injection ec tracking with hornet tool

Increased In Situ Remediation Efficacy with an Innovative Injection Technology

Electrical Conductivity Technology

Effect of Hornet Tool

Applied to Verify Post Injection Distribution of a Lime and Bentonite Gel Slurry at a Lead Acid Battery recycling facility

On distribution of a Lime and Bentonite Gel Slurry

In Situ Remediation Injections

Traditional remediation product injections in the environmental industry focus extensively on chemistry and biology, and the physical distribution of the agent in the aquifer has not received as much attention. For many remediation products, effective distribution or contact with the contaminant mass is crucial to successful remedial injection. Additionally, injected products often migrate to the surface adjacent to the injection rod string (blow-by), which substantially decreases remedial efficacy.

The historical thought process was that the zones of higher hydraulic conductivity would most likely also contain the larger contaminant mass. It was assumed that these zones of higher conductivity would receive the majority of the injected remediation product. However, practical experience indicates that this theory of hydraulic conductivity and injected product acceptance may not be uniformly applicable across contaminated sites.

The Project

•Injection Slurry = 2.5% Bentonite Gel + 10% Lime + 450 gal.

•Injection Interval 7 ft to 20 ft BGS

• Double Diaphragm Pump Set to 35 PSI used to Deliver Material

• Hornet Tool used to Pulse Injection Slurry

•Differential Pressure between Pump and Soil Matrix 12 - 22 PSI

To Increase the Groundwater PH in the Injection Zone

What is Conductivity?• EC responds to:

– Relative Soil Particle Size Distribution• Sand = Low EC versus Clay = High EC• Must compare to a continuous soil core to standardize EC data!

– Presence of conductive materials• Metal = Max EC Response

– Salts• Presence of High Salt Concentration = Higher EC Response

Compared With No Salts

• Data reported as milliSiemens per meter (mS/meter) and graphed over vertical profile.

• EC probe = established technology, reliable and reproducible results.

Conductivity Set up

General EC Response to Soil Particle Size Distribution

• Generates a fluid pressure pulse causes momentary elastic flexure of the soil pore structure.

• Increased Distribution

• Helps eliminate “day lighting” and “blow-by”

What is the Hornet Tool?

Photos

Equipment Diaphragm Pumps

Injection Ports

Isolation Probe

Injection Check Valve

Equipment – Probes and Valves

Hypothesis

•EC Probe Detects Lime and Bentonite Gel Slurry Mixture

•Pre-Injection EC Data Establish Baseline Soil Particle Size Distribution

•Post-Injection EC Graph Line Deflection From Pre-Injection Indicates Lime and Bentonite Gel Slurry Mixture

•Hornet Tool Influence Results by Reducing Day lighting and Blow-By

Injection Setup Without Hornet

Site OverviewBattery Recycling Facility

Injection Area

Data 5 FT OUT

CA2

Data 10 FT OUT

CA3

Lime Bentonite Gel and Lime Slurry

INJECTIONS

Site Photos

Results & Conclusions

• The EC data showed good comparisons between Pre and Post Injection Profiles– “Clay” Peaks were Identified with some slight depth shift

• EC can be used to verify deposition of a lime/bentonite slurry after injection by comparison to Pre-Injection control locations

• The Hornet Tool appears to have enhanced the distribution of lime/bentonite slurry by restricting Day-Lighting and Blow-By