Reedbeds for greywater treatment—case study in Santa Elena-Monteverde, Costa Rica, Central America

In much of rural Latin America, untreated greywater is piped straight to the nearest street or stream while only the blackwater from the toilet is plumbed to a rudimentary septic system. This practice constitutes a discernible health risk with significant environmental impact, such as in the case of Monteverde, Costa Rica. In this case study, we present a low-cost reedbed system for the treatment of domestic greywater designed upon ecological sanitation principles. A locally available plant, Coix lacryma-jobi, has proven to be a resilient and viable emergent macrophyte in reedbed systems and is to our knowledge the first time this species has been used for wastewater treatment. An environmental services contract (ESC) was also established in an attempt to provide a sustainable maintenance scheme. The quality of the treated greywater from this system achieves the Costa Rican guidelines for wastewater reuse which indicate that the design criteria for the treatment of greywater using reedbeds will be guided by pathogen removal.

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