Urban stormwater runoff is recognised as a substantial source of heavy metal contamination, which adversely impacts on water quality of regional receiving waterways. Conventional treatment of urban runoff mostly involves a filtration system using sand to retain particulate matters. Sand provides limited sorption of dissolved metals and the inclusion of commercial sorbents to these treatment systems is not cost effective due to the concentration of dissolved metals in the runoff. Recycled organic materials are by-products or waste from industrial or agricultural operations, and could be alternative low cost sorbents for stormwater treatment systems. The use of recycled sorbents also provides added value to the waste materials and reduces landfill disposal. The research explores the application of compost, zeolite, ash, and recyclable waste in urban runoff treatment, especially for dissolved metal removal. The research combines the two aspects of experimental studies and management analysis to develop a holistic approach to heavy metal control in urban stormwater systems. Experimental results of batch sorption test show that compost is suitable for removing dissolve copper in stormwater treatment. The comparison of the different mixing ratios between compost and glass beads in column test evaluates the optimum mixing sorbent and performance over a long period for copper removal. Substance Flow Analysis (SFA) of copper has been performed in the Upper Parramatta River Catchment, Sydney to identify the sources of copper associated with runoff, effect of using waste material such as compost in urban stormwater treatment and the copper load in urban stormwater runoff. This case study shows the relationship between copper input, copper stock, sorbent type and urban stormwater quality control in the system boundary of the catchment. Different scenarios of source control are evaluated to control copper load from the different sources. Source control focusing on roads and vehicles is the most effective copper control strategy. The combination of source control and stormwater treatment reduces copper in stormwater and receiving water. The thesis applies the analysis from SFA and experimental results to derive both a regional system-wide solution with source control, and an improved design of stormwater treatment for heavy metal removal using recycled organics.

Thesis (M.S. in civil engineering)--Washington State University. / Includes bibliographical references.

abstract: The current practice of municipal stormwater management in the United States has failed to effectively reduce the amount of pollutants discharged into surface waters. Water impairment as a result of polluted stormwater runoff from urbanized areas remains a significant concern despite federally mandated efforts to reduce the impact of these discharges. To begin addressing these shortfalls the Environmental Protection Agency contracted the National Research Council to investigate the extent of the stormwater program and to identify areas that require improvement in order to more effectively implement the program. Their findings indicated widespread, foundational flaws with the stormwater regulatory structure and proposed new permitting guidelines. The purpose of this study was to explore the specific shortcomings of stormwater management in the Maricopa County region and to suggest the establishment of a regional authority. Doing so would require an alternative permitting regime to replace the current approach of population based municipal permitting with a permit that considered the entire urbanized region. The organizational structure, legality concerns and intergovernmental partnerships needed to properly establish such a regional authority were part of this study. The effect of this approach suggested a more effective, efficient and economical model of municipal stormwater management that better addressed certain Integrated Urban Stormwater Management strategies and began to address the program weaknesses identified by the National Research Council. / Dissertation/Thesis / M.S.Tech Technology 2011

Climate models have anticipated higher future extreme precipitations and streamflows for various regions. Urban stormwater facilities are vulnerable to these changes as the design assumes stationarity. However, recent climate change studies have argued about the existence of non-stationarity of the climate. Distribution method adopted on extreme precipitation varies spatially and may not always follow same distribution method. In this research, two different natural extremities were analyzed for two separate study areas. First, the future design storm depth based on the stationarity of climate and GEV distribution method was examined with non-stationarity and best fit distribution. Second, future design flood was analyzed and routed on a river to estimate the future flooding. Climate models from North American Regional Climate Change Assessment Program (NARCCAP) and Coupled Model Intercomparison Project phase 5 (CMIP5) were fitted to 27 different distribution using Chi-square and Kolmogorov Smirnov goodness of fit. The best fit distribution method was used to calculate design storm depth as well as design flood. Climate change scenarios were adopted as delta change factor, a downscaling approach to transfer historical design value to the climate adopted future design value. Most of the delta change factor calculated were higher than one, representing strong climate change impact on future. HEC-HMS and HEC-RAS models were used to simulate the stormwater infrastructures and river flow. The result shows an adverse effect on stormwater infrastructure in the future. The research highlights the importance of available climate information and suggests a possible approach for climate change adaptation on stormwater design practice.

Stormwater is the component of runoff that is generated by human activities, and has gradually become a key issue in achieving sustainability in urban environments. When vegetation and soils are replaced with roads and buildings, less rainwater infiltrates into the ground or is taken up by vegetation, and more becomes surface runoff. A greater area of impervious surfaces leads to increased stormwater runoff volume and velocity, and consequently increases the risk off looding and erosion. Being able to reduce stream flows and pollution of surface flows, green roofs are one technology that may help in alleviating this storm water crisis. This thesis developed a different and effective methodology for quantifying the effects of green roofs on stormwater runoff and calculating the runoff volume and rate for residential housing communities before and after applying green roofs. The method utilizes local climate data like rainfall and evapotranspiration rate, the water use properties of vegetation like crop coefficients of plants, and the areas of impervious surfaces; and then compares the different effects of green roofs in different locations having disparate climatic conditions. It was found that the best way to achieve zero runoff was to green a portion of the total rooftop area and disconnect all impervious surfaces. Implications of this methodology on city planning and site design and for future research are then discussed. / Applied Science, Faculty of / Architecture and Landscape Architecture (SALA), School of / Graduate

The aim of the diploma thesis is to create an evaluation and recommendation of measures in the field of water management within green infrastructures of cities according to appropriate size. These measures apply to typical urban buildings managed by cities of this size. The first part of the diploma thesis deals with a research focused on the current state of stormwater management within the green infrastructure of cities. The legislative aspect is also outlined and measures and technologies for stormwater management are described. The practical part of the diploma thesis deals with a case study for the design of stormwater management within the green infrastructure of the city of Třešť. Stormwater management methods for various buildings owned by the city of Třešť are designed and economically assessed.

Bioretention cells (also known as rain gardens) are a Low Impact Development (LID) method for sustainable stormwater management. An increasingly popular form of urban stormwater infrastructure, bioretention cells use an engineered, vegetated-soil-system to both reduce quantity and enhance quality of stormwater. The ability of bioretention systems to remove common pollutants from urban stormwater runoff, and reduce runoff volume through evapotranspiration, in a temperature climate during plant senescence were assessed in this full scale field-based study. Stormwater run-off simulations were conducted for 5-, 10-, and 25-year return period storm events at a field site in Victoria, British Columbia, Canada. Tests were run on both, a vegetated cell planted with a mix of Betula nigra, Betula nana, and Salix lutea, and a control cell with turfgrass. Influent and effluent field parameters were recorded for pH and dissolved oxygen (DO), in addition to lab analyses conducted to quantify COD, TN, TON, TP, ortho-phosphate, and TSS removal from the stormwater. Water quality and hydrologic performance were results were compared between the vegetated and control cell using a Wilcoxon Signed Rank Test. In addition, hydrologic results were correlated with daily Evapotranspiration (ET) and meteorological station data using Spearman’s Rho Correlation. The vegetated cells were more effective (p value < 0.05) at retention of water volume, DO, COD, and orthophosphate, when compared to the control. Strong correlations (p value < 0.05) were found between the retention of water volume, and each of ET, maximum temperature, average temperature, minimum temperature, and average wind, for only the vegetated cells. / Graduate

Much of the past research and policy analysis on issues of western water has focused on inter-basin river agreements, large infrastructure that captures and distributes water, and conflict between agricultural and urban water demands. My dissertation asks a set of different questions: How is water governed and managed within communities of Utah? How are the organizations that manage water responding to changes in population, water availability, and water quality policy? The answers to these questions are essential for understanding the ways in which changes to water quantity and quality will be addressed in the present and coming years. To better understand the ways in which local water management organizations, including irrigation groups and municipalities, manage water in Utah, I conducted three major types of research activities. First, in 2013, I attended 18 meetings of local water management organizations and conducted 18 interviews of organization representatives that managed water within the Heber and Cache Valleys of northern Utah. In 2014, I built upon the knowledge learned in the 2013 observations and interviews, and conducted an online survey of stormwater managers throughout the state of Utah. To build upon survey responses, I then conducted 30 follow-up interviews of stormwater managers that represented municipal stormwater programs. This research was funded with a combination of support from the National Science Foundation’s iUTAH EPSCoR project (iutahepscor.org) and funds from the Utah Storm Water Advisory Committee, a group that represents municipal stormwater programs at the state level. My findings suggest that local water management organizations are already responding to growth and expansion in urban land use, rising uncertainties in water supplies, and shifting responsibilities for stormwater governance and management toward local governments. To cope with these changes, organizations are using a combination of strategies, including working with private consultants and collaborating with one another. With increasing pressures from environmental change and added responsibilities through decentralized water policies, it is expected that these adaptive strategies will persist or even spread to other local water management organizations yet to take on these behaviors.

Polluted runoff has been widely recognized by environmental scientists and regulators as the single largest threat to water quality in the United States. Contractor training and certification are among the four main Best Management Practices that the Environmental Protection Agency recommends to assist contractors in complying with Phase II Municipal Separate Storm Sewer Systems requirements that regulate construction sites stormwater runoff. The focus of the study is the review of training requirements for construction activities and stormwater permitting requirements in the states of Alabama, Arkansas, California, Florida, Louisiana, Maine, Maryland, Mississippi, and Tennessee. The review of the various training and certification requirements for the study states indicates the appropriateness and timeliness for the development and implementation of a model standard stormwater, erosion and sediment control training and certification program for contractors of construction sites of one acre or larger in Desoto County Mississippi to minimize stormwater pollution from construction sites.

The feasibility of installing biocidal beads into a catch basin filter insert for simultaneous stormwater disinfection and contaminant removal was tested. The catch basin filter insert (DrainPac®) was tested for its sediment, oil and grease, and coliform bacteria removal efficiency in conjunction with bench-scale testing of biocidal polymer beads. DrainPac® catch basin filters are composed of a metal frame, polypropylene filter fabric, and a high-density polymer support basket, and are installed below storm drains. A 12 x 41 in. DrainPac® filter (United Stormwater, Inc.) insert was set in a flume that simulated a large-scale catchment basin. Pond water was gravity fed to the flume at flow rates up to 200 gpm. The pond water contained fine sediments at concentrations ranging from 30-50 mg/L. The biocidal beads were tested in a small laboratory column for potential application to stormwater treatment. The head loss through the clean filter insert varied from 0.5 cm at 20 gpm to 9.1 cm at 200 gpm. Head loss of 21.5 cm occurred after 625 g of solids were added to the filter at 200 gpm at which point water began bypassing the filter fabric and flowing through the mesh screen. The highest flow rate that could be filtered through the loaded filter was 80 gpm. The DrainPac® filter removed total suspended solids with efficiencies ranging from 83% to 91% at flow rates of 20 to 200 gpm, with higher removal efficiencies at lower flow rates. The oil and grease removal efficiency of the DrainPac® filter ranged from 40% to 82%. The DrainPac® filter exhibited no removal of coliform bacteria under these test conditions. Biocidal brominated polystyrene beads, developed by Dr. S. D. Worley at Auburn University, were tested in a 1-cm diameter laboratory column apparatus for leaching of bromine compounds, which is important for determining if the filters will meet water quality regulations of the receiving waters. Removal efficiencies of coliform bacteria were tested in a companion study by Cal Poly graduate student Alex Bowerman. Pond water was passed through a 1-cm thick bed of beads in an up-flow direction. Leachate was analyzed for bromine, bromide, and bromoform. Leaching from both 0.3-mm and 0.8-mm biocidal beads was tested in the column apparatus. Samples collected for bromoform analysis were quenched with sodium thiosulfate, and the time before samples were quenched had a drastic effect on bromoform concentrations. Samples quenched after the collection of the total sample were assumed to be the most realistic for stormwater conditions since stormwater entering catch basins isn’t immediately discharged into its receiving waters. Effluent from a 1-cm bed of 0.3-mm beads at 0.56 mL/sec contained the following average concentrations: 0.47 mg/L bromine, 2.45 mg/L bromoform, and 0.53 mg/L bromide. The same conditions for 0.8 mm beads resulted in effluent containing the following average concentrations: 0.27 mg/L bromine, 0.06 mg/L bromoform, and 0.50 mg/L bromide. The much lower concentrations of bromine measured in the 0.8-mm bead leachate was likely due to the greater surface area of the smaller beads. The greater leaching of bromoform from the 0.3 mm beads may be partly attributed to the greater surface area of the smaller beads, but also the manufacturer of the beads reported that different production methods were used for the 0.3 mm beads. Higher bromine compound concentrations were found at lower flow rates, due to the longer contact times with the beads. Deionized (DI) water that was used to initially wet the biocidal beads before passing pond water through the column was also analyzed for bromoform. The DI flush water from the 0.3 mm beads contained 1.25 mg/L bromoform at a flow rate of 0.28 mL/sec. Bromoform concentrations in the DI flush water from the 0.8 mm beads at the same flow rate were below detection. Bromoform is expected to be formed as bromine is reduced to bromide by the presence of organics. Since there are no organics present in DI water to form such high concentrations of bromoform as those found from the 0.3-mm bead DI flush water, it appears that bromoform could have leached from the surface of the 0.3 mm beads. The longevity of the bromine treatment of the biocidal beads was tested on one set of 0.3-mm beads by simulating five use cycles, and also by testing another set of beads after dry storage. Each use cycle was simulated by pumping pond water through a 1-cm bed of 0.3 mm beads at 0.56 mL/sec for one hour and then connecting the column to an air pump to dry for 23 hours. After five simulated uses, leachate from the beads showed only a slight reduction in concentrations of bromine and bromide (21% and 4% less than fresh beads, respectively), while the concentration of bromoform was nearly 100 times less. The drastic decrease in bromoform concentration suggests that after five simulated uses, much of the bromoform was exhausted or conditions for the formation of bromoform were no longer present. For the dry storage test, 0.3 mm beads were wetted with 1-L DI water and then stored dry for 162 days. Then pond water was pumped through the column at 0.56 mL/sec and the leachate was analyzed. After dry storage for 162 days, the leachate showed no reduction in bromine concentrations compared to fresh beads, a 97% reduction in bromoform, and a 30% increase in bromide concentrations. This significant reduction in bromoform could be due to the volatilization of bromoform off the surface of the 0.3 mm beads during dry storage. The 0.3 mm beads are no longer being manufactured, and leachate from the 0.8 mm beads contained bromoform at concentrations below the potable drinking water maximum contaminant level of 80 µg/L. Under all tested conditions, bromine, bromide, and bromoform are present in the leachate from the biocidal beads, and thus their applicability for stormwater disinfection depends on the longevity of the bromine compounds in receiving waters, and on the regulations governing these compounds.