Numerous contaminated sites are located in the alluvial plains along rivers and canals, and the measurement of the Darcy flux is an element essential to understand the migration of the pollution plume.
On these sites, the hydraulic gradient is often very low – despite a significant flow-, and it is not easy, if not impossible, to estimate it with precision, especially on sites of small geographical extension
With a such inaccuracy, measuring the Darcy flux by multiplying this gradient by hydraulic conductivity is absolutely unreliable.
Nagaré directly measures the Darcy flux in a single well without the need to know the hydraulic conductivity or the gradient. Other advantages: – no disturbance of the aquifer – no contaminated water from pumping has to be treated
Who contributes to the pollution of the site ?
In densely industrialized areas, it is not uncommon for pollution sources to be multiple and additive.
Flux measurements make it possible to quantify these sources because the mass flows measured can be added together… unlike concentrations.
It is then possible to know the contribution of each actor to the overall pollution of the site and its impact on the river.