A good understanding of the various purification processes occurring within the reed bed discharge area, combined with the capacity to control the retention time and hydrodynamics of the reed bed, should make it possible to determine a more comprehensive approach, which will include consideration of both Science and Technology for Environmental Protection and the nature of the discharge environment at the design stage, as well as drafting a functional typology for reed bed discharge areas.
Exemplary features of the technical solutions implemented
Many different technical solutions have been put forward and include on-site instrumentation, assessment of pollution flows and oxygen metabolism, compilation of an inventory of flora, implementation of tracing, etc. The monitoring methodology used here is part of such a comprehensive approach.
List of skills that can be seen on the site
The Hannonville-sous-lès-Côtes reed bed consists of a small pond followed by a narrower channel with several meanders. At the exit, coarse materials such as gravel have been deposited to a depth of almost 30 cm. This deposit of coarse materials is completely under water, which means that all the effluent can flow through the interstices in the gravel. Macrophytic vegetation has grown significantly both on the banks and in the reed bed itself, and appears very well structured from both an ecological and an aesthetic point of view.
The appearance of a population of batrachians was observed on the site in the spring of 2014.
Year of inauguration: 2013
Surface area: approximately 1,750 sq. m (or 2 sq. m. per person equivalent)
Water depth 20 cm < h < 60 cm
Vegetation: Newly planted Reed Bed Discharge Area
On average, over the three measurement programmes already carried out, a slight reduction in concentration has been noted for parameters TP, NGL and COD (concentration yields calculated were respectively 17%, 21% and 30%). On the basis of results and observations originating from other sites, it seems likely that the reduction in pollutants will increase during the summer season.
IRH INGENIEUR CONSEIL
427 rue Lavoisier, 54714 Ludres
Players involved and their roles
IRH INGENIEUR CONSEIL
CONSORTIUM DU PROJET DE RECHERCHE ANR NOMME EPEC POUR EPURATION EN EAU COURANTE CONSTITUE DE DEUX ENTREPRISES (IRH IC, FLUVIAL.IS) ET DE TROIS INSTITUTIONS DE RECHERCHE (LRGP, IRSTEA, LSA)