Amendments have physical and chemical properties significantly different than natural soil and groundwater

Volume added usually 3% to 10% of pore volume

Actual radius of injected amendments can be tracked using surface geophysics, looking for change in total conductivity

Electrical Conductance of Sodium Persulfate Solution

0

2,000

4,000

6,000

8,000

10,000

12,000

14,000

0% 2% 4% 6% 8% 10% 12% 14% 16% 18% 20%

Sodium Persulfate (wt %)

Co

nd

uc

tan

ce

(m

Sie

ma

ns

/m)

25 deg C

35 deg C

45 deg C

____Seawater (3,000)____

____Brackish water (100)____ ____Fresh water (50)____

Potassium Permanganate 20 g/l (~ 2%) = ~1400 mS/m

Sodium Persulfate 20 g/l = ~1600 mS/m

Electromagnetic induction to map changes in ground conductivity

Uses separated antennas (coils) for transmitter and receiver at surface

Transmitter induces eddy currents in subsurface which produce a magnetic field read by receiver

Apparent conductivity is weighted average of subsurface conductivity from surface to max depth.

Two max depths: ~2.5 m, ~5.2 m

•10,000 lbs of persulfate injected in 11 DPT borings•Observations:

Uniformity of Injection in central areaSmall radius of influence, ~ 5 feet

2S1.5S

1S1W

No change from background

Increase due to persulfate

Increase from persulfate

Increase from persulfate

•Comprehensive Coverage of Site•10,000 lbs of K Permanganate•Observations:

oSignificant increase in total conductivity site wideoSite has since reached cleanup standards (5 µg/L)

2E

3E

2S

Gas Line

Permanganate

Water Line

Permanganate

Water Line

Permanganate

Electrical methods (electromagnetics, resistivity) can detect amendment addition

Physical measurements of injection radius can help guide effective remediation

Electrical resistivity tomography could be used for 2D and 3D imaging