CAREER: Elucidating hydrodynamic drivers of microbial water quality in drinking water distribution systems

Drinking water distribution systems (DWDS) are critical infrastructure that protect public health by ensuring the safety of drinking water as it travels from treatment plants to points of consumption. However, the quality of drinking water can degrade as it flows through the extensive pipe networks of DWDS. Growth of biofilms on the surfaces of water distribution pipes is a particular concern as it is detrimental to water quality in various ways, including by creating a protective environment capable of harboring pathogenic microorganisms, accelerating the decay of disinfectant residual, facilitating the formation of disinfection byproducts, and the release of compounds that cause problems with taste, odor, and water discoloration.

However, a fundamental understanding of the relationships between pipe hydrodynamics, biofilm properties, and water quality in DWDS has remained elusive. The overarching goal of this CAREER project is to advance the fundamental understanding of the impact of hydrodynamics conditions on the composition, structure, and stability of biofilms that form on the surfaces of drinking water pipes.

The successful completion of this project will benefit society though the development of fundamental knowledge to guide the management of DWDS with the goal of improving both the quality and safety of drinking water at the points of consumption. Additional benefits to society will be achieved through student education and training including mentoring of one graduate and two undergraduate students at West Virginia University.

The formation and growth of biofilms on the surfaces of drinking water pipes have a major impact on water quality and safety in drinking water distribution systems (DWDS). The structure and composition of the biofilms of water distribution pipes play a key role in modulating the quality of drinking water at the points of consumption. There are critical knowledge gaps in the fundamental understanding of these biofilms including the impact of diurnal fluctuations in hydrodynamic conditions on their structure, composition, stability, propensity for pathogen attachment/release, and potential to induce/catalyze the formation of disinfection by-products during water disinfection by chlorination or ozonation.

This CAREER project will address these knowledge gaps. The specific objectives of the proposed research are to: 1) evaluate biofilm physical characteristics and associated attachment and detachment of pathogens in DWDS in response to repeated variations in shear stress during water flow; 2) assess the impact of variations in hydrodynamic forces on the amount/composition of extracellular polymeric substances in biofilms and associated impacts to water quality; and 3) investigate the effect of variable hydraulic conditions on the formation of biofilms on sediment surfaces in DWDS.

The successful completion of this research has the potential for transformative impact by combining controlled bench-scale experiments to develop a mechanistic understanding of biofilms in drinking water pipes with the analysis of samples collected from a full-scale drinking water distribution system, and modeling to benchmark and validate the research findings. To implement the educational and training goals of this CAREER project, the Principal Investigator (PI) proposes to develop a new undergraduate course at West Virginia University that will focus on decentralized wastewater treatment technologies.

In addition, the PI plans to develop and deliver an education module entitled “Why Water Matters in Rural Communities” to K-12 students from rural communities in West Virginia with the goals of increasing awareness of water careers, promoting the recruitment of young professionals into local water and wastewater apprenticeship programs, and advancing the recognition of the essential role that water plays in supporting healthy and prosperous communities.

This project is jointly funded by the CBET Environmental Engineering program and the Established Program to Stimulate Competitive Research (EPSCoR).

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.