INITIAL AQUIFER PERFORMANCE TESTING RESULTS OF THE LAKE OKEECHOBEE WATERSHED RESTORATION PROJECT AQUIFER STORAGE AND RECOVERY WELLS

The Lake Okeechobee Watershed Restoration Project (LOWRP) is part of the Comprehensive Everglades Restoration Plan planning effort, the largest hydrologic restoration project in U.S. history. Designed to improve water levels and water quality in Lake Okeechobee, the LOWRP also will improve the quantity and timing of discharges to the St. Lucie and Caloosahatchee estuaries, increase the size and functionality of wetlands, and improve water supply for existing legal water users. The aquifer storage and recovery (ASR) program will consist of approximately 55 ASR wells completed in two separate flow zones; Upper Floridan aquifer (UFA) and the Avon Park permeable zone (APPZ). Each ASR well will be able to inject and recover approximately 5 MGD with a combined ASR wellfield capacity of 275 MGD of treated surface water to help fortify South Florida’s ecology and surface water systems.

Upon completion of construction, pre-acidization, and post-acidization step drawdown testing was performed to better understand well efficiency at 1.5 times the design rate of 5 MGD. Acidization and step drawdown testing was successful, especially in the case of the APPZ ASR (post-acidization step drawdown testing) which was tested at a maximum of 6,000 gpm and flowed artesian just above the design rate at 3,670 gpm. Preliminary findings and data from the four 5-day aquifer performance tests (APTs) at the C-38N and C-38S sites will help to determine aquifer hydraulics and evaluate if there is leakance between aquifers or semi-confining units. The APTs will consist of a simultaneous artesian flow tests and constant-rate pumping tests at 5,200 gpm (individually and simultaneously) on both the UFA and APPZ ASR wells. Drawdown and monitoring well water levels are plotted in real-time and will be immediately sent to modelers to be input into a groundwater model to determine adequate well spacing between future ASR well pairs.