AWWA MTC93022

This paper covers problems with disposal of brines or concentrate from membrane plants in Florida. Most problems stem from environmental concerns about discharge to surface water or aquifers. There are two main issues involved in the permitting of surface water disposal of membrane concentrate. The first centers around antidegradation issues and the prohibition on discharge of toxic substances to the aquatic environment. The second is the provision of a mixing zone at a point of discharge. One alternative is disposal of the waste to groundwater through injection wells or land application. However, regulations about water quality to protect groundwater limit the usefulness of this option. A third option is codisposal, when water is recombined with water it was separated from by the membrane process. Finally, there is some potential for reuse, meaning that it may be blended with ground or surface water. The author concludes that regulations of concentrate disposal will tend to keep the application of membrane processes near the coastlines. This is where the most feasible saline or brackish environments or deep injection wells are located.