CEE Seminar -A Sociotechnical Approach to Assess Equitable Access to Safe and Affordable Tap Water: Communities, Households, and Residents

Access to safe and affordable water is essential to promote public health and economic development. In recent years, millions of people have been exposed to tap water that violates federal guidelines for pathogens, nitrates, arsenic, and harmful disinfection by-products. In a community water system, water quality problems arise when stagnation leads to depleted chlorine residuals, growth of microbes, and potential spikes in disinfection by-products and heavy metals. Inequities in affordability may be heightened when households purchase bottled water, which is seen as a practical alternative in response to poor water quality at the tap. Similar dynamics occur on a smaller scale in premise plumbing, which is the portion of the drinking water distribution system inside buildings that includes pipes and fixtures. Water stagnates in premise plumbing systems due to intermittent uses at fixtures, which allows biofilms and opportunistic pathogens to flourish. Extended water age also increases the risk of lead and other heavy metals leaching from premise pipes and plumbing material. Water use habits around showering, watering lawns and gardens, drinking tap water, and washing hands affect not only the flows and quality of water in the premise plumbing, but also the exposure of an individual to unique water quality signatures. Across scales, exposure to poor water quality emerges due to the interactions among people and infrastructure, as changes in demands and intermittency of demands drive hydraulics and water quality dynamics.