I aim to use my expertise in environmental sciences, engineering, and system modeling to enable advanced analysis and improve environmental management outcomes. This page highlights projects that illustrate my experience in various environmental subject areas. Click on the subject areas in the collapsible menu below to read more about specific projects.
WATER RESOURCES & INFRASTRUCTUREGroundwater recharge using stormwater and recycled water
To help water planners make more informed decisions, I’ve developed AquaCharge–a tool that facilitates the design of infrastructure systems that recharge groundwater using stormwater and recycled water through spreading basins. AquaCharge is a systems-level planning tool that models and optimizes these infrastructure systems. Compared to designs identified using existing practices (e.g., spreadsheet, line-item design, or metaheuristic optimization methods), AquaCharge can identify global optimal solutions that reduce cost and energy use upward of 50%. AquaCharge can also provides users with robust, quantitative insights into the trade-offs between different system designs. This work helps water planners understand how recycled water could contribute to their water supply portfolios.
This project includes collaborating with water utilities in Southern California, the San Francisco Bay Area, and California’s Central Valley.
This project is ongoing. Contact me for updates.
Conceptual framework. AquaCharge considers options for producing recycled water, conveying this water to spreading basins, and operating the spreading basins. These options are optimized to minimize infrastructure life cycle cost and maximize groundwater recharge. The model output is an optimal infrastructure system design.
Spreading basin used for water banking in Kern County, California.
Meeting with Santa Clara Valley Water District to discuss opportunities for AquaCharge to inform their water reuse planning.
Meeting with Los Angeles-area water utilities to discuss opportunities for AquaCharge to inform their water reuse planning.
This project received multiple awards through the 2017 American Society of Civil Engineers Innovation Contest.
Additional references
- Project brief (2-pages) – AquaCharge: A design tool for balancing groundwater management trade-offs
- Journal article – Modeling and optimization of recycled water systems to augment urban groundwater recharge through underutilized stormwater spreading basins
- Journal article – System modeling, optimization, and analysis of recycled water and dynamic stormwater deliveries to spreading basins for urban groundwater recharge
- Journal article – Modeling cost, energy, and total organic carbon trade-offs for stormwater spreading basin systems receiving recycled water produced using membrane-based, ozone-based, and hybrid advanced treatment trains
- Press – New tool developed by Stanford engineers helps parched regions plan how to replenish aquifers
Treatment wetland technology diffusion
I led a student team to investigate the regulatory framework for unit process open wetlands, a low-cost, natural water treatment technology developed by ReNUWIt. Our team contributed sections to a white paper for technology diffusion workshop with researchers and industry professionals.
Shallow, open-water wetland cells at the Prado Wetlands in Orange County, California. Image credit: Scott Nygren
Additional reference
Briefing book – Technology Diffusion Workshop on Open Unit Process Wetlands
SOIL & GROUNDWATER CONTAMINATION
Environmental due diligence
I conducted environmental site assessments and regulatory compliance reviews at over 70 industrial, manufacturing, and commercial facilities as part of due diligence reviews in order to assess the potential for significant environmental liabilities. Facilities included chemical, automotive, electric utilities, pharmaceutical, metal fabrication, packaging, printing, construction material, and food service industries. Assessments included performing site visits, researching historical documents and environmental regulations, reviewing permits, and drafting reports.
Water quality data visualization
I developed ENVision, a free, interactive data visualization software to display water quality data form geographically distributed groundwater wells. This software can facilitate the identification of spatial trends.
Additional reference
Conference paper – ENVision: Visualizing water quality from geographically distributed wells.
Sample result from ENVision. Data visualization facilitates the identification of groundwater quality trends.
ENERGY & BUILDING SCIENCES
To evaluate the potential impact of various weatherization assistance strategies, I designed and implemented a method for evaluating how the effectiveness of home weatherization treatments varies geographically. These methods allow program managers to compare the trade-offs of different strategies with respect to reducing energy bills, energy consumption, and greenhouse gas emissions.
Additional references
- Journal article – Comparing the effectiveness of weatherization treatments for low-income, American, urban housing stocks in different climates
- Journal article – Greenhouse gas mitigation benefits and cost-effectiveness of weatherization treatments for low-income, American, urban housing stocks
Spray foam insulation is a common method to increase building energy-efficiency.
GLOBAL CLIMATE CHANGE & CIVIL CONFLICT
Working with a student team, I developed a decision-support method to quantify populations’ vulnerability and resilience to climate change as a potential predictor of civil unrest. This method applies concepts of weak signal analysis to identify trends from large datasets of environmental, social, economic, and political indicators. A company has adopted this tool and won over $1.2 million in research grants from the US Department of Defense for commercialization.
Conceptual framework. A population’s security (i.e., the strength to maintain stability) counterbalances the population’s risk of falling into a crisis cyclone trap of migration, poverty, environmental degradation, and conflict.
