This book highlights the environmental sustainability problems specific to the South Texas–Mexico border region, on both sides of the Rio Grande, focusing on water and air pollution. The region is beset by climate extremes, from severe drought conditions to hurricanes, providing specific challenges for the ecosystems and the populations existing within the region.   The water pollution research centers on:   ·         the Rio Grande and its feeder creeks ·         the outflows into the intercoastal waterways, marshes, lagoons, and bays ·         previously deposited metals in waterways ·         impacts of concentrated discharges on downstream receiving waters ·         hydrological conditions in a pilot-scale constructed wetland ·         water quality treatment ability of wetlands ·         the recovery of nutrient removal activity after major flooding damage and inundation   The air pollution research focuses on:   ·         the effects of air pollution on an individual’s health in municipalities on the Rio Grande  and in interior cities ·         the transport of ultrafine particles and other pollutants from industry and automotive sources ·         the influence of climate on air quality in the study cities   While the research centers on challenges of the South Texas–Mexico border region, findings and recommendations will be beneficial to researchers in other regions facing similar problems.