ENVIRONMENTAL IMPACTS OF AQUIFER STORAGE AND RECOVERY

Congress recently appropriated approximately $8 billion for Everglades Restoration in Florida. The U. S. Army Corps of Engineers plans to use much of those funds to construct 330 'aquifer storage and recovery' ('ASR') wells for injection and withdrawal of 'excess' water into the regional karst Floridan aquifer system underlying the Everglades. Although no 'excess' water occurs in nature, agricultural and urban stormwater runoff are considered 'excess' water. Treated effluent also is injected in Florida's existing ASR wells. No agencies have implemented monitoring programs to evaluate environmental damage caused by ASR injections and withdrawals. Examples of environmental damage caused by groundwater withdrawals in Florida include: altered natural hydroperiods (including seasonal fluctuations, flows and levels) of wetlands, lakes, and streams; reduced submarine groundwater discharge and spring discharge; saltwater intrusion; and associated depletion of lower-food chain levels, premature death of native trees, conversion/loss of natural habitat (e.g., destructive wildfires, alien species), and loss of natural terrestrial and coastal biodiversity. Areas surrounding Florida's long-term ASR wells exhibit impacts similar to those of municipal 'withdrawal-only' wells. Fluids injected into ASR wells generally are less dense than the formation water of the receiving aquifer, resulting in a tendency for injected fluids to migrate vertically upward, as well as laterally (into surface waters). Therefore, water quality-related environmental damage from induced discharge of injected stormwater runoff and treated effluent can occur, in addition to the water quality-related impacts described above. Evidence of surfacewater contamination from induced-discharge of injected fluids has been documented in Florida. The need for wide-spread monitoring of environmental harm, and re-establishing natural recharge is warranted before committing billions of tax dollars to 'ASR'.