Vulnerability assessment of hazardous material installations subject to sea level rise and storm surges in coastal Delaware
Brown, Sr., Joseph D.
University of Delaware
One of the most significant impacts of global climate change for Delaware will be changes to and losses of the State's coastal resources from sea level rise (SLR). These changes could have major economic and social consequences for a wide range of public and private interests through shoreline erosion, inundation of wetlands and uplands, changes to habitat and damage to public infrastructure. The research in this thesis conducts a vulnerability assessment to identify facilities under the regulatory authority of the Division of Waste and Hazardous Substances located in the path of rising water and storms, assess their vulnerability to damage which may cause release of hazardous substances, and, where appropriate, initiate action plans to prevent such releases. In 2009, DNREC formed a Sea Level Rise Technical Workgroup to provide the Department with planning scenarios for sea level rise to the year 2100. The group chose to recommend a range of three scenarios to DNREC because it is not possible to precisely predict future rates of sea level rise. The Technical Workgroup's recommended scenarios between now and the year 2100 are: 1. Low Sea Level Rise (SLR) Scenario - 0.5 meters (1.6 feet) 2. Intermediate Sea Level Rise (SLR) Scenario - 1.0 meter (3.3 feet), 3. High Sea Level Rise (SLR) Scenario - 1.5 meters (4.9 feet). In this thesis, interactive geospatial inundation maps were created from the DNREC Sea Level Rise Scenarios using ArcGIS software and hazardous materials storage facilities were identified in Delaware that were located within the 0.5, 1.0 and 1.5 meter SLR Scenario areas. Current and future storm surge effects were also evaluated. Through the use of results obtained from site inspections and the analysis of these maps in conjunction with DNREC personnel experienced with hazardous material facilities, a "At Risk" list was generated of those facilities and SIRS sites that had the greatest potential for impact from flooding and storm surge. Analysis also indicated that less than 11% of tank style storage vessels are located within the 1.5 meter SLR scenario inundation area. SIRS Sites were impacted to a greater degree with approximately 24% of all Delaware sites located within the 1.5 meter SLR scenario inundation area. As part of this assessment, the effects of storm surge were also given consideration, presenting data from a University of Washington Study indicating the average maximum estimated tidal heights above Mean Higher High Water (MHHW) along the coast of Delaware could range from 1.16 meters for a storm with a return frequency of once a year to 2.14 meters for a storm with a return frequency of once in 100 years by the year 2050. Another major finding of this assessment indicated that there are a large number of unregulated storage tanks and pressure vessels that pose a threat to public safety and environmental health during a flood event. Further study and site assessments are recommended beginning with those facilities "At Risk" of impact from a 1.5 meter rise in sea level.