Copano Bay currently exceeds fecal coliform Texas Surface Water Quality Standards for oyster water use. Aransas and Mission River Tidals currently exceed enterococci water quality standards for contact recreation use. The fecal coliform Copano Bay Bacterial Loadings Model will be used to support the TCEQ Total Maximum Daily Load (TMDL) program to develop the TMDLs for the three impaired water segments. The objectives of this research are to identify the major bacterial sources in the Copano Bay watershed, to calculate the total bacterial loadings (i.e., the TMDLs) from these sources, and to estimate the load reductions needed to bring each of the impaired segments into compliance with water quality standards. The potential bacterial sources that were considered in the model were wastewater treatment plants (WWTPs), waterbirds, livestock, failing septic systems, and other non-point sources that originate from different types of land uses (e.g., urban, forest, etc.). This thesis presents an analysis of the existing bacterial monitoring dataset for fecal coliform, including spatial and statistical analysis of the bacterial monitoring data, an estimation of fecal coliform loadings (the input into the models), including non-point and point source calculations, and a description of bacterial transport of fecal coliform from the sources in the watersheds, rivers, and Copano Bay using the model, including explanations for how the model parameters were determined. The main assumptions used in the model were that the fecal coliform bacteria decay (first-order reaction rate) in watersheds and along streams and channels, and Copano Bay is divided up into four Continuous Flow, Stirred Tank Reactors (CFSTRs). The results of the research include the modeled median fecal coliform concentrations throughout the watershed, the impact of different bacterial sources on each of the water segments in Copano Bay watershed, and the load reductions needed (and from what sources) to meet fecal coliform water quality standards. Cattle were determined (based on model results) to be the largest fecal coliform contributor of fecal coliform in Copano Bay. / text

This paper presents the results of a study on the effectiveness of porous overlays on urban highways. Permeable Friction Course (PFC) is a layer of porous asphalt applied to the top of conventional asphalt highways at a thickness of around 50 mm. PFC is often installed for safety and noise benefits, and is being seen as an emerging technology for meeting environmental requirements for stormwater discharge. The first objective of the study was to determine the impact of porous asphalt on the quality of stormwater runoff on highways with a curb and gutter drainage system. The quality of highway stormwater runoff was monitored before and after the installation of PFC on an eight-lane divided highway in the Austin, Texas area for 2 years. Observed concentrations of total suspended solids from PFC are 92% lower than those in runoff from the conventional pavement. Concentration reductions are also observed for nitrate/nitrite and total amounts of phosphorus, copper, lead, and zinc. The data shows that the results with curb and gutter are consistent with past results where runoff sheet flowed onto vegetated shoulders. The effect of two different binder compositions is also compared, showing an increase in zinc when recycled rubber is used. The second objective focuses on the drainage capabilities of PFC. While porous overlays can reduce stormwater accumulation on roadways, capacity at high rainfall intensities is limited. Installing subgrade underdrains within PFC could further improve stormwater conveyance. This research attempts to model the hydraulic profile of runoff as it approaches an underdrain with varying flow rates and grades. The results could assist TxDOT in the sizing and configuration of drains based on rainfall intensity and roadway geometry. / text

This report uncovers relationships between water quality and quality of life (QOL) through urban design. It shows that Smart Growth (a type of urban design) is a reasonable management practice for stormwater that can also positively affect our quality of life. This study is meant to support and inspire further research on how to link quantitative measurements of QOL with quantitative measurements of water quality through urban design characteristics. The report will introduce an ongoing study by PhD candidate, Suzanne Pierce, as her and her team currently combine water quantity/quality science with decision making. They are using the stakeholder process I served on, The Barton Springs Regional Water Quality Plan 2005, as a test bed for their creation. My hope is that this study will serve as a collection of data that Pierce’s group can draw from as they get closer to illustrating design choices for stakeholders as well as linking those choices to water quality and QOL. / text

The development of natural grass/scrubland for agricultural use within the Trans-Pecos basins has altered recharge mechanisms and raised questions about groundwater sustainability. Past efforts focused on recharge in arid basin systems used three main assumptions: there is minimal modern recharge, no widespread recharge on basin floors, and no recharge from anthropogenic sources. However, in the Trans-Pecos, nitrate (NO₃-) concentrations have increased in basin groundwater (up by 3-4 mg/l as NO₃- in 40 yrs), refuting the “classic” model and posing water quality risks. Grazing and irrigated agriculture have impacted basin hydrology by altering vegetation regime and the magnitude and spatial distribution of infiltration. This has increased recharge, Cl⁻, and mobile N flux to basin groundwater. A series of spatially-distributed net infiltration models were used to estimate potential recharge from natural and anthropogenic sources. Between 7-20% of potential recharge results from widespread recharge on the basin floors. Additionally, from 1960-2000, irrigation return flow may have contributed 3.0 × 10⁷ - 6.3 × 10⁷ m³ of recharge. These results are supported by field observations. Cores collected beneath agricultural land document changes in water content and pore water chemistry that imply increased downward flux of moisture and solute, and NO₃- and Cl- inventories beneath irrigated land are distinct in amount and profile from those in natural areas. There are significant implications for sustainability based upon the trends in groundwater NO₃- concentrations, core results, and net infiltration models: more recharge may enter the basins than previously estimated and there is a potential long-term concern for water quality. Due to thick unsaturated zones in the basins, long travel times are anticipated. It is unknown if NO3- and Cl⁻ flux has peaked or if effects will continue for years to come. Further study should be undertaken to examine anthropogenic impacts on basin water quality. Additionally, these impacts may occur in similar systems globally and there is considerable evidence for the re-evaluation of the validity of the “classic” model of recharge in arid basin systems. Future studies and management plans should incorporate potential impacts of changes in vegetation and land use on recharge processes and water budgets in arid basins. / text

This research identified and evaluated possible uses of environmental monitoring data collected and reported by industrial facilities under the Clean Water Act requirements and determined whether the current regulatory system supported any of those uses. Federal policies and state-level policies in the United States, Florida, and California were evaluated in order to determine whether the current regulatory system supported any of the identified uses. Monitoring programs and currently available monitoring data were evaluated from Hillsborough County, Florida, and Los Angeles County, California, from the perspective of 1) the current implementation of the monitoring program, and 2) perfect implementation under full compliance with the monitoring program. Four possible uses for monitoring data were identified by this research: (1) identification of high polluting facilities within a given jurisdiction, (2) assessment of pollutant load to receiving waterbodies, (3) documentat ion of improvement over time in the amount of pollutants discharged from a given industrial facility, (4) self-evaluation purposes, such as identifying on-site pollutant sources, adapting pollution prevention efforts, and evaluating the monitoring protocol. The research conducted a telephone survey and evaluated industrial facilities' reported analytical monitoring data. Telephone questionnaires were administered to 63 industrial facilities, and analytical monitoring data were obtained from industrial facilities in Hillsborough County, Florida and Los Angeles County California. The representativeness, sampling frequency and variation in the industrial facilities' analytical monitoring data do not assist in the identification of high polluting facilities within a given jurisdiction nor provide for documentation of facilities' improvements. Pollutant loads to receiving watebodies can not be assessed through the use of industrial facilities' analytical monitoring data because of the sampl e measurement, variation, and sample frequency of the data. Therefore, these uses can not be supported under current implementation/current data submitted or under perfect compliance. However, the telephone survey revealed facility operators are attempting to use the results from monitoring for self evaluation purposes.

The decline of coral reef habitats has been witnessed on a global scale, with some of the most dramatic decline occurring in the florida keys. as remote sensing can provide a synoptic view of coral reef ecosystems, 28 landsat images (1984-2002) were utilized to study water clarity and habitat change. first, the data were used to derive the diffuse attenuation coefficient (kd, m-1), a measure of water clarity, for 29 sites throughout the florida keys national marine sanctuary (fknms). landsat-derived kd values from bands 1 (blue) and 2 (green) provided useful information for 26 of 29 sites, whereas band 3 (red) provided no consistent data due to the high absorption of red light by water. it was not possible to assess long-term temporal trends as data were acquired, at most, twice a year. spatial variability was high between sites and between regions (upper, middle and lower keys) for bands 1 (0.019 m-1 - 0.060 m-1) and 2 (0.036 m-1 - 0.076 m-1). the highest kd values were f ound in the upper keys, followed by the middle and lower keys, respectively. this trend was corroborated by in situ monitoring of kd(par). second, the data were used to assess benthic habitat changes in eight coral reef sites located in the fknms. a mahalanobis distance classification was trained for four classes using in situ ground-truth data. overall coral habitat decline was 61% (3.4%/y), from 19% (1984) to 7.7% (2002). in situ monitoring data acquired by the coral reef evaluation and monitoring project (cremp) for the eight reef sites (1996-2002) showed a loss in coral cover of 52%, whereas the landsat-derived coral-habitat cover declined 37% for the same time period. a trend comparison between the full cremp percent coral cover data (1996-2004) and the full landsat-derived coral habitat class (1984-2002) showed no significant difference between the rates of change (ancova f-test, p = 0.303). The derivation of Kd and benthic habitat maps produced from Landsat data could provide c oastal marine managers another tool to help in the decision-making process.

In Kentucky, Best Management Practices (BMPs) were developed to protect the integrity of water resources during and after silvicultural operations, but their effectiveness is largely unknown. The study objectives were to (1) quantify the extent to which current BMPs minimized logging-related changes in stream water quality, channel morphology, and the content of woody debris and (2) quantify the extent to which modified BMPs influenced these characteristics. Six watersheds in eastern Kentucky were commercially logged in 2008-2009. In each watershed, one of three treatments was implemented (each replicated once). Treatment 1 (BMP) was based on current Kentucky BMPs. In treatments 2 (BMP+) and 3 (BMP++), current BMPs were modified with additional protective measures. Before the harvest, sampling sites were established in each watershed. Channel morphology and woody debris data were collected at each site in 2006 and again 2014. Data for water chemistry were retrieved from ongoing sampling records. BMP watersheds were compared to one another and to unharvested control watersheds in each year independently. Data within each individual watershed were also compared across years. The results indicate that current BMPs were effective in minimizing changes in the watershed characteristics examined here, and the benefits of modified BMPs were highly variable.

This investigation has documented the water quality impacts of stream channel recharge of sewage effluent northwest of Tucson and has evaluated the hydrogeochemical mechanisms potentially responsible for observed water quality changes. The evaluation was accomplished partly through construction of twelve monitor wells and implementation of a quarterly water quality monitoring program for surface water and groundwater. Constituents monitored included major inorganic chemical constituents, trace inorganics, trace metals, priority pollutants/trace organics and microbiological contaminants. ¹⁵N also proved useful in the study. The significance of a reducing zone immediately beneath the bed of the Santa Cruz River with respect to denitrification was documented. Findings of this investigation indicate that while sewage effluent is of poor quality with respect to drinking water standards, groundwater recharged by sewage effluent is of improved quality. Other findings include: * Nitrate in shallow groundwater near the Santa Cruz River in the Cortaro area appears to be primarily from stream channel recharge of sewage effluent; * Nitrate-N contents of effluent recharged groundwater averaged about 5 mg/1, well below the maximum contaminant level for drinking water of 10 mg/1, representing a 75 percent loss in total nitrogen during stream channel recharge of sewage effluent (assuming no mixing); * Both stream channel recharge of sewage effluent and agricultural deep percolation contribute to nitrate in shallow groundwater near the Santa Cruz River in the Marana area; * The reducing zone beneath the Santa Cruz River may be responsible for denitrification losses of up to 5 mg/1 of nitrate-N. This would explain approximately 30 percent of nitrogen losses, on average, between effluent and recharged groundwater; * The mechanisms of cation exchange and mixing with groundwater from other sources can explain the major changes in water quality between effluent and groundwater with respect to major inorganic chemical constituents; * Renovation of effluent with respect to coliform bacteria and enteric viruses content during recharge is not complete.

This dissertation work is part of a larger research effort involving soil-aquifer treatment (SAT). The dissertation's focus was to investigate meta-heuristic (global) optimization methods suitable for developing water resources decision support system (DSS), particularly to optimally design and operate groundwater storage and recovery projects. The effort included developing an integrated simulation-optimization management model for complex aquifer recharge/extraction operation considering water quality transformation. The research demonstrated successful integration of three-dimensional hydraulic, water quality, and particle tracking models with shuffled complex evolution (SCE) optimization algorithm. It also included developing the shuffled frog leaping algorithm (SFLA), a meta-heuristic optimization technique for solving discrete/combinatorial problems, and its application to aid decision making in water supply and distribution system optimization issues. SFLA is a memetic, meta-heuristic population-based cooperative search metaphor inspired by natural memetics. SFLA was developed by extending the logic of two existing global optimization techniques for continuous optimization problems. The local search is completed using an extension of the particle swami optimization (PSO) method, and the global exploration is performed by a technique similar to that used in the shuffled complex evolution (SCE) algorithm. SFLA was tested favorably on several literature test functions and engineering problems that present difficulties to many global optimization problems. The effectiveness and suitability of this algorithm has also been demonstrated by applying it to a groundwater model calibration problem and several water distribution system design problems that are considered as benchmark problems in the literature. The comparison of SFLA with other existing global optimization methods, such as genetic algorithms (GA), in terms of the likelihood and efficiency of converging to a global optimal solution, suggests that SFLA can be an effective algorithm for solving discrete/combinatorial optimization problems.

The boron isotopic ratios of three contaminated ground water samples and of leachate from four fly ash samples are shown to be significantly different than the isotopic ratio of naturally occurring boron in a selected ground water. Analysis is performed using thermal ionization mass spectrometry with a precision of less than 1 per mil. Inductively coupled plasma mass spectrometry is shown to be ineffective for this application. Boron is isolated from solution and concentrated using Amberlite IRA-743 resin with no isotopic fractionation observed. Boron desorption from fly ash is shown to be rapid. Boron isotopic analysis is shown to be a superior method to boron concentration analysis for identifying leachate in a ground water, (1) at the outer limits of a leachate plume, and, (2) when the difference between the boron concentration of the leachate and background water is small. The degree of contamination can be determined if both end members are known.