AWWA SRC57769

In South Florida, Class I injection wells have been a part of the waste disposal system for over 30 years. In the past several years, elevated concentrations of ammonia along with depressed salinity relative to native water in the Floridan Aquifer System have been reported in monitoring wells in aquifer zones overlying the injection zone. This finding has raised concerns of the regulatory agencies regarding the extent of migration of injected water. An investigation undertaken by the University of Miami evaluated the relative risk of injection well disposal versus the two other options permitted in south Florida. That study gathered water quality data on wastewater treatment plant effluent along with water quality data on the receiving waters. The results indicated that health risks associated with deep wells were generally lower than those of the other two alternatives, and that the proximity of injection wells to aquifer storage and recovery wells was found to determine the primary injection well risk. Additional data collection and analysis were recommended. That study was extended to evaluate other users of the Floridan Aquifer system for production or as aquifer storage and recovery, based on depth, location and proximity to an injection well. The results are significantly different when aquifer storage and recovery wells are moved to within the regulatory defined horizontal spacing, or the vertical distance decreases. This paper discusses and recommends that further risk assessment tools be developed, using the potential impact of pharmaceuticals on ASR and raw water supplies as a measuring stick. Includes 5 references, tables, figures.

Product Details

Edition:

Vol. - No.

Published:

01/19/2003

Number of Pages:

10

File Size:

1 file , 250 KB