Environmental Remediation

Before environmental regulation, some industrial and manufacturing companies dumped waste chemicals and other pollutants into waterways or buried them underground.

Over time, these hazardous materials can leach into drinking water sources or agricultural soil causing harm to human health and the environment. Environmental remediation methods have to be employed to purify the contaminated area. Let’s discuss what is environmental remediation.

What is Environmental Remediation?

Environmental remediation is the “remedying of” environmental hazards such as the removal of contaminants from buildings, soil, groundwater, sediment, or surface water. If a property is suspected of being contaminated, an environmental site assessment will be conducted. The assessment will include a sampling of the soil or water and chemical analysis.

Suspicion of contamination can be raised because of:

  • The historical use of the site, such as dumping of waste chemicals
  • The materials used and produced on the site, such as asbestos
  • Visible evidence, such as an oil spill

If the site assessment confirms hazardous contamination, professional environmental remediation of the site will be required. There are several types of remediation that can be employed.

Types of Environmental Remediation

1) Soil Remediation

Soil contamination involves the presence of chemicals or other toxic alterations in soil. Contamination is often caused by industrial activity, oil or chemical spills, agricultural chemicals, or the improper disposal of hazardous waste. Soil remediation is removing contaminants and revitalizing the soil.

Soil remediation: before and after

(Source: Public Lab)

2) Water Remediation

Surface water in waterways can be directly contaminated by hazardous materials released into the water or by runoff from the soil. Water remediation is the removal of contaminants from water.

Types of Environmental Remediation Technologies

Environmental remediation projects are classified as in-situ or ex-situ.

  • In-situ methods seek to treat contamination without removing the soil or groundwater.
  • Ex-situ methods involve excavation of affected soil and treatment at the surface and extraction of contaminated groundwater and treatment at the surface.

Environmental remediation uses a variety of technologies and methods for purifying contaminated areas. The methods used depend on the type and extent of the pollution, as well as the characteristics of the site itself.

1) Excavation

Excavation is the most common form of soil remediation. It involves excavating contaminated soil and taking it to a disposal site away from human or sensitive ecosystem contact. If soil is contaminated with pollutants that can’t be safely removed, the soil is excavated, placed into secure containers, and taken to a secure storage facility.

2) Pump and Treat

Pump and treat is the process of pumping out contaminated groundwater with a submersible or vacuum pump. It allows the extracted groundwater to be purified by slowly moving through vessels containing materials designed to adsorb the contaminants from the groundwater.

It is an excellent method to reduce high concentrations of pollutants quickly. However, It can be expensive and is typically a slow remediation process.

3) Thermal Desorption

Thermal desorption is a soil remediation technology that volatilizes the contaminants, such as oil, mercury, or hydrocarbon, to separate them from soil or sludge. After that, the pollutants can either be collected or destroyed in an off-gas treatment system.

Environmental Remediation: thermal desorption

Source: (SlideShare CDN)

4) Solidification and Stabilization

  • Stabilization involves the addition of reagents to contaminated soil or sludge to produce more chemically stable constituents.
  • Solidification involves adding reagents to a contaminated material to create physical stability to contain contaminants in a solid product and reduce air or rainfall access.

It is an established remediation technology for contaminated soils and treatment technology for hazardous wastes in many countries.

However, there is uncertainty over the durability and rate of contaminant release from S/S-treated material and the residual liability associated with immobilized contaminants remaining on-site.

5) Oxidation

Remediation by chemical oxidation is the injection of strong oxidants such as hydrogen peroxide, ozone gas, potassium permanganate that increase the oxygen content of the soil or groundwater to break down polluting chemicals before pumping it back to the surface. Oxygen injection promotes the growth of aerobic bacteria, which accelerate the natural break down of organic contaminants. However, the injection of gases into the groundwater may cause contamination to spread faster than average, depending on the site’s hydrogeology.

6) Nano-Remediation

Nano-remediation involves Nano-sized reactive agents injected or pumped in to degrade or immobilize contaminants such as lead or arsenic in groundwater. This process has been effective in remediation of contaminated groundwater in commercial settings.

7) Soil Vapor Extraction

Soil vapor extraction is the extraction of contaminated soil vapor with an electromechanical system and subsequently stripping it of the contaminants. It is effective remediation for contaminated soil, and also effective when remediation of contaminated soil and groundwater is necessary. Thermal oxidation is somewhat controversial because of the risks of dioxins released in the atmosphere through the exhaust gases or effluent off-gas.

Environmental Remediation: soil vapor extraction

(Source: Kajima Corp)

8) Bioremediation

Bioremediation is the use of microorganisms, such as fungi, bacteria, or specific plant species to remove pollutants like oil spills from contaminated sites. Bioremediation is often less expensive and more sustainable than other remediation processes. The EPA has raised concerns that the toxic contaminants could degrade the microbe’s genes and create more issues if the pathogens develop the ability to feed off of pollutants.

Environmental Remediation: Bottom Line

If environmental engineers have recommended your property undergo environmental remediation, you want the work done by qualified professionals. Ferro Canada’s team includes the most responsive, experienced, and dedicated environmental contracting professionals in the business.

Ferro Canada provides remediation work and abatement of environmental hazards, including asbestos, contaminated soil, lead, mold, PCB, contaminated storage tanks, and infectious materials.

Abatement & Remediation aren’t services we “also do.” It’s what we do. We do it right the first time. Call FERRO Canada.