Municipal infrastructure is typically implemented to address a social need, yet it is not regularly evaluated to assess its performance against its original objectives. In Texas, there are over 300,000 mostly Hispanic residents living in informal settlements mostly located along the Texas-Mexico border.Until the late 2000’s these residents were using contaminated wells, hauled water, cesspools, or nonfunctioning septic tanks.Consequently, the incidences of contagious diseases associated with poor water quality greatly surpassed the state average.This research explores the question of measuring the impact of water and wastewater infrastructure on water-borne diseases using the case study of Texas. Federal and state agencies invested on the order of $1 billion for first-time water and wastewater service for over 200,000 residents in these rural communities along the US Mexico Border. This study applies a two-way fixed effects regression model to evaluate results using data gathered from publicly available reports and over 90 interviews with service providers of how water and wastewater infrastructure performed in addressing contagious diseases.This quasi-experimental analysis exploited the size, location, and timing of wastewater infrastructure. Results show that residents in the most populated counties experienced a 24% reduction in hepatitis A incidence rate. However, tuberculosis and salmonellosis rates do not seem to be affected by infrastructure investment and continue to be a problem throughout the region. Many of the utility managers interviewed, especially in the more rural areas, coincided that even though population growth or economic development did not occur, they witnessed quality of-life improvements.