didn’t have information on research conducted in other parts of the world. We are now working on reef monitoring as part of the Mesoamerican Reef System in four countries. It is interesting to note that research, conservation, and monitoring is being carried out in an area that is not involved in protection. The information and experience from this project can be used for most reefs around the world that are not being legally protected.
Q: What other benefits do these wetlands provide?
Sánchez-Navarro: The wetlands have helped people understand how an aquifer works and, at the same time, to show that there are ways to treat water that can be used by everyone. We are receiving requests from the municipal authorities to give talks in the region because we have more knowledge in this area that anyone else here. Edith Sosa Bravo provided training to engineers, architects, and students that not only enhanced their knowledge on this subject but also raised their interest in applying new technologies.
Through our work in water treatment, we were able to increase our participation in various local, regional, and national committees such as the committee for clean beaches and another on solid waste management. It has also allowed us to participate in the regional strategy for water management and a restoration group. Our work has made water quality management part of the development of the region.
Q: How has this project helped you as an organization?
Sosa Bravo: There used to be a great lack of knowledge about water resources. Although we knew of the existence of subterranean rivers, we did not know how they were affected by human activities. More people are now aware of the impact on the aquifer system and, especially when the government is not providing water treatment, know that there are alternative technologies. We trained people in the region to prevent the contamination of the aquifer mantle — we didn’t have people trained in these technologies before, but now we do.
Sánchez-Navarro: We have become a much stronger stakeholder and always make the connection between water and its impact on the condition of the coral reef and on public health. If we don’t treat the pathogens in the water, it ultimately has an effect on the health of the communities. Having an ongoing work program has helped us to coordinate with other stakeholders such as The Nature Conservancy and other regional groups, and to understand the importance of networking. We have strengthened our work and have learned about this unique ecosystem.
Sosa Bravo: The other stakeholders in the region such as local governments, schools, and research centers now consider us as a more serious NGO with more established and better designed programs. We have an interdisciplinary approach in our work with all stakeholders to reach common goals.
Sánchez-Navarro: CEA is a center where people can come to obtain technical and scientific information on coral reefs and water in the region. People are beginning to trust our work. Thanks to help from NFWF, we were able to evolve from carrying out small projects to developing programs that have a larger impact. We have concluded, along with hotel owners and local proprietors that we need a legal mechanism to protect the coral reef.
Q: What are the main goals?
Sánchez-Navarro: Even though the government has built a water treatment plant, less than 50 percent of the villagers are connected and the rest continue to pour their waste into the ground. The water treatment plant uses chlorine that is then discharged into the groundwater layer. The challenge is now to ensure that chlorine is no longer used. The government uses technology dating back to the 1960’s rather than new ones.
With this in mind, it is important to ensure that everyone is connected to the treatment plant and that we have a good water treatment system because we are still detecting a high level of nutrients in the water. We need to reduce pollution in the Akumal region and continue to produce publications, and give talks and presentations, and share information so that there is change in how water is treated. We need to make people aware that there is a link between our actions and the condition of the coral reef.
Q: Have you received help from the authorities?
Sánchez-Navarro: We have had a good relationship with the authorities over the past years. They are willing to work with us as long as we provide the funding. They have told us repeatedly that they can’t take on any new projects because of lack of funding. They do help us obtain permits for our studies quickly, and have invited us to present the results but if we ask them to make changes, then we don’t get the same response or it takes longer than expected.