Comparing health outcomes and point-of-use water quality in two rural indigenous communities of Baja California, Mexico before and after receiving new potable water infrastructure

One of the United Nations Millennium Development Goals is to reduce the global proportion of people who do not have access to safe drinking water. In the past, the typical strategy to reach this goal has been the use of investment-intensive centralized infrastructure development for water supplies. However, there is increasing evidence suggesting that improving water quality at the source does not guarantee safe water at point-of-use. This study examined water quality, waterborne disease incidence and water system use over time in two small rural indigenous communities of Baja California, Mexico, before and after drinking-water infrastructure improvements. Community Promotoras collected data on the incidence of gastrointestinal illness through face-to-face surveys. Concurrently, water samples from the old and new water sources and household water storage containers were analyzed for fecal coliforms. Although source water quality was significantly improved in both communities (p < 0.05), neither community had a significant decrease in the level of contaminated drinking water sampled at the household level. No significant decrease in gastrointestinal illness was found after the improvements to the source water supply. These results indicate that point-of-use contamination and acceptance of the new sources may be a critical point for intervention when attempting to assure access to safe water, especially in rural communities.