REMEDIATION TECHNOLOGIES

For over 25 years, SCG has been designing, building, and operating remediation systems across North America. From our roots in system design and manufacturing to our experience in technology application, our clients have come to trust our expertise on their toughest soil and water remediation challenges.

SCG has successfully completed hundreds of remediation projects and supplied hundreds of system designs, manufactured systems, and pilot tests. The SCG advantage comes from our experience in both the design/build and application of remediation systems on complex sites ranging from small retail properties to large mega complexes. SCG can help our clients by providing site specific solutions to meet their site conditions and goals.

MULTI-PHASE VACUUM EXTRACTION (MPVE)

Multi-Phase Vacuum Extraction (MPE or bio-slurping) is a versatile mass recovery and remediation technique which can be tailored to a variety of remedial goals. MPVE utilizes vacuum to extract liquid, aqueous, and vapour phase contamination from the subsurface. MPE systems utilize a single vacuum pump, liquid air separator and treatment streams for the vapour, LNAPL and aqueous phase contaminants.

The system is installed in a well field using specifically configured surface or subsurface piping. Once the system is installed and operational it is capable of recovering a variety of contaminants in various phases. This in situ extraction technique is adaptable and versatile for use under a variety of site conditions and contaminant types.

MPE can be used on a multitude of contaminants. It is most effective on, but not limited to, volatile chemicals and low viscosity LNAPLs. MPE can be used in almost all soil types. However some factors do affect MPE’s effectiveness. MPE relies on subsurface airflow to extract volatiles, while mobilizing aqueous and free phase contamination from soils. Therefore it is not necessarily the soil type that is a complicating factor but how that soil is distributed. MPE is a very effective in situ technology with a wide range of applications. MPE’s effectiveness comes from its ability to manipulate groundwater elevation while applying a significant vacuum gradient to further enhance flow through the target horizon.

MPE can remove contaminates present in all phases, this is the physical recovery component of an MPE system. MPE also stimulates airflow and liquid flow thereby increasing the available oxygen in the subsurface. This enhances the physical and biological destruction of contaminates in situ, hence its other name, bio-slurping. MPE also offers an economical advantage over competing technologies due to its use of two separate processes to achieve contaminate reduction, all while utilizing the same infrastructure.

In situations where air flow is restricted due to sub surface conditions or the viscosity of the contaminant is low, MPE can be combined with other technologies to enhance remediation efforts. Combining surfactants, Permeable Reactive Barriers or increasing the temperature of the soil with thermal energy, can contribute to faster and more effective recovery essentially reducing the the time required to achieve closure.

SOIL VAPOUR EXTRACTION

Soil Vapour Extraction (SVE) is an in situ remediation process that removes volatile contaminants from soils in the vadose or unsaturated zone. SVE involves utilizing a vacuum pump and associated piping infrastructure, tied to recovery or collection wells to extend the vacuum influence over an area of contaminated soil. SVE relies on vapor phase recovery and the augmentation of natural weathering plus bioremediation to achieve remedial goals.

The soil contamination types generally used with SVE are volatile and easily degraded chemicals such as benzene. Once removed from the subsurface, these contaminants are typically treated using an oxidizer or vapour phase carbon. SVE is not applicable for contamination located below the groundwater table. SVE alone has limited success on contaminants present in the capillary zone as a result of mounding that can occur when vacuum is applied.

SVE technology is applicable for many soil types. Air flow through the soil is an important process in SVE remediation. The more porous and permeable the media the more effective SVE will be. SVE remediation techniques can also be augmented using air sparging (i.e., in situ air stripping(more info on opposite side of page)) or through thermal enhancements. SVE is economical to apply in situ if the contaminant of concern is volatile/semi-volatile and located in the vadose zone.

AIR SPARGING

Soil vapour extraction techniques can be augmented using air sparge. Air sparging is a process which involves injecting air into contaminated ground water to drive VOC’s (Volatile Organic Compounds) into the vadose zone above the water table through a process known as volatilization. In addition to this process, air sparging also increases bio-augmentation within the impacted areas enhancing bacterial culture and increasing the rate of degradation of a contaminant. The VOCs are then removed by the vapour extraction techniques described previously. Heat application has proven to increase mobilization of certain contaminants. SCG have successfully used heat from post treatment exhaust streams re-injected back into the subsurface to increase mass recovery and decrease project time lines.

Effective characterization of the impacted areas helps to determine well locations and screen depths. SCG can assist with this delineation process. We can derive optimal air flows and frictions losses from known volumes of impacted soil and ground water, ensuring the site specific selection of equipment.

The images below depict a conceptual design drawing, (top left) photograph of an SCG manufactured Air Sparge blower (top right) and an AuctoCAD drawing of a typical Air Sparge manifold.

HYDRAULIC CONTROL/WATER TREATMENT SYSTEMS

Water treatment is often required to meet local discharge criteria. SCG understands that there are many factors to consider when faced with discharging excavation water. Some factors include:

EXCESSIVE FLOW RATES
ELEVATED CONTAMINANT CONCENTRATIONS
SEDIMENT MANAGEMENT
STRICT DISCHARGE CRITERIA

SCG has 25 years of experience in the manufacture, design and operation of successful water treatment systems for a variety of contaminants and flow conditions. SCG is always available to support our clients, ensuring the full functionality of our systems and the timely execution of projects.

SCG not only manufactures proven water treatment systems, we also operate, maintain and optimize our systems in a variety of field environments. This knowledge and hands on experience helps us constantly improve our systems cost efficiency and ease of operation. We understand that water treatment technology needs to operate on sound scientific principles as well as be user friendly and low maintenance in the field.

SCG employs a number of advanced remediation technologies to remove soil and groundwater contamination.

Once identified and delineated, contamination is removed using one or more of our remedial systems. We’ll identify and design the best removal system for your site and get to work cleaning soil, water & groundwater. It’s what we do.