The Need for a Water Treatment Plant Expansion and Advanced Treatment

Due to economic growth throughout the region and to address the needs of its member governments, the Piedmont Triad Regional Water Authority plans to expand its John Franklin Kime Water Treatment Plant. The facility will be expanded from its current production capacity of 14.7 million gallons per day to a finished water production capacity of 26.7 MGD. In addition, PTRWA wants to proactively address emerging compounds that have been detected in its water supply reservoir by moving forward with adding advanced treatment to the expanded water treatment facility. 

From Pilot Study to Preliminary Engineering Report

PTRWA partnered with HDR to conduct an alternative analysis to help the region select an advanced treatment technology. The primary objective was to evaluate process alternatives, select an approach, and confirm preliminary design criteria for a surface water treatment plant expansion that will also handle emerging contaminants. The existing surface water treatment plant utilizes SuperPulsators, granular media filters, low-pressure membrane filtration and GAC contactors. Multiple treatment strategies were tested at the bench- and pilot-scale level to handle PFAS, 1,4-dioxane, iron and manganese, and organics removal.

The main four advanced treatment technologies evaluated were reverse osmosis membranes, ozone/advanced oxidative processes, UV/advanced oxidative processes, and granular activated carbon. We conducted chlorine dioxide testing, assisted PTRWA in the start-up and operation of a reverse osmosis membrane pilot and coordinated additional bench-scale testing to confirm design criteria for treatment alternatives. Following testing completion, we developed candidate treatment trains that incorporated long-term build-out needs along with recommended treatment technologies that handle emerging contaminants while also addressing iron, manganese, and organics removal.

Following the successful study, PTRWA selected RO membranes for advanced treatment. The next phase of this project will be the design-build of these recommended improvements.