Magali Dechesne

• PhD in Urban Hydrology
• R&D Expert at Veolia Recherche & Innovation

Effect-based methods (EBM) have great potential for water quality monitoring as they can detect the mixture effects of all active known and unknown chemicals in a sample, which cannot be addressed by chemical analysis alone. To date, EBM have primarily been applied in a research context, with a lower level of uptake by the water sector and regulato...

The evolution of the climate in the future will probably lead to an increase in extreme rainfall events, particularly in the Mediterranean regions. This change in rainfall patterns will have impacts on combined sewer systems operation with a possible increase of spilled flows, leading to an increase of untreated water volumes released to the receiv...

Water safety plans (WSPs) are intended to assure safe drinking water (DW). WSPs involve assessing and managing risks associated with microbial, chemical, physical and radiological hazards from the catchment to the consumer. Currently, chemical hazards in WSPs are assessed by targeted chemical analysis, but this approach fails to account for the mix...

The design of urban drainage systems often relies on the coupling of optimization algorithms and process-based models, with the latter informed by design storms. However, such practice may not yield systems that are robust with respect to a broad array of rainfall conditions. To tackle this problem, we contribute a novel computational framework cha...

Demain se prépare aujourd'hui. Une fois sensibilisé, chacun a un rôle à jouer dans l'adaptation au changement climatique. Les outils de sensibilisation contribuent à cette nécessaire prise de conscience. Ainsi, Kairos est un outil didactique, dynamique et facile de prise en main permettant de saisir aisément les principaux enjeux climatiques d'un t...

In an industrial symbiosis initiative (IS-I), an initiating actor faced with a situation aims to enroll other actors in a collective action, or response, to address the situation. The rational myth theory embeds this “situation-response” pair. This paper explores the relevance of rational myth, along with that of plausible promise, to understand th...

The concepts of industrial symbiosis (IS) and bioeconomy (BE) both focus on ways to reduce dependence on non-renewable resources. However, these two frames of reference have rarely been considered as part of a joint strategy to achieve sustainability. Here, we describe how they inter-operate, in well documented IS case studies, to identify current...

Cyanobacteria are known to produce a wide array of metabolites, including various classes of toxins. Among these, hepatotoxins (Microcystins), neurotoxins (Anatoxin-A and PSP toxins) or cytotoxins (Cylindrospermopsins) have been subjected to numerous, individual studies during the past twenty years. Reports of toxins co-occurrences, however, remain...

Observed taxa with known or suspected potential toxin production

Le changement climatique aura un impact sur la disponibilité des ressources en eau. Il est essentiel de pouvoir quantifier cet impact, à l’échelle locale, afin d’être en mesure d’adapter les systèmes de production d’eau potable. Veolia a développé une méthodologie pour évaluer la pérennité d’un service de production d’eau potable à l’horizon 2041-2...

Climate change will strongly impact water resources and consequently all relying services. In France, for example, hydrological projections are: uncertain trend for rainfall, with most models agreeing on a declining trend in summer precipitation from-16% to-23% ; significant overall decrease in the annual average river flows from 10% to 40% ; nearl...

Veolia a développé deux produits innovants dans Waternamics, la gamme de produits digitaux intégrés pour le grand cycle de l’eau, dédiés à la gestion quantitative raisonnée des ressources en eau à l’échelle du service d’eau potable. Resources Report est un bulletin de situation hydrologique, consultable en ligne, qui informe la collectivité et le g...

The invention pertains to a system for quantitative water management comprising the following elements: at least two interconnected water production entities (U), each production entity (U) being defined by a maximum production flowrate, at least one water resource (S) linked to one at least of the production entities (U), each water resource (S) b...

The invention relates to a method for determining a maximum allowable volume of water that can be removed over time from an underground water source, the volume of water being removed at a removal point and the hydrogeological state of the underground water source being qualified by piezometric measurements on a reference piezometer, the method bei...

The BSH webtool (Veolia Hydrological Situation Report) was the subject of a poster at the 95th ASTEE Symposium. This tool presents the daily status of water resources and the daily drinking water production. It promotes effective and balanced quantitative management, especially during water stress events, based on operating data.

Diffuse nitrate (NO3) contamination from intense agriculture adversely impacts freshwater ecosystems, and can also result in nitrate concentrations exceeding limits set in drinking water regulation, when receiving surface waters are used for drinking water production. Implementation of near-natural mitigation zones such as reactive swales or wetlan...

Urban Heat Islands (UHI) are a growing concern among cities all around the world, as climate change will increase their effects on public health and energy consumption. In France and Europe, UHI mitigation strategies are included in the adaption part of Climate Plans of municipalities. Numerous mitigation solutions have already been identified (cit...

The cyanobacterial toxins cylindrospermopsin (CYN), anatoxin-a (ATX-a) and saxitoxins (STX) have been detected in many freshwater resources throughout the world and at all latitudes, but their occurrence has not been an issue in France so far. As they may be a problem for the safety of drinking water, Veolia began screening of French freshwater res...

During the last decade, the source to tap risk-based approach to pathogens in drinking water has been largely promoted. This paper addresses the issue of source water pathogen contamination, which is the first step of quantitative microbial risk assessment. It is focused on a selection of pathogens considered to be a major risk to human health. Sou...

Infiltration basins are frequently used for stormwater drainage. They can operate for periods over 20 years but long-term evolution is not well understood or controlled. The two main problems encountered are clogging, which compromises the hydraulic capacity of the basin, and possible contamination of underlying soil and groundwater. This paper foc...

In order to characterize soil pollution in stormwater infiltration basins, four basins of the Lyon area were selected and sampled. Altogether, 66 soil samples were collected. Each sample was analyzed for pH, cationic exchange capacity, particle size distribution, total organic carbon, total nitrogen, total phosphorus, metals, total hydrocarbons and...

Infiltration basins are frequently used for stormwater drainage. Because stormwater is polluted in highly toxic compounds, assessment of pollution retention by infiltration basins is necessary. Indeed, if basins are not effective in trapping pollution, deep soil and groundwater may be contaminated. This study's objective is to investigate soil poll...

Infiltration basins are frequently used for stormwater management even though their long-term evolution is not well understood nor controlled. The two main problems encountered are clogging which compromises the hydraulic capacity of the basin and possible contamination of underlying soil and groundwater. This paper defines a framework for evaluati...

Storm water infrastructures based on pipe networks have reached their limits (concentration of the pollution, increase in flooding risks of and in investment costs). The managers and the designers turn towards new stormwater approaches such as infiltration strategies supposed to be more sustainable (easy integration in urban area, reduction of peak...

Storm water infrastructures based on pipe networks have reached their limits (concentration of the pollution, increase in flooding risks of and in investment costs). The managers and the designers turn towards new stormwater approaches such as infiltration strategies supposed to be more sustainable (easy integration in urban area, reduction of peak...

Infiltration basins are good systems to decentralize stormwater management. They are widely used in Lyon, France, as a result of urban development. But, because of topsoil clogging, infiltration basins can become unsustainable over time. This paper defines context indicators for assessing the present state of selected basins: a clogging indicator a...

Decentralization of stormwater management is necessary in order to achieve sustainable urban storm drainage. This research deals with evaluating long-term performance of infiltration basins by modeling their structural and environmental evolution. System modeling is carried out with a LCA (Life Cycle Assessment) point of view. In the first place, s...

Decentralization of stormwater management is necessary in order to achieve sustainable urban storm drainage. This research deals with evaluating long-term performance of infiltration basins by modeling their structural and environmental evolution. System modeling is carried out with a LCA (Life Cycle Assessment) point of view. In the first place, s...

In the near future, drinking water services may undergo many changes (water scarcity, contamination peaks, growing water demand) and it is the role of water utilities to anticipate new water schemes and develop tools to secure drinking water production. The paper will discuss water portfolio management, the concept of managing multiple water resour...

objectifs de cette recherche sont d'approfondir les connaissances sur le fonctionnement quantitatif et qualitatif des bassins d'infiltration d'eaux de ruissellement sur le long terme, de tester des modèles et des méthodes d'études et de proposer un outil d'évaluation de la performance d'un bassin d'infiltration. L'approche menée est une approche gl...