Evaluation of point of use drinking water treatment systems for colonias in the Southwest United States
Clean drinking water is often taken for granted in first world countries, such as the United States. However, thousands of colonias residents (settlements in the Southwest US that lack access to basic infrastructure) still lack access to clean drinking water. Such is the case in the Paso Del Norte Region. In Doña Ana County, NM, and El Paso County, TX, colonia residents typically rely on shallow domestic wells and hauled water, respectively. However, both water sources can pose health concerns from elevated total dissolved solids and microbiological contamination. With connection to centralized water treatment and distribution still years away, colonias require a more immediate and effective solution for their current situation. This research proposed that such a solution could be achieved with a point-of-use (POU) water treatment system. The goal of this project was to provide colonia residents with an economically, socially, and environmentally sustainable water treatment system. The objectives of this study were to: (1) assess user preferences and actual water quality data in order to design a household-level water treatment system; (2) develop a holistic point-of-use technology evaluation system that can be used by residents to screen and select a POU drinking water system for their home; and (3) evaluate methods for preserving water quality in drinking water storage tanks. First, focus group studies were conducted in colonias to discuss possible water treatment options and record residents’ perceptions and preferences. Water samples were collected from willing participants and analyzed for basic drinking water quality parameters. Second, many types of commercially available water treatment technologies were reviewed and analyzed, and a five-component evaluation and ranking system was developed to facilitate selection and implementation in colonias. Third, experiments were performed to evaluate the efficacy and feasibility of using copper and/or hypochlorite treatment to control algae and preserve water quality in storage tanks. The research performed in this study showed that colonias that rely on groundwater face more challenges, in the form of microbiological contamination and high salinity, than colonias that rely on hauled water. A treatment train of basic cartridge filtration and point-of-use desalination was proposed to address the water quality issues in colonias relying on well water or hauled water. It was also determined that the most economically, socially, and environmentally sustainable system was an under-the-sink reverse osmosis (RO) unit. This research also yielded a system of preserving water quality in drinking water tanks, which includes chlorine monitoring and dosing, periodic tank cleaning, and the possible use of copper as an algaecide.
Campos Flores, Isaac, "Evaluation of point of use drinking water treatment systems for colonias in the Southwest United States" (2015). ETD Collection for University of Texas, El Paso. AAI3724910.