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As American cities continue to expand and their existing transportation infrastructure becomes strained from increased demand, many cities have turned to light rail transit to not only alleviate congestion but also to provide an economic development stimulus to the areas around the stations. This report focuses on determining the economic impact on areas surrounding announced light rail stations in Austin, Texas while also attempting to quantify changes in land use and demographics experienced in a city who has an established light rail line; Dallas, Texas. In addition to examining any changes associated with the announcement and construction of a light rail project this report will qualitatively examine the role of these project in stimulating gentrification in station areas and what effect gentrification will have in preventing low-income households from accessing the improved transit system. The report will also propose actions that could ensure that these households continue to have access to public transportation, which would mitigate the strain of increasing transportation costs. / text

Drainage area is a measure of the number of acres feeding into a creek. Drainage area threshold is the amount of acreage required for the creek to be included on a map. Watersheds mapped according to higher drainage area thresholds will show creek systems that are shorter and concentrated at the bottom of the watershed. Watersheds mapped according to lower drainage area thresholds show creek systems that are longer and extend further up the watershed. Since all watersheds are subject to different land uses, soil types, geology, etc., they should be mapped according to different drainage area thresholds. Headwaters are where creeks begin. There is empirical evidence that properly functioning headwaters significantly reduce erosion, improve water quality, slow stormwater flows, and provide habitat. If municipalities use lower drainage area thresholds to define their creeks, they can include more headwaters in their creek setback requirements. This professional report identifies the Harris Branch watershed as being under relatively more pressure to develop and exhibiting more environmental risk than other watersheds in Austin, Texas’ Desired Development Zone. Creeks in the watershed are redrawn according to reduced drainage area thresholds using a simple ArcGIS analysis. The analysis reveals a critical mass where creek setbacks appear to be too extensive. If creeks with a drainage area of 5 acres are protected by development code, the setbacks created have excessive branching that could be too restrictive for development. A critical mass ratio should be considered when determining which drainage area threshold is most appropriate for a watershed. The critical mass ratio is equal to the number of branches allowed per a specified distance of creek centerline. The process of identifying this critical mass ratio can help growing cities find a balance between the need to encourage development in designated areas and the need to protect natural creek systems everywhere. I recommend that municipalities review the effects of reducing drainage area threshold for each watershed, and then identify the drainage area threshold that, when protected by setback requirements, allows for extended and connected greenways as well as an increase in density. / text

The Jollyville Plateau Salamander (JPS), Eurycea tonkawae, is a species of salamander endemic to Texas, the United States. It is a candidate for protection under the Endangered Species Act. This report assesses the JPS population abundances at Lanier Spring, Long Hollow Creek at Wheless Spring, and Ribelin Spring in Austin using a mark-recapture method. The maximum likelihood estimation method was used to obtain the population size estimates under two models, the M₀ model and the M[subscript t] model. The M₀ model assumes that every animal has the same capture probability in the population for each sampling period while the M[subscript t] model allows capture probabilities to vary by time. Simulations were performed by using an MCMC algorithm based on the M₀ model. Between 2007 and 2009, the population size estimates for JPS (>16mm snout-vent length, (SVL)) at Lanier Spring varied between 86 and 554 under the M₀ model, between 80 and 549 under the M[subscript t] model, and between 76 and 564 using MCMC simulations. During 2007 monitoring periods, the population size estimates for JPS (>16mm SVL) at Ribelin Spring varied between 105 and 236 under the M₀ model, between 104 and 196 under the M[subscript t] model, and between 105 and 265 using MCMC simulations. During 2007 and 2008 monitoring periods, the population size estimates for JPS (>16mm SVL) at Wheless Spring varied between 368 and 1087 under the M₀ model, between 339 and 1075 under the M[subscript t] model, and between 411 and 1098 using MCMC simulations. Different estimation methods yielded consistent estimates. No clear population trends were detected due to the big fluctuations in estimates in this study. / text

With the large growth in use of social media by teenagers, young adults and adults alike, there has also been a boom in the number of charitable nonprofit organizations that are adopting the medium to reach out to existing and potential supporters. But has social media been an effective tool in spreading out the word about a cause while retaining and recruiting donors and volunteers? This multimedia report aims at analyzing how three Austin-area nonprofits are using Facebook and Twitter to connect to constituents, as well as how online and offline constituents are responding to this relatively new approach. In order to do that, a series of interviews were conducted with nonprofit professionals, supporters, and industry and academia experts. In addition to that, constituents were surveyed about their engagement with the organizations both online and offline. To view this project in its entirety, including the video interviews, please visit http://evamenezes.com/mastersreport/. / text

This report studies the built environment of Civitan Park, located in Austin, Texas. Through studying and observing how park design can influence adults’ ability to engage in daily physical activity, alternative design recommendations are suggested for Civitan Park in order to create a park more able to be used by adults for physical activity and in turn, decrease obesity rates. / text

There is an ever increasing need to ‘Close the Gaps’ in higher education and increase college enrollment rates. Colleges have responded to this need through numerous recruitment efforts yet limited research exists on the successful components of model programs that have been established. This study explored components of College Connection, a nationally recognized recruitment initiative by Austin Community College. College Connection is geared toward increasing the college-going rate in central Texas by providing all high school seniors with the tools, support, and guidance to enroll in college. The research was conducted through a qualitative study of graduating high school seniors from two different high schools in central Texas. The study explored whether students were participating in the four ‘required’ components of College Connection, and if so, were the ‘optional’ and ‘recommended’ support services at each of the high schools being utilized. It was also important to examine which of the student support services offered on the high school campuses were most helpful according to students. Factors that students perceived were preventing them from participating in enrollment activities were also explored. Additionally, themes and recruitment strategies that emerged from the qualitative interviews were collected and used as suggestions to refine current practice. Background data on the participation rates, success, and retention of students who had participated in College Connection showed enormous progress in central Texas. This study, however, reaffirmed the idea that “students don’t do optional,” and it was essential to have students in all high schools participate in all of the enrollment steps. None of the participating students in this study attended any of the ‘optional’ evening or Saturday events held on their high school campus. The study went on to reveal that even the ‘required’ enrollment components at one of the high schools were not being required of all high school seniors. This prevented many graduating high school seniors from participating in enrollment activities and gathering college information as was intended. Furthermore, both high schools elected not to schedule any of the optional or recommended components the college had offered such as registration support, teleconferencing or campus tours. This study overall found that students who did participate in the required enrollment activities found the college support services to be extremely “helpful and informative.” It also became evident that the recruitment efforts at both high schools had begun to establish a college-going culture where students were familiar with college enrollment steps and terminology, and all but one student mentioned they would be pursuing higher education after high school graduation. / text

In natural waters, high concentrations of ammonia are toxic to fish, and the oxidation of ammonia to nitrate (NO₃-) consumes large quantities of dissolved oxygen. The influent to municipal wastewater treatment plants in the United States typically contains approximately 40 mg/L of ammonia nitrogen (NH₃₋ N). Almost all of this ammonia must be removed in a wastewater treatment process before the effluent is discharged to the natural environment. This dramatic decrease is accomplished by the aerobic biological process of nitrification, in which ammonia is oxidized to nitrate Biological denitrification is an anoxic biological process in which nitrate (NO₃-) is reduced to nitrogen gas (N₂). Denitrification can increase the alkalinity in activated sludge aeration basins and decrease the concentration of filamentous organisms. The staff at the City of Austin Water Utility decided to implement a denitrification system at Walnut Creek Wastewater Treatment Plant to control filamentous organisms and increase the alkalinity within the aeration basins. The denitrification configuration that the staff implemented was unconventional because no structural changes were made to the aeration basins to encourage denitrification. However, the system functioned well and allowed operators to turn off one of the two air blowers, which saves the plant a significant amount of energy. The current operation has occasional problems, where the alkalinity in the aeration basin decreases or the effluent ammonia increases. When the alkalinity decreases to the point where the pH drops to near 6.0, operators are forced to add chemicals to increase the alkalinity. When the effluent ammonia increases to near the permitted concentration (2.0 mg NH₃-N/L),operators are forced to turn back on the second blower which eliminates the anoxic zone. These problems occur most often during the winter, when the wastewater is the coldest. The wastewater temperature at Walnut Creek varies from a high of 30°C during the summer to a low of 18°C during the winter. The goal of this research was the identification of ways to make the operation more robust which would prevent the need for chemical addition and minimize the use of the second blower. Laboratory-scale reactors were operated to assess possible improvements that could be made to the operation and configuration of the denitrification system at Walnut Creek. The data observed in the laboratory scale experiments showed that the population of denitrifying bacteria limits denitrification and is especially important during the winter. Increasing the solids retention time to 20 days appeared to be the best way to increase the population of denitrifying bacteria and improve denitrification. Improvements can also be made by increasing the volume of the anoxic zone. Increasing the volume of wastewater and biomass recycled will most likely not benefit denitrification until other improvements have been made. Recommendations to the City of Austin Water Utility include the following: 1) increase the solids retention time at Walnut Creek, 2) Increase the volume of the anoxic zone, 3) Separate the anoxic zone from the aerobic section of each aeration basin, 4) During the winter, operate the flow equalization basins to reduce the dissolved oxygen entering the anoxic zone, 5) Continually mix some of the effluent from the aeration basins with the primary effluent in the flow equalization basins. / text