Griffin Fluid Management

Airport Expansion PFAS Treatment Project

Austin, Texas

ENGINEER

Walter P. Moore & Associates

TIME

February 2016- March 2016

GRIFFIN DIFFERENCE

The deep excavation dewatering system was successfully completed in just over 1-month and stayed in operation for the duration of the 9-month project. Due to the unexpected contamination, Griffin’s ability to quickly modify the scope of the project and provide water treatment was essential in keeping to the construction schedule. To ensure early detection of any media breakthrough, and to prevent any out of compliance discharges, Griffin incorporated the use of lead-lag series configuration in our treatment methodology.

THE CHALLENGE

Construction of a new deicing facility at the airport required lowering groundwater more than 35 ft. for an excavation approximately 250 x 200 ft. During the start of the dewatering project, the groundwater was found to contain perfluorinated alkyl acids (PFAS) which are among EPA’s list of emerging contaminants. The PFAS family of chemicals is made up of various long and short chain compounds, that are often difficult to treat. A sophisticated water treatment system was needed to discharge any water from the site.

THE SOLUTION

To obtain the required drawdown, 20 deep wells were installed to 50 ft. surrounding the Soil Nail and Shotcrete shoring system. 1-2 HP submersible pumps were installed in each well. The entire system pumped approximately 500 GPM and provided water level drawdown to more than 35 ft. below ground surface for the duration of the project.

To treat the water for discharge, Griffin applied an innovative mix of filtration media to treat for both long and short chain PFAS. The system continuously handled the 500 GPM flow from the dewatering wells. The treated water was comprehensively tested and the PFAS were reduced to non-detectable levels at the end of the treatment train.