Exploring the Relationship Between Water Quality and Conservation
Declining water usage in buildings around the country is presenting water utility managers with unique challenges. One of the most notable is reducing the opportunity for pathogens such as Legionella spps. and Pseudomonas aeruginosa from surviving in plumbing system pipes and contaminating drinking water.
A project being conducted by Michigan State University (MSU) Biosystems and Agricultural Engineering (BAE) researcher Dr. Jade Mitchell, and her colleagues with EPA National Priorities grant funding is exploring the relationship between water quality and conservation. One of the project objectives is to arrive at a better understanding of how building design, materials used to construct pipes, and water usage affect the growth of opportunistic pathogens in drinking water.
The researchers are coupling water quality models with quantitative microbial risk assessment to help predict the level of potential health risk that exists in drinking water when it flows from the tap, information needed to more accurately inform future risk management decisions and plumbing design.
“The lack of understanding that exists regarding reduced water flows and water usage presents a potential barrier to further water conservation efforts as the human health risks from increased exposure to pathogens may increase,” Mitchell said. “A better understanding of the complex plumbing environment and potential sources of human exposure determined through this project will help to address this barrier and reduce the health risks associated with (drinking water) plumbing systems.”
The researchers have submitted for review the first set of dose-response studies for these pathogens, thereby expanding the capacity for risk assessment, a process that formally integrates science across different domains to characterize pathogen risks in terms of health outcomes.
Additional quantitative microbial risk assessments are ongoing in Mitchell’s lab to determine at what concentrations other naturally occurring pathogens found in plumbing systems – those that are ever-present but unlikely to pose a human health risk – can become a concern. These benchmark calculations can also be used in the construction of future sampling, monitoring, and management protocols for ensuring safe drinking water. The work specifically targets the inhalation route of exposure which has been less formally considered in drinking water safety.
According to Mitchell, an incredible asset to the MSU study was having the opportunity to work with Whirlpool’s Retrofitted Net-zero Water, Energy, and Waste (ReNEWW) home located in West Lafayette, Ind. Every hour, more than 75,000 flowmeter data points are taken for analysis, which equates to 1.8 million readings per day.
One of Mitchell’s collaborators, Dr. Pouyan Nejadhashemi (BAE) will use the results of these studies to develop a decision support tool for regulators, municipalities, and building designers.
More information on water safety and conservation can be found on the Center for Plumbing Safety website.
Contact Dr. Jade Mitchell for more information.