Current Search: Gurr, Eric (x)
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- Title
- PILOT STUDY OF NUTRIENT LOADING IN A WET DETENTION LAKE.
- Creator
-
Gurr, Eric, Nnadi, Fidelia, University of Central Florida
- Abstract / Description
-
Florida is surrounded by water, and its many internal lakes and rivers have long been recognized for their excellent fishing and boating. This notoriety draws land developers to the lake shores to establish residential and commercial infrastructure. This land development brings with it flood plain alteration, water level stabilization, and increased nutrients which cause adverse impacts to our lakes. In response, the United States Environmental Protection Agency (EPA) passed the Federal Clean...
Show moreFlorida is surrounded by water, and its many internal lakes and rivers have long been recognized for their excellent fishing and boating. This notoriety draws land developers to the lake shores to establish residential and commercial infrastructure. This land development brings with it flood plain alteration, water level stabilization, and increased nutrients which cause adverse impacts to our lakes. In response, the United States Environmental Protection Agency (EPA) passed the Federal Clean Water Act (CWA) in 1972 which set the framework for the water quality standards for the entire United States. As a result of the CWA many point sources were eliminated, but in the process it became apparent that nonpoint source loads represented even more of a threat. To further study the physical and chemical characteristics of urban runoff the Nationwide Urban Runoff Program (NURP) was established in 1978. This research lead to a series of management options, named Best Management Practices (BMPs) which proposed various structural and non-structural methods to reduce nutrient loads. But the research and data collection on the effectiveness of these systems to remove nutrients is in its infancy. The main objective of this study was to generate accurate and effective water quality and water quantity data that future stormwater management decisions can be based upon. More specific, this study established automatic monitoring sites throughout the City of Kissimmee, Florida to determine the pollutant loadings into the tributaries of Lake Tohopekaliga. These monitoring sites are located such that inflows from outside the city limits can be isolated and external pollutant loads quantified. Also, additional internal monitoring sites were established to determine the pollutant loads of internal sections of the city. Data from these internal monitoring sites will also be used to determine the variable pollutant removal efficiencies and hydraulic fluctuations of natural, irregular riverine systems. The secondary objective of this study was to perform a pilot study using the discrete grab samples in tandem with the continuous hydraulic and hydrologic data from the monitoring stations. An existing lake within the project limits was chosen for the pilot study area. Monitoring stations are located at the influent and effluent sections of the lake which provided data on the hydraulic and hydrologic parameters. The pilot study determined the nutrient loads to and from the lake and checked for any seasonal variations in pollutant loading or removal efficiencies. For the purpose of this pilot study, only total nitrogen and total phosphorous were examined for two monitoring sites. The nutrient removal efficiency was performed using both the event mean concentration method and the summation of loads method to check for seasonal variation. There were no storm event concentrations available for used in this analysis, however, there were 25 discrete grab samples collected on a bi-monthly basis over a twelve month period. This data was used with corresponding five-minute rainfall and flow data from both the inflow and outflow points. The results of this study did not reveal any seasonal variation in the nutrient concentrations either flowing into or out from the lake. Although there were some relatively lower values in late spring, the concentration levels of total nitrogen did not seem to vary significantly from its mean value of 0.90 mg/l throughout the year. The concentration levels of total phosphorus did range from 0.02 mg/l to 0.48 mg/l, but not in relation to either season or flow volume fluctuations. The lake showed no net removals of total nitrogen and was actually found to be releasing total phosphorus to the downstream receiving waters. The findings of this study are limited due to the fact that the period of pilot study was only for twelve months and there were no rainfall events used in the analysis. Rainfall events are typically high sources of nutrient loads to a lake. The lower efficiencies were probably due to missing the actual higher nutrient load concentrations during the rainfall event. However, even considering the lack of event data, the nutrient removal efficiency for the pond was still low. This analysis did serve well as a basis for performing future analysis once additional data, including rainfall events, has been collected.
Show less - Date Issued
- 2007
- Identifier
- CFE0001912, ucf:47474
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001912
- Title
- INNOVATIVE POLLUTANT LOAD MONITORING.
- Creator
-
Gurr, Eric, Nnadi, Fidelia, University of Central Florida
- Abstract / Description
-
Modern streamflow measuring equipment, water quality sampling techniques and a better understanding of pollutant washoff are continuously being developed as today's society is in critical need of improving water management, minimizing developmental impacts and preventing environmental hazards. In particular, the study of the spatial, temporal and volumetric characteristics of annual pollutant loading caused by variations in precipitation, land use and other anthropogenic factors is of great...
Show moreModern streamflow measuring equipment, water quality sampling techniques and a better understanding of pollutant washoff are continuously being developed as today's society is in critical need of improving water management, minimizing developmental impacts and preventing environmental hazards. In particular, the study of the spatial, temporal and volumetric characteristics of annual pollutant loading caused by variations in precipitation, land use and other anthropogenic factors is of great significance due to their relation to future global water demands. The research presented here falls in three parts. In the first part of the dissertation, an acoustical doppler velocity profiler installed in a submerged concrete channel is proposed to continually measure the annual fluctuation in streamflow levels down to dry channel conditions. The tailwater influenced, intermittent streamflow conditions for the City of Kissimmee, Florida were selected for the evaluation of this approach under a 3-year study from 2006 to 2008. The performance of these concrete channels were systematically evaluated by comparisons with established field measurement techniques over various stream configurations and flow conditions. The second part of this research investigates the dynamics of flood wave detection with respect to enabling an automatic water quality sampler to start collecting samples. The main focus was on the accurate detection of flood waves in the absence of rainfall and the presence of fluctuating baseflows and stream stages. In the 3-year study, it was shown that a dual parameter trigger, utilizing independent measuring equipment, resulted in accurate flood wave detection with minimal false triggering of the autosampler. In addition, an incremental or percent deviation from a moving average of stage or flow proved to be a more consistent indicator for the presence of a flood wave. In the third part of this work, the frequency of water quality sampling and the associated level of detail for sampling of rainfall events were investigated with respect to accurately depicting annual pollutant loads. It was found that the seasonal variations in baseflow pollutant loads are not accurately represented by current 4-quarter grab sampling. Also, significant pollutant loading within rainfall events may not be captured by only performing grab sampling during baseflow conditions. In addition, although increased pollutant concentrations were observed within the initial 30 minutes of the flood wave, their actual loadings did not represent a significant impact on the annual pollutant loads. A bi-weekly grab sampling frequency was found to be adequate in many cases to depict the annual pollutant loads, but depending upon the targeted constituent and particular streamflow condition, rainfall event sampling might also be necessary. The results of this research complemented with other studies will promote better understanding of intermittent streamflows, accurate flood wave detection, and assessment of annual pollutant loads to our nation's waterbodies.
Show less - Date Issued
- 2011
- Identifier
- CFE0004002, ucf:49159
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004002