GeoSierra PRB Installation
Azimuth oriented vertical hydraulic fracturing— also known as vertical inclusion propagation (VIP) — is an alternate mode of constructing iron PRBs in-situ, resulting in significant cost savings and allowing reactive barriers to be installed to greater depths than conventional technologies. GeoSierra Environmental has used the orientated VIP technology to install iron PRBs at numerous sites with geologies ranging from silts to clays, glacial tills to highly permeable sands and gravels with depths ranging from 15 feet to greater than 120 feet.
Some advantages of orientated VIP placed PRBs include:
- Passive Treatment Resulting in Long Term Cost Savings
- Minimal Site Disturbance
- No Excavation / Disposal of Contaminated Material
- Deep Application of Treatment Technology
- Minimal Impact on Groundwater Flow Regime
- Permanent Remedy
VIP placed PRBs are constructed from a series of wells installed along the barrier's azimuth or bearing. Each well is installed using conventional drilling methods and comprised of a specialized casing grouted into the boreholes. A controlled vertical inclusion is initiated in each well at the required azimuth orientation and depth. Iron filings are injected into the wells in a highly viscous cross linked proprietary gel that forms the continuous permeable iron reactive barrier. The barrier's geometry can be monitored in real time to ensure the barrier is constructed as designed.
When compared to oil and gas hydraulic fracturing techniques that may destroy formation permeability through exceptionally high injection flows and pressures, GeoSierra Environmental’s VIP technology aims to preserve formation permeability by mechanically placing the PRB through low flow and low pressure injection techniques. Additionally, while large scale energy fracturing programs utilize numerous additives, GeoSierra Environmental’s gel combination is comprised of food-grade ingredients.
GeoSierra Environmental’s technology and installation methods advance with each new project. We apply continuously improving best practices along with our patented tools and processes to remediate groundwater plumes that in most cases, because of their depth, would otherwise be impossible to reach. That doesn’t mean we do not install shallow walls, because we do and we have. In fact, because of the many advantages of our installation technology, in addition to being the preferred choice for deep PRB installations, we are also often the best choice to design and install PRBs at depths less than 40 feet. Having said this, it is worth noting all of the significant additional benefits to be gained by GeoSierra Environmental installed PRBs.
- Construction of deep PRB systems with significant cost savings and superior remediation efficacy over alternative remedies.
- Proven technology with demonstrated effectiveness of placement of iron PRBs at both deep and shallow depths.
- Installation of a continuous iron filing PRB with high permeability and porosity.
- Minimal impact on the natural groundwater flow regimes.
- Quality assurance and verification tests for confirmation of constructed PRB geometry, continuity, iron loading, coalescence and hydraulic characteristics.
- Minimally invasive installation in congested workplaces in and around buildings and within areas with underground and overhead utilities and narrow right of ways.
- Trenchless construction - no excavation and minimal site disturbance.
- Very safe with low risk exposure to personnel and property.