Groundwater Pilot Treatment System Update May 2017

Agenda Background for Pilot Treatment System Testing Pilot Treatment System Configuration Pilot Testing Results Observations / Questions Next Steps

Agenda Background for Pilot Treatment System Testing Pilot Treatment System Configuration Pilot Testing Results Observations / Questions Next Steps

Background Feasibility Study Analysis Option D4 Extraction and ex-situ treatment of high concentration impacted groundwater with re-infiltration of treated groundwater upgradient of extraction point Agreed Order No. 2692, Amendment No. 1 Conduct Pilot Treatability Testing Construct and operate pilot system under Ecology oversight

Agenda Background for Pilot Treatment System Testing Pilot Treatment System Configuration Pilot Testing Results Observations / Questions Next Steps

Pilot System Configuration System Components Groundwater extraction well Extracted groundwater holding tanks Walnut Shell Filter Pretreatment metering system Treated groundwater holding tanks Filter backwash tanks Re-infiltration system

Agenda Background for Pilot Treatment System Testing Pilot Treatment System Configuration Pilot Testing Results Observations / Questions Next Steps

Pilot Plant Testing Pilot System Test Program Initial testing protocol Fixed flowrate ~32 gallons /minute (2.7 gpm/ft2) Impact of pretreatment with castor oil Two runs – 0 ppm castor oil Two runs – 8 ppm castor oil Two runs – 4 ppm castor oil Process parameter Bed Volumes (BVs) Sampling Frequency Initially every 50 BVs

Pilot Plant Testing Groundwater PCB Pilot Plant Testing Testing with 0 ppm castor oil Run 1 ~85% PCB removal efficiency through 800 BVs Linear drop off in efficiency to ~30% by 1,600 BVs Backwash contained minimal PCB levels, less than 2% of loading Run 2 Initial removal efficiency ~80% through 50 BVs Backwash contained slightly higher PCB levels

Pilot Plant Testing Groundwater PCB Pilot Plant Testing Testing with 8 ppm castor oil Run 3 Dosing system initially overshot set point - ~30 ppm Initial removal efficiency ~90% through 800 BVs Drop off in efficiency to ~80% for 800 to 1,600 BVs Run 4 Initial removal efficiency ~80% through 250 BVs Rapid drop off in efficiency to ~45% through 1,600 BVs

Pilot Plant Testing Groundwater PCB Pilot Plant Testing Testing with 4 ppm castor oil Run 5 Initial removal efficiency ~70% through 200 BVs Drop off in efficiency to ~40% for 600 to 1,600 BVs Run 6 Initial removal efficiency ~60% through 200 BVs Slow drop off in efficiency to ~45% through 1,600 BVs

Pilot Plant Testing

Agenda Background for Pilot Treatment System Testing Pilot Treatment System Configuration Pilot Testing Results Observations / Questions Next Steps

Observations / Questions High oil level in Run 3 may have impacted subsequent runs Run 3 (~30 ppm) showed fairly consistent removal efficiency between 90% and 80% Run 4 (8 ppm) started with lower initial removal efficiency, ~80%, but removal efficiency did not remain stable Run 5 (4 ppm) started with ~70% removal efficiency but removal efficiency did not remain stable Run 6 (4 ppm) started with ~60% removal efficiency but removal efficiency did not remain stable

Observations / Questions Extracted groundwater concentrations are highly variable with single extraction point at about a 50 gpm extraction rate Extraction system design likely critical for maximizing concentration in extracted groundwater

Observations / Questions With oil being continuously added, why did removal efficiency drop off over time for Runs 4, 5, and 6? Does the excess oil added in Run 3 and the stable removal efficiencies indicate that a significant oil dose rate is required? At higher oil dose rates is there a risk of oil breakthrough to the treated water side?

Agenda Background for Pilot Treatment System Testing Pilot Treatment System Configuration Pilot Testing Results Observations / Questions Next Steps

Next Steps Groundwater PCB Pilot Plant Testing Future testing Castor oil additions based on Run 3 results 15 ppm castor oil 30 ppm castor oil Coagulant additions Single dose demonstration runs System flux rate Increase flux rate to evaluate impact on removal efficiency Oil breakthrough of filter Sample treated water for oil/grease

Next Steps Groundwater PCB Pilot Plant Testing Backwash water management Backwash treatment is the second step of the process Need to transfer PCB to a non-water media for disposal Backwash water testing Bench scale testing of algae process for incorporating PCB into biomass for disposal Awaiting full laboratory results from samples

Questions?