New Groundwater Techniques and Technologies

1. New Groundwater Techniques and Technologies 17th Annual RETS REMP Conference June 25-27, 2007 Eric L. Darois, CHP EPRI Consultant/RSCS Inc.

2. Project Scope • Evaluate New and Current Technologies for Groundwater Sampling • Evaluate New and Current Technologies for Contaminated Groundwater Detection • Evaluate New and Current Technologies for Contaminated Groundwater Remediation

3. Technology Conferences • 7th Passive Sampling Workshop and Symposium, Reston Virginia, United States Geological Survey (USGS), April 2007 • 2007 Ground Water Summit, Albuquerque New Mexico, National Ground Water Association (NGWA), April 2007

4. Passive Sampling Technologies • SPMD’s • Semi-Permeable Membrane Devices (SPMD’s) • These accumulate contaminants within an absorption media, typically a polyethylene absorption media. • The Gore Module • Developed exclusively produced by and for GORE-TEX® • Similar to SPMD’s, does not collect a sample of water, uses a patented absorption material. • Consists of a tube of GORE-TEX® fiber containing absorption beads. • Has pore sizes large enough to allow volatile and semi-volatile gas phase contaminants to diffuse and to accumulate on the absorption material. • Pore size restricts liquid phase water from entering the sampler. • PDBS • Passive Diffusion Bag Samplers (low-density polyethylene diffusion bag samplers) • Collects groundwater samples using a tube of Low Density Polyethylene (LDPE). • Fits into a 5 cm dia. well. • Filled with DI Water, sealed at both ends and lowered into Well. • Averages Concentration over 1 – 2 weeks – no additional equipment • RCDMS • The Regenerated Cellulose Dialysis Membrane Sampler (RCDMS) • Similar to the PDBS. • Pore size between 5-20 microns. • May Be Susceptible to Degradation

5. Passive Sampling Technologies (con’t) • RPP • The Rigid Porous Polyethylene sampler (RPP) • Also Similar to PDBS and RCDMS • Porous polyethylene membrane with pore sizes ranging between 6 and 15 microns. • Limited to 100mL sample • The Snap Sampler • Groundwater passive grab sampler. • Device consists of a sample bottle, trigger lines, end caps and springs • Sample Volumes of 40 and 125 mL. • The Hydra Sleeve • Groundwater passive grab sampler. • Disposable thin-wall sleeve of polyethylene sealed on the bottom and fitted with a one way reed valve on the top. • Effectively Collects a Core of Water ~1000 mL

6. Passive Sampling Comparisons

7. Tritium Groundwater Contamination DetectionSoil Vapor Extraction System (SVES) • Current EPRI Research Initiative • 4 Project Phases • 1 Develop Predictive Model • 2 Laboratory Testing of Model • 3 System Test at a Decommissioning Site with Characterized H-3 Plume • 4 System Test at Operating NPP • Currently Beginning Phase 2

8. SVES Basis • Research Currently at the Armagosa Desert Research Site

9. SVES Principle • Extract Soil Vapor from Vadose Zone • Condense Vapor, Analyze for H-3 • The Vadose Zone H-3 Vapor “Plume” Likely Extends Well Beyond Contaminated Groundwater • If the H-3 Vapor is Within the Extraction Zone of Influence, Detection will Occur. • System May Provide Early Indication of H-3 Subsurface Leak.

10. Project Objectives • Determine Physical System Configuration Requirements • Determined Required Data for System Installation • Evaluate Sensitivity of SVES to “detect” Groundwater Contamination • Provide for Data Assessment Methodologies • Prediction of: • Soil Gas Velocity • Radius of Influence • Subsurface Release Activity

11. SVES Model • Principal Parameters • Soil Gas Velocity, • Air Permeability, and • Pressure Gradient.

12. Model Assumptions • The thickness of the vadose zone is relatively constant, homogeneous and isotropic within the extraction point’s ROI, i.e. construction backfill. • An impervious or semi-pervious surface barrier to atmospheric gas transfer and direct infiltration of precipitation to the vadose zone is in place, i.e. pavement or concrete. • A detection or change in condensate activity concentration is due to a soil vapor plume entering the ROI of an extraction point and is not the result of diffuse background H-3 activity in the soil. • The approximate cross-sectional area OR volume of contaminated soil AND the approximate distance from the extraction point can be determined. • Soil vapor within the capillary fringe of the liquid plume has the same activity concentration as the liquid release.

13. Conceptual Design • Each Extraction Capable of Covering Large Areas

14. Specific Discharge and Capture Ratio • Specific Discharge Within Plume Front • Total Discharge at Plume Front, Qr • Geometric Capture Ratio,

15. Ideal and Non-Ideal Conditions • System is More Effective with Concrete or Asphalt Cover

16. Cylinder-Sphere Model – Non-Ideal Total Surface Area

17. Additional Model Considerations • Thick Vadose Zone • 3-D Rendering to Determine Shape Surface Areas

18. SVES Benefits • Fewer GW Monitoring Wells • More Effective Sentry System • Onsite Analysis for H-3 • More Effective Early Warning Methodology • Less Dependent on Precise Placement • Less Invasive (Push-Probe Installation Method) than Traditional GW Monitoring Well

19. Project Schedule • Phase 1 – Complete • Phase 2 – 12/31/2007 • Phase 3 & 4 – 12/31/2008