Innovative Injection Technologies for Effective Remediation
The best reagent in the world fails if it doesn't reach the contamination. IET engineers select and deploy the injection method that matches each site's geology, contaminant distribution, and project constraints — from simple direct push to first-of-its-kind HDD injection.
Technology Selection is Half the Battle
In-situ remediation failures are more often caused by poor reagent distribution than by the wrong chemistry. A high-quality ISCO oxidant injected into a clay lens via standard direct push may treat only a fraction of the contaminated volume. Choosing the right delivery system — matched to soil permeability, depth, and formation heterogeneity — is as critical as choosing the right reagent.
IET's Injection Delivery Methods
Each method is suited to a different set of site conditions. IET often combines multiple approaches on a single site.
Direct Push Injection (Geoprobe / DPT)
Most CommonA Geoprobe or similar direct push rig advances small-diameter tooling to the target depth, where reagent is injected at controlled pressure and flow rate. The rod is then retracted and the injection point is grouted. Fast, low-cost, and effective in soft to medium-hard soils above about 100 ft depth.
Permanent Injection Well Network
Source Zones & Large PlumesPVC or stainless steel injection wells are installed across the treatment zone. Reagent is distributed through a manifold system using pumps or gravity feed, enabling sequential or simultaneous injection across dozens of points. Ideal for recurring injection programs and large footprint sites.
Recirculation / Push-Pull Systems
Plume ContainmentReagent is injected upgradient while groundwater is extracted downgradient, creating a controlled treatment front that intercepts the contaminant plume. Hydraulic control prevents off-site migration while in-situ reactions destroy dissolved-phase contaminants.
Hydraulic Fracturing-Enhanced Injection
Low-Permeability SoilsControlled fluid pressure creates fracture networks in clay, silt, and bedrock formations before or during reagent injection. Dramatically expands the treatment radius in formations where conventional injection would achieve poor distribution.
Large-Volume Gravity Feed / Infiltration Galleries
Vadose ZoneFor vadose zone soil treatment, reagent is fed via surface infiltration galleries or trench systems, allowing gravity to draw treatment through the unsaturated soil profile. Effective for large-area petroleum hydrocarbon impacts in shallow sandy soils.
Horizontal Directional Drilling (HDD) Injection
Under StructuresIET performed the first-of-its-kind unidirectional HDD injection of ISGS reagent at a New Jersey Superfund site — delivering >100,000 gallons of treatment beneath an active highway. HDD enables subsurface treatment access where vertical drilling is impossible.
Quick Selection Guide
Match your site conditions to the right injection approach.
| Site Condition | Recommended Approach |
|---|---|
| Sandy / silty soils, moderate depth (< 80 ft) | Direct Push (Geoprobe) injection |
| Clay or low-permeability till | Hydraulic fracturing-enhanced injection |
| Fractured bedrock with isolated zones | Pneumatic fracturing + targeted injection |
| Large plume, multiple injection events needed | Permanent injection well network |
| Active plume requiring hydraulic control | Recirculation / push-pull system |
| Under building or active infrastructure | Horizontal Directional Drilling (HDD) |
| Shallow vadose zone, large area | Gravity feed / infiltration gallery |
Common Questions
Not Sure Which Injection Method Fits Your Site?
IET's engineers evaluate your site data and recommend the optimal delivery approach — at no charge.