Coffee Wastewater in our Ecosystems

Coffee wastewater represents 25% of the post-harvest contaminant load. If left untreated, this wastewater—called honey water—threatens coffee farm ecosystems. Honey water is a byproduct of coffee washing, a process during which coffee farmers wash recently harvested coffee cherries.

The Alianza Café and Maximizing Opportunities for Coffee and Cacao in the Americas (MOCCA) projects, led by TechnoServe, are promoting the use of vetiver grass in Peru for the treatment of coffee wastewater. Vetiver is a plant that, thanks to its deep root system, has the capacity to filter the honey water resulting from coffee washing. Vetiver prevents the honey water from reaching clean sources of organic matter and becoming a source of contamination or disease.

Meet José and Jesús, Two Coffee Producers in Peru

José and Jesús standing in front of vetiver plants on their farm.

To better understand how this technology works, we went deep into the Amazon region of Peru to the province of Rodriguez de Mendoza. There, we met José Salazar and Jesús Rodríguez, two coffee producers who live in a small community in the “Peruvian jungle belt,” a geographical area characterized by its cloud forests and a megadiverse ecosystem that preserves unique species of flora and fauna.

“We have been coffee growers for 22 years, dedicated to this crop because it produces income to support our children,” said Jesús while closing the cage of the chickens on their farm.

In 2022, the couple joined the MOCCA program. José and Jesús were motivated to acquire new knowledge that would allow them to improve the productivity of their coffee farm. They participated in training modules on fertilization, pest and disease management, selective harvesting, and waste management.

The U.S. Department of Agriculture Food for Progress funded The Maximizing Opportunities for Coffee and Cacao in the Americas (MOCCA) program, which seeks to expand agricultural productivity and trade.

Coffee growers implemented a system for treating coffee honey water on their farms with the help of TechnoServe program technicians. This use of a filtration well with vetiver plants provided by MOCCA is one of the greatest advances recognized by coffee growers.

The Rainforest Alliance Accepts Vetiver Filtration as a Suitable Treatment for Managing Honey Water

vetiver treats coffee wastewater — Coffee producers posing with vetiver plants.

The MOCCA project saw encouraging results from a 2019 study that took random samples from 200 ponds established as part of the Alianza Café initiative financed by the U.S. Agency for International Development. The MOCCA project presented the study results to the Rainforest Alliance (RA) and requested their endorsement of the use of vetiver in the RA certification scheme. In 2022, thanks to the joint efforts of both projects implemented by TechnoServe, the RA team of certifying auditors was notified of the acceptance of this technology in the certification scheme.

Vetiver has several benefits. It is easily accessible to small-scale producers and is a low-cost filtration alternative. Producers don’t have to make large investments to implement a treatment plan with vetiver.

Maintenance: An Important Element in Treatment Plants

“We tend to believe that [the plants] work by themselves, but in reality, maintenance is necessary,” explained a specialist at the Rainforest Alliance. “Although, vetiver, due to its natural characteristics, does not require very strict maintenance. A periodic review should be followed to ensure that the plants are alive and that they are reproducing. Therefore, a seed bank will definitely be required to be able to plant new plants if necessary. Another important element is that [vetiver] produces almost no waste. If we compare it with other treatment plants, which require filter media and produce special wastes, the question is what to do with this waste? While with this natural filtration system, no waste is produced.”

Treating Honey Water

vetiver plants treating wastewater — Installing vetiver plants.

While honey water continues to be a challenge in Peru, over 310 families are now addressing it adequately through these treatment plants. Vetiver plants are significantly contributing to counteracting the pollutants produced at the farm level, especially soil and river pollutants. Neutralizing these pollutants is important because of their negative effect on neighboring plots and their association with the spread of insects, which are not conducive to maintaining a healthy environment.

With TechnoServe’s help, we are properly managing coffee waste and making the most of it to produce organic fertilizers,” said Jesús Rodríguez. “Before, we did not find any effective solution to treat honey water, and we did not know what to do with this waste. We have obtained good results with the well with vetiver plants to avoid contamination and care for the environment.”

For more information on the treatment of honey water and the installation of vetiver filtration wells, please consult our manual of good practices for the management of coffee waste at www.mocca.org/recursos/cafe.

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Giselle Alemán Ayala is a regional communications manager at TechnoServe.

Vetiver: The Low-cost Innovation to Treat Coffee Wastewater