Subtitle D of the Resource Conservation and Recovery Act (RCRA) requires a post closure period of 30 years for non hazardous wastes in landfills. Post closure care (PCC) activities under Subtitle D include leachate collection and treatment, groundwater monitoring, inspection and maintenance of the final cover, and monitoring to ensure that landfill gas does not migrate off site or into on site buildings. The decision to reduce PCC duration requires exploration of a performance based methodology to Florida landfills. PCC should be based on whether the landfill is a threat to human health or the environment. Historically no risk based procedure has been available to establish an early end to PCC. Landfill stability depends on a number of factors that include variables that relate to operations both before and after the closure of a landfill cell. Therefore, PCC decisions should be based on location specific factors, operational factors, design factors, post closure performance, end use, and risk analysis. The question of appropriate PCC period for Florida’s landfills requires in depth case studies focusing on the analysis of the performance data from closed landfills in Florida. Based on data availability, Davie Landfill was identified as case study site for a case by case analysis of landfill stability. The performance based PCC decision system developed by Geosyntec Consultants was used for the assessment of site conditions to project PCC needs. The available data for leachate and gas quantity and quality, ground water quality, and cap conditions were evaluated. The quality and quantity data for leachate and gas were analyzed to project the levels of pollutants in leachate and groundwater in reference to maximum contaminant level (MCL). In addition, the projected amount of gas quantity was estimated. A set of contaminants (including metals and organics) were identified as contaminants detected in groundwater for health risk assessment. These contaminants were selected based on their detection frequency and levels in leachate and ground water; and their historical and projected trends. During the evaluations a range of discrepancies and problems that related to the collection and documentation were encountered and possible solutions made. Based on the results of PCC performance integrated with risk assessment, projection of future PCC monitoring needs and sustainable waste management options were identified. According to these results, landfill gas monitoring can be terminated, leachate and groundwater monitoring for parameters above MCL and surveying of the cap integrity should be continued. The parameters which cause longer monitoring periods can be eliminated for the future sustainable landfills. As a conclusion, 30 year PCC period can be reduced for some of the landfill components based on their potential impacts to human health and environment (HH&E).

Dumping of municipal solid waste (MSW) generated due to anthropogenic activities in any barren land or out fields causes severe hazards to human populations, ecosystems and the environment. In order to avoid this, it is required to design landfills in an engineered and scientific manner. Therefore, it is necessary to understand the behaviour of landfills over a period of time, to design landfills for site specific conditions. In this thesis such an attempt is made to evaluate performance of conventional landfill system using a large scale anaerobic reactor in the laboratory. The performance of the containment (bottom liner and final cover) systems is evaluated through numerical modelling and reliability based analysis. Response Surface Methodology (RSM) is used to develop linear regression models. Influence of various parameters and their uncertainty on the reliability of the containment systems are studied for various scenarios and conditions. Reliability assessment of containment systems play a decisive role in taking remedial measures in order to reduce its adverse affects on the environment and human health in the vicinity of landfill sites. On the other hand, pre-assessment of risk guides the engineers, planners and decision makers in achieving the goal of sustainable solid waste management as well as safe landfills. The thesis also includes assessment of vulnerability of groundwater to contamination, identification and ranking of suitable sites for municipal solid waste (MSW) disposal in the Bengaluru district, using remote sensing and Geographic information system (GIS) integrated with analytical hierarchy process (AHP), a multi criteria decision making tool. The study considers various land use, geological, hydrogeological and environmental factors as criteria. As a result, two most suitable locations are identified around the Bengaluru city and their descriptions are provided. Further, reliability analysis of the suitability of sites is evaluated considering criteria as random variables. The proposed reliability based approach helps the decision makers and planners to choose site locations having low probability of environmental pollution. The provided methods in the thesis can be effectively used for engineered design of landfills.

Growing environmental awareness has led to developments within landfill engineering, increasing the amount of research with the aim of constructing safe, stable landfills with optimal geometry. EU member states are forced to improve waste disposal policies through directives (Council of the European Union 1999) enforced in member countries through local legislation (in the UK, The Landfill (England and Wales) Regulations 2002). This research focuses on several aspects of waste barrier in situ performance. A field study was conducted on a landfill side slope to investigate geosynthetics mechanical behaviour in service conditions and on a landfill capping to investigate capping geosynthetic drainage system performance in situ conditions and pore water distributions along the capping. Further site derived data were collected in order to validate numerical modelling approaches, to increase confidence in a design processes and to investigate mechanisms incorporated in the liner s performance. The side slope studies revealed an additional factor affecting lining components displacement along the slope: geomembrane and geotextile response to atmospheric conditions. The capping study allowed production of recommendations for future capping designs. These can be used to considerably enhance capping stability.

There are over one thousand closed ‘small’ landfills in Ontario, each with differing circumstances and potential problems. This project proposes a method of addressing such dormant sites in situ, based upon a case study in Hamilton. Of the four closed landfills within Hamilton city limits, three of them lie in the low lands of the Red Hill Creek Valley. Perched at the source of the Red Hill Creek, the Upper Ottawa Street Landfill introduces unspoken toxins into the ecosystem of the entire valley. As the storm water catchment for the escarpment watershed, the creek serves a critical role in the recreational green belt which divides Hamilton and Stoney Creek. The source of this creek must be celebrated, not fenced off from public access due to landfill hazards. This proposal investigates beyond material recovery, into the possibilities of resource, ecosystem, and community recovery. Landfill mining, material sorting, and power generation through incineration are employed to reduce landfill volume. As the landfill is consumed, a new landscape is constructed, providing improved flood-prevention at the creek and a sanitary lined landfill for those materials remaining on site. Creek, forest, and field habitats are restored on site without the threat of contamination from landfill contents. The public can safely view the landfill mining operations from an elevated walkway, having new experiences with every visit. As the boundaries of the closed landfill are stripped away, the source of the Red Hill Creek and the new recreational parkland are made publicly accessible. Using this design as a reference, the equipment and operations designed for this site can be developed into a province-wide proposal.

There are over one thousand closed ‘small’ landfills in Ontario, each with differing circumstances and potential problems. This project proposes a method of addressing such dormant sites in situ, based upon a case study in Hamilton. Of the four closed landfills within Hamilton city limits, three of them lie in the low lands of the Red Hill Creek Valley. Perched at the source of the Red Hill Creek, the Upper Ottawa Street Landfill introduces unspoken toxins into the ecosystem of the entire valley. As the storm water catchment for the escarpment watershed, the creek serves a critical role in the recreational green belt which divides Hamilton and Stoney Creek. The source of this creek must be celebrated, not fenced off from public access due to landfill hazards. This proposal investigates beyond material recovery, into the possibilities of resource, ecosystem, and community recovery. Landfill mining, material sorting, and power generation through incineration are employed to reduce landfill volume. As the landfill is consumed, a new landscape is constructed, providing improved flood-prevention at the creek and a sanitary lined landfill for those materials remaining on site. Creek, forest, and field habitats are restored on site without the threat of contamination from landfill contents. The public can safely view the landfill mining operations from an elevated walkway, having new experiences with every visit. As the boundaries of the closed landfill are stripped away, the source of the Red Hill Creek and the new recreational parkland are made publicly accessible. Using this design as a reference, the equipment and operations designed for this site can be developed into a province-wide proposal.

<p>It is estimated that 22 000 contaminated areas exist in Sweden today. In order to classify the risk of contaminant migration from these areas and to prioritize which of these contaminated areas should first be treated, the Swedish Environmental Protection Agency (EPA) has designed a method, for the investigation of contaminated areas (MIFO). One of these contaminated areas is the landfill Gräsötippen outside Köping. The landfill has been used by both Yara AB and the Köping municipality between the years 1945 and 1975, and both industrial and household waste have been deposited there. The aim of this report is to survey which contaminants that can be found in the soil and water in the landfill Gräsötippen and to evaluate the migration of these contaminants. With help of this information, the landfill will then be risk classified according to MIFO. The goal is that this report will provide a basis for future studies and remedial measures at the landfill.</p><p>To get a picture of what has been deposited at the landfill Gräsötippen, employees and former employees at Yara and others with connection to the landfill have been interviewed. Piezometers have been installed in and around the landfill so as to provide information on groundwater levels and movement, and for the collection of groundwater samples. Soils samples were collected as well. The water and soil samples were analyzed with regard to metals, organic compounds and nutrients. Furthermore, groundwater flow has been modeled using VS2DI, in order to get a picture of the groundwater’s flow direction and velocity under the landfill.</p><p>In the water samples, only lead was detected with levels over the Maximum Contaminant Level (MCL) from the EPA. Relatively high levels of nutrients were also detected. In the soil, carcinogenic PAH, PCB, aliphatic hydrocarbons, aromatic hydrocarbons, arsenic, lead, cadmium, mercury and zinc were detected over the EPA MCL. The landfill Gräsötippen has a good location in an area with deep clay, which prevents rapid spreading of contaminants. No high levels of contaminants are leaching out today. The spreading of the contaminants is minor; most of the contaminants are fixed in the soil and do not spread to the surroundings. The water flow’s primary direction from the landfill is south but there are also flows to the west and east. Today, there are a number of proposals with regard to decreasing the risk for future contaminant dispersal from the landfill and to keep control of the water that is used in the area. A few of these proposals are to finally cover the landfill, to analyze the grass and plants in the enclosed pasture on the landfill, and to continuously analyze the water in the installed piezometers and drinking water wells on and around the landfill. The landfill Gräsötippen is classified to risk class 3, moderate risk, according to MIFO.</p> / <p>Det uppskattas idag finnas 22 000 förorenade områden i Sverige. För att kunna riskklassa dessa förorenade områden och prioritera vilka som först bör efterbehandlas har Naturvårdsverket utarbetat en Metodik för Inventering av Förorenade Områden (MIFO). Gräsötippen utanför Köping är ett av dessa förorenade områden. Deponin har använts av både Yara AB och Köpings kommun mellan åren 1945-1975 och fungerat som deponi för både industri- och hushållsavfall. Syftet med denna rapport är att kartlägga vilka föroreningar som finns i mark och vatten i Gräsötippen och tolka föroreningarnas spridning. Utifrån den informationen ska deponin sedan riskklassas enligt MIFO. Målet är att rapporten ska kunna fungera som underlag för framtida åtgärdsplaner för Gräsötippen.</p><p>För att få en bild över vad som har deponerats på Gräsötippen har anställda och före detta anställda vid Yara samt andra som har haft anknytning till Gräsötippen intervjuats. Grundvattenrör har installerats i och runtom deponin för att det skulle kunna tolkas hur grundvattnet rör sig under deponin och för att det skulle kunna tas prover på grundvattnet och jorden. De vatten- och jordprover som togs, analyserades med avseende på metaller, organiska föreningar och närsalter. Dessutom har en modellering utförts i VS2DI för att få en bild över grundvattnets flödesriktning och hastighet under deponin.</p><p>I vattenproven detekterades endast bly över Naturvårdsverkets riktvärde samt relativt höga halter av närsalter. I jorden detekterades cancerogena PAHer, PCB, alifater, aromater, arsenik, bly, kadmium, kvicksilver och zink över Naturvårdsverkets riktvärden. Gräsötippen är bra placerad i ett område med tjock lera som förhindrar snabb spridning och idag lakas inga höga halter av föroreningar ut. Spridningen av föroreningar är liten, istället ligger de flesta föroreningarna fast i marken och sprids därmed inte till omgivningen. Vattenflödets huvudriktning från deponin är söderut, men det sker även flöden åt både väster och öster. Det finns i dagens läge en del förslag på åtgärder som bör utföras på Gräsötippen för att minska risken för framtida spridning och upprätthålla kontroll på det vatten som används i närområdet. Några av dessa åtgärder är att sluttäcka deponin, att analysera gräs och växter i hagen på deponin samt att kontinuerligt analysera vattnet i grundvattenrören och brunnarna på och runt Gräsötippen. Vid riskklassningen av Gräsötippen enligt MIFO, klassas den till riskklass 3, måttlig risk.</p>

The recent lowering of the arsenic MCL from 50 ppb to 10 ppb in 2006 will cause many utilities to implement new technologies for arsenic removal. Most of the affected utilities are expected to use adsorption onto solid sorbents for arsenic removal, especially in the arid Southwest, where conserving and re-using water is of utmost importance. This would cause the generation of more than 6 million pounds of arsenic residuals every year, which then would be disposed of in landfills. This thesis effort focuses on the testing of different aluminum and iron (hydr)-oxide based sorbents that are likely to be used for arsenic removal and assessing the behavior of these Arsenic Bearing Solid Residuals (ABSRs) under landfill conditions. It was demonstrated that the Toxicity Characteristic Leaching Procedure (TCLP) test underestimates the arsenic mobilization in landfills. Desorption of arsenic from ABSRs was quantified as a function of the range of pH and concentrations of competitive anions like phosphate, bicarbonate, sulfate and silicate and NOM found in landfills. The effect of pH is much more significant than the anions and NOM. Arsenic release due to competition of different anions is neither additive nor purely competitive. Landfill conditions were simulated inside long-term, continuous flow-through column reactors, and arsenic mobilization from sorbents was measured under those conditions. The results indicate that under reducing conditions, and in the presence of other competitive anions and high organics, microbes reduce arsenate to arsenite, which is a much more mobile species. Fe(III) is also reduced to Fe(II) under these conditions. Arsenic is transported in the particulate phase, associated with the iron, much more than in the dissolved phase. It was also observed that the sorbent itself might leach away at a faster rate than the arsenic sorbate causing a depletion of surface sites and a sudden spike in the release rate of arsenic, after a long residence time. Finally, investigation of different solid sorbents indicate, that the rate of leaching and the form of arsenic released varies widely and is independent of the respective adsorption capacities, even under similar leaching conditions.

No description available.

Student Number : 9902262G - MSc Dissertation - School of Molecular and Cell Biology - Faculty of Science / Anaerobic fermentative bacteria degrade waste components in landfills where methane (CH4) and carbon dioxide (CO2) are the primary biogases emitted and methanotrophic bacteria in the cover soil oxidise the emitted CH4. Three bi-phasic bench-scale landfill bioreactors were commissioned to evaluate soil nutrient addition effects on CH4 formation and oxidation and to isolate inherent soil methanotrophs using Nitrate Mineral Salts (NMS) medium. Set A soil contained no nutrient additions, Set B soil contained 50 μM nitrate and 150 μM phosphate and Set C soil contained dried sewage cake. Bioreactors were run for a 4 week period and pH, anaerobic gas emissions, volatile fatty acids (VFA), bacterial counts and scanning electron microscopy (SEM) analyses were performed. A pilot study revealed that pH dictated the stability of methanogenesis, where increased VFA levels inhibited methanogenesis. Furthermore, it was revealed that modifications of the NMS medium were needed to enrich for methanotrophs. An in depth study showed that the Set C anaerobic reactor produced the most methane with Set B the least. The hypothesis that methane oxidation in the soil could regulate methane formation in the waste could not be conclusively observed, as a lack of aeration in the soil reactors is believed to have prevented the proliferation of methanotrophs here. No methanotrophs were successfully isolated from soil, but rather major heterotrophic bacterial interference was observed. SEM revealed the presence of rod and cocci forms of bacteria in both leachate and soil, consistent with literature reports, which indicated that the bench-scale landfill bioreactors were capable of promoting bacterial growth.

Thesis advisor: Rudolph Hon / Groundwater in the Shepley's Hill Landfill (SHL) area had a high arsenic concentration for at least 20 years. This study is aimed at understanding the migration pathways of arsenic in the SHL area and postulating the possible sources and mechanisms for the mobilization of arsenic. A direct-push sampling technique (DPT) was applied in the summer of 2010 within the SHL and its downgradient area, which provided groundwater samples from various depths and locations. A long-term monitoring dataset from 1998 to 2009 was utilized as a subsidiary source for temporal analysis. Spatial distributions of arsenic and other major dissolved compositions were analyzed. Extremely high arsenic concentrations (up to ~ 15000 µg/L) were detected in the deep glacial sand deposits close to a peat layer within the SHL. Arsenic concentrations decrease dramatically in the downgradient area north of the SHL. The transport of arsenic in the SHL area is similar to that of iron. The source of arsenic is likely to been within the boundary of the SHL. The glacial sand overburden within the SHL provides enough source for the arsenic mobilization. A possible mechanism of arsenic mobilization in the SHL area is that the reductive dissolution/desorption of arsenic from iron bearing minerals under a lasting reducing environment created by decompositions of organic matter in waste and peat. / Thesis (MS) — Boston College, 2013. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Earth and Environmental Sciences.