Land reclamation has become a common operation to create valuable land in coastal areas. The impact of this process on coastal environments and marine ecology has been widely studied and is well recognized.
Remediation and How You Can Reclaim the Environment
Environmental remediation involves the removal of contaminants or pollutants from the soil, groundwater, surface water, or sediments. The action of remediation is subject to an array of regulations and can also be based on human health assessments as well as ecological risks.
An assessment of the site is required once it is suspected of being contaminated. The evaluation consists of the site’s historical use and the materials used and produced on site. It will also consist of sampling the soil or water through chemical analysis.
There are a lot of remediation technologies, but they can generally be classified in ex-situ and in-situ. The ex-situ process involves excavation of affected soils and their treatment at the surface. It also consists of the extraction of contaminated groundwater and its treatment at the surface.
The in-situ process seeks to treat the contaminated soil without removing it from the ground or water. There are many methods used for remediation of oil-contaminated sediments and soil.
Soil Remediation and Techniques Involved
Soil remediation techniques are needed for a number of clean up projects:
- If you have had an underground tank buried and decide to remove it
- If your facility worked with dangerous and hazardous chemicals and are now going to close
- You want your plant area cleaned where hazardous waste is present
Each of the soil remediation processes are performed to reclaim the environment from where the material has been collecting. The process has sometimes been referred to as ‘soil washing’ due to the various processes involved which will decontaminate the soil.
To determine which process will work best for your needs, a professional remedial specialist will need to take a sample of your soil and have it tested to determine what contaminants are present. Based on the findings of the sample test, an application for treating your area will be chosen.
Encapsulation is a little bit different in terms of remediation. This process prevents further spreading of contaminants rather than filtering them from the soil. It is often referred to as a quarantine of the soil because instead of treating the pollutant, it is just isolated to prevent the contamination from spreading further.
The most used technique of encapsulation consists of mixing contaminated soil with cement, concrete, and lime. With this mixture, the soil is prevented from coming in contact with the pollutants captured inside the mixture. While this method is effective, it does not allow you to reclaim the environment from which the waste has been captured. Therefore, this method should only be used on soil that will never be used for any other use, especially to grow anything.
Excavation or Dredging– The process of excavation or dredging can be a simple process of remediation. It can mean the contaminated soil is hauled away to a regulated landfill, or it can involve aerating the excavated material which has been proven to be able to remediate volatile organic compounds. If the contamination affects a bay bottom or river, then dredging of the mud containing the pollutants can be conducted.
Thermal Soil Remediation– Soil remediation using the thermal soil process removes certain types of contaminants by heating the soil to high temperatures. Thermal Soil is typically reserved for environments that have become tainted by contaminated water or hydrocarbon compounds.
This type of contamination results from compounds such as petroleum products and oil and might be the choice when removing underground tanks. Thermal soil remediation is performed by baking the soil and causing the pollutants to evaporate.
Through this process, the treated soil is cooled and then removed from the machinery performing the remediation. Once the process is done, the soil is then ready to be recycled.
Bioremediation– Bioremediation uses biological mechanisms instead of a mechanical method of filtering to take out the contaminants. Bioremediation is also called ‘in situ remediation’, and when contaminated soil is treated in situ, it is performed by applying anaerobic bacterium and engineered aerobic to it. These compounds feed on specific types of contaminants that the soil is contaminated with.
The bacterium works on consuming and breaking down the hydrocarbons and other contaminants in the soil. This process is a lot like yeast feeding on sugar in a batch of beer. When the bacteria die, this means the contaminants are consumed.
There have to be specific and stable conditions present in order for bioremediation to work. When a soil temperature is 70 degrees, this process works best. It can work in colder climates if you keep the soil covered, but the process will take longer.
Air Sparging-Air Sparging method of remediation is used when toxic gases or vapors have contaminated the soil. The difference with this method is that it has to be applied directly to the soil instead of being used on soil extracted for treatment.
Air sparging is performed by injecting vast volumes of pressurized air into the contaminated soil or underground water. Volatile organic compounds are removed that could otherwise be removed with carbon filtering systems. This method is most often used for removing hydrocarbon contaminants, but its best use is when it is applied before the soil is removed, as it must be completed in situ.
Facility Site Closures with Remedial Services
There have been debates at hazardous waste sites across the country on whether or not to change cleanup objectives when facilities decide to close. It is being found that some residual contamination stays in the subsurface, but has not shown an adverse risk to the environment of human health.
The current regulatory framework for remediation of hazardous waste sites, such as those from facilities that generated hazardous waste in their daily operations, evolved from a complicated collection of federal and state statutes. There are two federal programs governing subsurface cleanup efforts, and most states have their own systems in place as well. When you have decided to close a facility, you want to use the services of a professional remedial service to ensure all rules and statutes are being followed.
Tank Removal and Soil Remediation
The EPA’s underground tank removal guidelines require that contaminated UST (underground storage tank) have to be cleaned up, and the underground water sources need to be protected. The environment must be returned to a safe one for those who live and work around these sites.
Petroleum releases are able to hold contaminants such as MTBE and these make water unsafe or unpleasant to drink. Release of these contaminants could result in explosion hazards, long-term health effects, and fire. Proper remediation must be performed on these tank areas, and the land should be cleaned well enough so the environment can reclaim it and make it safe for everyone.
Remediation for Pit and Lagoon Cleaning
If your lagoon or pit has reached the end of its life cycle and is no longer needed, you need to consider lagoon remediation. By going through a remedial service company, you can reclaim the environment of the lagoon or pit by cleaning it out and filling it to meet the standards set by your community and the state.
Once a lagoon is excavated, soil samples need to be taken and then analyzed to make sure there are no residual elements left behind that could cause legal ramifications down the road. There are typically three steps to cleaning a pit or lagoon:
- Extraction of the sludge from the base of the lagoon or pit. In some cases, the sludge can be removed while the pit or lagoon is still in use.
- Once the sludge is extracted, it is processed to recover any oils.
- Reduce the amount of solids before the final disposal process is ready to be implemented.
When sludge is extracted from a pit or lagoon, it is processed through screening equipment and filter press equipment. This process will further separate and maximize oil recovery as well as minimize sludge disposal.
When the extraction is ready for disposal, there are three separate methods of final disposal management:
- Fuel blending
- Secondary treatment of solids
Once the lagoon or pit have met the environmental standards, it can be filled in.
Concerns with Lagoon Sludge Disposal
A primary mechanism for treating wastewater within a lagoon system is the solids settling to the bottom. When the solids settle, they will contain sand, dirt, and other debris along with inorganic compounds, nutrients, heavy metals, and biological floc. Over time it is these components that become the sludge within your lagoon.
When sludge reaches a certain depth, you will need to have it removed and disposed of in order for the lagoon system to be functional. This process can be accomplished through the services of a professional remedial services company.
Services engaged in the collection, treatment, and disposal of waste materials will collect the waste material, provide treatment to the environment to maintain environmental standards set forth by your community and state, as well as dispose of the waste safely and properly.
Once the sludge is removed from your pit or lagoon, the remedial services company will want to reclaim the environment by reducing the radiation exposure to the surrounding area as well as the area of the lagoon or pit. The process is done for more than just removing radiation threats; it is done to protect people and the environment from possible harmful effects involved with exposures to ionizing radiation.
Our land, air, and water are the most important assets we have. Taking proper care of these should be a top priority to everyone to ensure our generation and generations to come can continue to enjoy a healthy and safe environment in which we live.