Green Goes to Gray

Martha Podren, MS graduate 2003

The overwhelming fact of life in Monteverde is water: water in mists, fogs, drizzles and gushes, in droplets, puddles and torrents. It is hard to imagine that the luster of this wet and shining world could be fading, but increasing water pollution in Monteverde points to just this possibility.

Global warming and deforestation in the lowlands have almost certainly contributed to water problems in the Monteverde Zone through decreasing rain and mist, according to J. Alan Pounds, Robert Lawton and other researchers. But a more humdrum threat is produced by gray water, drain water teeming with shampoo, detergents, housecleaning products, pesticides and other wastes.

Gray water from growing numbers of residents and tourists pours out of kitchens, laundry rooms and showers into roadside gutters, untreated here as it is all over Costa Rica. The gutter water rushes into streams and rivers, collecting soil, grease, oil and litter as it travels down slope.

In flatter, lower-elevation towns of the Zone, gray water presents a potential health threat. Dr. Mauricio Quesada Rosales of the Monteverde Clinic warns that dengue and malaria may threaten these towns because gray water is not carried off. Instead, it stagnates in streets and gutters, allowing mosquitoes to breed.

Gray water is undercutting the viability of the Monteverde region not only as an eyesore and a health danger, but also because it degrades the streams that its diverse animal species — and ultimately its human residents — depend on. Says local activist Patricia Jimenez, “I have always found it ironic that in this place where there’s so much attention to protecting habitat, all the rivers, every one of them, are dirty, polluted in some way.” She and staff at the Monteverde Institute are working to minimize these environmental and economic risks.

To initiate the effort, the Monteverde Institute started a water quality-monitoring program in 1999. Staff collect water samples from 10 sites every two weeks, testing for key indicators of water quality. The amount of oxygen in each sample is measured, as well as the amount of organic and chemical pollution.

The difference is marked between the Quebrada Maquina, the stream that goes through the relatively unpopulated Monteverde community, and the Quebrada Sucia, which runs through booming Santa Elena.

Compared with the upper Quebrada Maquina, the Sucia has over ten times the amount of fecal coliform, bacteria from fecal waste. It also contains significant amounts of phosphates and nitrates, pollutants that encourage an explosion of algae growth. When the algae die back, the decomposition process robs the water of oxygen essential for animal life. The amount of oxygen that will be exhausted during this process is measured with a test called biochemical oxygen demand (BOD). The Sucia has two to three times the amount of BOD as the Maquina.

Institute staff member Stewart Dallas has been working on several projects that are models for treating gray water in mountainous regions like this one. At the Monteverde Community Arts Center, he built a reed-bed, a small constructed wetlands that relies on gravity. The reed-bed is a shallow trench lined with plastic and filled with gravel that allows solids to settle out of the gray water as it passes through. The trench is planted with water-tolerant plants whose roots break down bacteria and absorb oxygen-depleting nutrients.

Jimenez, a Santa Elena resident, was convinced that this reed-bed treatment could also work in her neighborhood, where the problem of gray water has been ignored by government authorities.

A reed-bed on her property was built in 2001 with a grant from the Ford Motor Corporation and help from Institute staff and volunteers. It accommodates her own and two other neighbors’ houses. Dallas monitors the treated water and notes, “It’s as good or better than many of the streams around here at present, more than adequate to support fish and other stream life.”

This low-tech, low-cost technology provides one part of the solution; public support for improvement supplies another. A new district council was formed in March, 2002 to govern six towns, including Monteverde and Santa Elena. Preliminary results from a recent development survey by the University of South Florida Globalization Research Center and the Monteverde Institute show that 90% of residents within the council jurisdiction do want gray water management and 82% would be willing to pay for it.

But without a local government that regulates new construction, requires treatment for wastewater and provides the means to build treatment facilities, tourists, then residents, may well begin to flow out of Monteverde along with the gray water.

(This piece first appeared in the Tico Times, Costa Rica’s national English-language newspaper.