Climate change, sea level rise, and storm surge events are now significant factors threatening critical water and wastewater infrastructure. Extreme storm events have increased the need for the preparation required to face the challenges of climate change. In October 2012, Hurricane Sandy impacted 13 wastewater treatment facilities in New York City alone, causing millions of dollars in damage. Sandy was only a tropical storm, with a wind speed of $22.35{\mathrm{ms}}^{-1}$ ($50\mathrm{mi}/\mathrm{h}$ ), when it made landfall in New York; however, it caused havoc because it combined with other local cascading events. The storm damage was caused by cascading synergistic events, including storm surge, sea level rise, and rain, rather than a singular decisive event of factor. The disaster left behind by Superstorm Sandy alone magnifies the dire need to understand the damage scenarios and consequences, and to identify resiliency plans and mitigation strategies that take into account a multitude of parameters that contributed to the intensified and devastating impacts. This work formulated the critical factors into a new concept introduced here as total water level (TWL). Using hydrodynamic models, the flood depths and elevations were calculated for various return periods and hurricane categories for coastal and riverine flooding, considering TWL to demonstrate the role of cascading events. The results show the compound effect of extreme storm events as hurricane surge combines forces with sea level rise and rainfall events; it translated into an additional 2.74–4.26 m of flooding in two studied locations.

Subsurface fires and smoldering events at landfills can present serious health hazards and threats to the environment. These fires are much more costly and difficult to extinguish than open fires at the landfill surface. The initiation of a subsurface fire may go unnoticed for a long period of time and undetected fires may spread over a large area. Unfortunately, not all landfill operators keep or publish heat elevation data and many landfills are not equipped with a landfill gas extraction system to control subsurface temperatures generated from the chemical reactions within. The timely and cost-effective identification of subsurface fires is an important and pressing issue. In this work, we describe a method for using satellite thermal infrared imagery at a moderate spatial resolution to identify the locations of subsurface fires and monitor their migration within landfills. The focus of this study was the Bridgeton Sanitary Landfill in Bridgeton, MO, USA where a subsurface fire was first identified in 2010 and continues to burn today. Observations from Landsat satellites over the last seventeen years were examined for surface temperature anomalies (or hot spots) that may be associated with subsurface fires. The results showed that the locations of hot spots identified in satellite imagery match the known locations of the subsurface fires. Changes in the hot-spot locations with time, as determined by in situ measurements, correspond to the spreading routes of the subsurface fires. These results indicate that the proposed approach based on satellite observations can be used as a tool for the identification of landfill subsurface fires by landfill owners/operators to monitor landfills and minimize the expenses associated with extinguishing landfill fires.

Wastewater treatment plants (WWTPs) in the City of New York, United States, are particularly vulnerable to frequent extreme weather events, including storm surges, high-intensity rainfall, and sea level rise, and are also affected by the cascade of these events. The complex structural configuration of WWTPs requires very fine-scale flood risk assessment, which current research has not pursued. We propose a robust technique to quantify the risk of inundations for the fourteen WWPTs through an automated sub-basin creation tool; 889 sub-basins were generated and merged with high-resolution building footprint data to create a comprehensive database for flood inundation analysis. The inundation depths and extents for the WWTPs and flood-prone regions were identified from hydrodynamic modeling of storm surge and sea level rise. The economic damage due to flooding for the WWTPs was also quantified using the HAZUS-MH model. Results indicated that the storm surges from various categories of hurricanes have the dominant impacts on flood depths around WWTPs, followed by high-intensity rainfall. Sea level rise was shown to have a relatively minor impact on flood depths. Results from economic damage analysis showed that the WWTPs are subjected to damage ranging from USD 60,000 to 720,000, depending on the size of the WWTP and the extremity of storm surge. The method of analyzing the inundation status of the research object through the sub-basin enables more accurate data to be obtained when calculating the runoff. It allows for a clearer view of the inundation status of the WWTPs when combined with the actual buildings. Using this database, predicting flood conditions of any extreme event or a cascade of extreme events can be conducted quickly and accurately.