This article from Phys.org discusses ways to ensure against pathogens that are prone to develop in low-flow plumbing systems.
As more and more plumbing systems experiment with lower flow rates in and effort to conserve water. However, the diameter of plumbing pipes has remained the same, causing water to age in the pipe, increasing the danger of opportunistic pathogens such as the bacterium Legionella pneumophila (the cause of Legionnaires' Disease).
New research at Purdue University -- funded by the EPA and in partnership with Michigan State University and San Jose University -- hopes to provide guidelines for system designers, facility managers and health officials. According to Janice Beecher, director of the Institute of Public Utilities Policy Research & Education at MSU:
Lower usage and lower flows in water systems are raising engineering, economic, and public health issues, so an interdisciplinary approach is needed... This research is especially timely in terms of the urgency of optimal infrastructure investment with a focus on ensuring safe drinking water.