Wastewater treatment in Las Vegas, Santa Barbara, Honduras

Abstract

The Municipality of Las Vegas, Honduras is located immediately to the west of Lake Yojoa, the largest inland lake in Honduras. Beginning in 2005, the Massachusetts Institute of Technology (MIT) began working with stakeholders around the lake to assess anthropogenic environmental impacts on the lake. In January 2008, a technical team composed of Dr. Eric Adams from MIT, Aridai Herrera a civil engineer from Malcolm Pirnie, and MIT students Anne Mikelonis and Matthew Hodge, traveled to Las Vegas to work with the Municipality on domestic wastewater discharge, one of the previously identified environmental impacts on Lake Yojoa. In preliminary discussions with the Municipality, the team identified three goals for the project: evaluate the performance of the existing wastewater treatment facility, test the possibility of enhancements to this facility, and evaluate options for expanded sewerage and wastewater treatment throughout Las Vegas. The results of this project are a set of three recommendations for the Municipality to improve wastewater treatment. First, regular maintenance of existing facilities is necessary to achieve optimal performance for existing wastewater infrastructure. Second, substantial non-waste water is entering the sewerage leading to an average daily flow of 1,000 L/person/day that has diluted concentrations of important wastewater contaminants. This situation makes any treatment difficult and prior to expanding sewerage, it is valuable to Las Vegas to investigate the source of non-waste water and to reduce the total flow to existing infrastructure. Finally, if the first two recommendations are acted upon, expanded treatment is subject to the constraints of Las Vegas, which are limited land availability and limited technical expertise.

(cont.) Given this situation, a low maintenance small footprint technology like Imhoff tanks or septic tanks will provide economically efficient primary wastewater treatment for the Municipality.