Monitoring Of Waste Disposal Sites Research Articles

A UAV-Based Thermal-Imaging Approach for the Monitoring of Urban Landfills

The monitoring of waste disposal sites is important in order to minimize leakages of biogas, produced by anaerobic digestion and potentially explosive and detrimental to the environment. In this research, thermal imaging from unmanned aerial vehicles (UAVs) has been proposed as a diagnostic tool to monitor urban landfills. Since the anaerobic decomposition produces heat along with biogas, thermal anomalies recorded over the soil are likely to be associated with local biogas escaping from the landfill terrain and leaving a local thermal print. A simple and novel approach, based only on the processing of thermal maps gathered by the remote sensing surveys, has been proposed for the estimation of the fugitive methane emissions from landfills. Two case studies, concerning two Italian landfills, have been presented. For one of them (Mount Scarpino, Genoa), significant thermal anomalies were identified during several UAV flights and the relevant thermal images processed to obtain a rough estimation of the associated methane leakages. For the second landfill (Scala Erre, Sassari), the thermal map did not reveal any anomaly attributable to local biogas emission. Despite some limitations outlined in the paper, the present approach is proposed as an innovative method to identify significant biogas leakages from an urban landfill and to provide a preliminary evaluation of the methane production potential.

The geology and hydrogeology of buried bedrock valley aquifers on Cape Breton Island, Nova Scotia: an overview

Buried bedrock valley aquifers are common across Canada, where multiple glaciations have buried both pre-glacial and Pleistocene valleys. These aquifers are becoming increasingly important as a supply of potable groundwater, for supporting aquatic habitat, and as part of strategies in adapting to a changing climate. However, in Canada, there are considerable knowledge gaps at national, regional, and local scales, such that many buried bedrock valleys remain unidentified or underexplored. Cape Breton Island provides a hydrogeological view into the roots of an ancient mountain range, now exhumed, glaciated, deglaciated, and tectonically inactive. Since the Cretaceous, a variety of geological processes have formed several buried bedrock valley aquifers over the island. These aquifers are important in providing municipal and commercial groundwater supplies, controlling mine dewatering, protection of salmonids, design and monitoring of waste disposal sites, and geotechnical investigations for infrastructure design. Of 150 sites assessed, 61% provided evidence of buried aquifers comprising unconsolidated sand and gravel of Cretaceous, Pleistocene, and Holocene ages. These sites provided the basis for five conceptual, 3-D hydrogeological block models. Three hydrogeological case studies provided further insight into the functioning of two of these models. Future studies should identify and characterize aquifers in high demand areas and/or those that support important riverine ecosystems. Research should focus on aquifer properties, groundwater-stream interaction, and the impact of changing climate with sea-level rise.

Mapping Waste-disposal Sites Using SPOT Remote Sensor Data: Riyadh Case

Four SPOT multispectral subscenes at scale of 1/100000 (spatial resolution 20 m) and covering the City of Riyadh and surroundings were used to map waste-disposal sites on the outskirts of this rapidly expanding city. Digital image processing techniques, using Earth Resources Data Analysis System (ERDAS) software, were employed for this purpose. The results showed that digitally processed remote sensor data could be valuable source of information for inventory and monitoring of waste-disposal sites and their effects on the urban and suburban environment. Further, the results could well serve as valuable input layer for a more sophisticated geographic information system (GIS) of the city.

Compliance with California Title 23 and SWAT in an Arid Environment: Use of Oil-Well Data to Minimize On-Site Investigations

California Title 23 and the Solid Waste Assessment Test (SWAT) program, as administered by the Regional Water Quality Control Boards (RWQCB), require extensive characterization and monitoring of waste disposal sites. Typical SWAT/Title 23 investigations require multiple characterization boreholes in addition to groundwater and unsaturated zone monitoring. In an arid environment such as the southwestern San Joaquin Valley, many of these requirements become impracticable. Regions such as these are often characterized by extreme depths to groundwater, non-potable groundwater, and moisture deficient and hydrocompacted soils. Through the use of oil-field data, an accurate portrayal of subsurface conditions at a SWAT-ranked site was possible. Because of the extensive background material available and the relatively benign nature of the site, a single borehole was deemed by the REQCB to be an acceptable characterization of the site. As predicted from the background data review, this borehole was drilled to 1,000 ft in depth without encountering a water-saturated interval capable of yielding a sample. In addition, oil-saturated intervals were encountered beneath the site as predicted.