COLLECTION AND DIGITIZATION OF UNDERGROUND INJECTION CONTROL (UIC) CLASS V NON-ASR WELL DATA IN SOUTHEAST FLORIDA

Coastal communities, like Broward (BC) and Miami-Dade Counties (MDC) of Southeast Florida, are experiencing increasing challenges from sea-level rise and saltwater intrusion. As in several coastal communities, BC and MDC are faced with increasing population sizes and rapid development that makes these challenges more pressing. To mitigate this, the counties, USGS, and the South Florida Water Management District have established a network of monitoring wells to observe water quality near municipal wells and track saltwater intrusion into the Biscayne Aquifer. These stations are primarily focused on the saturated zone at the base of the aquifer and are located further inland with few stations near the coastline and barrier islands. Therefore, our understanding of the saltwater-freshwater interface closer to the shoreline and barrier islands is limited.

The Florida Department of Environmental Protection (FDEP) regulates well construction through the Underground Injection Control (UIC) program. This program includes wells designed for a variety of purposes including treated wastewater disposal, oil and gas production, aquifer storage and recovery, and other uses, such as stormwater drainage, which frequently takes the form of rooftop rainwater injection in dense urban areas. Our project focused on UIC Class V Non-ASR wells within 1 kilometer of the shoreline in MDC and BC to gain a better understanding of the saltwater-freshwater interface. ArcGIS Pro was utilized to identify the target wells and the FDEP database website Oculus was used to obtain the Well Certification of Completion reports.

Approximately 10,000 Class V Non-ASR wells were identified within 1 kilometer of the shore. Data collected and digitized from the scanned online Portable Document Format (pdf) reports include diameter, well and casing depth, total dissolved solids, static and pumping water level, specific capacity, and coordinates. Using these data, transmissivity of the aquifer was calculated and the approximate position of the saltwater interface was mapped. These data will provide a better understanding of the saltwater extent proximal to the shoreline in the Biscayne Aquifer and help to enable estimation of the impact of recharge water fluxes at depth from injected rooftop rainwater, which is not currently a factor considered in models of the Biscayne Aquifer.