Colonias are self-built neighborhoods of mostly low-income families that lack basic infrastructure. While some funding from the state government has built roads and provided electricity, water and sewage systems are still lacking for many of the estimated 400,000 colonias’ residents in Texas. Of those that do have tap water, the supply is either inadequate or of questionable quality. Some colonias residents have access only to off-the-grid water supplies, and residents collect their water from community wells, or, if fortunate, from a personal well. Many of these wells are self-built and therefore shallow. In Nueces County, the groundwater in several colonias has been reported to contain arsenic, while poor sanitation practices (i.e., self-built septic systems) and heavy rainfall events in the region compromise the microbial quality of the groundwater. The naturally occurring arsenic in the aquifer and microbial contaminants from flooding events mean that the only available drinking water source in these colonias is contaminated throughout the year. In this research, datasets on water quality in nine colonias in Nueces County were collected both in wet (after a major rain/flooding event) and dry (no significant rainfall for four weeks) periods. The water quality analyses included traditional microbial quality assessment (total coliforms, Escherichia coli, and heterotrophs), pH, hardness, total dissolved solids, and a suite of metals that are relevant to human health (e.g., arsenic and lead). Microbial community analyses also were completed on select samples to assess the shifts in microbial ecology between wet and dry periods. Results reveal that water quality varies based on environmental conditions and presents a serious risk to human health. Water sampled during the wet period had extensive microbial contamination with elevated heterotrophs and total coliforms, and E. coli was identified in some samples. In the dry period, water from a number of colonias exhibited elevated levels of arsenic (above United States Environmental Protection Agency’s Maximum Contaminant Level of 10 µg/L). This study is one of the first to systematically investigate water quality in Texas colonias, and the results highlight how water quality in these communities is compromised year-round, going between microbial contamination in wet events and arsenic contamination in dry events.
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Structural equation modeling to identify social drivers for water use in low-income communities in Southern Texas
The colonias in Texas along the Mexican border are self-built neighborhoods of low-income families that lack basic infrastructure. While some funding from the State of Texas has built roads and provided electricity, water and sewage systems are still lacking for many of the estimated 400,000 colonias’ residents. Of those that do have tap water, the supply is either inadequate or of questionable quality. These communities have suffered from waterborne disease, such as cholera epidemics, over the past few decades. This research is the first to collect a comprehensive dataset on water use, socio-economic parameters, and actual water quality in selected colonias in several counties in Texas. A quantitative statistical model has been developed using structural equation modeling, that relates social drivers for water use and management with actual water quality. Water quality parameters measured in these communities include traditional microbial indicators (total coliforms, E. coli, and heterotrophs), pH, hardness, free and total chlorine, and metals (arsenic and lead). The model explores relationships among latent variables relating water, health, and living situation to assess potential impacts of a water treatment technology in these low-income households. The study provides quantitatively reports for the need and desire of adopting a point-of-use treatment system, evaluates the relationship between perceived versus actual water quality, and determines the factors that influence the choice of drinking water. This model can be adopted for identifying social drivers for water use and management in other low-income communities in the United States.
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- Award ID(s):
- 1805958
- NSF-PAR ID:
- 10174734
- Date Published:
- Journal Name:
- 257th American Chemical Society National Meeting
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Since the late 1970s, the term “colonias” (in English) has described low-income, peri-urban, and rural subdivisions north of the U.S.-Mexico border. These communities are in arid and semi-arid regions—now in a megadrought—and tend to have limited basic infrastructure, including community water service and sanitation. Recent scholarship has demonstrated how colonias residents experience unjust and inequitable dynamics that produce water insecurity in the Global North. In this review, we explain why U.S. colonias are an important example for theorizing water insecurity in the United States and beyond in the Global North. Tracing the history of water infrastructure development in U.S. colonias, we show how colonias are legally and socially defined by water insecurity. We draw on the published literature to discuss key factors that produce water insecurity in U.S. colonias: political exclusion, municipal underbounding, and failures in water quality monitoring. We show that water insecurity had led to negative outcomes—including poor water access, risks to physical health, and mental ill-health—in U.S. colonias. We present four possible approaches to improving water security in U.S. colonias: (1) soft paths & social infrastructure for water delivery, (2) decentralized water treatment approaches, such as point-of-use, point-of-entry, and fit-for-purpose systems; (3) informality, including infrastructural, economic, and socio-cultural innovations; and (4) political, policy, and law innovations and reforms. At the same time, we reflect seriously on how water security can be ethically achieved in partnership and aligning with the visions of U.S. colonias residents themselves.more » « less
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Legionella andPseudomonas detected at every site at least once andMycobacterium detected at most sites. However, only one sample had quantifiablePseudomonas aeruginosa through quantitative polymerase chain reaction (qPCR), and no samples had quantifiableLegionella pneumophila orMycobacterium avium , indicating a low human health risk. This study establishes spatial variations in PAB associated with varied hydraulic conditions as an important factor driving microbial community within a chlorinated DWDS.
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