Unmanned aerial vehicles for the assessment and monitoring of environmental contamination: An example from coal ash spills

• Published in: Environmental pollution (1987) 2016-11, Vol.218, p.889-894
• Main Authors: Messinger, Max, Silman, Miles
• Format: Article
• Language: English
• Subjects: Aircraft; Chemical Hazard Release; Coal - analysis; Coal ash; Coal Ash - analysis; Environmental Monitoring - instrumentation; Environmental Monitoring - methods; North Carolina; Pollution monitoring; Remote Sensing Technology - instrumentation; Rivers - chemistry; SfM; Spill monitoring; Structure-from-motion; UAV; Unmanned aerial vehicles; Unmanned aircraft; Water Pollutants, Chemical - analysis; Water Supply - standards
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/j.envpol.2016.08.019

Unmanned aerial vehicles (UAVs) offer new opportunities to monitor pollution and provide valuable information to support remediation. Their low-cost, ease of use, and rapid deployment capability make them ideal for environmental emergency response. Here we present a UAV-based study of the third largest coal ash spill in the United States. Coal ash from coal combustion is a toxic industrial waste material present worldwide. Typically stored in settling ponds in close proximity to waterways, coal ash poses significant risk to the environment and drinking water supplies from both chronic contamination of surface and ground water and catastrophic pond failure. We sought to provide an independent estimate of the volume of coal ash and contaminated water lost during the rupture of the primary coal ash pond at the Dan River Steam Station in Eden, NC, USA and to demonstrate the feasibility of using UAVs to rapidly respond to and measure the volume of spills from ponds or containers that are open to the air. Using structure-from-motion (SfM) imagery analysis techniques, we reconstructed the 3D structure of the pond bottom after the spill, used historical imagery to estimate the pre-spill waterline, and calculated the volume of material lost. We estimated a loss of 66,245 ± 5678 m3 of ash and contaminated water. The technique used here allows rapid response to environmental emergencies and quantification of their impacts at low cost, and these capabilities will make UAVs a central tool in environmental planning, monitoring, and disaster response. [Display omitted] •UAVs provide new opportunities to accurately quantify pollution.•We used UAV imagery and structure-from-motion to estimate the volume of coal ash spilled from a settling pond.•We provided an independent estimate of the volume of the spill using low-cost, easy-to-use technology. We demonstrate the utility of UAVs in rapidly responding to environmental emergencies and measuring their impacts through the case study of a coal ash settling pond rupture.