By Barbara Anne Pressman
This summer, the Columbia Water Center Aquanaut interns addressed a variety of water-related questions affecting the United States, with funding and guidance provided by Veolia Foundation, Veolia Water and members of Growing Blue. Nelson Dove, Christine Wen, Mary Williams, Christopher Economides and Daniel Shi were selected to expand the repertoire of data-driven tools the Columbia Water Center is developing which are making an impact on the water crisis experienced both here and around the world.
Dove is working on his second year toward a master of science in earth resources engineering (M.S. expected: 2014). After graduating from The Citadel with a bachelor of science degree in civil engineering and serving four years in the Marines, he became interested in the global water crisis and wanted to use his engineering degree to solve problems. In his “Study of Public and Private Utility Water Rates,” he asks what variables are the most influential to rate-setting for public and private utilities, how are the two types of utilities responding to different climate conditions, and is there a way to predict rates?
Using data over the last decade from public utilities (from the American Water Works Association) and private utilities (from the National Association of Water Companies), Dove used financial and operational metrics along with climate and demographic data to search for patterns in the way the utility companies set rates. While both public and private water utilities have increased their rates at about the same pace, private utilities have had higher rates throughout. When companies’ long-term debt was normalized over their total water sold, private utilities appeared to be reducing their amounts of debt, with only three of the 56 companies increasing their debt over the time span, while nearly all public utilities increased their debt. He found that there were multiple instances of private utilities expanding their reach by purchasing other utilities, which would have an impact on debt levels.
For both public and private utilities, the size of the company and primary source of water showed to be two of the most influential drivers on water rates. He also observed that companies experience what has been termed a “drought hangover,” whereby water usage remains low for years following a drought, thereby affecting utilities’ cost recovery. In future research, Dove plans to determine whether a Bayesian model of different econometrics and climate information can accurately predict water rates for both public and private utilities.
Dove is in his second year as a board member of the Columbia University Aquanauts. For students who want to do research in water issues, he recommends getting involved in clubs like the Aquanauts. He stresses the importance of knowing how to use programs such as Microsoft’s Excel, R (an open-source programming language for statistical computing), and ESRI’s ArcGIS. He said this paid internship made it possible for him to remain in New York City during the summer months and continue to do impactful water research.
Wen, a graduate student working on her masters in urban planning (M.S. expected: 2015), and Williams, a freshman working on her bachelor’s degree in earth and environmental engineering (B.S. expected: 2015), worked together on their project, “Assessing Long-term and Seasonal Climate Change Impact on U.S. Groundwater Systems.” First, they looked into what trends they could identify for shallow and deep wells on a continent-wide basis. Then they conducted a case study to see if there was consistent behavior for different wells within one aquifer over a given time period. Finally, they took one typical year and looked at seasonal factors affecting groundwater levels. Using the Mann-Kendall time series trend test, they were able to determine that the response time lag for shallow and deep wells to respond to precipitation most likely takes less than one year for shallow wells and between one to two years for deep wells.
Wen, who is from Canada, learned of the Aquanauts summer internship after emailing the Columbia Water Center to inquire about research opportunities. She finds the internship is a good way to combine her physics skills with doing meaningful work. She suggests students who want to do work on water problems should hone their computer programming and mapping (GIS) skills, and take liberal arts classes to broaden their thinking.
Williams comes from Napa, Calif., and is interested in water resources, and how society deals with water as a resource and a hazard. She feels that the fact the internship is a paid position adds a level of responsibility and rigor to the internship. Her suggestions to prospective water researchers are to pursue skills in climate systems science, spatial mapping, Matlab (a programming language) and Excel.
Shi is working on his bachelor of science degree in economics, (B.S. expected: 2015), and this is the second year he has been an Aquanaut summer intern. He continued his work to understand the relationship between climate and drought indices. This summer his work focused on trying to understand if there was any relationship between large-scale climate indicators and Normalized Deficit Indexes — a measure of the impact of dry periods — for different areas in the United States. “If there is a relationship, we want to know what would be the best suite of predictors for forecasting such drought/water stress at a specific regional scale,” Shi said.
Shi conducted Spearman, Kendall, and Pearson statistical analyses between the climate data and Normalized Deficit Index data to look for such possible relationships. He also used a principal component analysis to help investigate this relationship. For now, the focus was on Missouri. Preliminary research is showing that certain climate indicators are better at predicting water stress than others, and he plans to continue testing which predictors are best for different regions and then run the analysis for the entire country before announcing his findings.
Although Shi is majoring in economics, he came to the Columbia Water Center in 2012 with a developed interest in climate research from his father, who works in the field. Last year he was the principle author of a published white paper, “America’s Water Risk: Water Stress and Climate Variability,” and was amazed that Upmanu Lall, the director of the Columbia Water Center, would let him “run with it” the way he did. He said Naresh Devineni, a former associate research scientist at the Columbia Water Center, gave him a lot of help in the beginning, but once he saw Shi could do the analysis, he was allowed to perform most of the data modeling on his own.
Shi suggests Aquanauts who want to do research should not be afraid to ask for help. “The teamwork at the Water Center is really helpful; and make use of the weekly research meetings,” Shi said. For future student researchers, he recommends becoming proficient in Matlab and getting familiar with data collection and organization.
Economides, a graduate student in the masters of science in sustainability management program (M.S. expected: 2014), dedicated his summer to the project “Green Infrastructure: A Closer Look at Stormwater Management, Low Impact Development and Best Management Practices.” Economides prefers the American Rivers Organization definition of green infrastructure: “an approach to water management that protects, restores or mimics the natural water cycle. Green infrastructure is effective, economical and enhances community safety and quality of life.”
The primary purpose of green infrastructure is to reduce the negative effects of stormwater runoff, which can overwhelm systems designed to carry both sewage and stormwater runoff, causing polluted overflows. His research of the 10 most populous cities in the United States shows that New York City has the most robust green infrastructure plan.
By planting trees and addressing non-point source controls such as blue roofs, green roofs, bioswales, bioretention, porous pavement, subsurface detention and implementing “Bluebelt” systems, New York City hopes to reduce the combined sewage overflow volume by an additional 3.8 billion gallons per year. By investing in green and blue infrastructure systems, the city already has saved billions of dollars over traditional “gray” water treatment facilities. Other cities included in Economides’s study were Philadelphia, Chicago, Phoenix, Los Angeles, San Diego, Washington, D.C., Dallas, San Jose, San Antonio and Houston.
Economides emphasizes the importance of doing the “valuable work” of coming up with sustainable solutions. He feels that the paid internship heightens the employee/client relationship so that both parties take it more seriously. He recommends students pay attention to the news and understand the connections between conservation, urban ecology and green infrastructure.
All-in-all, the Columbia University 2013 Aquanauts summer internship made a big difference in the lives of each of the interns. Paid internships are few and far between but are critical to make it possible for the best students to apply their education and unique perspectives. Organizations with forethought like Veolia Water, Veolia Foundation, and the members of Growing Blue gave these students the chance to make an impact in the water research community. The Aquanauts, individually and collectively, have been able to contribute to the body of knowledge and tool box of solutions to tackle what we all know is one of the most limiting factors to a sustainable future: protection of our water resources.
Barbara Anne Pressman is a communications intern with the Columbia Water Center.
