1. Ultra-Trace PCB Sampling

2. Why High Volume Sampling?
Increased demand for detecting lower concentrations of contaminants in waters and sediments
Need to integrate water samples both spatially and temporally
Challenge of collecting solid fraction from water column in analytical volume
Ability to capture discrete timepoints
Field proven– logistically feasible

3. Traditional High Volume Systems
TOPS – USGS
Infiltrex – Axys technologies

4. Key Components of HVS systems
Process Pump
Solids Separator
Dissolved filter
Key Components of HVS systems
Precision pump – flow and volume monitoring
Solids separator – Glass fiber filter wound or flat disk
Dissolved phase filter – XAD resin or Polyurethane foam

5. Issues with HVS Systems
Mechanical solids separation with filters biases dissolved phase extraction and provides inconsistent results
XAD resin is costly and prone to field and lab contamination
Pump systems -too large and often unreliable
Centrifuge options – too large for most field projects

6. Polyurethane foam vs. XAD
PUF material is field proven in air and water studies
PUF is significantly less expensive
PUF material has better recoveries in dynamic spike studies (PAHs, PCBs, Dioxins, Pesticides)
PUF material is less prone to field and lab contamination

7. XAD Resin vs. PUF media
Recovery
Dioxin compounds

8. Dynamic Field Spiking of PUF media
Recovery
Dioxin compounds

9. Vortex Efficiency Study
Experiment was conducted at CAS laboratories in Kelso, WA
Done to evaluate the efficiency of a Krebs vortex separator to remove suspended sediment.
Particle standards from 0.1 micron to 180 microns were mixed in 5 gallon carboys and sampled pre and post vortex separator.
40 sample sets were completed to evaluate efficiency.
A LISST particle analyzer was used to sample the suspended sediments pre and post vortex separator.
The LISST particle analyzer measures particles using a laser and presents both concentration and particle size distribution data.

10. Test Set-up
LISST 100X
HVS System
Solids Sample

11. Results – Pre Vortex

12. Results – Post Vortex

13. Vortex solids separation
Vortex systems provides consistent separation of solids with minimum disturbance to dissolved phase
The vortex cylinder utilizes pressure from the pump and does not require independent propulsion (eg. centrifuge)
Vortex systems are easily field maintained and cleaned.

14. Vortex Separator Recovery modeled (%) (Krebs Engineers)

15. Gravity Consulting HVS system PR-2900
Picture 1 – Gravity PR-2900 System Overview
Gravity Consulting HVS system PR-2900
Vortex Separator Solids chamber Flat Disk Filter (142 mm) Dissolved Phase Trap (PUF)

16. Projects using Gravity’s HVS system
Snake River – NPDES studies
Willamette River – CERCLA project
Port of Longview/Lost Angeles – CERCLA Department of Energy - multiple nuclear sites
Department of Defense – multiple navy facilities
Upper Columbia River –RCRA study
Passaic River – CERCLA Project
Gulf of Mexico MC252 spill - NRDA

17. Passaic River
Heavily industrialized segment of river containing PCBs, dioxins, heavy metals,
and other hazardous substances from historical and ongoing
sources

18. Upper Columbia River
Historic mining operations associated with heavy metal, PCBs and organic contamination.
Study was conducted over 160 miles of river