Flux measurements provide useful information at almost every stage of the remediation process and for contaminated site management: better risk characterization to support optimal remediation selection and design (pre), remediation performance monitoring and optimization (during), and long-term monitoring (post).
Especially complex remediation processes obtain a rapid and direct added value. Imagine for complex sites that are contaminated by a mix of pollutants with an erratic dispersion pattern or hard-to-reach sites where the contamination is situated below buildings. Also for brownfield projects, flux sampling offers a guaranteed added value. By strategically employing flux monitoring, savings from 20 to 30% upon the total remediation cost are definitely within reach.
Before contaminated sites can get reallocated, the necessary soil investigations and possible remediation efforts need to be executed, in cooperation with the government.
In complex cases, this is often accompanied by a long and frustrating process, in which regularly unforeseen costs arise.
Soil remediation projects are exceptionally expensive, which makes it imperative to remediate correctly. Remediating too long, too much or too little will lead to a huge waste of resources, which will render redevelopment of contaminated soil a lot more expensive and possibly financially unprofitable.
That is why executing the remediation based on accurate data that can also indicate the mobility of contamination is of invaluable importance. Therefore it is crucial to map out clearly the spreading risks of groundwater contamination.
In situ measurements of contaminant fluxes deliver essential data that can be used to optimize the design of remediation measures. High flux zones can be indicated and in situ remediation techniques can be dimensioned based on the actual and local pollutant load.
Differences in source strength can be determined from the flux results, which localizes the most hazardous sources. This can be put to immediate use in the remediation plan: Which contamination to remediate and which not? Which zones should we focus on first? Which remediation efforts result in the most efficient removal of pollutant loads?
Besides designing the remediation measures, follow-up of the efficiency of these remediation measures is more accurate as well. This can be done by following the decrease in pollutant load and pollutant flux, typically downstream from the treated source or plume zone.
Pollutant fluxes are very useful to determine the effectiveness of the natural decomposition process, also known as natural attenuation. The natural decomposition or the decrease in pollutant loads can be calculated by the difference in total pollutant load between two cross sections of the contamination plume. Monitoring of decomposition parameters, nutrients and fluxes to subsidiary products also results in highly valuable information.
Often it is not realistic, and technically and economically not even possible, to remove all contamination (completely). A risk-based management keeps in mind the actual risks for people and environment. Flux sampling offers a reliable basis for such risk management. The actual mass and speed with which a contamination reaches a receptor, evaluates precisely the risks for this receptor.