Stormwater impoundments are one of many types of best management practices (BMP) designed and implemented to regulate water quantity and improve the quality of runoff from urban areas. Studies of water quality in urban impoundments have indicated that conventional designs are however, not very effective at removing solids and associated pollutants. Accordingly, many urban impoundments are being re-designed to improve downstream water quality. However, few studies have systematically monitored and quantified post-design water quality improvements of urban impoundments. This thesis examines changes in the water quality performance of an urban impoundment (Columbia Lake) in Waterloo, Ontario resulting from redesign of the lake for the pre-design period (2003 and 2004) and the post-design period (2006 and 2007). To achieve this goal, four years of water quality data collected at the inlet and outlet of Columbia Lake as part of the Laurel Creek Monitoring Program was measured. Water chemistry parameters included total phosphorus (TP), soluble reactive phosphorus (SRP), suspended solids (SS), dissolved oxygen (DO), pH and total dissolved solids (TDS). Inlet and outlet discharge (Q) were measured to determine the water retention time in the lake. Concentrations and loads of TP and SS for the post-design period (2006 and 2007) were compared to those for the pre-design period (2003 and 2004). During the pre-design period (2003 and 2004), inflow TP concentrations ranged from 18 to 372 µg L-1 with an average (mean ± standard error) of 56±7 µg L-1, while outflow TP concentrations ranged from 37 to 266 µg L-1 with an average of 116±6 µg L-1. Post-design TP concentrations ranged from 10 to 124 µg L-1 with an average of 53±5 µg L-1 and from 14 to 147 µg L-1 with an average of 44±3 µg L-1 at the inflow and outflow, respectively. Pre-design SS concentrations ranged from 1.8 to 168.5 mg L-1 with a mean of 19.0±3.2 mg L-1 and from 4.0 to 194.7 mg L-1 with a mean of 66.6±4.7 mg L-1 at the inflow and outflow, respectively. Post-design SS concentrations varied from < 0.1 to 25.8 mg L-1 with an average of 8.5±0.8 mg L-1 and from < 0.1 to 42.5 mg L-1 with an average of 14.5±0.8 mg L-1 at the inflow and outflow, respectively. Sedimentation/resuspension dominated the TP and SS transfer via Columbia Lake. Pre-design TP loads (log-transformed) strongly correlated with SS loads at the inflow and outflow (r = 0.661 and 0.777, p = 0.0001). These parameters were more strongly correlated during the post-design period (r = 0.794 and 0.915, r = 0.0001), which indicates that particulate P (PP) was a dominant fraction of TP and that the release of dissolved phosphorus (DP) from bottom sediments was considerably decreased following the redesign. No significant difference was observed between inflow and outflow SRP concentrations. Discharge strongly affected TP and SS loads at the inflow and outflow during the pre- and post-design periods (r > 0.79, p = 0.000 for all). After the redesign of Columbia Lake, the average net internal P loading rate decreased from 198% to 22% for TP. The primary factor influencing the observed decreased post-design TP and SS outputs was the removal of sediment from the lake. Bottom sediment removal and changes to the lake bathymetry reduced sediment resuspension and P desorption, which decreased the average net internal SS loading rate from 828% to 154%. The Columbia Lake Water Quality Model developed by Stantec Consulting Ltd. (2004) underestimated the post-design outflow TP and SS concentrations mainly because it did not include terms that account for factors such as bioturbation, wave induced resuspension and biological activity.

Stormwater impoundments are one of many types of best management practices (BMP) designed and implemented to regulate water quantity and improve the quality of runoff from urban areas. Studies of water quality in urban impoundments have indicated that conventional designs are however, not very effective at removing solids and associated pollutants. Accordingly, many urban impoundments are being re-designed to improve downstream water quality. However, few studies have systematically monitored and quantified post-design water quality improvements of urban impoundments. This thesis examines changes in the water quality performance of an urban impoundment (Columbia Lake) in Waterloo, Ontario resulting from redesign of the lake for the pre-design period (2003 and 2004) and the post-design period (2006 and 2007). To achieve this goal, four years of water quality data collected at the inlet and outlet of Columbia Lake as part of the Laurel Creek Monitoring Program was measured. Water chemistry parameters included total phosphorus (TP), soluble reactive phosphorus (SRP), suspended solids (SS), dissolved oxygen (DO), pH and total dissolved solids (TDS). Inlet and outlet discharge (Q) were measured to determine the water retention time in the lake. Concentrations and loads of TP and SS for the post-design period (2006 and 2007) were compared to those for the pre-design period (2003 and 2004). During the pre-design period (2003 and 2004), inflow TP concentrations ranged from 18 to 372 µg L-1 with an average (mean ± standard error) of 56±7 µg L-1, while outflow TP concentrations ranged from 37 to 266 µg L-1 with an average of 116±6 µg L-1. Post-design TP concentrations ranged from 10 to 124 µg L-1 with an average of 53±5 µg L-1 and from 14 to 147 µg L-1 with an average of 44±3 µg L-1 at the inflow and outflow, respectively. Pre-design SS concentrations ranged from 1.8 to 168.5 mg L-1 with a mean of 19.0±3.2 mg L-1 and from 4.0 to 194.7 mg L-1 with a mean of 66.6±4.7 mg L-1 at the inflow and outflow, respectively. Post-design SS concentrations varied from < 0.1 to 25.8 mg L-1 with an average of 8.5±0.8 mg L-1 and from < 0.1 to 42.5 mg L-1 with an average of 14.5±0.8 mg L-1 at the inflow and outflow, respectively. Sedimentation/resuspension dominated the TP and SS transfer via Columbia Lake. Pre-design TP loads (log-transformed) strongly correlated with SS loads at the inflow and outflow (r = 0.661 and 0.777, p = 0.0001). These parameters were more strongly correlated during the post-design period (r = 0.794 and 0.915, r = 0.0001), which indicates that particulate P (PP) was a dominant fraction of TP and that the release of dissolved phosphorus (DP) from bottom sediments was considerably decreased following the redesign. No significant difference was observed between inflow and outflow SRP concentrations. Discharge strongly affected TP and SS loads at the inflow and outflow during the pre- and post-design periods (r > 0.79, p = 0.000 for all). After the redesign of Columbia Lake, the average net internal P loading rate decreased from 198% to 22% for TP. The primary factor influencing the observed decreased post-design TP and SS outputs was the removal of sediment from the lake. Bottom sediment removal and changes to the lake bathymetry reduced sediment resuspension and P desorption, which decreased the average net internal SS loading rate from 828% to 154%. The Columbia Lake Water Quality Model developed by Stantec Consulting Ltd. (2004) underestimated the post-design outflow TP and SS concentrations mainly because it did not include terms that account for factors such as bioturbation, wave induced resuspension and biological activity.

The presence of nutrients in snowmelt runoff from agricultural watersheds has been reported by previous studies. However, no study has answered the most important question what areas of the watershed contribute nutrients to snowmelt runoff? or addressed the factors that control snowmelt runoff water quality. This study was designed to (1) find the areas that contribute nutrient to snowmelt runoff (termed as critical source areas, CSA), and (2) understand the source and transport factors that control the snowmelt runoff water quality in the Canadian prairies. The findings of this study will provide vital information to understand snowmelt runoff water quality and for sustainable management of soil nutrients and snowmelt runoff water quality in the Canadian prairies. <p>Source and transport factors and snowmelt runoff water quality were studied for two years on shoulder, backslope and footslope landform segments. The distribution of fall soil nutrients in the top 5 cm soil layer (available soil P [ASP], nitrate [NO3-] and ammonium [NH4+]), snow depth, snow water equivalent (SWE), snowmelt runoff and snowmelt runoff water quality (total P [TP], total dissolved P [TDP], NO3-N and sediment) were studied using closed and open plots placed on each landform segment. The influence of source and transport factors was evaluated in relation to snowmelt runoff water quality. <p>The ASP had a distribution pattern of backslope < shoulder < footslope in 2003 before manure application (bma) and shoulder = backslope = footslope in 2004. The NO3- distributed as shoulder = backslope = footslope in 2003 (bma) and shoulder < backslope < footslope in 2004. However, NH4+ had a stable distribution of shoulder = backslope < footslope in 2003 bma and in 2004. The pre-melt SWE increased in the down slope direction having the lowest in the shoulder and backslope and the highest in the footslope in 2005. The average daily snowmelt runoff from 1 m2 plots did not vary between the shoulder and the backslope. Infiltration was dominant in 2004 while runoff was dominant in 2005. Of the three landform segments, the shoulder was the greatest contributor of runoff to the depression. The backslope contributed the least. <p>Hog manure injection did not seem to influence snowmelt runoff water quality. Most nutrients and sediments were from the land surface. Analysis revealed that fall soil nutrient concentrations were not a dominant factor controlling the nutrients in the snowmelt runoff in this site. However, snowmelt runoff volume controlled snowmelt runoff water quality. Snowmelt runoff water quality did not vary between the landform segments. However, as a result of the dominance of shoulder in this landscape, the total transport of nutrients and sediment was the highest from shoulder. Where landform characteristics are similar to the study watershed, it may be argued that all landform segments are CSA. Runoff volume is the most influential factor in determining the importance of CSA and controlling the snowmelt runoff water quality.

The primary aim of the research summarized in this thesis was to confirm or refute that algae are involved in metal sedimentation from surface water, and whether this activity, if any, is enhanced by increased phosphorus availability. <p>A small-scale laboratory-based experiment was devised to elucidate the role of the chlorophyte alga Chlamydomonas noctigama in the removal of arsenic, nickel and uranium from mine water. Results indicated that the presence of <i>C. noctigama</i> significantly enhanced the removal of these metals relative to treatments without cells. Metals were present in greater concentrations in particulate matter in treatments with cells compared to treatments without cells, and there was a corresponding decrease in the concentrations of dissolved metals. This leads to the conclusion that sedimentation was mainly biotically induced. <p>Additional evidence of biotic involvement in metal removal from water by <i>C. noctigama</i> was obtained by using EDX spectroscopy and X-PEEM spectromicroscopy to observe complexation of arsenic, nickel and uranium to C. noctigama cells. Arsenic, the metal which was present at the lowest concentration in the DJX water, was present on scanned cells in low concentrations, and nickel and uranium, which were present at high concentrations in the DJX water, were present at higher concentrations. Examination of a single cell using X-PEEM spectromicroscopy showed uranium co-localized with carbon and phosphorus on the exterior of the cell. Crystalline particulate matter may have increased in the presence of cells. EDX spectroscopy showed that the crystalline particulate matter was possibly hydroxyapatite that contained various metals, including arsenic, nickel and uranium. EDX spectroscopy was used to determine the frequencies at which the cell-metal and particulate matter-metal associations occurred, and the relative concentrations of the metals associated with particulate matter. <p>No correlation between metal removal and phosphorus concentration in the media, or between algal density and phosphorus concentration was observed. However, phosphorus concentrations were not growth-limiting in these experiments, and so the effect of phosphorus on abiotic precipitation of metals remains unclear. <p> Results suggest two mechanisms by which <i>C. noctigama</i> may remove arsenic, nickel and uranium from solution: by direct sorption to the exterior of the cell, and by sorption to a cell product. <p>An experiment using cells preserved in Lugols iodine (a common phytoplankton sample preservative) indiated that Lugols preserved samples could not be used to quantify metals using spectroscopy. Consequently, historical samples preserved with Lugols iodine cannot be analyzed by this method.

Currently influence of water quality of water resource is greatly affected typhoon and rainstorm caused by climate change. Additional factors are including over cut trees, soil-rock flood and bad conservation of water-soil in hillside. Thus many researchers used ¡§membrane technology ¡§to remove pollutants such as suspended solids, alga, heavy metals and organic toxics. This work is studying performance of advanced water treatment processes using UF and LPRO membranes in a plant (noted as plant A). During the period of research; we analyzed items such as turbidity, TOC and hardness and operation parameters to investigate the efficiency of UF and LPRO. Results showed the traditional treatment processes has not effective removal on TOC, Fe ions ,Mn ions and hardness in raw water in plant A. But the removal efficiency was over 80% by using the later treatment of UF/RO. When plant A operated at good control and well detergent-wash, the life of UF/RO system is longer.

Rainwater harvesting is a familiar term for Bangladesh. People in areas that lack drinking water, particularly the coastal areas and the rural areas in the country, practice rain water harvesting. The high annual rainfall in the country makes rainwater harvesting a logical solution for the arsenic contamination of ground water in Bangladesh (Rahman et al. 2003). Also, the increasing population in the urban as well as rural areas is putting increased load on underground aquifers which is evident in the fact that the piezometric level in Dhaka has decreased by more than 65 feet in the last decade. The annual rain fall that the city receives may be an effective answer to the recharge of aquifers. Rain water harvesting during the rainy season can reduce the increasing load on groundwater levels. This study aims to provide some guidelines for economic rainwater harvesting system, especially for urban areas for specific user groups. These guidelines were formulated through literature review, analysis of some case studies on rainwater harvesting, and, to a certain extent, practical experience of the researcher. Data from secondary sources have also been used for the purpose. The guidelines have been formulated using existing data on rainwater harvesting systems. Based on these guidelines, a mathematical model has been developed to figure out cistern sizes for collection of rainwater. The solution is applied to a typical plan of an apartment house in Dhaka (multistoried) using programming and visualization so as to demonstrate the scope and benefit of integration of rain water harvesting technique with the architectural design. The harvested rainwater definitely does not meet the basic domestic requirement, but supplements it during the rainy season which, most importantly, is usable for individual household use. Large-scale rainwater harvesting also, hopefully, results in a decrease of seasonal flooding in the urban areas. The products of this research are a) a computer program for sizing cisterns and b) an animation of the proposed rainwater harvesting system that may be used as a tool to demonstrate the benefits of the technique.

In the premise of consideration of age-longed development, it consists of very complicated and challengeable strategies to deal with managerial problem on river basin. This study is focus on the field of Tam Sui River. It is difficult to use numerical simulation in the following situation: The affect of tide on tidal river, the complication of hydrodynamic, and the formation of net-type Tam Sui River by three main confluents. The purpose of establishing hydrodynamic and water quality modeling with STELLA, a software used in systematic dynamic is to provide a valuation benchmark in water quality management. In water system, we want to understand the correlation and mechanism among parameters, and these will help us investigate and analyze the problems in water plan. We also want to make the best choice and decision and gain the biggest efficiency by understanding the characteristics and the contents of water quality. We use one dimension of movement equation in programming STELLA. And we solve hydrodynamuc in different time and different place by using¡unon-linear implicit finite-difference ¡v. In the result of our study, it can not completely simulate the whole situation of turbulence. But in the period of typhoon and flood, the prediction of water line is similar with the real survey in the complexit field. And the one-dimension model is easier to deal with and time-saver than 2-dimension model and 3-dimension model. In the aspect of water quality, we try to apply related mass balance equation in Water Quality Analysis Simulation Program (WASP) to find the chemical reaction among 8 parameters including chlorophyll A, organic phosphorus,inorganic phosphorus,organic nitrogen,ammonia,nitrate,carbonaceous biochemical oxygen demand,dissolved oxygen.After the test and verification, the simulation result meets our expectation and the theoretic value. This model could be extensively applied

The Kaoping River watershed is the largest and the most intensively used river basin in Taiwan. It is 171-km long, drains a catchment of more than 3,250 km2. Both point and non-point source (NPS) pollutants are now the causes of biochemical oxygen demand (BOD), nutrients, and suspended solids (SS) in the river. The main water pollution sources are livestock wastewater from hog farms, municipal wastewater, industrial wastewater, and NPS pollutants from agricultural areas. After the implementation of the hog ban in the Drinking Water and Source Water Protection Area (DWSWPA), all of the half million hogs have been removed or relocated in 2001. Thus, the municipal wastewater and NPS pollutants become the major concerns after 2001. In this study, the potential NPS pollution sources located in the Kaoping River watershed are investigated. Investigation results show that there are 827 potential pollution incidents, which cover 2,610 hectors in the Kaoping River watershed. Orchard farms are the major potential pollutant sources, which cover 60% of the total area of the potential pollutant sources. Moreover, results reveal that mango and betel palm farms dominated the illegal farmland areas, and are scattered around the river corridors. Field investigations indicate that major BOD, total phosphate (TP), total nitrogen (TN), and SS loadings came from the betel palm and orchard farms. The calculated total loadings of BOD, TP, TN, and SS are 69,000, 9,200, 58,500, and 487,500 kg/yr, respectively. Among the four major reaches (Lo-Non, Chi-San, Chu-Ko, and I-Lao creeks), the Lo-Non creek discharge the major pollutant loadings into the Kaoping River. Thus, the highest degree of protection is given to the Lo-Non creek. An integrated watershed management model was applied to investigate potential NPS pollution management plans in the Kaoping River watershed. Based on the results from the field investigation and model simulation, the following remedial strategies have been taken to reduce the impacts of NPS pollution on the water quality of Kaoping River: application of best management practice for NPS pollutant control; application of natural treatment systems for stormwater runoff treatment; and construction of the watershed geographical information system (GIS) and real time water quality monitoring system to effectively manage the watershed. Linking land utilization information with the NPS pollution simulation model may further provide essential information of pollution potential of NPS pollution for all sub-regions in the river basin. Results and experience obtained from this study will be helpful in designing the watershed management and NPS pollution control strategies for the Kaoping River watershed and other similar river basins.

Abstract The main purpose of this study is to develop a hydrodynamic and water quality model using the system dynamic software-STELLA for the tidal river simulations. The model consists of three modules: the hydrodynamic module simulates the water level variation and the dynamic flow conditions in tidal rivers; the transport module simulates the temporal and spatial variations of dissolved matters; and water quality module simulates the bio-chemical reaction processes and the fates of the water quality variables. Water quality module was established from the conceptions of WASP6 with some modifications. Eight state variables are included in the water quality module, i.e. chlorophyll-a, organic phosphorus, inorganic phosphorus, organic nitrogen, ammonia, nitrate, carbonaceous biochemical oxygen demand, and dissolved oxygen. Most the hydrodynamic and water quality models, either imported or domestic developed, were coded in FORTRAN or other conventional programming languages. In this study, the system dynamics software STELLA has been used to construct the model. The study has overcome the difficulty of using STELLA to simulate space continuity and unsteady state condition of tidal river systems. By using STELLA, the environment model can easily be integrated with researches in social-economical studies. The theories and the developments of the model are described in the thesis, the calibration and verification processes of the model using observation data of the Tamshui River system are also describe in detail. The model can be used not only to simulate and to predict the tidal flow, salinity, temperature, and water quality conditions in the Tamshui River, but also be used to evaluate the effects of various water quality purification methods and strategies. Therefore, this model can also assist policymakers to make better decisions on the balancing the economic developments with environmental protections.

Under the Clean Water Act (CWA) program the Texas Commission on Environmental Quality (TCEQ) listed 110 stream segments with pathogenic bacteria impairment in 2000. The current study was conducted to characterize the watersheds associated with the impaired waterbodies. The main characteristics considered for the classification of waterbodies were designated use of the waterbody, land use distribution, density of stream network, average distance of a land of a particular use to the closest stream, household population, density of on-site sewage facilities (OSSF), bacterial loading due to the presence of different types of farm animals and wildlife, and average climatic conditions. The availability of observed in-stream fecal coliform bacteria concentration data was evaluated to obtain subgroups of data-rich and data-poor watersheds within a group. The climatic data and observed in-stream fecal coliform bacteria concentrations were analyzed to find out seasonal variability of the water quality. The watershed characteristics were analyzed using the multivariate statistical analysis techniques such as factor analysis/principal component analysis, cluster analysis, and discriminant analysis. Six groups of watersheds were formed as result of the statistical analysis. The main factors that differentiate the clusters were found to be bacterial contribution from farm animals and wildlife, density of OSSF, density of households connected to public sewers, and the land use distribution. Two watersheds were selected each from two groups of watersheds. Hydrological Simulation Program-FORTRAN (HSPF) model was calibrated for one watershed within each group and tested for the other watershed in the same group to study the similarity in the parameter sets due to the similarity in watershed characteristics. The study showed that the watersheds within a given cluster formed during the multivariate statistical analysis showed similar watershed characteristics and yielded similar model results for similar model input parameters. The effect of parameter uncertainty on the in-stream bacterial concentration predictions by HSPF was evaluated for the watershed of Salado Creek, in Bexar County. The parameters that control the HSPF model hydrology contributed the most variance in the in-stream fecal coliform bacterial concentrations corresponding to a simulation period between 1 January 1995 and 31 December 2000.