TranslateSanitary Cleaners — Supplemental Reductive Dechlorination Program
Synergistic ZVI + Microbial ERD Targeting PCE/TCE/DCE/VC in Bedrock Fractures
20,320 sq ft
Total Area Treated
14 wells
Injection Points
2,812 cu yd
Treatment Volume
4 injection days
Program Duration
Site Background & Objective
The Sanitary Cleaners site at 4403 Ringgold Road in East Ridge, Tennessee (near Chattanooga) has been impacted by chlorinated volatile organic compounds (CVOCs) from historic dry cleaning operations. IET evaluated the site's current and historical groundwater data, boring logs, and site maps provided by Terracon Senior Geologist John D. Reinert, P.G.
An initial injection program completed in April 2012 was successful in dramatically reducing groundwater impacts. This supplemental design targets remaining impacted areas, focusing on wells not previously utilized and addressing persistent contamination in bedrock fractures and overburden soils at the soil-bedrock interface.
The site geology features shallow bedrock with monitoring wells approximately 18 feet bgs. The dissolved plume is believed to be migrating through shallow bedrock fractures or along the bedrock interface, requiring higher injection pressures (up to 175 psi) to open the existing fracture network.
IET Remedial Objective:
Accelerate both abiotic and microbial reductive dechlorination, mitigate off-site migration, treat sorbed and dissolved CVOCs, and create ideal subsurface conditions for complete mineralization of TCE, PCE, cis-1,2-DCE, and vinyl chloride — without generating waste streams or requiring disposal permitting.
Treatment Design — 4 Areas
IET designed the program around 13 previously installed bedrock wells and one existing injection gallery. Click each area to expand details.
Treatment Area
5,024 sq ft
Target Depth
15–20 ft bgs
Injection Points
4 wells
Area Cost
$15,734.60
Treatment Area
11,778 sq ft
Target Depth
15–20 ft bgs
Injection Points
6 wells
Area Cost
$39,863.51
Treatment Area
2,118 sq ft
Target Depth
15–20 ft bgs
Injection Points
3 wells
Area Cost
$19,875.19
Treatment Area
1,400 sq ft
Target Depth
3–7 ft bgs
Injection Points
1 wells
Area Cost
$9,479.60
Total Sq Ft
20,320
Total Cubic Yards
2,812
Total Injection Points
14
Total Project Cost
$84,952.90
IET 3-Step Patented Injection Process
Subsurface Pathway Development
Nitrogen gas is injected via IET's proprietary closed trailer system at pressures up to 175 psi to develop fractures and voids without introducing oxygen. Pathway development verified by observing a substantial pressure drop. For bedrock wells, inflatable packers isolate 5-foot intervals, applied well-by-well at low pressure gradually increasing. Adjacent wells temporarily plugged to prevent short-circuiting.
Remedial Material Injection
Immediately following gas injection, a solution of sodium sulfite (oxygen scavenger), red yeast extract (methane inhibitor), nutrients, Vitamin B2, Vitamin B12, ZVI, Provect-ERD and/or Provect-IR is injected into fractures and voids. The sodium sulfite prevents ZVI oxidation by dissolved oxygen. Nutrients support ATP-ADP synthesis and organelle development for sustained microbial activity.
Post-Injection Gas Flush
Injection lines are cleared with compressed gas, forcing all injectants into the created formation pathways and upward into the vadose zone for maximum distribution. Ensures complete material delivery and removes residual liquid from injection lines.
Amendment Program — Synergistic Technology Stack
IET's multi-amendment approach utilizes compounds with staggered hydrogen release profiles (0–1,500 days) to create sustained reducing conditions without methane stalling.
| Amendment | Total Qty | Function & Mechanism |
|---|---|---|
| Provect-IR | 1,900 lbs | Controlled-release electron donor (365–1,500 day release). Contains ZVI, propionate, yeast extract, kelp, sulfite, and red yeast rice methane inhibitor. IET patented. |
| Provect-ERD | 2,217 lbs | Emulsified electron donor substrate for enhanced reductive dechlorination (3–5 year release). 60–70% fermentable carbon with anti-methanogenic reagents. |
| ZVI (Zero Valent Iron) | 2,441 lbs | 25-micron colloidal iron suspension. Drives abiotic reductive dechlorination, generates H₂ for microbial processes, reduces ORP, and precipitates free sulfide to prevent dechlorination stalling. |
| Vitamin B12 | 323.7 g | Cobalt-containing coenzyme that mediates reductive dechlorination of PCE and TCE. Critical for vinyl chloride → ethylene conversion (rate-limiting step). Catalyzes Fe⁰ surface reactions. |
| Vitamin B2 (Riboflavin) | 4,480 g | Electron shuttle that enhances reductive processes. Supports microbial cofactor requirements for dechlorination pathways. |
| Sodium Sulfite | 140 lbs | Oxygen scavenger that creates strictly anaerobic conditions required for reductive dechlorination. Also reduces dissolved iron and provides sulfate source. |
| Nutrients (N + o-PO₄) | 140 lbs | Macro/micronutrient blend for ATP-ADP synthesis, organelle development, and sustained microbial metabolic activity. |
| Calcium Propionate | 300 lbs | Short-chain carbon electron donor (0–100 day release) to jumpstart microbial activity and create immediate reducing conditions. |
Staggered Hydrogen Release Profile (Single Injection):
Post-Injection Monitoring Plan
IET includes 6 quarterly data analysis reports at no additional charge as a value-added service (based on data provided by Terracon).
Field Parameters (each event):
- Dissolved Oxygen (DO)
- Oxidation/Reduction Potential (ORP)
- Specific Conductivity
- pH
- Temperature
- Groundwater Elevation
Lab Analyses (Method 8260 VOCs):
Sampling schedule: T-0 (pre-injection), 90, 180, 270, 360 days
IET Patent Portfolio — Applied to This Project
This remedial design is covered by six IET United States Patents representing over 28 years of in-situ bioremediation innovation.
US 7,044,152
Apparatus for In-Situ Remediation Using a Closed Delivery System
Issued: May 16, 2006
US 7,129,388
Method for Accelerated Dechlorination of Matter
Issued: October 31, 2006
US 7,531,709
Method for Accelerated Dechlorination of Matter (continuation)
Issued: May 12, 2009
US 8,147,694
Method for Treatment of Groundwater and Soils Using Seaweed and Kelp
Issued: April 3, 2012
US 9,126,244
Use of Encapsulated Substrates Controlling Release Rates of Organic Hydrogen Donors
Issued: September 8, 2015
US 9,221,699
Inhibition of Methane Production During Anaerobic Reductive Dechlorination
Issued: December 29, 2015
Related IET Services & Resources
Contact IET About a Similar Project
IET has completed 1,500+ in-situ field applications over 28 years. Wade Meese, VP: 740-965-6100 | info@iet-inc.net
