A pilot test is considered a crucial step in understanding how a site will respond to remediation, especially when the remedial strategy is complex or there are high levels of uncertainty in the input data. Pilot tests give site-specific information on the performance, applicability, and feasibility of a remediation system in order to determine whether any active remediation system can effectively accomplish the desired objectives. Generally, the time spent at the front end of a project will result in time and money saved during full-scale remediation.
RemedX have created a system which can test multiple in-situ remediation technologies on-site to collect valuable data for the design of a full-scale remediation operation. The system is trailer mounted, fully automated and complete with data logging. The pilot test trailer is capable of analysing 6 different remedial technologies; Soil vapour extraction, Dual phase extraction, Multi-phase extraction, Steam enhanced extraction, Air sparging and LNAPL Skimming.
Having the system operated by experienced remediation scientists and the use of advanced instrumentation ensures that the data collected is accurate and can be interpreted correctly to give you important information regarding the site’s future remediation options.
Bioremediation is a relatively low-cost and effective process that is widely utilised for organic contaminants and can often be performed on site. It is not, however, appropriate for all circumstances.
A thorough analysis of the soil characteristics is needed to determine if organic contaminants could be biodegraded by soil microorganisms and if so, what is the likely duration of this process. Under favourable conditions, microorganisms can completely metabolise organic contaminants and convert them into non-toxic by-products, such as carbon dioxide and water or organic acids and methane. However, bio-remediation is not possible in all circumstances. Low permeability soils have proven to be difficult to supply oxygen and nutrients to and elevated contaminant levels can be poisonous to microorganisms, inhibiting their activity.
Hence a feasibility study is needed prior to execution to determine whether bioremediation is a viable option for the specific site, soil type and contamination level. The study will provide key design data on the potential rate and effectiveness of bioremediation to determine the potential for full-scale bioremediation of a site. The feasibility study can also assess the benefits of adding different microbes to the contaminated soil to enhance bioremediation speed and efficiency.
Soft or extremely compressible soils are often found on many civil engineering locations that lack adequate strength to sustain the loading either during construction or throughout the service life. The soils can also have elevated levels of contaminants which are considered harmful to human health and aquatic environments. In these circumstances soil stabilisation or solidification can be performed to both improve the structural properties of the soil and incapsulate the contamination within the re-engineered material. No reduction in contaminant mass occurs but its mobility is reduced and therefore the contamination cannot migrate to receptors effectively removing the contaminant pathway.
The applicability of soil stabilisation varies depending on soil characteristics, site geology, contamination extent, future material uses or external demands. Therefore, a feasibility study can be undertaken prior to full scale remediation. This study can evaluate the effectiveness of traditional binders and alternative binders which are often inexpensive and have a lower carbon footprint.
Soil stabilisation mix designs would be established at the feasibility study stage of the project. These would consist of mixing soil samples from the specific site with a variety of binders to reach the required geo-technical and geo-environmental properties of the stabilised material. These mixes can be undertaken in small scale lab trials or larger field trials.
Leachability testing of the material is usually undertaken to demonstrate the success of the encapsulation of contaminants.
The feasibility studies will allow the development of a detailed design to facilitate the future remediation of a specific site ahead of the development and construction.