1. Groundwater Pilot Treatment System Update May 2017

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

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

4. 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

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

7. 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

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

13. 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

14. 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

15. 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

16. 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

17. Pilot Plant Testing

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

19. 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

20. 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

21. 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?

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

23. 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

24. 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

25. Questions?