LEE Water-Infra aNalytics  | LEE-WIN

Research Interests

Juneseok Lee, Ph.D., P.E., D.WRE

I have been conducting research into various aspects of Drinking Water Infrastructure Modeling/ Analytics, including both i) water supply/distribution and ii) premise plumbing (Figure 1). I am particularly interested in developing integrative water quality and hydraulic modeling in premise plumbing and water distribution systems, water-energy nexus, and water-infrastructure resilience & asset management.
As the name of my research website indicates, Lee Water-Infra Analytics, I am interested in approaching research problems from a predictive and prescriptive analytics perspective.    
Predictive analytics includes forecasting, causal relationships, and various types of data mining including, but not limited to, spatio-temporal cluster analysis, and machine learning techniques such as artificial neural networks.  Prescriptive analytics refers to optimization techniques such as integer programming, evolutionary algorithm, multi-objective decision modeling, and simulation–optimization.  In my research, I typically use MATLAB, R, Python, and GIS in conjunction with water systems & quality simulation models such as EPANET and EPANET-MSX.  To account for the embedded uncertainty and randomness in water-infrastructure elements, I apply descriptive analytics such as families of probability distributions, bootstrap analysis, Bayesian analysis, and non-homogeneous Poisson processes. 

My overall research goal is to protect public health and improve social well-being by enhancing the water quality and the hydraulic and structural integrity of our drinking water infrastructure.  My research philosophy can be summarized as follows:  

  • Solve real-world engineering problems to address gaps in the knowledge base of the drinking water industry and research community;
  • Apply analytical methods to develop a better understanding of causality in our drinking water infrastructure systems;
  • Fulfill my lifetime goal of contributing significantly to the development of innovative and futuristic drinking water infrastructure systems to meet society’s future needs.
List of my particular research interests, as well as the details, are in the following: I) Premise Plumbing Systems, II) Drinking Water Supply/ Distribution Systems, and III) Emerging Drinking Water/ Plumbing Industry  Issues.

 Figure 1 Drinking water infrastructure: water distribution and premise plumbing systems

I.  Issues in Premise Plumbing

Innovative Plumbing Code
Demand variation over time can be regarded as responses to socioeconomic and climatic factors at multiple time scales, which is stochastic processes.  Also, it is well known that short term and small scale human activities have great influence on long term, larger scale behaviors of environment.  The objective of the reserach is to develop new  paradigmns in plumbing design for effective water management. 
Service Lines Failure Analysis
According to the AWWA (2007), the majority of water leaks occur at service lines, service fittings, and connections. It is evident that service lines are responsible for the largest volume of real water losses.  Given that the condition of the nation’s existing water infrastructure is deteriorating, it is thus essential to ensure that service lines are maintained to a high level of integrity to protect public health. So far, best management practices for water service lines have not as yet been well addressed in research community. The objective of the research is to: (i) explain the precise failure mechanisms that affect water service lines and (ii) develop a set of recommendations for improved best management practices.  The research results will help reduce growing concerns among water utilities and consumers regarding water efficiency and the public health issues.
Smart Water Systems
Many countries have problems related to water scarcity and are thus seeking to promote greater water efficiency.  A Micro Water Grid (MWG) is a high-efficiency water management system that integrates Information and Communication Technologies (ICT) for the water distribution systems in individual buildings.  More accurate forecasting of hourly water demand is necessary if these systems are to function correctly and is thus the focus of this research.  The forecast and observed values are compared.  
Decentralized Water-Infrastructure Systems
The goal of this project is to determine the environmental impacts of Decentralized Green Water-Infrastructure Systems (DGWIS) by performing a simulation optimization analysis of proposed DGWIS in urban buildings.  The study specifically focuses on reusing/recycling of rainwater and greywater to meet water demand in urban buildings and using renewable energy for water treatment and distribution.  The integration of solar and other renewable energy technologies and decentralized water-Infrastructure in our research can induce a significant opportunity and innovation for water and energy conservation and reduce the carbon footprint of water consumption in urban environments.  The study addresses fundamental research questions in optimization and environmental impacts of proposed DGWIS systems and helps solve important and sustainable water and energy planning and management problems in urban areas. 

Residential Water Demand Analysis
Residential water demand has been extensively studied over more than four decades, but as yet there is no consensus on the best or most appropriate model from a practical perspective. Conservation and sustainability programs with new metering incentives have increased the necessity for an easy to use forecasting model for water resource management based on a better understanding of the factors driving residential water demand.  Analytical techniques have increased in complexity, advancing with new tools for computing and data collection such as GIS and remote sensing.  This research will help provide the knowledge base for the future studies and recommendations are made for addressing/ bridging the gap between drinking water industry and research community. 

II.  Issues in Drinking Water Distribution Systems

Water Mains Integrity Program
Drinking water infrastructure entails significant operational and managerial responsibilities related to the need to safeguard public health.  To help meet its complex water-related challenges, a new Mains Integrity Management Program is developed as sub-program of Asset Management Program. The specific objectives are to i) achieve lowest life cycles (affordability), ii) quantify and manage risk, iii) renew the infrastructure, and iv) deliver excellent service to customers.  This research outcomes will lay the foundation for a standardized platform of sustainable life cycle assessments for individual elements of the water infrastructure based upon a systematic approach. Many of those in the post-war baby-boomer generation are likely to retire over the next decade, and it is thus imperative that better systematic decision support systems be adopted to address the resulting challenges for the water industry.
Hydraulic Transients Impacts Analysis
The major objectives of this research are to: (i) observe pressure variations at the T-junctions in service lines, (ii) compare the hydraulic transients’ characteristics with and without a leak.  To accomplish objectives (i) and (ii), an instrumented PVC piping network was built to represent real service lines and used to demonstrate that leaks attenuate the transient pressure peak values compared to no leak situations.  The results of this study shed new light on the precise relationships between hydraulic transients and water leaks.
Optimal Flushing Program
It is critical to assess the effectiveness of current flushing practices, and to subsequently develop an optimal flushing protocol and associated practical guidance that considers a broad range of system parameters (geographical conditions, water quality, pipe age and material, etc.). This is to develop optimal Flushing Operations for Long-Term Water Quality Improvement Considering Water Loss, Cost, Public Perceptions and Risk; Operational Response of Flushing for Contaminant in Water Systems (right flushing intensity/ frequency applied to right systems, at the right time) as well as effects of Dead-end Flushing on Water Quality.  The objective is to find optimal sets of flushing procedures in a water distribution network by minimizing the impact on the population. 
On-line Real-time System Monitoring and Modeling
Water quality model is used to describe water quality in the drinking water distribution systems.   The stochastic nature of water demand is integrated within the framework of EPANET-MSX using the EPANET programmer's toolkit.  Command line programming via a dynamic link library (DLL) of commands in an integral programmer’s toolkit enables customization of complex multispecies reaction expression and rates of chemical reactions. MATLAB is utilized to link each modeling component.
Well's Asset Management
The objective is to develop an Enterprise-level well's asset management standards/ framework for the systematic evaluation of well performance and rehabilitation considering risk and cost-benefit assessment. The capacities of GIS, CMMS, WEMAT, are linked to support efforts to i) gather all the information in one place including production records, ii) plan for an effective management program, iii) establish confidence in the well rehabilitation outcomes.  The linked Business Intelligence model can provide a continuous baseline to facilitate optimized rehabilitation decisions. 

III.  Issues in Drinking Water/ Plumbing Industry

Optimization of General Rate Case
General Rate Case process is the main mechanism by which capital projects are planned, analyzed, and approved into Rate Base. This process has become increasing complex and administratively burdensome as it pertains to finding and justifying the “correct” (optimal) mix of capital projects that satisfy complex and potentially conflicting customer service and business goals. This is especially true when considering budgetary limitations, water quality and public health goals, and customer and regulator sentiment. This focus area would strive to research and develop a formal/mathematical decision support system (likely using integer based optimization tools) to help fully vet and analyze (even optimize) the total project decision space in preparation for final submittal. 
Multi-objective Optimization applications to Water Utility Management
This study focused on the development of a multi-objective decision model for optimal operation of a state-wide water distribution system.  Taking into account a broad range of technical, legal, financial, social, and environmental factors, the new model provides information that is critical if managers are to fully understand the current status and performance of water utilities.  The results of this research are expected to provide near real-time information on the operation and management of water utilities and enable the utility to incorporate a number of Effective Utility Management (EUM) elements into its enterprise-level operations.
Non-Revenue Water Issues
The American Water Works Association (AWWA, 2007) estimated that approximately $325 billion needs to be spent on upgrading water systems in the United States in the next 20 years. It is well known that water leakage rates in drinking water distribution systems can be as high as 32% in some utilities.  Recent drought issues in California also make the water loss as one of the top priority issues as part of the sustainable water resources management practices. The objective of the research is to: (i) estimate the water losses in drinking water distribution systems in Bay Area, (ii) measure economic and environmental impacts due to physical and apparent water losses, (iii) determine economically sustainable optimal level of water leakage level to balance water loss and economic benefits.  The research results will also help water utilities establish optimal strategies toward their water loss reduction programs.
Homeowner Concerns and Preference Analysis of Plumbing Issues
This study applied formal preference elicitation methodologies, Conjoint Analysis and the Analytical Hierarchical Process, to examine the actions taken by homeowners living in a pipe failure prone area and the preventive actions they might use to minimize their risk due to corrosion, cost, as well as other issues related to home plumbing. Health, taste, and odor were dominant considerations for consumers.  Interestingly, some respondents responded one way when stating preferences but behaved differently when making real-life choices.  This information will be helpful for policy experts and utility companies seeking new ways to deal with premise plumbing issues. 
Preference Analysis of Bottled Water
Bottled water consumption increases day by day despite its high prices, shelf life and questionable water quality, and potential environmental impacts compared to tap water.  This phenomenon raises a question of how people make a decision on whether bottled or tap water. The goal of the research is to elicit preferences for tap vs bottled water attributes using a multi-criteria decision modeling technique. To formulate the model, five attributes are considered: i) convenience, ii) environmental impacts, iii) health impacts, iv) cost and v) taste/ odor of water. This will enable us to determine their attribute rankings as well their final choices. The results from this research will be helpful to policymakers, water utility managers, educators, researchers, and other professionals concerned with the drinking water.