When planning for sea level rise (SLR), it is important to understand its specific effects. This dissertation presents a review of recent research on potential pathways for contaminant releases related to SLR, and adaptation measures to prevent or minimize impacts. SLR can increase salinity in soils, sediment, soil pore water, surface water and groundwater in coastal areas and further inland. It can change the geomorphology of aquifers, reducing their capacity. Groundwater rise, flooding, soil and ecosystem salinization, liquefaction, earthquakes, release and/or precipitation of contaminants, and corrosion of metal and concrete materials may result. These may damage contaminant containment and wastewater conveyance infrastructure causing releases of toxic chemicals. Released contaminants could affect structures, agriculture, public health, and the environment. Once tetra-/tri- chloroethene (PCE/TCE) contamination is released into the soil and water, microbial metabolism of PCE/TCE and associated electrolytic cell activity can cause corrosion of metal, pipelines, and concrete. Furthermore, PCE may diffuse through certain water pipe materials into the water supply. Salinity and pH changes associated with SLR may mobilize and increase the bioavailability and ecotoxicity of heavy metals. Saline and freshwater mixing often create natural biogeochemical reactors (where oxygen, metals, water, organic matter, salt, and nutrients mix) that can directly mineralize PCE/TCE without accumulation of intermediate daughter products. Similar chemical transformations have been observed in lab settings in microbial electrolytic cells (MECs). Microbial fuel cells (MFCs) can also be used to remove HMs through heavy metal reduction at cathodes. Integrating MECs/MFCs and/or the bioelectrochemical reactions into the built environment may be an effective method for eliminating and buffering against PCE/TCE and HM hazards. Mapping of pollution vulnerability areas and natural biogeochemical reactors could guide and facilitate regional and site-based remedial design, and facilitate development of affordable and sustainable nature-based adaptation solutions designed to mimic these systems. Based on the literature review, predictors of PCE/TCE pollution vulnerability were identified and evaluated for statistical and physical significance using geostatistical and statistical analysis, and the Weight of Evidence methods. Decision tools developed included GIS geospatial risk indices and maps, and a numeric model of seawater intrusion and PCE/TCE fate and transport using MODFLOW 6, MT3DMS, and MODPATH. Regulatory engineering, policy, procedural, decision-making, and science, technology, and engineering recommendations were made for effective adaptation.
