Browsing by Author "Goemans, Christopher G., committee member"

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Open Access
An advanced decentralized wastewater management planning study and demonstration project for the CSU Foothills Campus
(Colorado State University. Libraries, 2010) Gallagher, Neal Thomas, author; Sharvelle, Sybil, advisor; Roesner, Larry A., committee member; Goemans, Christopher G., committee member
Expansion of development on the Colorado State University's (CSU) Foothills Campus has required examination of alternative methods to manage wastewater produced within the campus. This work builds off previous work which demonstrated that reuse of graywater and treated blackwater effluent could greatly reduce the cost of supplying wastewater treatment for the Foothills Campus (Criswell & Roesner 2005). The objective of this work was to provide insight into innovative decentralized wastewater technologies and management techniques to lay the groundwork for planning and design of optimal decentralized wastewater treatment architecture for the Colorado State University Foothills Campus. This objective was met through a planning study and a demonstration project examining anaerobic digestion of blackwater. A planning study was performed providing four potential scenarios for management of wastewater on the Foothills Campus. Source separation was recommended for proposed development, however combined plumbing in existing development was left unaltered. Four different wastewater streams were identified by type and level of treatment necessary: blackwater, graywater, laboratory process water, and laboratory sink water. Anaerobic digestion was recommended for primary treatment of blackwater because of the renewable energy (methane biogas) and nutrient rich effluent which are produced. Constructed wetland treatment was recommended for graywater and laboratory process water, to provide a source of reusable water for irrigation or toilet flushing. Technical feasibility of treatment of graywater from a campus setting in a constructed wetland has been previously examined, showing substantial levels of treatment. Technical feasibility of anaerobic digestion of blackwater from a campus setting is further examined in this study through a 108 L upflow anaerobic sludge blanket (UASB) treating raw blackwater from a building on the Foothills Campus. Reactor operational OLR varied between 0.21-0.39 kg COD/m3•d and HRT varied between 2.6-4.0 days during the study period. Total reactor operational time was 108 days at an effluent temperature of 28°C. Substantial removal of COD (72%), TSS & VSS (95%), and indicator organisms (1.4 log E. coli & 1.1 log fecal coliforms) was achieved over the study period. Effluent containing 79 mg/L dissolved ammonia nitrogen showed potential for use as fertilizer. Methane biogas produced during digestion (137 L CH4/kg CODinput) provided potential as a source of renewable energy. Overall performance of the UASB was sufficient for pretreatment of Foothills Campus blackwater. However, further examination of effluent, solids, and biogas reuse potential is necessary to determine supplementary treatment requirements and desired applications for extracted resources.
Embargo
Analysis of municipal water use in urban regions across the contiguous United States
(Colorado State University. Libraries, 2024) Dezfooli, Donya, author; Arabi, Mazdak, advisor; Sharvelle, Sybil, committee member; Carter, Ellison, committee member; Goemans, Christopher G., committee member
Urban water use in the United States faces increasing social and environmental pressures. Challenges such as population growth, urbanization, extreme weather events, and climate change threaten the balance between water supply and demand, jeopardizing access to safe and reliable drinking water for city dwellers. Additionally, the traditional linear "take-make-waste" approach, once common in addressing water-related issues, has proven unsustainable due to its reliance on finite energy and resources. Therefore, it is imperative to shift from this linear model to a more integrated and sustainable approach, known as "One Water". This shift requires a comprehensive understanding of the mechanisms enabling transitions to sustainable and resilient urban water systems, as well as the development of models and methodologies to guide the transition toward net-zero water communities. To achieve this, the dissertation first aims to deepen the understanding of factors influencing transitions towards sustainable urban water management. This is based on a series of expert interviews conducted with different utilities across North America. The qualitative data analysis provides valuable insights into the complex context of urban water management. The results revealed that achieving social and environmental justice is a prominent driver for utilities to initiate their transition, followed by concerns about climate change, water quality impairments, groundwater depletion, and population growth. Further investigations identified several barriers to the One Water transition. These barriers are not merely financial and technical but also stem from a lack of regulatory frameworks, insufficient community support, and institutional obstacles. Therefore, institutional and regulatory solutions are needed more than technological innovations to support this paradigm shift. Our findings also emphasized the importance of cultural change and the necessity of fostering a One Water mindset among stakeholders at all levels. Additionally, feedback from the participants contributed to a more comprehensive and inclusive definition of One Water. Second, a municipal water demand model was developed using the Integrated Urban Water Model (IUWM) to understand urban water use patterns and influencing factors across urban areas within the Contiguous United States (CONUS). Municipal water use data from 99 cities across the U.S. from 2005 to 2017 was used to calibrate and regionalize model parameters for urban regions across the CONUS. The results identified key factors influencing the regionalization of water model parameters, including "July vapor pressure deficit," "number of employees in other services (except public administration)," and "July precipitation." The study reveals that predictive water use and related uncertainty vary across ecohydrological regions within the CONUS. This variation is significantly influenced by climatic and socio-economic factors, with arid and southern cities showing the highest uncertainty. While densely populated areas exhibit more predictable patterns, small cities demonstrate the highest level of uncertainty in water use projections, primarily due to a higher share of single-family homes and increased outdoor water consumption compared to larger cities. Third, the developed IUWM model was used to estimate municipal water demand across urban areas within the CONUS for the period of 2035-2065 under different future climate and land use scenarios. The results indicated that population growth and land use change are primary drivers of urban water demand. While there are minor annual fluctuations reflecting the effects of different climate scenarios, the hot climate model presents the worst-case scenario, with the lowest reduction in water use intensity and the highest increase in water demand. In this scenario, the average water use demand is projected to increase by 52%, while the average water use intensity (ML/sq.km) will fall by 10%. The projected changes in water use are highly variable across the CONUS, with significant increases expected in urban areas located in the West and Northwest (e.g., Washington and California), Southwest (e.g., Arizona, Utah, Colorado, and New Mexico), Midwest (e.g., Michigan and Wisconsin), and Great Lakes region (e.g., New York and Pennsylvania). Our findings suggest that projections of future municipal water demand are surrounded by considerable uncertainties, particularly in cities located in arid and tropical regions. Furthermore, the results show that while increased urban density typically reduces water use intensity in most areas, increases are expected in parts of the Midwest, Northeast, and West. These trends suggest that once cities reach certain development thresholds (around 50% developed area), densification may no longer effectively reduce municipal water demand, leading to increased indoor and CII (commercial, industrial, and institutional) water consumption, thereby undermining the expected benefits. This highlights the need for effective mitigation strategies, such as demand management and the use of alternative water sources, alongside higher-density development policies to ensure sustainable urban water management in the future. Overall, this dissertation provides a comprehensive understanding of urban water demand in the United States, aiming to achieve sustainable urban water management. The insights gained from this study highlight the importance of integrating land use and water management and fostering collaboration among all stakeholders to achieve the One Water paradigm shift. The results will benefit urban planners and water managers, helping them develop effective strategies to mitigate adverse effects and ensure sustainable water resources for the future.
Open Access
Exploring humans' reactions to degraded natural environments through photographic stimuli
(Colorado State University. Libraries, 2021) Dao, Truc Anh, author; Steger, Michael F., advisor; Dik, Bryan J., committee member; Aloise-Young, Patricia A., committee member; Goemans, Christopher G., committee member
The discrepancy between the imminent threat of climate change and the public lack of meaningful response to that threat has been a puzzling phenomenon. One of the approaches proposed to answer the question about human behaviors regarding climate change is Terror Management Theory (TMT). TMT posits that human share a universal fear of death, such that once exposed, people will engage in some defense mechanisms to ward off those fears. One of those mechanisms involves reassuring oneself of possible symbolic or literal immortality by adhering to shared beliefs within a group, or cultural worldviews. Natural environments can be a source of existential threat to humans as they are inherently associated with both life and death. Therefore, confrontation with nature can provoke anxiety about death, which in turn motivates people to distance themselves from nature. This current project explored the effects of viewing images of different types of environments on people's thoughts of death and worldview defense behavior through four experimental studies. In the first and fourth study, participants viewed and wrote about one of three sets of seven randomly assigned images of the environment (i.e., intact nature, degraded nature, nature with visible human constructions). Participants' thoughts about mortality were assessed via a word completion task. In the second and third study, participants also viewed and wrote about seven images according to their conditions. Next, participants were told that they were going to read two brief essays written by foreign students about the United States. Half of the participants read a pro-American essay and the other half read an anti-American one. In prior studies, participants' reactions to the author of the essay were indicative of whether or not they engage in worldview defense. While data from the first study provided support for degraded nature increasing thoughts of death, the three subsequent studies presented mixed results. Future research on existential anxieties and their effects on people's response to threats might help further explore humans' climate change responses.
Open Access
Household's willingness-to-pay estimation for safe drinking water: a case study in Vietnam
(Colorado State University. Libraries, 2013) Khuc, Quy Van, author; Loomis, John B., advisor; Kling, Robbert, committee member; Goemans, Christopher G., committee member
This thesis explores consumer behavior of households for drinking water by surveying and analyzing 235 households (HHs) in Hanoi and Hai Duong in the North of Vietnam, and Ho Chi Minh in South of Vietnam. Two classical methods have been employed, Contingent valuation method (CVM) and averting behavior method (ABM). Binary logit regression can help to identify internal and external factors influencing the decision of whether or not to pay for clean drinking water. In addition, the linear regression method allows to explore and to quantify the magnitude of relationship between the dependent variable and independent variables. Generally, about half of the households surveyed are willing to pay for better drinking water. Most of them are HHs living in two major cities, Hanoi and Ho Chi Minh City. On average for all of the sampled households, the value of willingness-to-pay makes up small percentage of household income, just 0.247% of total household income. The decision to pay for water depends on both internal factors: the level of education and awareness, as well as external factors: living conditions and existing water source. For those households that are willing to pay to get clean water services, income, and current status of water resources are strong variables. In addition, those households that are actively looking for information and learning related to water often pay a fee for water use. Different measures are practiced by HH's to prevent diseases caused by possible polluted drinking water. Of the five averting activities, boiling water is HHs' priority in rural areas due to low cost while buying bottled water is HH's choice in the city because of the convenience. Young people tend to use bottled water more than old people. Using a water filter increases amount of money they would be willing to pay for clean water, while income and habitat of using drinking water are also strong factors in determining willingness to pay a higher monthly water bill. This survey has compared two values: the value of WTP and the cost of averting expenditure (CAE). My results showed that WTP is not always greater than CAE. Empirical results have policy implications on drinking water price strategies and drinking water related projects investment in Vietnam. Policy-makers or planners should consider income, gender, level of education, existing water sources, lifestyles, and locale when making drinking water price strategies and water related investment.
Open Access
Social networks for collaborative water management: a methodological approach to addressing wicked environmental problems
(Colorado State University. Libraries, 2017) Anson, Alison A., author; Cross, Jennifer E., advisor; Goemans, Christopher G., committee member; Taylor, Peter L., committee member
Lake pollution caused by human activity on nearby land is currently seen as one of the most pressing issues facing fresh bodies of water worldwide and particularly in the Midwestern United States. In Menomonie, a small lake-shore town in Wisconsin, lake pollution from phosphorus eutrophication has become an unhealthy nuisance for the residents that reside there. Eutrophication is the build-up of algae in waterways when there are too many nutrients, such as phosphorus, concentrated in the water. Attempts have been made by government officials, practitioners, researchers, and community members to clean up the lake or tackle the root of its cause with limited success. This research argues that this "wicked" pollution problem, while environmental and scientific in nature, cannot be resolved without a much more thorough analysis of the social aspects involved in decision-making and collaborative knowledge acquisition. I conducted a mixed methods study using interviews, digital surveys, and Social Network Analysis (SNA) of the community in question to reveal how network structure, network interactions, and actor characteristics play a role in this community's collaborative effort to address lake pollution. The following research shows that SNA, alongside qualitative field study, can reveal significant findings about the network and the environmental problem.
Open Access
The economic value of whitewater sports in the Cache la Poudre Canyon, Colorado
(Colorado State University. Libraries, 2011) McTernan, James A., author; Loomis, John B., advisor; Goemans, Christopher G., committee member; Shields, Martin, committee member
This thesis estimates the non-market benefits associated with non-commercial Whitewater Sports in the Poudre Canyon of the Cache la Poudre River. We used a Contingent Valuation Model (CVM) and a Travel Cost Model (TCM) to estimate benefits to all non-commercial users at two different river locations. Using CVM, we found the consumer surplus estimates to be between $55.36 and $93.36 per trip, depending on the model specification. This equates to a per season consumer surplus of between $596,283 and $1,005,581 for a 30 day season and between $1,192,620 and $1,917,894 for a 60 day season. For the TCM, consumer surplus was estimated at either $88.01 or $129.41 depending on the specification. This equates to ranges of per season consumer surplus of $947,956 and $1,393,875 respectively for a 30 day season and $1,895,999 and $2,787,880 respectively for a 60 day season.
Open Access
Three essays on energy inputs, technology, and conservation policy in irrigated agricultural production
(Colorado State University. Libraries, 2019) Hrozencik, R., author; Suter, Jordan F., advisor; Manning, Dale T., advisor; Goemans, Christopher G., committee member; Bailey, Ryan T., committee member
This dissertation explores the role of energy inputs, irrigation technology, and conservation policy in irrigated agricultural production. In the first chapter, I utilize empirical and simulation modeling to understand the impact of non-linear energy pricing on groundwater use decisions in the Republican River Basin of Colorado. The second chapter empirically investigates how peer effects and resource availability influence a producer's choice to adopt a resource-conserving irrigation technology using data from the Trifa Plain of Morocco. The third chapter develops a hydroeconomic model which pairs groundwater demand with a physical model of resource dynamics to quantify how a groundwater conservation policy implemented within a subsection of the Republican River Basin of Colorado creates resource and input market spillovers.
Open Access
Three essays on the use of spatial data to inform environmental and resource management
(Colorado State University. Libraries, 2022) Sheng, Di, author; Suter, Jordan F., advisor; Manning, Dale T., committee member; Goemans, Christopher G., committee member; Bailey, Ryan T., committee member
This dissertation consists of three essays that use of spatial data to inform trade-offs related to environmental and resource management. The first essay explores how a spatially targeted differentiated payment design can reduce the social cost of achieving a given level of ecosystem service (ES) provisions. Performance comparisons between uniform payments and differentiated payments for ecosystem services help to identify the context under which differentiated payments offer the largest advantage relative to a uniform payment. A mathematical programming model is developed to explore the performance of different payment schemes and to derive generalized lessons from simulations. Then generalized lessons are evaluated with two case studies related to water quality management. It is found that the simulations and case studies align with each other in terms of the total cost reductions, but they diverge in the payment rate choice due to the underlying distributional differences. The findings suggest that a higher payment rate for parcels that systematically provide higher levels of ES can reduce the social cost of providing the ES of interest, particularly for cases where the mean ES provision benefits across land types are different and ES provision targets are relatively low. In the second essay, I examine whether China's pilot carbon emission trading system (ETS) has the co-benefit of reducing local PM2.5 levels. Two ETS pilot provinces are selected to be the treated group, while the control group is constructed with institutional knowledge. Static and dynamic difference-in-differences designs are adopted and compared to reveal the ETS treatment effect. The spatial and temporal variation in the ETS pilot areas allows me to adopt a dynamic two-way fixed effects model to estimate heterogeneous treatment effects on the treated areas. I find that the ETS improves the local air quality in Hubei but not in Guangdong. A further analysis suggests that a sector-standards based allowance allocation mechanism can cause local air quality to deteriorate. The third essay revisits the groundwater resource value question in the Ogallala aquifer through estimation of an econometric model of agricultural land prices that includes fixed effects, with the repeated transactions from the ZTRAX data product. Saturated thickness is used to present the groundwater availability and the study includes irrigated parcels only. Heterogeneous responses in land values to groundwater stock changes are found across Colorado and Nebraska. The marginal value of groundwater stock is highest at low levels of groundwater availability, which implies that additional groundwater depletion in Colorado is more costly than depletion in Nebraska.
Open Access
Vulnerability of U.S. river basins to water shortage over the 21st century
(Colorado State University. Libraries, 2021) Heidari, Hadi, author; Arabi, Mazdak, advisor; Warziniack, Travis, committee member; Brown, Thomas C., committee member; Bailey, Ryan, committee member; Goemans, Christopher G., committee member
Future changes in climate and population across the United States may cause a decrease in freshwater availability and an increase in water demand. These trends may lead to more frequent water shortage conditions when water demand exceeds water supply. The enhanced characterizations of changes in both long‐term anomalies such as aridity and evaporative indices and short-term anomalies such as multi-year and interannual water shortage events in a changing environment are requisite to the appropriate management and planning of future water resources, and improved implementation of regional adaptation and mitigation strategies. The main goal of this dissertation is thus to assess shifts in hydroclimatic conditions and water shortage (IDF) relationships across the conterminous United States (CONUS) over the 21st century. To achieve this goal, first, the effects of climate change on the regional hydroclimatology of U.S. river basins were assessed over the 21st Century to determine regions with prolonged dry or wetting periods. This analysis shows that U.S. river basins within the CONUS can be clustered into seven groups with unique hydroclimatic behaviors in response to climate change that are highly associated with regional landform, climate, and ecosystems of river basins. The South United States is more likely to experience warmer and drier conditions meaning higher chances of aridification. Second, the impact of climate change on hydroclimatic conditions of U.S. national forests (NFs) and national grasslands (NGs) was investigated. The results of this study indicate that NFs and NGs are more likely to experience larger changes in hydroclimatic variables compared to the average of the United States. The findings help environmental scientists and forest managers to mitigate the negative consequences of climate change on forest and grassland resources. Third, shifts in hydroclimatology of U.S. megaregions in response to climate change were investigated. This analysis reveals that Houston may experience more arid climatic conditions with higher evaporative loss of freshwater resources in the future. These steps provide an improved understanding of the effects of climate change on the regional aridification or desertification across the CONUS. To accomplish the goal of the study, fourth, a probabilistic approach was developed to improve the characterization of both within-year and over-year socioeconomic droughts in a changing environment. The proposed approach provides a procedure to update sub-annual socioeconomic drought IDF relationships while taking into account changes in water supply and demand. Fifth, the developed probabilistic approach was applied to examine the effects of urban development patterns, i.e., sprawl versus high-density development, on the socioeconomic drought characteristics. The results of this study highlight that urban regions under the sprawl development pattern are likely to experience more frequent socioeconomic drought events with higher intensity and longer duration compared to the high-density development pattern. Finally, the developed approach was implemented across the CONUS to characterize vulnerability of U.S. river basins to water shortage from 1986-2015 to 2070-2099 periods. The results show that prolonged water shortage conditions in drier basins and interannual water shortage events in wetter basins are likely to be the main concerns in the future and should gain more attention in future water resource planning and management.