Дисертації з теми "Stormwater retention basins"

University of Central Florida College of Engineering Thesis
The movement and fate of heavy metal inputs (Cd, Zn, Mn, Cu, Al, Fe, Pb, Ni and Cr) from highway runoff were investigated in a three-year study on 1.3 hectare retention facility near the Maitland Interchange on Interstate 4, north of Orlando, Florida. Physical characteristics of the retention pond and surrounding watershed were defined and field instrumentation was installed. Stormwater samples were collected over a one-year period, representing a wide range of intensities and antecedent dry periods. Stormwater characteristics were compared with average retention pond water quality to determine removal efficiencies for heavy metals within the pond. A total of 138 core samples were collected in the pond over a three-year period to investigate the horizontal and vertical migrations of heavy metals within the pond. Sediment core samples were also carried through a series of sequential extraction procedures to examine the type of chemical associations and stability of each metal in the sediments. An apparatus was built which allowed sediments to be incubated under various conditions of redox potential and pH to investigate the effects of changes in sediment conditions on the stability of metal-sediment associations. Five groundwater monitoring wells were also installed to monitor metal movement and accumulations under stormwater management systems. Heavy metal inputs from highway runoff were found to be predominantly particulate in nature, with dissolved fractions for most metals of only 25 percent. Upon entering the retention pond, most metal species settled into the sediments within 60-90 m of the inlet. Removal efficiencies for metals after entering the pond averaged 70-90 percent for particulate species and about 50 percent for dissolved species. Sediment concentrations of heavy metals were highest near the surface, with rapidly decreasing concentrations with increasing depth. Metal-sediment associations appear to be very strong for most metals, with the vast majority of metal inputs into the pond over the eight-year life still remaining in the top 10 cm. Concentrations of all heavy metals measured were higher in groundwaters beneath the pond that in the pond water; but for most metals, the increases only extended to depths of 1-3 m beneath the pond. In general, metal concentrations beneath swale areas were significantly higher than concentrations beneath the retention pond. Due to slow groundwater movement in the area, the effects of increased metal concentrations are very localized. Evidence was presented to suggest that mobilization of metals into groundwaters could substantially increase with time if maintenance procedures are not conducted.
Ph.D.
Doctorate
Civil Engineering and Environmental Sciences
Engineering
Environmental Engineering
390 p.
xix, 390 leaves, bound : ill. ; 28 cm.

Diversion of the first flush of storm runoff to a detention basin for pollutant removal is an efficient way to control nonpoint source pollutant in urban areas. This can be achieved by a diversion box and detention basin system. To numerically simulate the response of the system to a design rainfall event and the associated pollutant loadings for a given drainage area, a desk top model has been developed for"user-friendly"' application in personal computers. Hydrographs and pollutographs are generated at the inlet and outlet of the diversion box and the detention basin.These hydrographs and pollutographs are examined and the peak outflow and peak pollutant concentrations are compared with allowable outflow and pollutant concentration for urban stormwater quality and quantity management. This model is designed for both the analysis and design of the system.
M.S.

Modern urban stormwater infrastructure includes vegetated bioretention facilities (BRFs) that are designed to detain water and pollutants. Phosphorus (P) is a pollutant in stormwater which can be retained in BRF soils in mineral, plant, and microbial pools. We explored soil properties and phosphorus forms in the soils of 16 operational BRFs in Portland, OR. Since soil hydrology can significantly impact P retention, we selected BRFs along an infiltration rate (IR) gradient. We conducted sequential fractionation and tests of P pools and measured P release in a subset of soils after drying and flooding samples for ten days. We hypothesized that mineral or organic soil P forms would be correlated with IR, and that vulnerability to P release would depend on the interaction of drying and flooding treatments with P forms and pools. IR did not significantly explain differences in P forms. Soil TP was elevated across all sites, compared with TP in agriculturally-impacted wetlands and was substantially composed of soil organic matter (OM)-associated P. Phosphorus sorbed to mineral Fe and Al oxides- was variable but positively correlated with water-extractable P. The concentration gradient of water-extractable P was primarily controlled by overall P pools. Experimentally induced P releases were seen in 5 of 6 soils exposed to drying conditions, presumably released through microbial mineralization of OM. Only one site showed significant P release following the flooding treatment. Our measurements supported the idea that Fe and Al oxides provide P sorption capacity in these BRF soils. Variable inputs of P to BRFs through stormwater and litterfall may contribute to variability in P profiles and P release vulnerability across sites. Design specifications and management decisions relating to bioretention soils (e.g. establishment of acceptable soil test P levels, focusing on P forms known to influence vulnerability of P release) may benefit from detailed biogeochemical investigations.

I evaluated the effectiveness of plant roots to increase infiltration rates within stormwater bioretention facilities (SBFs), roadside planter compartments that filter stormwater. SBFs attenuate harmful effects of stormwater by reducing peak flow and retaining pollutants, with increased infiltration that improves both these functions. Researchers have shown that roots can increase infiltration within greenhouse, lab, field, and test SBF settings. However, no researchers have yet measured either the extent to which different root characteristics can increase infiltration or the variation in root characteristics and their effect on infiltration rates among plant assemblages within currently functioning SBFs. To determine if root-enhanced infiltration was occurring within SBFs, I hypothesized 1) there is a relationship between root characteristics and infiltration during late spring, and 2) seasonal root growth increases infiltration rates. Within Portland, OR, I measured infiltration rate from January 2014 to February 2015 and root characteristics from January-February (J-F) and May-June (M-J) 2014 in ten SBFs with "Elk Blue" rush (Juncus patens) and 1 or 2 trees of less than 8.4 cm stem diameter. During M-J, four root characteristics showed a positive relationship with infiltration rate, and two root characteristics showed a strong positive relationship with infiltration rate within the topsoil. Also, a relationship was shown between the increase (J-F to M-J 2014) in three root characteristics and the increase in infiltration rate. To determine if root morphology and infiltration rates differed among SBFs with two different dominant vegetation taxa (small and large root biomass), I hypothesized 3) Juncus patens and tree dominant assemblage (greater root biomass) exhibits greater infiltration compared to the Carex dominant assemblage, 4) the increase in infiltration rate and root characteristics from J-F to M-J is greater in the Juncus compared to the Carex assemblage, and 5) root surface area density (RSAD) within Juncus SBFs shows a positive relationship with infiltration rate in late spring. I measured infiltration rate from January 2014 to February 2015 and root characteristics from January-February (J-F) and May-June (M-J) 2014 among five large-root (Juncus and tree) and five small-root biomass (Carex sp) SBFs. Juncus SBFs showed greater values for three root characteristics during J-F and five root characteristics during M-J 2014 compared to Carex SBFs. Also, Juncus SBFs showed an increase from J-F to M-J 2014 for five root characteristics while Carex SBFs showed no root increase. Juncus SBFs showed a relationship with four root characteristics and Carex SBFs a showed relationship with one root characteristic and infiltration rate. This work strongly suggests plant roots increase infiltration, and thus the primary functions of SBFs. Different root characteristics appear to increase infiltration rate at different depths. Data also show larger-root biomass plants increase infiltration rate to a greater degree than smaller-root biomass plants. I recommend considering several site and facility characteristics when determining the potential for root-enhanced infiltration. When selecting plant species to enhance infiltration, I recommend using several criteria, determining root characteristic values at certain depths, considering installation approaches, and accounting for regional climate changes.

My deepest respect and appreciation are extended to Dr. L. Gray Wilson for providing the opportunity to conduct this research, for his advice and assistance during the course of the research, and for his review of and suggestions for improving this manuscript. I would also like to thank Michael Osborn for his assistance. This research was funded by the City of Tucson. The assistance and direction provided by Mt. Bruce Johnson and Mt. Joe Babcock at Tucson Water are gratefully acknowledged. My thanks are also extended to Dr. Daniel D. Evans, Dr. L.G. Wilson, and Dr. Stanley N. Davis for serving on my thesis committee. Bruce Smith's assistance is gratefully acknowledged. Bruce spent two long days with 110-degree temperatures In a parking lot describing the lithology of sediment samples collected during the drilling phase of this research. He also determined the moisture content and particle size distribution on samples collected from the borehole. The assistance of Ralph Marra and Steve Brooks is also gratefully acknowledged. Ralph waded through city and county bureaucracies to determine zoning at each dry-well site. Steve assisted with collecting dry-well settling chamber sediment samples.

Thesis (M.Eng.Sc.)--University of Adelaide, Dept. of Civil and Environmental Engineering, 2000?
Corrigenda pasted onto front end-paper. The CD contains Excel spreadsheets containing data collected. Bibliography: leaves 209-222.

Monitoring of a regional stormwater management facility, located on the Virginia Tech campus in Blacksburg VA, was conducted in order to assess its efficacy in reducing nonpoint source pollutant losses downstream. The facility design includes both an upper water quality (wet) pond and a lower 100-yr-event quantity (dry) pond. These on-stream ponds capture both baseflow and storm runoff from the southern portion of the Virginia Tech campus and surrounding lands, and release the water back to the unnamed stream shortly above its conjunction with Stroubles Creek, a tributary of the New River. Monitoring sites for flow measurement, water quality sampling, and biotic assessments (habitat evaluation and rapid bioassessment of benthic macroinvertebrates) were located above and below each of the ponds.

Both grab samples and automated samples were collected at these stations. Between 1997 and 1999, water quality grab samples included 35 baseflow samples and 22 stormflow samples. The grab samples were analyzed for concentrations of total suspended solids (TSS), metals, bacteria, and nutrients as well as temperature, pH, dissolved oxygen, conductivity, total organic carbon (TOC), and chemical oxygen demand (COD). Automated flow-weighted sampling was initiated in February of 1999 and results are reported through the end of October 1999. Thirty-three storms in 1999 were monitored for flow and various water quality parameters (TSS, TOC, COD, and nutrients). Pollutant loads and pollutant removal estimates were calculated with regard to the wet pond, dry pond, and the combined facility. Two types of pollutant removal efficiencies were calculated: (1) the EMC efficiency, based on pollutant concentrations from individual storms; and (2) the SOL efficiency, based on pollutant loads, to estimate long-term performance over the study period. Benthic macroinvertebrate sampling and habitat assessment were performed in both 1997 and 1999. In addition, a preliminary investigation of pond characteristics was conducted, including measurements of water quality and composition, sediment deposition and composition, and residence time.

As a system, the stormwater management facility appears to have minimum impact on improving the downstream water quality. Pollutant concentrations and loads both appear to increase downstream of the facility as compared to upstream, during both storm event and baseflow periods. Monitoring results of the benthic assemblages showed evidence of moderate to high impairment at all sampling locations, and habitat assessments showed evidence of high sedimentation levels within the stream, even after installation of the stormwater management facility. Total suspended solids (TSS) concentration removal efficiency was 10% for the combined wet pond and dry pond system, much lower than the 80 to 90% TSS removal expected for properly functioning stormwater management facilities (Hartigan, 1989). There is some evidence of sedimentation within the ponds because of a slight reduction in sediment-bound constituent export, but the dissolved nutrient constituents had either very low and most often negative (indicating pollutant export) removal efficiencies. Concentrations of metals measured in the stream often exceeded their respective acute and chronic water quality criteria at all sampling locations.

Pollutant removal efficiencies measured in the wet pond are atypical of those reported in the literature (Schueler, 1993). Insufficient residence time (two days compared to the optimal two weeks), and wet pond embankment failure are likely the principal causes of the wet pond's inadequate performance and thus, the inadequate performance of the overall facility. TSS removal efficiencies were low in the wet pond (19% for concentrations and 33% for loads) compared to the 80 to 90% expected for similar ponds. Nevertheless, the wet pond reduced the concentrations of several pollutants typically associated with TSS and not likely to be associated with the fill material for the wet pond embankment. Zinc concentrations in sediment cores were highest near the pond inlet, where the majority of sedimentation occurs. During storm events, the following results were noted. Copper and zinc concentrations in 1998 were lower at the pond outlet as compared to the pond inlet, and TOC concentrations and loads were also reduced by the wet pond (13% for concentrations and 12% for loads). However, sedimentation is also expected to remove phosphorusl, and wet pond phosphorus loads were only reduced by 10% and 3% for orthophosphorus and total phosphorus, respectively.

Because the wet pond is undersized with respect to the watershed it serves (surface area less than 1% of the watershed area (0.87 ha), as compared to the 3% ratio often recommended for optimal pollutant removal (Athanas, 1988)), higher removal efficiencies were found during baseflow periods. The greatest reductions in baseflow concentrations were for ammonia (67%), nitrate (57%), total nitrogen (54%), and COD (45%). However, the residence time of two days appears to be insufficient to reduce fecal coliform concentrations in the stream, and over 40% of the fecal coliform samples collected exceeded the water quality standard for contact recreation (DEQ-WQS, 1997). Furthermore, the wet pond did not appear to reduce TSS or TOC during baseflow periods. Export of TSS (-29% EMC efficiency) and TOC (-44% EMC efficiency) from the wet pond during baseflow periods is likely due to the wet pond embankment failure as well as pond eutrophication. Eutrophication processes are favored by the water temperature increase as flow passes through the shallow wet pond. The wet pond increased downstream temperatures by approximately 8°C above inflow temperatures during the summer, and to levels above 21°C which cannot be tolerated by sensitive coldwater species (Schueler, 1987).

The dry pond did not remove dissolved nutrient constituents or other pollutants during baseflow periods, but there is some evidence of sedimentation within the dry pond during storm events. During storm events, the dry pond was effective in removing TSS, with a concentration removal efficiency of 69% (EMC efficiency) and loading removal efficiency of 43% (SOL Efficiency). Removal of TKN and total phosphorus (36% and 37% respectively for concentrations) within the dry pond is further evidence of sedimentation within the dry pond.

The wet pond embankment was built in 1997, and monitoring occurred during a potential stabilization period when evidence of water quality benefits are slow to appear, especially with respect to downstream habitat and aquatic communities. Some benefits which could have been observed more immediately may have been negated or masked by the progressive erosion of the wet pond embankment as a result of a design flaw. Further complicating the results is the appearance; based on observations of extended drawdown time and results from a water budget analysis in the wet pond (where inflow substantially exceeds inflow); that groundwater interacts with the pond in a complicated fashion, possibly including both recharge and discharge.

To fully understand the impact of the stormwater management facility on the water quantity and quality within this tributary of Stroubles Creek, monitoring efforts should continue after the wet pond embankment is repaired and is fully operational. If biotic community improvement is desired, the stabilization period could be defined by the time necessary to flush out accumulated sediment within the channel. Monitoring efforts should also expand to include the investigation of the groundwater regime and water level fluctuations within the wet pond. Further measurements of pollutant removal processes and influences upon those processes within the wet pond should also be considered. Last, the influence of the stormwater management facility on downstream flow regimes should be investigated to assess the adequacy of its performance with regard to flow control and prevention of stream channel degradation.
Master of Science

L'objectif de ce travail est d'évaluer le transfert des métaux lourds au sein d'une installation de traitement des eaux de ruissellement routier et de développer un procédé épuratoire qui permettrait de parfaire le traitement de ces eaux. La démarche scientifique déployée a d'abord consisté en la caractérisation des flux métalliques acheminés dans un bassin de rétention recevant des eaux de ruissellement provenant d'une autoroute et en l'évaluation du transfert de cette pollution métallique vers la végétation environnante. Les résultats de cette première étude ont permis de mettre en évidence : (1) un transfert des métaux lourds (Cd, Ni, Zn) des compartiments eau - sol vers les macrophytes aquatiques présent sur le site, (2) la capacité de ces macrophytes à accumuler des polluants métalliques au sein de leurs tissus et (3) le caractère bioindicateur de ces macrophytes pour assurer une surveillance de la pollution métallique présente dans les eaux de ruissellement. Compte tenu de la capacité des plantes à accumuler des métaux, en particulier au niveau de leurs racines, un procédé de phytoremediation appelé marais flottant a été proposé pour affiner le traitement des eaux de ruissellement. Les performances épuratoires de ces systèmes ont été évaluées en microcosmes et la faisabilité technique de pouvoir implanter de tels systèmes directement à la surface d'ouvrages existants a également été appréhendée. Les résultats ont démontré que les marais flottants peuvent tout à fait être mis en œuvre à la surface de bassins de rétention sous réserve que les matériaux choisis pour la construction de ces systèmes soient adaptés aux conditions environnementales. Les résultats ont également mis en évidence la capacité des marais flottants à éliminer les métaux présents en phase aqueuse ainsi que l'importance du réseau racinaire qui se développe dans la colonne d'eau sur la rétention des polluants et la filtration des particules fines en suspension. Enfin, cette étude a démontré que les marais flottants peuvent être considérés comme des systèmes de traitement pérennes et nécessitant très peu de maintenance.

The master thesis deals with sanitation installations and gas installations in the new multifunctional building situated in Kroměříž. The theoretical part is focused on analysis of the topic. It describes in detail possibilities of rainwater management and it compares its design by both valid standarts and valid regulations. Technical part solves sanitation installations and gas installations of assigned building with the chosen option.

The City of Winnipeg Water and Waste Department presently operates and maintains 70 Stormwater Retention Basins (SRB's) within its boundaries. Limitations on the number of harvestable basins exist due to time, availability of equipment, site conditions at some stormwater retention basins, and budget. These problems, in addition to the rapid proliferation of weed and algae concentrations observed subsequent to harvesting, resulted in questions with respect to the impact mechanical harvesting has upon chlorophyll a concentrations in SRB's. Water quality analysis indicated that subsequent to harvesting activities, no reduction in chlorophyll a concentration was observed in any of the test basins, despite the removal of aquatic vegetation during harvesting. Plausible explanations for the increase in chlorophyll a following harvesting were discussed and investigated. Historically, harvesting activities had been supported with the application of copper sulphate and simazine based sterilents until the recent ban of these products from SRB application necessitated research into alternatives. Review of alternative emerging weed and algae control methods indicated that the most promising methods available to supplement o replace the aquatic weed harvesting program included sterilized grass carp and the use of the commercially available herbicides Reglone A and Karmex DF. Investigation into the effectiveness of the herbicides Karmex DF and Reglone A indicated that both provided promise as competitive means for weed and algae control, and either could prove to be an important supplement to, or a replacement for, conventional harvesting practices. (Abstract shortened by UMI.)

The efficacy of sedimentation ponds as a means of sediment and heavy metal remediation is investigated, with particular regard to the physical and chemical conditions that may lead to remobilisation of metals from the sediments
Thesis (M.Eng.Sc.) -- University of Adelaide, Dept. of Civil and Environmental Engineering, 2001

A project report submitted to the Faculty of Engineering, University of the Witwatersrand, Johannesburg, in partial fulfillment of the requirements for the degree of Master of Science in Engineering. Johannesburg, 1997
Detention storage IS a well tested, and generally accepted, method of attenuating flood hydrographs, but relatively littlo data is available from the monitoring of full scale instc'lations An onstrearn pond was constructed at Sunninqhill Park and details of 15 inflow and outflow hydro [Abbreviated Abstract. Open document to view full version]
MT2016

Provides insight into the pollutant removal ability of a primary pond in the Barker Inlet Wetland System, one of the largest constructed wetlands in the world. Results show that storm size influences pollutant removal, however significant removal was acheived across a wide range of flow conditions.
Thesis (M.Eng.Sc.) -- University of Adelaide, Dept. of Civil and Environmental Engineering, 2000?

Cape Town, South Africa, falls within a winter rainfall region, making it difficult to assess the feasibility of rain- and stormwater harvesting. The reason for this is because the region’s high water demand period coincides with the low rainfall summer season, thereby limiting the availability of this alternative water resource when most needed. During this study, rainwater harvesting for toilet flushing purposes, collected from roof surfaces, was practically assessed by means of inserted flow meters at a pilot study site in Kommetjie, Cape Town. The combined and single system roof- and land surface runoff yields and savings of commercial buildings within the Kommetjie business area, were also theoretically assessed by making use of a mathematical roof- and land surface runoff model specifically developed during this study. The statistical testing of the hypotheses statements relating to the pre- and post-harvesting savings at the pilot study building, compared against the average actual municipal water usage, were performed. Hypotheses testing were also performed in order to compare the theoretical rain- and stormwater runoff yields for the commercial business area against the average actual municipal water consumption. The conclusions drawn from this study indicated that valuable potable water, as well as related financial savings, can be achieved within a winter rainfall region, thereby making rain- and stormwater harvesting a feasible option for commercial businesses in Cape Town.
Environmental Sciences
M.Sc. (Environmental Management)