Biofilm in premise plumbing could pose both direct and indirect public health risks by impairing water quality integrity and serving as a reservoir of harmful microorganisms. Practical and effective strategies to minimize biofilm occurrence and reduce public health risks, however, remain to be developed, due to the lack of adequate understanding of the microbial processes underlying biofilm occurrence, particularly in premise plumbing which represents over 85% of the total distribution system but has not received adequate research attention. The research objective of the proposed project is to identify the processes responsible for the survival and adaptation of biofilm microbial communities in premise plumbing. The research will be conducted by using community-level characterization of biofilm functional processes. This research will use a community-level approach combining high-throughput DNA microarray-based functional analysis and 16S rRNA gene-based molecular microbial ecology tools for the characterization of biofilm microbial communities in premise plumbing systems of distinct characteristics.
This research will provide much needed insight into fundamental processes controlling biofilm persistence which would enable the development of effective strategies for the minimization of biofilms in premise plumbing by targeting key processes that facilitate biofilm occurrence. Results from this work will also enable improved risk assessment, design guidelines and regulations for premise plumbing by providing much needed data regarding the impact of plumbing material, water use pattern, environmental factors, and water quality characteristics on microbial contamination in premise plumbing.
Improved understanding of the microbial processes controlling the development of biofilm in water distribution systems, particularly premise plumbing, will lead to more effective strategies to minimize microbial contamination of drinking water and enhanced safety of drinking water. This will lead further to minimized occurrence of waterborne diseases, increased use of public water supply, and reduced use of additional purification devices and bottled water. Our society will benefit through reduced heath care costs and more sustainable uses of energy and resources. In addition, the proposed research provides an excellent example of the application of genomics and microbiology in environmental engineering. Thus the infusion of research results from the proposed work into classroom teaching will better prepare students for learning and working in the increasingly interdisciplinary filed of environmental engineering. More importantly, the participation of minority students from a local urban high school in the proposed project will ensure that underrepresented students have the educational exposure crucial to their success in learning and working in the engineering profession.
Safe drinking water at the tap is a necessity for our society. Microbial contamination of drinking water in the distribution system could lead to massive outbreak of waterborne diseases with enormous health and economic impacts. Biofilm as the most prevalent and persistent form of microbial contamination is a common presence of most water distribution systems. The public health risk from biofilm occurrence is particularly important in premise plumbing, the portion of the water distribution system in buildings and homes, which is characterized by longer residence times, more stagnation, lower flow conditions, and elevated temperatures compared to the main distribution system. These unique characteristics of premise plumbing can magnify the potential public health risk associated with microbial growth and biofilm development by impairing water quality integrity and serving as a reservoir of harmful microorganisms. Practical and effective strategies to minimize biofilm occurrence and reduce public health risks, however, remain to be developed, due to the lack of adequate understanding of the microbial processes underlying biofilm occurrence, particularly in premise plumbing which represents over 85% of the total distribution system but has not received adequate research attention. Therefore, it is important to identify the processes responsible for the survival and adaptation of biofilm microbial communities in premise plumbing. Research conducted in this project revealed that piping materials had major impact on the microbial composition of biofilm, with iron pipes supporting the most complex biofilm and the least diverse biofilm found in copper pipes. Characteristics of the water treatment process were also shown to have significant impact on biofilm composition, with disinfection as the most influential treatment step. In particularly, free chlorine level and organic carbon content, which are closely related to the treatment process, exhibited the highest correlation to biofilm composition in premise plumbing. Thus, this work provides much needed insight into fundamental processes controlling biofilm persistence which would enable the development of effective strategies for the minimization of biofilms in premise plumbing by targeting key processes that facilitate biofilm occurrence. Additionally, results from this work will also enable improved risk assessment, design guidelines and regulations for premise plumbing by providing much needed data regarding the impact of plumbing material, water use pattern, environmental factors, and water quality characteristics on microbial contamination in premise plumbing. This project contributed to the development of human resource critical for maintaining the U.S. technological edge by supporting the research work of one PhD student, two MS students, two undergraduates, and four high school students. Notably, half of these students are from underrepresented groups in STEM disciplines. Due to the multi-disciplinary nature of this study, these students have received interdisciplinary trainings much needed to prepare them for competing in the world of technology innovation and development. Furthermore, high school outreach activities performed in this project through the Pre-Collegiate Research Scholar Program have provided the educational exposure crucial to student success in learning and working in the engineering profession and other STEM fields, resulting in increased participation of the Pre-Collegiate Research Scholar Program and STEM career choices by the program participants.
