This master´s thesis deals with the possibility of restoration of lake or pond ceased to exist and its influence on surrounding landscape. The author focusses on the restoration of particular pond and possibilities of it´s use and economical evaluation of the project.

The dissertation deals with clogging of reservoirs and ponds by redundant sediments which penetrate water system by erosion. It describes methods of extracting pond sediments. It contains measurement of dewatering of sediments on hydrocyclone and design of laboratory hydrocyclone and filter unit. In the conclusion there is design of technology of dewatering sediments which were extracted by wet method by drainage excavator. Numerical simulation of flowing in hydrocyclones is simulated in the CFX programme and dewatering technology is simulated in the CHEMCAD programme.

As stormwater flows over roads, sidewalks, and other impervious surfaces, it picks up pollutants that are deposited on these surfaces. One common pollutant transported by stormwater is road salt. While the application of road salt is crucial for wintertime public safety, road salt has a host of negative environmental impacts. Road salt has been linked to increasing levels of dissolved solids in groundwater, vegetation damage, and behavioral changes in aquatic organisms. Studies have shown that these impacts are concentrated around salt storage facilities. As a result, the United States Environmental Protection Agency issued many state departments of transportation municipal separate storm sewer system (MS4) permits. In Utah, road salt is stored at Utah Department of Transportation (UDOT) maintenance stations, which are regulated by a Phase I MS4 permit. To comply with their MS4 permit, UDOT constructed retention ponds to capture salt-laden stormwater and truck wash water. However, without information and established maintenance and management plans informing pond design, these retention ponds suffer from design issues such as overflow throughout the winter season. Through pollution prevention assessments, pond and tap water analysis, pond sediment analysis, and surface water quality modeling at 11 UDOT maintenance stations, this project provides UDOT with site design guidelines and best management practices to ultimately reduce the impact of UDOT road salt facilities on the environment.

The diploma thesis is maping the World Pond Hockey Championship which helds place in Canada. The aim of this work is to analyze and characterize men's and women's teams that has participated at World Pond Hockey Championship. In the theoretical part of the thesis I was focusing on the history of men's and women's hockey on natural ice surfaces. I also characterized the World Pond Hockey Championship, rules of this sport and other big pond hockey tournaments. The practical part is devodet to the analyze of differencies between regular World Ice Hockey Championship and World Pond Hockey Championship. Furthermore the practical part analyzes men's and women's teams that has competed at the World Pond Hockey Championship. The analyze was done by my own observation, interviews with the players and coaches and also by the quantitative research from relevant sources.

If not purified leachate from landfills would cause damages on the environment. At most landfills in Sweden local treatment of leachate is achieved, at the rest the leachate is transported to sewertreatment. While no comprehensive legal provisions for discharge exist in Sweden there is a difference in discharges between the installations for landfill. If no comprehensive legal provisions is produced guidance must improve. Treatment of leachate and self monitoring system at fifteen installations in Sweden has been studied and compared. A study of literature about different treatment solutions has also been performed. Practical information about the landfills has been gathered through visits. Processes of treatment described in literature correspond to measures. Variations exists between the self monitoring systems at the installations both between parameters for analyses, how often controls take place and were testpoints are situated. Knowledge of reactions and techniques for treatment of compounds common in leachate exist. Further research about compounds whose effect we do not know for certain must be achieved. / Lakvattenrening och egenkontrollprogram vid femton deponier i Sverige har studerats och jämförts. En litteraturstudie angående olika reningstekniker har även utförts. Information om deponierna och reningsprocesserna har inhämtats via studiebesök och miljörapporter. Vid jämförelse av rening har olika processer studerats separat. Den beskrivning av processerna som finns i litteraturen stämmer väl med uppmätta resultat. Exempel på detta är ammoniumhalter som reduceras i luftad damm, halter totalkväve som minskar genom rening i Satsvis Biologisk Reaktorteknik och reducerad halt suspenderat material som inträffar vid rening genom markfilter. Egenkontrollprogrammen vid de olika deponierna varierar dels i avseende på vilka parametrar som kontrolleras och dels hur ofta kontroller utförs och var provpunkter är belägna. För de vanligast förekommande ämnen som existerar i lakvatten finns kunskap om reaktioner och fungerande tekniker för rening. Problem uppstår för de ämnen vilkas reaktioner och förändringar man ej känner till. Farhågor finns dessutom att det i lakvatten finns föreningar vars existens och verkan vi ej känner till. På grund av detta krävs ytterligare forskning på lakvatten.

The chemical characterization of sediments accumulated in catch basins and stormwater ponds provides important information for assessing risks associated with management of these residuals upon removal of accumulated deposits in stormwater systems. In this study, over a period of 15 months, more than 150 residual samples were collected from 77 catch basin units and 22 stormwater ponds from 16 municipalities throughout the state of Florida. Concentrations (mg/kg) of metals and metalloids (arsenic, barium, cadmium, chromium, copper, lead, mercury, nickel, selenium, silver, and zinc) and trace organics (volatile organics, semi-volatile organics, herbicides, and pesticides) in the sediments were measured. In addition, the synthetic precipitation leaching procedure (SPLP) was utilized to evaluate pollutant leachability risk for a subset of the samples collected. Measured pollutant concentrations were compared to corresponding risk-based guidelines in Florida (i.e., Florida soil cleanup target levels) to assess potential human health risks of beneficial use of these residuals through land application. Leached concentrations were compared to risk-based water quality guidelines (i.e., Florida groundwater cleanup target levels) to examine the potential for groundwater contamination. Although several metals (arsenic, barium, chromium, copper, nickel, lead, and zinc) were routinely detected in the catch basin and stormwater pond sediments, their concentrations were generally lower than the Florida's risk-based cleanup target levels for soils. A small number of organochlorine compounds (e.g., 4,4′-DDE, 4,4′-DDT) were detected, but only in a limited number of the samples (less than 10%); leaching of trace organic pollutants above the Florida risk-based groundwater thresholds was rare. The results suggest that when land-applied or beneficially used, these residuals are not expected to pose a significant threat to human health or the environment and the results of this research will provide stormwater managers and environmental management authorities with a useful resource to examine proper disposal and beneficial use of catch basin and stormwater pond sediments.

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

京都大学 / 0048 / 新制・課程博士 / 博士(地球環境学) / 甲第20595号 / 地環博第166号 / 新制||地環||33(附属図書館) / 京都大学大学院地球環境学舎環境マネジメント専攻 / (主査)教授 柴田 昌三, 教授 山下 洋, 准教授 深町 加津枝, 教授 横山 壽 / 学位規則第4条第1項該当 / Doctor of Global Environmental Studies / Kyoto University / DFAM

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