Recent regulatory changes have necessitated the development and evaluation of technologies used to treat arsenic, perchlorate, and nitrate in drinking water. Currently, the most widely used and accepted treatment technologies for the removal of these contaminants involve the generation of a concentrated waste stream, which must be further treated or disposed. Carollo’s team, including Applied Research Associates, Environmental Engineering and Technology, and Caltech, was selected by the American Water Works Association Research Foundation to investigate arsenic, perchlorate, and nitrate brine and concentrate treatment alternatives, which are critical waste management issues.
The objectives of this proposed research are to:
• Identify different types of residuals generated and approaches required to meet overall arsenic, perchlorate, and nitrate treatment goals.
• Develop and evaluate processes to manage and treat concentrate waste streams.
• Review pertinent regulations and compare costs and implementation issues associated with various treatment and disposal scenarios.
• Describe the results of this work in a document that will serve as a tool to help utilities develop residuals minimization and handling strategies. During this project, tests were performed to stabilize or treat sludge from conventional treatment, backwash water from filtration process, liquid brine from ion exchange, or concentrate from high-pressure membrane.
This study demonstrated technologies that can be implemented for the treatment of various types of residuals. The final assessment provided a basis for utilities to evaluate overall contaminant management strategies and included evaluations of various residual management costs, discharge alternatives, and regulatory perspectives.
Carollo was selected as the prime contractor for one of the most competitive arsenic projects in AwwaRF history.