Cementos Progreso: A Guatemalan wetland.

Cementos Progreso, Guatemala: A Guatemalan wetland

The Cementos Progreso operation in Guatemala uses wetlands to clean sewage water. In 2000, the San Miguel plant constructed a system which involves a three-stage process - wetland, lagoon, wetland - which, over the years, has evolved into a close-circuit approach treatment system with a goal of zero discharge.

Clean water is a necessity for a good quality of life. In Guatemala, the cost of clean water for personal and agricultural purposes is not normally borne by the end user, and there are few regulations regarding wastewater discharges into water bodies. As a result, there are very few adequate treatment plants.

Countrywide, less than 10% of municipal authorities have their own treatment plants, which results in large amounts of untreated domestic and industrial wastewater being discharged into rivers and lagoons. The objective of this initiative was to artificially simulate the processes that take place in natural wetlands to avoid environmental impact on surface water bodies, and to do so efficiently and cost-effectively.

Organic matter from sewage water is decomposed by micro-organisms (bacteria, fungi and protozoa) to create energy. This is then absorbed by plant roots and converted into more complex compounds (by natural biochemical reactions), before being trapped in growing vegetation biomass. Vegetation is removed monthly to be composted naturally through earthworm activity, and used as organic fertilizer either in the cement plant's gardens or in reforestation initiatives.

The microclimate of the constructed wetland provides an ideal habitat for a variety of flora and fauna, which contributes to increased biodiversity at the manufacturing site. The effluent quality complies with legal wastewater discharges and is recycled onsite for gardening. This means that less of the existing fresh water is used for gardening, and sewage water is not discharged into rivers. The next step is to use the wetland effluent for the care of quarry areas under rehabilitation and effectively achieve the zero discharge goal.

Wetland reconstruction is inexpensive, low maintenance and effective. Furthermore, it contributes to enriched biodiversity, as well as having obvious aesthetic advantages. Cementos Progreso is currently sharing its experience with municipal authorities so that the approach may be replicated for residential and industrial applications.