Browsing by Author "Loftis, Jim C., advisor"
Now showing 1 - 7 of 7
Results Per Page
Sort Options
Item Open Access Characterization and mass balance modeling of dissolved solids concentrations and loads in the South Platte River system, northeastern Colorado(Colorado State University. Libraries, 2011) Haby, Paul Andrew, author; Loftis, Jim C., advisor; Garcia, Luis A., committee member; Steele, Timothy D., committee member; Waskom, Reagan M., committee memberDriven by an increasing population in the South Platte River Basin, water which was historically used for agricultural purposes is being diverted to urban areas in order to satisfy increasing municipal and industrial demands. This trend is changing the timing, location, volume, and quality of return flows to the river. The quality of return flows is of particular concern in the lower reaches of the South Platte River Basin where salinization of irrigated soils has emerged as a concern. This study addresses the critical need for a comprehensive understanding of salinity status and provides the basis for understanding the processes involved in the origin, flux, and ultimate destination of salts throughout the basin. The first phase of this research utilized historical monitoring data in order to characterize dissolved solids status and trends within the basin. Specific objectives of this phase were: (1) the compilation and assessment of available historical streamflow and dissolved solids concentration data, (2) the estimation of daily dissolved solids loads at selected monitoring sites, (3) the characterization of spatial patterns in dissolved solids concentrations and loads, and (4) the determination of temporal trends in dissolved solids concentrations and loads. The second phase of this research provides a quantification of salt balance and prediction of future streamflow and dissolved solids concentrations resulting from proposed water resource projects. The salt balance of the mainstem of the South Platte River was evaluated through the development of a reach-based water and dissolved solids budget. Components of the budget included upstream inflow, tributary contributions, major point sources, diversions, and downstream outflow. Residuals of the mass balance were used to quantify unmeasured streamflow and salt contributions to the river, the majority of which occur via ground water inflows. In the final phase of this study, a dynamic streamflow and salt mass simulation model was developed to assess water-quality impacts of water development projects. Based on mass balance concepts, this model allows for the evaluation of changes in streamflow, dissolved-solids loads, and dissolved-solids concentrations along the middle and lower portions of the South Platte River resulting from single or multiple user-configurable upstream water diversion and reuse projects. Details of the model development and operation are presented along with results of simulations of several case studies. The results of these simulations highlight the utility of a dynamic streamflow and salt mass simulation model in the evaluation of future water-quality conditions and demonstrate the importance of combined evaluation of multiple proposed water development projects.Item Open Access Cooperative design of a water quality monitoring system for the Big Thompson River Watershed, Colorado(Colorado State University. Libraries, 1999) Greve, Adrienne I., author; Loftis, Jim C., advisor; Ward, Robert, committee member; Laituri, Melinda, committee memberWater from the Big Thompson River and the Colorado-Big Thompson Project (a trans-mountain diversion of Colorado River water to the Big Thompson River) is a valuable resource to the North Front Range region of Colorado. The water is utilized for many purposes (e.g. municipal, irrigation, industrial, recreation, and ecosystem health). Over half a million people depend on the Big Thompson system for drinking water. In recent years a slow decline in water quality has been observed at some locations, particularly in reservoirs lower in the watershed. This trend, coupled with increased pressure to provide accurate data about water quality, has lead a group of stakeholders in the Big Thompson Watershed to seek a better way in which to monitor and manage their water, through cooperation. Stakeholders within the Big Thompson Watershed, who make up a group called the Big Thompson Watershed Forum (BTWF), formed a partnership with Colorado State University to design a water quality monitoring network. The design process was broken down into five steps: objectives, variables, monitoring locations, sampling frequency, and cost analysis. Each step was completed in a cooperative manner, through a series of meetings with BTWF members. The meetings provided an opportunity for members of the BTWF to shape the monitoring system based upon concerns and priorities specific to the watershed. The resulting water quality network is governed by five objectives. The objectives address regulatory requirements within the watershed, eutrophication of reservoirs, and the estimation of loads, spatial trends, and temporal trends. A variable list of 38 water quality parameters was defined as the minimum group of variables that meet the informational goals laid out in the objectives. The list included 12 inorganic variables, nine metals, five organic parameters, seven microbiological variables, and five field parameters. Monitoring locations were defined based on the objective list, already existing monitoring sites, and watershed hydrology (e.g. mixing distance, confluence locations, diversions). Thirty-nine monitoring locations were chosen; 29 moving water sites and 10 reservoir sites. Each site was given a priority rating of high or low. The group of 31 high priority sites is the smallest network that satisfies the needs of all BTWF participants. The seven low priority monitoring locations will be sampled if financially feasible. Sampling frequency was determined on a seasonal basis. Three seasons were determined based on annual flow and water temperature cycles. It was originally hoped that historical data could be used to estimate background variability, allowing the sample size required for a specified level of accuracy in mean and trend detection to be determined. Only 11, of the 38 variables on the variable list, had historical data available, and only three, of the 11, had enough data to accurately estimate background variability. Sampling frequencies for variables with inadequate historical data were based a maximum frequency set for each season. During seasons one and two, no variable is to be sampled at a frequency higher than twice a month except for biological parameters. The maximum frequency during season three is monthly. The cost estimate step was utilized as a feasibility check on the monitoring program. The aim for the cooperative monitoring program was more thorough information for the same or less cost. If the monitoring program cost exceeded the sum of all current monitoring budgets, adjustments were made in variables, monitoring sites, and sampling frequency. The final cost estimate was $405,259.00 per year, roughly the same as the $401,500.00 currently spent. In order for an undertaking such as this design and monitoring program to succeed, all participants must be willing to compromise and devote large amounts of time in order to allow for a truly cooperative effort. Those individuals most active in the design process typically represented local entities. The resulting monitoring network therefore gave higher priority to local water quality concerns, highlighting the differences between local informational needs and those defined by state and federal governments. The monitoring system currently includes a set of objectives, variable list, monitoring network, and sample frequency. They have been developed, discussed, and agreed upon by all BTWF participants. The completion of the monitoring network indicates that the BTWF is on its way towards the final goal of a long-term monitoring program operated by, and benefiting all agencies involved.Item Open Access Design of a water quality information system for source water assessment: a Denver water case study, Denver, Colorado(Colorado State University. Libraries, 2002) Twenter, Justin C., author; Loftis, Jim C., advisor; Ward, Robert C., committee member; Smith, Freeman, committee memberThe questions water quality information systems are being called upon to answer are changing as the management of water quality shifts from a historically point source control framework to investigation of non point sources of pollution. A specific example is that of large Public Water Systems (PWS), providers of drinking water to the public within larger municipalities, who have managed the quality of the source water, from which they draw their supplies, primarily at the intake to the treatment system. In the case of contamination, the potential of finding a new source of supply is rare for large PWSs and thus new emphasis is placed on protection of current supplies to diminish the risk of contamination. This idea of moving farther up into the watershed for water quality management of drinking water supplies is presented by the U.S. Environmental Protection Agency (USEPA) in the Source Water Assessment and Protection (SWAP) program. This thesis proposes a process by which a large PWS can incorporate existing knowledge concerning water quality monitoring into a practical application for production of usable, defensible information used in the management of water quality. The source water quality monitoring system for Denver Water, a large PWS serving the City and County of Denver, Colorado and surrounding areas, is reviewed within this work. The review is presented as an updated water quality monitoring design for Denver Water’s entire source area. The emphasis of the design is placed on the need to connect the information needs of management, in this case Denver Water, with the feasible products of water quality monitoring. Analysis was conducted to determine reasonable sampling frequencies for estimation of mean concentrations, trends, and pollutant loads for physical and chemical water quality parameters identified. Additionally, 48 sampling sites were selected for the source area of approximately 2.5 million acres. In the end, Denver Water is presented a functional monitoring system which enables information production to meet needs for management of the vast area from where they draw drinking water.Item Open Access Information goals for a regional ground water quality monitoring system for the San Luis Valley(Colorado State University. Libraries, 1994) Bagenstos, Dennis J., author; Ward, Robert C., advisor; Loftis, Jim C., advisor; Durnford, Deanna S., committee member; Smith, Freeman, committee memberThe residents of the San Luis Valley of Colorado are dependent on ground water resources for agriculture, the economic base of the region, as well as most of their drinking water. The quality of this water, as a result of its extensive use, has become a concern in recent years. This concern has been expressed not only by local residents, but also the general public, as demonstrated by the numerous state and federal laws that address ground water quality issues. This concern tends to be addressed in a rather piecemeal fashion, particularly with regard to efforts to measure water quality in the San Luis Valley. Each concern and law appears to require its own separate monitoring program. Can the information needs generated by both local concerns and legal mandates be integrated into a more coherent set of information goals that would guide a unified monitoring program? What information would such a program need to produce? The purpose of this research was to develop a set of water quality "Integrated Information Goals" defined as the integration of those information needs extrapolated from the laws, regulations, and groups involved in water quality management in the Valley. In order to develop these information goals, the following tasks were defined: 1) Examine, through the review and identification of federal, state and local laws, regulations, implementing agencies, and concerned groups, the current structure of nonpoint source pollution management with respect to ground water quality in the San Luis Valley. 2) Based on the review in (1) above, define information goals for a monitoring design for the San Luis Valley. 3) Specify the Integrated Information Goals needed to support ground water quality management in the San Luis Valley. Upon completion of these tasks, five information goals were defined: 1. Baseline water quality of the shallow unconfined and the deep confined aquifers, 2. Source impacts to correlate water quality problems with land use practices, 3. Water table levels, 4. Water quality trend detection, 5. BMP analysis. Options for implementation of a monitoring system were also presented.Item Open Access Performance modeling of stormwater best management practices with uncertainty analysis(Colorado State University. Libraries, 2009) Park, Daeryong, author; Roesner, Larry A., advisor; Loftis, Jim C., advisorBest management practices (BMPs) contain many uncertainties that make it difficult to determine their performance with a model. Moreover, predicting BMP performance with existing methods is not easy. The major research objective of this dissertation is to incorporate uncertainty analysis in a BMP performance model to better represent its treatment performance. The k-C* model is used in this study to simulate BMP performance, and the study assumes that the influent event mean concentration (Cin) and aerial removal constant (k) include uncertainty. Both Cin and k represent data and model uncertainty. To evaluate the model, three different uncertainty cases, uncertainty in Cin, k, and both Cin and k, are applied to the total suspended solid (TSS) data of detention basins and retention ponds. To evaluate uncertainty values, three different uncertainty analysis methods, the derived distribution method (DDM), the first-order second-moment method (FOSM), and the latin hypercube sampling (LHS), are applied to each case. TSS, as a representative pollutant, and detention basins and retention ponds, as representative BMPs, are utilized in this study. The observed datasets are selected from the International Stormwater BMP database. By incorporating uncertainty analysis into the k-C* model, the effect of BMP surface area and inflow on the effluent event mean concentration (Cout) of TSS can be quantified for detention basins and retention ponds. These effects are not large in detention basins but are noticeable in retention ponds. In addition, the k-C* model with uncertainty analysis is applied to a hypothetical watershed to show how uncertainty might be used improve the probability of compliance with TMDLs.Item Open Access Water-quality data analysis protocol development(Colorado State University. Libraries, 1990) Harcum, Jonathan Brooks, author; Loftis, Jim C., advisor; Ward, Robert C., advisor; Hirsch, Robert M., committee member; Salas, Jose, committee memberSeveral agencies have developed networks to routinely monitor water quantity and quality in an attempt to assess society's influence on the environment, including the impacts of modern agriculture. Data from these networks are often plagued with attributes that inhibit analysis and interpretation. As more and more emphasis and public pressure is placed upon demonstrating environmental results, it is increasingly necessary that a consistent protocol for analyzing data from water quality monitoring networks be developed. Common data record attributes which inhibit data analysis include distribution applicability, variance heterogeneity, seasonality, serial correlation, extreme events, censoring, erroneous observations, small sample size, missing values, different sampling frequencies, multiple observations and measurement uncertainty. Each data record attribute is described in this study. In establishing a protocol to analyze water quality data, the handling of censored data and detection of trends in the presence of serial correlation and missing data are particularly difficult to quantify. This study focuses on these issues of protocol development. Seventeen procedures are evaluated for estimating the mean, median, standard deviation and interquartile range from data sets with singly and multiply censored observations. The results from this evaluation support previous investigations. In addition, the "no censoring” rule was found superior to methods which used censored observations for estimation of the mean, median and standard deviation. This study also compared the use of the Mann-Kendall tau test (and variations) for evaluating monotonic trends in water quality data. The Seasonal Kendall (Mann-Kendall) tau test should be used for data records with no serial correlation and five or less (ten or more) years of record. An ideal test for short data records which have serial correlation was not found in this study. The Seasonal Kendall tau test with serial correlation correction should be used for data sets of at least ten years of record and serial correlation. Furthermore, if monthly data sets have on the order of 40 to 50 percent missing values, monthly data should be collapsed to quarterly data by computing seasonal means or medians.Item Open Access Watershed-based methodology for assessment of nonpoint source pollution from inactive mines(Colorado State University. Libraries, 1995) Caruso, Brian S., author; Loftis, Jim C., advisor; Ward, Robert C., committee member; Ramirez, Jorge, committee member; Walters, Richard W., committee memberA watershed-based methodology for the screening-level assessment of nonpoint source pollution from inactive and abandoned metal mines (lAMs) was developed, tested, and evaluated in this study. The methodology is intended for use by state and federal agencies responsible for management of these sites, and was designed to generate the common types of baseline site characterization information required for targeting streams and contaminant source areas for remediation. These information goals have been defined as part of this study prior to developing the assessment methodology, and are based on generalized but clearly stated lAM management goals that are most common among agencies. The research involved the following; (1) Identifying typical water quality and hydrologic characteristics of and assessment methods for lAMs. (2) Defining lAM management goals and information goals for targeting. (3) Identifying and evaluating attributes of data derived from typical synoptic surveys of lAMs. (4) Identifying common data gaps and data collection and analysis methods to fill these gaps. (5) Identifying and evaluating applicable assessment and data analysis methods to achieve the stated information goals. (6) Developing, testing, and evaluating the assessment methodology. The Cement Creek Basin, part of the Upper Animas River Basin above Silverton in the San Juan Mountains of southwestern Colorado, was used as the primary case study to develop the recommended methodology. The study showed that the potential error and uncertainty in the data and derived information should be considered explicitly in the assessment process in order to target remediation with a known degree of confidence. Confidence intervals, therefore, should be computed for statistical estimators. Visual aids for data presentation and usage should be used and include graphs, mapping of information, and if possible, GIS. Targeting in Cement Creek and at other sites can be accomplished effectively using the recommended methodology. Some data gaps exist in Cement Creek and at most lAMs with regard to targeting remediation. These can be filled when the required information goals are not met with existing data and when resources are available using some of the methods discussed in this study. The recommended methodology is applicable to and would be very useful for other lAMs.