Alternative solutions for wastewater treatment in U.S.-Mexico border colonias: an analysis from socio-economic and technological perspectives

Inadequate wastewater treatment often leads to severe water quality and public health problems. Its effects are very pronounced in the low-income, rural subdivisions along the U.S.- Mexico border. These communities, called colonias, typically have no electricity, running water, or plumbing for waste disposal, are characterized by high disease incidence rate, and have a migratory population which contributes to the diffusion of health problems and public concern in both the U.S. and Mexico. The border pair cities of El Paso, Texas, and Ciudad Juarez, Chihuahua, are representative of the situation for many large and small communities along the U.S.-Mexico border. The additional issues of rapid population growth and a scarce water supply compound these problems in this region. This study has developed a transferable/adjustable framework, employing a set of socioeconomic, physical and technological criteria, for selecting wastewater treatment alternatives for low-income communities. Using this framework, we have identified an appropriate wastewater treatment system for a set of five colonias located in the El Paso/Ciudad Juarez border region. In our analysis, we investigated five low-cost, low-technology alternatives to traditional wastewater treatment service, including pond systems, constructed wetlands, on-site septic systems, slow sand filtration, and trickling filter systems. Based on this assessment, we recommend a constructed wetland system for the case study site. Our framework, along with the case study results and design of the recommended system, will be provided to planning and funding organizations in the study region. Among the recipients are the Lower Valley Water District Authority (LVWDA), the El Paso Interreligious Sponsoring Organization (EPISO), and the Texas Water Development Board (TWDB)