Washed up: reducing the harmful effects of waste water from coffee production

Wind the clock back a few decades, and Ken Calvert, a retired Energy and Wastes Treatment Engineer, says it wouldn’t be uncommon to find black water flowing up to 20 kilometres downstream from a coffee processing plant. “Historically, coffee factories were not liked much by the people in nearby communities,” says the New Zealand researcher. “The black colour of the water was naturally a bit of a problem for them.” The dangers of wastewater from coffee processing, Calvert explains, are about a lot more than aesthetics. The effluents from washed and semi-washed methods are loaded with organic matter and high in toxicity. The results can lead to degradation of the level of oxygen in water, which can kill off virtually all aquatic life.      Unfortunately, wind the clock back to today and in many places wastewater continues to flow straight from the factory to local water sources, with minimal purification efforts. Although the damaging effects of wastewater are becoming increasingly known, with coffee mostly grown in developing countries, limited resources don’t help the sustainability cause. “The problem with coffee is that it’s a Third World product,” he says. “These countries are slower to deal with the effects of waste as they just don’t have the resources.”
Vera Espindola Rafael, Latin America Field Coordinator for Coffee, Cocoa and Tea for UTZ Certified, has made similar observations on the poor state of wastewater treatment in many growing countries. “From what I’ve seen, some have the resources [to treat wastewater], and some don’t,” she says. “Sadly, sometimes you just see a small tube running straight into the river.”
With hardly enough resources to run processing factories, and virtually no financial incentive to limit wastewater, it’s little wonder that for years these effluents have been ignored. However, research efforts by Calvert, Espindola and others, have recently taken an incentive approach towards improving the environmental situation. Where resources are limited, the solution to wastewater is being found in innovative models, using natural local materials, and in some cases providing a welcome by-product in the form of renewable energy.   For Calvert, the first part of the solution has come from inspiration in the local landscape. Plant species that have the ability to thrive where other plants suffer, he’s found, can have their aggressive nature used to an advantage. “Our world is full of horror stories about such introduced species which, transported away from their old natural enemies have recreated entire environments to their own advantage,” he writes in one report for his consultancy Renertech. “However, it is these same species which can clean up immense amounts of pollution from other quarters.”
Calvert has studied the use of some  of these “aggressive” plants in wetlands where wastewater is discharged. These plants pump the oxygen down to their root system, and re-oxygenate the water. TechnoServe’s Coffee Initiative has taken a similar approach to treating wastewater, recommending the use of the Vetiver System. The project uses a wetland grass native to India to deal with wastewater. “Traditionally wet mills use evaporation ponds that risk seepage into rivers and pose a major safety hazard, often being very deep and permanently containing water,” says Carole Hemmings, Regional Manager, Agronomy and Sustainability at TechnoServe. “Correctly sited, a Vetiver wetland offers an environmentally friendly solution to the waste water problem. Densely planted Vetiver rows both filter and take up the waste water, eliminating both the water and the smell; the perfect cheap and simple solution.” As the rule of matter goes, of course, these toxic materials don’t simply disappear. In some cases, the plants produce a by-product in the form of bio-gas. In a new set of pilot studies, this bio-gas is being captured and used as a renewable energy source. Where farmers could be provided with an economic incentive to produce their own energy, this fortunate by-product has the potential as both an economical and environmentally sustainable development. This innovation could also be a historical first, as the first coffee project at the source to generate carbon credits. Calvert first explored these options in a Renertech report in 2006, writing: “The use of carbon credits may assist the coffee growing and processing industries of the Third World to bring back some profitability to what has been an industry under pressure.” Today, this theory is being put to the test thanks to an UTZ Certified-led project that could see the first carbon credits generated at origin. In February this year, UTZ’s Field Development researcher Espindola presented the first steps of the group’s efforts in generating bio-gas from wastewater. The process uses anaerobic microorganisms that convert organic pollutants to bio-gas, which contains methane and carbon dioxide. While this method is currently in use in some places such as Costa Rica, Espindola says that the gas is typically burnt off rather than used as energy. Which, she points out, is certainly better than not treating the water at all. “It’s the decision of each plantation what they want to do with their wastewater,” she says. “To do this [flame the gas] is at least something.”  For Espindola’s project, however, the breakthrough step will be to create a renewable energy source in seeing how that bio-gas can be used on site. Following UTZ and partner Solidaridad’s research, the project received funding from the Dutch govoernment a Dutch NGO Hivos in May 2010 to work in Central America. The project will focus on Nicaragua, while also including pilot sites in Guatemala and Honduras. The timing of the project’s launch was too late for the 2010-11 harvest, however Espindola is confident they’ll do better the second time around, having already done a fair amount of groundwork. They have decided to focus on larger plantations and smallholders. For large plantations they see the the potential for these companies to obtain carbon credits under the WWF’s Gold Standard scheme which is currently being explored with project partner Climate Neutral Group. “In our work, we need to make a business case,” says Espindola. “If you want a farm to upscale, you need to show them the cost benefit. With the environment, you can’t always show the cost – unfortunately no one really wants to pay for the environment.” Many certification schemes have tried to put a price on the environment, in rewarding farmers’ for sustainability efforts. Unfortunately, as Calvert explains, protecting a selective part of the environment can come at the cost of another. He points to one experience in Guatemala as an example. One farmer was having to cut down local trees to get enough firewood to fuel his processing plant. When one nature-friendly program became aware that they were chopping down trees and endangering local wildlife, the farmer was forbidden to cut down any trees. As he was still in need of energy, however, he turned to buying black oil. “This is the kind of oil that only burns in furnaces, it’s the dregs of the petroleum industry,” says Calvert. As the oil comes at both a high price for the environment and a high price tag, the farm owner is desperate for another source. As such, Calvert will be travelling to the farm this year to explore the use of renewable bio-gas from wastewater. Espindola points out that better treatment facilities will do little to mitigate the harm from drawing on water resources. There is a need to not only treat water accordingly, but also to limit the amount of water used. “You could produce even more bio-gas by producing more wastewater, and of course this isn’t something we want to promote,” she says. In this end, advances in equipment by South American companies have made tremendous steps in reducing the amount of water needed to process coffee. A 2008 Spread project, focusing on the use of water in Rwanda, looked at these pulping technologies which mechanically remove the mucilage instead of using water to ferment the beans. The Spread project compared energy and water usage, as well as quality outcomes. Generally, it was found that while the South American equipment used slightly more fuel, water usage was reduced from over 20,000 litres of water per tonne, to between 200 and 850 litres. In terms of quality, the study found that the beans processed through the water-saving South American equipment were “significantly better than that [traditional technology] pulping system for flavour, finish, cupper points, and per cent cupping score”. The purpose of the Spread project was to convince  buyers of the taste integrity of coffee processed in these methods. The project states that: “some coffee buyers will avoid operations not using the old traditional method.” The results show the true cost of ‘washed’ and ‘semi-washed’ coffee – that come in at 100 times the amount of water used in a region where the resource is scarce. 

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