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Recently, emphasis has been placed on finding a reliable estimation of soil water content. In this study, two capacitance sensors EC5 and 5TE (METER Group) were utilized. These sensors provide many benefits relative to other sensors in that they are cost-effective and very economical regarding energy use, operate at a high measurement frequency of 70 MHz, and are dedicated to measuring at a small volume because of their small size. This makes them suitable for the context of use in this research, which consists of multiple sustainable drainage systems SuDS. Several studies have evaluated these two types of sensor but not for urban soils with specific characteristics. In addition, results from the literature are divergent and the published calibration data are limited. Therefore, an in-depth investigation of their accuracy is assessed in this paper. At first, the literature&rsquo, s existing procedures and methods were examined. The sensor-to-sensor variability, as well as repeatability, were tested in soil and solutions. Additionally, a field calibration method was conducted to estimate the effects of soil texture on sensors readings. Two laboratory calibration methods having different principles were also applied, compared to each other and to the field calibration as well. Results revealed weak sensor-to-sensor variability (coefficient of variation up to 15% in soil) and also good repeatability (0.1%), for both sensors. A soil-specific calibration equation has improved the estimation of the volumetric water content. In case of soil having high field bulk density, the undisturbed soil calibration method described and proposed in this paper gives promising results. The latter method yields a volumetric water content (VWC) prediction accuracy of 0.025 m3∙m&minus, 3 on a sandy loam soil. This paper presents a large knowledge of capacitance sensors measurement technique as well as their calibration procedures and methods. Limitations of existing procedures have been identified and key elements for selecting the appropriate one are suggested. Derived calibration equations have also been provided for three urban soils with different particle size distribution, ranging from sandy loam to silt loam. Accurate monitoring of soil moisture content in urban soils is thus achievable.

International audience; Road runoff is contaminated by various micropollutants and may be treated using low impact development techniques, such as stormwater biofilters. Better understanding the processes, such as filtration, sorption and leaching, which affect pollutants in these systems is essential to reliably predicting treatment performance and optimizing system design. Field data from an in situ monitoring campaign, wherein dissolved and particulate concentrations of a wide range of micropollutants (trace metals, polycyclic aromatic hydrocarbons, bisphenol-A, alkylphenols and phthalates) were characterized in untreated road runoff and biofilter outlets for 19 rain events, are used to explore transport and retention processes. Although retention of the particulate phase of pollutants was generally quite effective, unusually high particle concentrations were observed at biofilter outlets for three winter events. Particle characterization in road runoff and outlet waters revealed that this degraded performance was due to poor filtration rather than particle erosion, which was attributed to the relative abundance of small (

This article describes a stochastic method to calculate the annual pollutant loads and its application over several years at the outlet of three catchments drained by separate storm sewers. A stochastic methodology using Monte Carlo simulations is proposed for assessing annual pollutant load, as well as the associated uncertainties, from a few event sampling campaigns and/or continuous turbidity measurements (representative of the total suspended solids concentration (TSS)). Indeed, in the latter case, the proposed method takes into account the correlation between pollutants and TSS. The developed method was applied to data acquired within the French research project "INOGEV" (innovations for a sustainable management of urban water) at the outlet of three urban catchments drained by separate storm sewers. Ten or so event sampling campaigns for a large range of pollutants (46 pollutants and 2 conventional water quality parameters: TSS and total organic carbon (TOC)) are combined with hundreds of rainfall events for which, at least one among three continuously monitored parameters (rainfall intensity, flow rate, and turbidity) is available. Results obtained for the three catchments show that the annual pollutant loads can be estimated with uncertainties ranging from 10 to 60%, and the added value of turbidity monitoring for lowering the uncertainty is demonstrated. A low inter-annual and inter-site variability of pollutant loads, for many of studied pollutants, is observed with respect to the estimated uncertainties, and can be explained mainly by annual precipitation.

International audience; Jérémie Sage, Elissar El Oreibi, Mohamed Saad, Marie-Christine Gromaire (2016). Modelling the temporal variability of zinc concentrations in zinc roof runoff – Experimental study and uncertainty analysis, Environmental Science and Pollution Research, pp. 1-15. The final publication is available at Springer via http://dx. ABSTRACT This study investigates the temporal variability of zinc concentrations from zinc roof runoff. The influence of rainfall characteristics and dry period duration is evaluated by combining laboratory experiment on small zinc sheets and in-situ measurements under real weather conditions from a 1.6 m² zinc panel. A reformulation of a commonly used conceptual runoff quality model is introduced and its ability to simulate the evolution of zinc concentrations is evaluated. A systematic and sharp decrease from initially high to relatively low and stable zinc concentrations after 0.5 to 2 millimetres of rainfall is observed for both experiments, suggesting that highly soluble corrosion products are removed at early stages of runoff. A moderate dependence between antecedent dry period duration and the magnitude of zinc concentrations at the beginning of a rain event is evidenced. Contrariwise, results indicate that concentrations are not significantly influenced by rainfall intensities. Simulated rainfall experiment nonetheless suggests that a slight effect of rainfall intensities may be expected after the initial decrease of concentrations. Finally, this study shows that relatively simple conceptual runoff quality models may be adopted to simulate the variability of zinc concentrations during a rain event and from a rain event to another.

Runoff infiltration in Sustainable Drainage Systems enables the interception of a part of urban contaminant fluxes owing to several processes. The soil's ability to retain dissolved pollutants is generally assessed via sorption isotherms obtained from batch studies; however, the experimental points are not always in the same range as runoff concentrations. The present work (i) explores the consequences of modelling runoff–soil interactions from out-of-range equilibrium concentrations and (ii) proposes an improved method to ensure that experimental points fall within the desired range. Uncertainty analysis demonstrates that for a non-linear isotherm, using an extrapolated relationship may introduce significant biases in the ensuing estimations. Therefore, the proposed method consists of anticipating the equilibrium state of batch tests to accurately set the experimental conditions and reach appropriate concentrations. It is successfully applied to the determination of the sorption properties of copper and zinc onto three soils with different electrolyte solutions, as well as those of bisphenol A and three alkylphenols onto one soil. The contrasting affinities between the studied species and the soil materials could be related to their intrinsic properties and the soils' pedological parameters, as well as the presence of salt or dissolved organic ligands which partially inhibited metal sorption.

International audience; The treatment efficiency of a vegetative filter strip and a biofiltration swale treating heavily loaded road runoff are evaluated. Concentrations measured in water drained from the two systems are compared to those in untreated road runoff collected from a reference catchment for a wide range of contaminants including organic carbon, nutrients (N and P), metallic trace elements, and organic micropollutants (polycyclic aromatic hydrocarbons (PAH), total petroleum hydrocarbons (TPH), alkylphenols, bisphenol-A, phthalates), in both total and dissolved phases. Predominantly particulate pollutants, including Pb, Zn and PAH, were very efficiently removed (around 90%) for most events. However, poor particulate removal was observed during a winter period. Relatively few pollutants were significantly removed in the dissolved phase and observed concentration reductions tended to be lower than those of suspended solids and associated pollutants; as such, lower removals were observed for total concentrations of moderately particulate micropollutants, including bisphenol-A, alkylphenols and phthalates. In addition, some pollutants appear to be emitted from various biofilter components (filter media, drainage and lining materials), as low or negative concentration removals were observed during the first months of operation of the biofiltration swale.

International audience; Roof maintenance practices often involve the application of biocide products to fight against moss, lichens and algae. The main component of these products is benzalkonium chloride, a mixture of alkyl benzyl dimethyl ammonium chlorides with mainly C12 and C14 alkyl chain lengths, which is toxic for the aquatic environment. This paper describes, on the basis of an in-situ pilot scale study, the evolution of roof runoff contamination over a one year period following the biocide treatment of roof frames. Results show a major contamination of roof runoff immediately after treatment (from 5 to 30 mg/L), followed by an exponential decrease. 175-375 mm of cumulated rainfall is needed before the runoff concentrations become less than EC50 values for fish (280 mu g/l). The residual concentration in the runoff water remains above 4 mu g/L even after 640 mm of rainfall. The level of benzalkonium ions leaching depends on the roofing material, with lower concentrations and total mass leached from ceramic tiles than from concrete tiles, and on the state of the tile (new or worn out). Mass balance calculations indicate that a large part of the mass of benzalkonium compounds applied to the tiles is lost, probably due to biodegradation processes. (C) 2015 Elsevier Ltd. All rights reserved.

Les flux de polluants associés aux eaux pluviales urbaines sont un facteur majeur de dégradation des milieux aquatiques superficiels dont la gestion est devenue un réel enjeu écologique au cours des dernières décennies. De nombreuses solutions techniques ont ainsi été développées afin de limiter la formation du ruissellement à l'amont des bassins versants urbains. Néanmoins, alors que la plupart des pays ou collectivités aspirent à la maîtrise de cette pollution, les réglementations ou prescriptions données aux opérationnels demeurent assez hétérogènes. L'objectif de cet article est donc, en se basant sur une synthèse bibliographique à l'international des pratiques de gestion des eaux pluviales, d'analyser les différents critères pouvant être donnés aux aménageurs en considérant à la fois leur pertinence pour la maîtrise des flux de polluants et les implications de leur définition en termes de choix ou de dimensionnement des techniques alternatives. Alors que les critères hydrologiques volumiques, directement rattachés au fonctionnement des techniques alternatives, semblent être préférables pour une maîtrise à la source des polluants ruisselés, cette étude indique que l'adoption de solutions de gestion à moindre impact des eaux pluviales demeure probablement très dépendante des outils de sélection ou de conception des techniques alternatives mis à disposition des aménageurs.

Alkylphenol (AP) and bisphenol A (BPA) contamination of urban runoff has already been established. Potential sources of these contaminants in runoff are endogenous to the urban watershed and are mainly related to traffic and leaching from construction materials. This article summarizes the results of experimental work carried out on a selection of building materials, automotive materials, and consumables, which can be in contact with rain, to assess their potential emission of alkylphenols, alkylphenol ethoxylates, and bisphenol A into runoff. 36 samples of materials, new and used, across 7 major families of building materials (PVC, concrete, polycarbonate, SBS-modified bitumen, drainage materials) and automotive materials (body, tires) were subjected to leaching tests with methanol and then, for a selection of them, with water. Automotive fluids were also directly analyzed. The results demonstrate the ubiquitous presence of APs and BPA in urban materials and their extractable character with water. The compounds with the strongest emission rates were bisphenol A and nonylphenol. The most important BPA emissions into water (10 to 300 ng/g) were measured for polycarbonate, tires, some car bodies, and PVC. Nonylphenol was leached in large quantities (1 to 10 ng/g) from PVC, some concretes, SBS-modified bitumen, and body samples. The tires were the only materials having a strong emission in octylphenol (1 to 10 ng/g). The analysis of automotive fluids confirmed the presence of BPA (0.3 to 5.5 g/L) and nonylphenol (2.3 to 2.9 mg/L) in brake fluids, while APs and BPA were found at trace levels in coolants and windscreen washer. Graphical abstract ᅟ.

International audience; Among the processes governing contaminant retention in soil-based Sustainable Urban Drainage Systems (SUDS), quantifying the relative contribution of particle settling and filtration requires a tracer of runoff-generated solids. Since zirconium (Zr) is a widely used geochemical invariant in pedological approaches, with few anthropogenic sources, the present investigation aims to assess whether its use may be extended to sediment identification in SUDS. High-resolution horizontal and vertical soil sampling was carried out in 11 infiltration systems, as well as in road-deposited sediment. Following elemental analysis via X-ray fluorescence spectrometry, the spatial distribution of both Zr and urban-derived metals could be determined. Zr content in sediment was found to be fairly stable and significantly lower than in soil. In most devices, Zr and metals exhibited "mirror" trends, both horizontally and vertically, i.e. a deficit of Zr could be observed in the most contaminated area. This indicated a "dilution-like" mixture of soil and sediment, the fraction of which could be calculated and appraised spatially. The vertical profiles proved the occurrence of bed filtration over 5 to 15 cm, and enabled the calibration of a simple filtration model. The uncertainties associated with the determined filter coefficient were found to be comparable to the other experimental methods – with the additional improvement that the present approach does not require water sampling.

International audience; Depuis quelques décennies, on observe le développement de systèmes végétalisés conçus pour stocker, filtrer et parfois infiltrer à la source les eaux de ruissellement urbaines. Dans le monde anglophone de nombreux guides ont été publiés afin d'encadrer la conception et la maintenance de ce type d'ouvrage, qualifiés de bioretention. Ces guides, issus de retour d'expérience dans ces pays, proposent des préconisations relatives à l'emplacement des ouvrages, leurs modes de vidange, les caractéristiques des couches du filtre, les critères et méthodes de dimensionnement, le choix des végétaux et l'entretien des ouvrages. Comme ces techniques sont encore relativement peu diffusées en France et ne font pas encore l'objet de tels guides, cet article a pour vocation de dresser une synthèse d'une sélection de ces guides. Abstract: Over the past few decades, vegetated systems designed for the on-site storage, filtration and sometimes infiltration of urban runoff have been developed and become increasingly popular. Across the English-speaking world, one can find a great many guides providing detailed information as to the design and maintenance of this type of system, referred to as bioretention. These guides, which present advice as to where to locate these systems, how to drain them, the characteristics of the filter media, sizing methods, plant choice and system maintenance, contain a wealth of valuable information and feedback from the experience in these countries. As this technique is relatively new in France and no such detailed guidelines yet exist, this article synthesizes the information from a selection of these guides. 2

International audience; The increasing use of infiltration-based systems for stormwater management questions the soil's ability to act as a long-term filter for runoff contaminants, and brings about operational matters regarding the most effective maintenance practices to enhance contaminant retention in SUDS. This paper reports the vertical extent of metal and PAH contamination in the soil of seven source-control devices in operation for more than 10 years, assessed via a two-step sampling strategy to optimize the representativeness of the contamination profiles. Metal distribution was typically characterized by a significant surface buildup, followed by a decrease in concentrations with increasing depth, usually coming close to the background values. PAH were more heterogeneously distributed with depth, but their accumulation was globally restricted to the upper 10-40 cm. This indicates an interesting potential for pollution interception by the upper horizons of soil, but does not necessarily prevent from downward fluxes, even while measuring low surface contents, as deeper strata may have lesser retention capacities. Specific amendments of the surface soil may help prevent this problem. Surface soil renewal – which would be necessary over 2.5 to 30 cm in four sites, according to the "strictest" standards for soil remediation – may regenerate the soil's sorption potential, but such a practice could disrupt the interactions with the local ecosystem, so this should be carried out exceptionally and not as a preventive measure.

International audience; Sewage systems are a vital part of the urban infrastructure in most cities. They provide drainage, which protects public health, prevents the flooding of property and protects the water environment around urban areas. On some occasions sewers will overflow into the water environment during heavy rain potentially causing unacceptable impacts from releases of untreated sewage into the environment. In typical Life Cycle Assessment (LCA) studies of urban wastewater systems (UWS), average dry-weather conditions are modelled while wet-weather flows from UWS, presenting a high temporal variability, are not currently accounted for. In this context, the loads from several storm events could be important contributors to the impact categories freshwater eutrophication and ecotoxicity. In this study we investigated the contributions of these wet-weather-induced discharges relative to average dry-weather conditions in the life cycle inventory for UWS. In collaboration with the Paris public sanitation service (SIAAP) and Observatory of Urban Pollutants (OPUR) program researchers, this work aimed at identifying and comparing contributing flows from the UWS in the Paris area by a selection of routine wastewater parameters and priority pollutants. This collected data is organized according to archetypal weather days during a reference year. Then, for each archetypal weather day and its associated flows to the receiving river waters (Seine), the parameters of pollutant loads (statistical distribution of concentrations and volumes) were determined. The resulting inventory flows (i.e. the potential loads from the UWS) were used as LCA input data to assess the associated impacts. This allowed investigating the relative importance of episodic wet-weather versus “continuous” dry-weather loads with a probabilistic approach to account for pollutant variability within the urban flows. The analysis at the scale of one year showed that storm events are significant contributors to the impacts of freshwater eutrophication and ecotoxicity compared to those arising from treated effluents. At the rain event scale the wet-weather contributions to these impacts are even more significant, accounting for example for up to 88% of the total impact on freshwater ecotoxicity. This also allowed investigating and discussing the ecotoxicity contribution of each class of pollutants among the broad range of inventoried substances. Finally, with such significant contributions of pollutant loads and associated impacts from wet-weather events, further research is required to better include temporally-differentiated emissions when evaluating eutrophication and ecotoxicity. This will provide a better understanding of how the performance of an UWS system affects the receiving environment for given local weather conditions.

International audience; This article presents a dual approach to assessing annual flows of metals and PAHs in stormwater for three urban watersheds of different land uses. An assessment of the contributions of primary sources of pollution, based on a SFA approach (substance flow analysis) is conducted so as to identify the relative contribution of emissions from automobiles (tires, brakes, fuel…), leaching from building materials (roof cover and singular elements of roofs) and atmospheric fallout. These flows are compared with those calculated at the outlet of the storm drainage system by a method combining the analysis of micro-pollutants in a limited number of stormwater samples and continuous measurement data of rain, flow and turbidity. This work allows to highlight the dominant diffuse sources of runoff contamination, key indicators for their quantification but also to diagnose gaps in current knowledge.; Cet article présente une double approche d’évaluation des flux annuels de métaux et de HAP dans les eaux pluviales de trois bassins versants urbains d’occupations du sol différentes. Une évaluation des contributions des sources primaires de pollution, par une approche de type « SFA » (analyse de flux de substances) est conduite afin d’identifier la contribution relative des émissions dues à l’automobile (pneus, freins, carburants…), au lessivage des matériaux de construction (couvertures et éléments singuliers de toitures) et aux apports atmosphériques. Ces flux sont confrontés à ceux évalués à l’exutoire du réseau pluvial par une méthode combinant l’analyse des micropolluants dans un nombre limité d’échantillons d’eaux pluviales et des données de mesure en continu de pluie, débit et turbidité. Ce travail permet de mettre en évidence les sources diffuses dominantes, des indicateurs clés pour leur quantification, mais aussi de diagnostiquer des lacunes dans les connaissances actuelles.

This study aimed at i) providing for a large range of pollutants (n=77) information on their occurrence and concentration ranges in stormwater, ii) assessing the land use influence on stormwater quality and iii) analyzing the contribution of total atmospheric fallout (TAF) and endogenous sources to this contamination. Additionally, for poorly documented pollutants such as nonylphenol and octylphenol ethoxylates (NPnEO and OPnEO), this study reported for the first time levels for some new concerning metals (As, Ti, Cr, V) and organic pollutants such as polybromodiphenylethers (PBDEs), some pesticides and bisphenol A (BPA). For most of the pollutants, the stormwater quality at the outlet of three urban catchments exhibiting a different land use patterns did not significantly differ, suggesting that land use does no significantly influence the stormwater micropollutant contamination. No significant difference in terms of partitioning between all sites was also observed, indicating the not site-dependence. Finally, the contributions of TAF to stormwater contamination for micropollutants were rather low or very low. This underlines not only for PAHs as previously demonstrated in the literature but also for a larger range of molecules such as BPA, NPnEO, OPnEO and PBDEs a high local production related to the leaching of urban surfaces, buildings and vehicles. Knowledge gained in this study may be used soon to elaborate relevant decision support tools for i) urban stormwater practitioners and/or ii) watershed managers to reduce stormwater pollutant discharges; Cet article synthétise les résultats du projet INOGEV sur les concentrations de micropolluants organiques et métalliques dans les eaux pluviales strictes. Ce projet a permis non seulement d'étudier certains polluants jusqu'à lors faiblement documentés dans la littérature mais également d'établir les ordres de grandeurs des concentrations totales, dissoutes et particulaires dans les eaux pluviales. Excepté pour quelques micropolluants pour lesquels le trafic automobile est une source importante de contamination (certains métaux, HAP) et les PBDE, aucune différence significative n'a été obserÎe entre les trois bassins versants étudiés, la variabilité inter-éÎnementielle des concentrations sur un même site étant du même ordre de grandeur que la variabilité inter-sites. De manière générale, la distribution des polluants entre phases dissoute et particulaire dépend des propriétés physico-chimiques des molécules. Les métaux sont préférentiellement associés aux particules :) > 50% for As, Cd, Mo, Ni, V, Cu et Zn; et > 80% for Co, Cr, Pb et Ti. Pour les composés organiques, cette répartition dépend fortement du coefficient octanol - eau (Kow). Au regard des processus de production et de transfert sur les surfaces urbaines, les résultats indiquent pour un large panel de molécules que les apports atmosphériques ne contribuent que minoritairement à la pollution obserÎe aux exutoires, leur contribution n'excédant généralement pas 30%. Démontré pour les métaux et les HAP à travers des études antérieures, ce résultat est innovant pour les autres molécules étudiées et vient confirmer une production locale importante.

La contamination en alkylphenols (AP) et en bisphenol A (BPA) des eaux de ruissellement urbaines est averee. Les sources potentielles de ces contaminants dans les eaux de ruissellement sont endogenes au bassin versant et sont liees en particulier a la circulation automobile et au lessivage des materiaux constituant l’enveloppe bâtie et les infrastructures urbaines. Cet article synthetise les resultats d’un travail experimental mene sur une selection de materiaux de construction, de materiaux et de consommables automobiles entrant en contact avec la pluie afin d’evaluer leur potentiel d’emission des AP, alkylphenols ethoxyles et BPA dans le ruissellement. 36 echantillons de materiaux, neufs et usages, appartenant a sept grandes familles de materiaux de construction (PVC, beton, polycarbonate, bitume modifie SBS, materiaux de drainage) et de materiaux automobiles (carrosserie, pneus) ont ete soumis a des tests de lixiviation au methanol puis, pour une selection d’entre eux, a des tests de lixiviation a l’eau. Trois types de fluides automobiles (liquide de frein, lave-glace et liquide de refroidissement) ont ete extraits directement. Les resultats demontrent la presence ubiquiste des composes recherches dans les materiaux urbains, ainsi que leur caractere extractible a l’eau. Les composes avec les plus forts taux d’emission sont le BPA et le nonylphenol (NP). Les emissions dans l’eau en BPA les plus importantes (10 a 300 ng/g) ont ete mesurees pour le polycar bonate, les pneumatiques, certaines carrosseries de voiture et les PVC. Le NP a ete lixivie par l’eau en quantite importante (1 a 10 ng/g) depuis les PVC, certains betons, les bitumes modifies SBS et les echantillons de carrosserie. Les pneus sont les seuls materiaux presentant une forte emission en octylphenol (OP) (1 a 10 ng/g). L’analyse de fluides automobiles a confirme la presence du BPA (0, 3 a 5, 5 g/L) et du NP (2, 3 a 2, 9 mg/L) dans les liquides de frein, tandis que les AP et le BPA peuvent etre trouves a l’etat de traces dans les liquides de refroidissement et lave-glaces.

Stormwater runoff infiltration brings about some concerns regarding its potential impact on both soil and groundwater quality; besides, the fate of contaminants in source-control devices somewhat suffers from a lack of documentation. The present study was dedicated to assessing the spatial distribution of three heavy metals (copper, lead, zinc) in the surface soil of ten small-scale infiltration facilities, along with several physical parameters (soil moisture, volatile matter, variable thickness of the upper horizon). High-resolution samplings and in-situ measurements were undertaken, followed by X-ray fluorescence analyses and spatial interpolation. Highest metal accumulation was found in a relatively narrow area near the water inflow zone, from which concentrations markedly decreased with increasing distance. Maximum enrichment ratios amounted to > 20 in the most contaminated sites. Heavy metal patterns give a time-integrated vision of the non-uniform infiltration fluxes, sedimentation processes and surface flow pathways within the devices. This element indicates that the lateral extent of contamination is mainly controlled by hydraulics. The evidenced spatial structure of soil concentrations restricts the area where remediation measures would be necessary in these systems, and suggests possible optimization of their hydraulic functioning towards an easier maintenance. Heterogeneous upper boundary conditions should be taken into account when studying the fate of micropollutants in infiltration facilities with either mathematical modeling or soil coring field surveys.

International audience; To meet the need for an operating protocol to measure the distributions of suspended solid settling velocities within urban drainage, the CEREVE research laboratory has developed and validated the VICAS protocol. This procedure makes it possible, through the use of a compact, inexpensive and easy-to-operate settling column, to measure the settling velocity of suspended solids conveyed by either storm water or combined sewage, immediately after collecting a reduced volume sample (4.5 L), and without any pretreatment steps. Two measurement data processing methods were developed and may be easily implemented by means of a series of macros written in Excel. Tests were also conducted for the purpose of evaluating the level of measurement uncertainty specific to the protocol.

International audience; The increasing use of Sustainable Urban Drainage Systems (SUDS) for stormwater management raises some concerns about the fate of ubiquitous runoff micropollutants in soils and their potential threat to groundwater. This question may be addressed either experimentally, by sampling and analyzing SUDS soil after a given operating time, or with a modeling approach to simulate the fate and transport of contaminants. After briefly reminding the processes responsible for the retention, degradation, or leaching of several urban-sourced contaminants in soils, this paper presents the state of the art about both experimental and modeling assessments. In spite of noteworthy differences in the sampling protocols, the soil parameters chosen as explanatory variables, and the methods used to evaluate the site-specific initial concentrations, most investigations undoubtedly evidenced a significant accumulation of metals and/or hydrocarbons in SUDS soils, which in the majority of the cases appears to be restricted to the upper 10 to 30 cm. These results may suggest that SUDS exhibit an interesting potential for pollution control, but antinomic observations have also been made in several specific cases, and the inter-site concentration variability is still difficult to appraise. There seems to be no consensus regarding the level of complexity to be used in models. However, the available data deriving from experimental studies is generally limited to the contamination profiles and a few parameters of the soil, as a result of which “complex” models (including colloid-facilitated transport for example) appear to be difficult to validate before using them for predictive evaluations.

Measuring the turbidity of urban sewage is interesting because in raw waste water, pollutants are mainly particulates and/or bound to particulates. Moreover it is a real time and continuous measurement. This paper deals with knowledge elements and methods for the determination of the components of the uncertainty on turbidity measurement on water samples (principle of measurement, calibration, drift,...). These methods contribute to the use of this measurement technique by operators of urban drainage systems. They were applied for comparing experimental results obtained with various devices and various calibration and sampling strategies. The level of overall short term accuracy reached for turbidity measurement in urban waste water is satisfactory, provided that the non-linearity of some devices to corrected if needed.

Afin d’analyser la representativite des echantillons preleves sur les sites de l’OPUR, deux approches ont ete suivies : theorique et experimentale. L’analyse theorique a permis de respecter 7 criteres sur 9 recommandes lors du choix et de l’installation d’un preleveur automatique. Les tests experimentaux ont montre : une homogeneite satisfaisante des concentrations dans les differentes sections de mesure, une bonne representativite des prelevements quand les tuyaux sont propres, une contamination des echantillons par encrassement des tuyaux de prelevement a cause de l’erosion des biofilms, une influence de la temperature et de la duree de conservation sur les echantillons destines a l’analyse d’ammonium et de parametre dissous. La contamination sera eliminee par des prelevements d’eau usee puis d’eau propre avant chaque campagne de mesure et par la mise hors d’eau des tuyaux de prelevement. Toutes les analyses seront realisees immediatement.

International audience; The characterization and control of runoff pollution from nonpoint sources in urban areas are a major issue for the protection of aquatic environments. We propose a methodology to quantify the sources of pollutants in an urban catchment and to analyze the associated uncertainties. After describing the methodology, we illustrate it through an application to the sources of Cu, Pb, Zn, and polycyclic aromatic hydrocarbons (PAH) from a residential catchment (228 ha) in the Paris region. In this application, we suggest several procedures that can be applied for the analysis of other pollutants in different catchments, including an estimation of the total extent of roof accessories (gutters and downspouts, watertight joints and valleys) in a catchment. These accessories result as the major source of Pb and as an important source of Zn in the example catchment, while activity-related sources (traffic, heating) are dominant for Cu (brake pad wear) and PAH (tire wear, atmospheric deposition).

International audience; : Three catchments, equipped with sustainable urban drainage systems (SUDS: vegetated roof, underground pipeline or tank, swale, grassed detention pond) for peak flow mitigation, have been compared to a reference catchment drained by a conventional separate sewer system in terms of hydraulic behaviour and discharged contaminant fluxes (organic matter, organic micropollutants, metals). A runoff and contaminant emission model has been developed in order to overcome land use differences. It has been demonstrated that the presence of peak flow control systems induces flow attenuation even for frequent rain events and reduces water discharges at a rate of about 50% depending on the site characteristics. This research has also demonstrated that this type of SUDS contributes to a significant reduction of runoff pollutant discharges, by 20%-80%. This level of reduction varies depending on the considered contaminant and on the design of the drainage system but is mostly correlated with the decrease in runoff volume. It could be improved if the design of these SUDS focused not only on the control of exceptional events but also targeted more explicitly the interception of frequent rain events.

International audience; Although the need for on-site runoff and pollution control is generally well accepted by both scientists and practitioners, there is no real agreement on the suitability of the different stormwater management criteria given to practitioners for the design of source-control systems. Hydrologic criteria, directly related to the sizing of stormwater management facilities, are for instance either expressed as flow-rate or volume targets. While these criteria are usually assume to provide adequate runoff or pollution control, their comparison has only received scant attention and the specification of these volume or flow-rate control targets often remains poorly justified. Tin this article, a methodology is there fore developed to investigate the suitability of different flow-rate or volume based stormwater management scenarios for on-site pollution control. Flow-rate control and volume-reduction strategies are simulated over a 15-year rainfall period with a relatively simple and conceptual “urban catchment + BMP” modelling system, for which different scenarios can be considered in terms of runoff and pollutant wash-off dynamics or stormwater facility design. First results indicate that the capture of relat ively small runoff volumes, later infiltrated or lost through evapotranspiration, can result in a significant reduction of pollutant loads discharged to surface waters or sewer systems, although BMPs efficiency appears quite sensitive to pollutant washoff dynamics.; Bien que la maîtrise à la source des flux d’eau et de polluants soit à l’heure actuelle largement encouragée pour limiter les impacts du rejet d’eaux pluviales urbaines sur les milieux récepteurs, les critères de gestion donnés aux aménageurs demeurent assez variables d’un pays à l’autre et restent souvent peu explicites. Les critères hydrologiques sont par exemple fréquemment exprimés comme des objectifs de réduction des débits de pointe et plus rarement d’abattement des volumes ruisselés. Si ces critères sont généralement supposés permettre de limiter les rejets de contaminants à l’amont, peu d’éléments objectifs permettent toutefois de réellement quantifier leur effet, et la détermination de valeurs optimales pour la régulation des débits comme pour l’abattement des volumes ruisselés demeure par ailleurs une question ouverte. La méthodologie présentée ici vise donc à analyser la pertinence des approches d’abattement des volumes ruisselés ou de régulation des débits pour la maîtrise à la source des flux de polluants. La mise en oeuvre de ces deux stratégies a été simulée (sur une période de 15-ans) à partir d’un modèle relativement simple d’ouvrage perméable végétalisé vers lequel seraient dirigées des eaux de ruissellement de chaussées urbaines. Les premiers résultats indiquent que l’abattement de volumes de ruissellement modérés pourrait donner lieu à une réduction importante des flux de polluants dirigés vers les milieux, bien que l’efficacité des solutions mises en oeuvre semble dépendante de la dynamique d’émission des contaminants considérés.

International audience; This study compares the effectiveness of two different thickness of green roof substrate with respect to nutrient and heavy metal retention and release. To understand and evaluate the long term behaviour of green roofs, substrate columns with the same structure and composition as the green roofs, were exposed in laboratory to artificial rain. The roofs act as a sink for C, N, P, zinc and copper for small rain events if the previous period was principally dry. Otherwise the roofs may behave as a source of pollutants, principally for carbon and phosphorus. Both field and column studies showed an important retention for Zn and Cu. The column showed, however, lower SS, DOC and metal concentrations in the percolate than could be observed in the field even if corrected for run-off. This is most probably due to the difference in exposition history and weathering processes. (C) 2013 Elsevier Ltd. All rights reserved.

International audience; In France, the utilization of harvested rainwater (HRW) has grown in recent years and thus raises the questions related with its quality corresponding to some types of use. Some utilizations are currently regulated: outdoor uses (such as lawn watering and floor cleaning) and indoor uses (toilet flushing, floor cleaning and, "for experimental use", laundry washing). If the French regulation requires some obligations of means corresponding to certain categories of HRW uses, there are no quality criteria determining the reference values of a set of well-defined parameters neither appropriate analytical methods in order to adequately characterize the HRW quality regarding its uses. In this context, the aim of this paper is threefold. The first is, from the identification of frequently used parameters for assessing the HRW quality in the scientific literature, to suggest a set of relevant parameters according to different categories of HRW uses. The second is to propose some adapted standard protocols for analysis of fecal indicators in order to assess the quality of the HRW. The final objective is to analyze some foreign existing regulations specifically dedicated to quality assessment of the HRW towards establishing guidelines values according to the uses. © ASEES, 2013.

International audience; A method for benzalkonium analysis has been developed to measure benzalkonium concentration in dissolved and particulate fractions from urban runoff samples. The analysis was performed by liquid chromatography coupled with mass spectrometry (LC-MS/MS). The dissolved matrix was extracted by Solid Phase Extraction (SPE), with cationic exchange and the particles by microwave extraction with acidified methanol. Recovery percentages were closed to 100% for benzalkonium C12 and C14. The protocol was applied to roof runoff samples collected after a roof demossing treatment, and to separative stormwater samples from a 200 ha catchment. The results illustrate an important contamination of the roof runoff, with a maximum concentration close to 27 mg/L during the first rain. The benzalkonium concentration (sum of C12 and C14) stayed high (up to 1 mg/L) even 5 months after the treatment. Benzalkonium concentration measured in stormwaters was low (0.2 µg/L) but with contaminated suspended solids (up to 80 µg/g). © 2012 Elsevier Ltd. All rights reserved.

International audience; A sampling campaign was conducted in order to determine alkylphenol (AP) concentrations in stormwater as well as potential AP sources in suburban environments. An analytical procedure was developed to quantify APs in bulk atmospheric deposition, building runoff, road runoff and stormwater. Both nonylphenols and octylphenols could be quantified in each sample. Median stormwater concentrations amounted to: 470 ng/l for nonylphenols, and 36 ng/l for octylphenols. These concentrations are 3 times higher than those found in atmospheric deposition, thus proving that local human activity constitutes a significant source of contamination. The contributions of the various sources to stormwater have been assessed from mass balances at the catchment scale. 70% of AP mass in stormwater originates from building and road emissions. Annual AP fluxes have been extrapolated from the total AP mass measured over our sampling periods for atmospheric depositions (44 to 84 µgNP/m(2)/yr) and stormwater (100 to 190 µgNP/m(2)/yr). Moreover, since APs were mainly found in the dissolved fraction, runoff treatment devices based on settling are unlikely to be very efficient.

International audience; An observatory of urban pollutants was created in Paris for the purpose of assessing the dynamics of wastewater and wet weather flow (WW and WWF) pollutant loads within combined sewers. This observatory is composed of six urban catchments, covering land areas ranging in size from 42 ha to 2581 ha. For a wide array of parameters including total suspended solids (TSS), chemical and biochemical oxygen demand (COD and BOD(5)), total organic carbon (TOC), total Kjeldahl nitrogen (TKN), heavy metals (Cu and Zn) and polycyclic aromatic hydrocarbons (PAHs), this article is intended to evaluate the contributions of wastewater, runoff and in-sewer processes to WWF pollutant loads through the use of an entry-exit mass balance approach. To achieve this objective, a total of 16 rain events were sampled on these sites between May 2003 and February 2006. This study has confirmed that at the considered catchment scale (i.e. from 42 ha to 2581 ha) the production and transfer processes associated with WWF pollutant loads do not vary with basin scale. Entry-exit chemical mass balances over all catchments and for a large number of rain events indicate that wastewater constitutes the main source of organic and nitrogenous pollution, while runoff is the predominant source of Zn. For Cu, PAHs and TSS, the calculation underscores the major role played by in-sewer processes, specifically by sediment erosion, as a source of WWF pollution. A significant loss of dissolved metals was also observed during their transfer within the sewer network, likely as a consequence of the adsorption of dissolved metals on TSS and/or on sewer deposits. Moreover, the nature of eroded particles was examined and compared to the various sewer deposits. This comparison has highlighted that such particles exhibit similar organic and PAH contents to those measured in the organic layer, thus suggesting that the deposit eroded during a wet weather period is organic and of a nature comparable to the organic layer. Despite the extent of initial field investigations, no organic deposit was observed to be present on sewer lines within the catchments, which implies that this organic deposit is probably present in another form or to be found elsewhere in the main trunks.

De nombreux travaux de recherche ont montré que les matériaux de couvertures constituent une source importante de métaux dans les eaux de ruissellement urbaines. Dans le cadre de la mise en œuvre de la Directive Cadre Européenne sur l'eau (2000/60 CE), la quantification de ces émissions s'avère nécessaire, imposant le développement d'outils permettant une telle évaluation à grande échelle. L'étude porte sur un petit bassin versant urbain (assaini en réseau séparatif), sur lequel des échantillonnages ont été réalisés: retombées atmosphériques, ruissellement de chaussées, de toitures et eaux pluviales à l'exutoire du bassin. L'objectif est (1) de vérifier la contribution des matériaux de toitures aux émissions de Zn et de Pb à l'échelle du bassin et (2) de voir comment les modèles précédemment développés dans le cadre du programme de recherche TOITEAU (à l'échelle de bancs d'essais expérimentaux) peuvent être appliqués à des échelles spatiales différentes (toit et bassin versant) pour la quantification des ces émissions. Les résultats obtenus confirment la forte contribution des matériaux de toitures aux flux de Zn et Pb dans les eaux de ruissellement à l'échelle de bassin. Dans le cas du Zn, les modèles mis en place à petite échelle ont pu être transposés et validés à l'échelle du toit et du bassin versant. La transposition des modèles d'émission du plomb est plus difficile, du fait de l'estimation délicate des surfaces concernées.

International audience; A substantial database of annual metal runoff loads, obtained from a 14-month field exposure campaign on 12 different metal roofing materials at two sites within Paris conurbation, is presented herein. Thirteen metallic species have been considered. A comparison among the various roofing materials yields a ranking of their runoff pollution potential, which highlights that aluminum, coated products, and stainless steel display the lower emission levels, before zinc and copper materials. Lead materials appear to release more metallic species, and tend to do so in quite large quantities. Whatever the material family considered, older materials apparently release more metallic species with higher levels of emission. In considering zinc emissions from zinc-based materials, it is clear that surface coatings significantly reduce zinc emissions (40% less for the Zn-3(PO4)(2) surface-treated Anthra zinc, compared to natural zinc; and 99% less for prepainted galvanized steel compared to standard galvanized steel). In the case of Anthra zinc however, surface treatment induces the release of Ni into the runoff, and Ni constitutes a priority pollutant in the European Water Framework Directive (2000/60 CE). A high level of consistency with literature data has been found for Zn runoff when considering runoff rates reported at the same inclination.

Turbidity sensors can be used to continuously monitor the evolution of pollutant mass discharge. For two sites within the Paris combined sewer system, continuous turbidity, conductivity and flow data were recorded at one-minute time intervals over a one-year period. This paper is intended to highlight the variability in turbidity dynamics during wet weather. For each storm event, turbidity response aspects were analysed through different classifications. The correlation between classification and common parameters, such as the antecedent dry weather period, total event volume per impervious hectare and both the mean and maximum hydraulic flow for each event, was also studied. Moreover, the dynamics of flow and turbidity signals were compared at the event scale. No simple relation between turbidity responses, hydraulic flow dynamics and the chosen parameters was derived from this effort. Knowledge of turbidity dynamics could therefore potentially improve wet weather management, especially when using pollution-based real-time control (P-RTC) since turbidity contains information not included in hydraulic flow dynamics and not readily predictable from such dynamics.

International audience; The elaboration, management, and design of the sedimentation devices require an improved knowledge not only on the suspended solids (SS) settling velocity but also on the distributions of these particulate pollutants by category of SS settling velocity. Nevertheless, there is currently a lack of available data regarding the settling velocity grading of particle bound pollutants. As a consequence, this study investigating the settling velocity grading of particle bound polycyclic aromatic hydrocarbons (PAHs) in wet weather flows within combined sewers was launched. The pursed objectives were to compare the SS and PAH settling velocity grading curves and hence to assess whether or not PAHs were associated with a specific settling velocity category. Investigations were carried out for three storms at two sampling sites within the Parisian combined sewer. Results indicate that most of PAHs seem to be preferentially associated with particles with a settling velocity >0.3 mm s(-1).

International audience; An observatory of urban pollutants was created in Paris in order to assess, at the urban catchment scale, the quality of sanitary sewage and pollutant loads during dry weather periods in the Paris combined sewer. Investigations were carried out for six urban catchments (varying from 42 to 2580 ha) focusing on a wide range of parameters, including: suspended solids (SS), chemical and biochemical oxygen demand (COD and BOD5), total organic carbon (TOC), total Kjeldahl nitrogen (TKN), heavy metals (Cd, Cu, Pb, Zn), and aliphatic and polycyclic aromatic hydrocarbons (AHs and PAHs). Despite the marginal intra-site variability of some pollutants, which serves to reflect the impact of point sources, this work attests to the spatial homogeneity, at the physical scales considered, of wastewater quality and pollutant loads within the Paris combined sewer network. These results imply that similar production and transfer processes are occurring within sewers during dry weather periods and strongly suggest that data obtained on one specific catchment could be extrapolated to smaller or larger catchments that display quite similar land use and sewer characteristics.

International audience; Settling velocities of TSS and of particulate pollutants (COP, PDCO, PTKN, PCu, PPb, PZn, PPAH) measured on a wide range of wet weather flow (WWF) samples collected at different levels of the Parisian combined sewer system are reported. The recorded V30 (0.01 to 0.1 mm s(-1)) and V50 (0.09 to 0.6 mm s(-1)) values exceed by a factor 10 those of dry weather sewage and also exceed the values measured for pavement runoff. These values lie however often below the 0.28 mm s(-1) reference value considered in France for the design of WWF settling facilities. A decrease in settleability is observed between a small upstream catchment and larger scaled downstream catchments. The settling behaviour of particulate pollutants varies depending on the considered parameter and can differ significantly from the TSS behaviour, due to a non homogeneous distribution of micropolluants over the different classes of particles. PZn and PTKN appear far less settleable than TSS, whereas PPAH show higher settleability.

International audience; The important organic pollution of combined wet weather flows (WWF), its acute impact on receiving waters have been widely demonstrated. The main three possibly origins for this organic pollution are: runoff water (streets and roofs), wastewater and erosion of sewer sediments in combined sewer system. This work, for tracing the origin of organic particles bound in combined sewer system, has been focused on the innovative use of sterols. So, eight sterols have been selected and analysed for each kind of sample. Results are represented in contents of sterols (mu gg(-1)) and in sterol profiles (%). The comparison of contents and profiles leads the separation between two groups: runoff water, characterized by the total absence of coprostanol, epicoprostanol and coprostanone, and the group of sewer deposits (gross bed sediment (GBS), organic layer (OL), biofilms) and wastewater. Moreover, sewer deposits and wastewater can be distinguished by their sterol contents and profiles. To evaluate their contribution to WWF a comparison between sterol signatures is done which shows that these effluents have a strong similarity in profiles and in contents of sterols to the organic layer.

A survey, concerning the use of both hydraulic and pollutant load models for sewers system, was conducted in 2001 among 124 French companies and organisations working in the field of sewer operation. Whereas operational uses of hydrodynamic sewer models are now very widespread, the survey underlined the low level of use of urban drainage pollutant load models. When a pollutant load model is used, mainly for sewer diagnosis and for impact assessment studies, it is usually limited to very simple approaches like multiplying a volume by a constant concentration. The application of more elaborated models is limited by the quantity and the quality of data available, the cost of these data and by the level of training needed to master such complex models. This survey confirms that there is a gap today between the tools available on the market for urban drainage pollutant load simulations and the tools that are needed, or that can be applied, by operators.

International audience; River basin metal pollution originates from heavy industries (plating, automobile) and from urban sources (Paris conurbation: 2740 km2 , 9.47 million inhabitants). The natural sources of metal have been found to be limited due to sedimentary nature of this catchment and to the very low river sediment transport (10 t km − 2 y − 1). Several types of data have been collected to build the metal budget within the whole Seine River basin: field surveys, economical statistics and environmental models. Environmental contamination and related fluxes have been measured on atmospheric fallout, rural streams particles, and Seine River particles upstream and downstream of Paris and at river mouth. Metal pathways and budgets have been set up for (i) a typical cultivated area, (ii) a Paris combined sewer system, (iii) Paris conurbation and (iv) the whole catchment metal retention effect in floodplain and dredged material. Metal fluxes to the estuary have been decomposed into natural, urban domestic and other sources. The latter are within 1–2 orders of magnitude larger than waste water fluxes directly released into rivers according to an industrial census. These fluxes have been further compared to the annual use (1994–2003) of these metals. Metal excess fluxes exported by the river are now a marginal leak of metal inputs to the catchment (i.e. "raw" metals, metals in goods, atmospheric fallout), generally from 0.2 to 5‰. However, due to the very limited dilution power in this basin, the contamination of particles is still relatively high. The Seine River basin is gradually storing metals, mostly in manufactured products used in construction, but also in various waste dumps, industrial soils, agricultural and flood plain soils.

International audience; An experimental on-site observatory of urban pollutant loads in combined sewers was created in the centre of Paris to quantify and characterise the dry and wet weather flow in relation to spatial scale. Eight rainfall events were studied from April 2003 to May 2004. Samples were analysed for suspended solids, organic matter, nitrogen and heavy metals. Results confirm the extent of wet weather pollution. They have shown the relative homogeneity of SS and organic matter characteristics from one urban catchment area to another. Two groups of heavy metals were identified. The first one concerns Cu, which has a higher concentration in wet weather flow (WWF) than in dry weather flow (DWF), and runoff. The second includes Cd, Pb and Zn, where higher concentrations were measured in urban runoff than in WWF and DWF. A first evaluation of contribution of wastewater, urban runoff and sewer deposit erosion sources to wet weather pollution was established and has highlighted the contribution of wastewater and sewer deposits to this pollution. However, it has shown that sewer deposit erosion remains an important source of wet weather pollution at different spatial scales.

International audience; Experiments performed on "Marais" catchment, in central Paris, aimed to follow up the duality of wet weather Rows from the entry to the exit of a combined sewer network. SS, VSS, GOD, BOD5, Cd, Cu, Pb, Zn concentrations were measured for an important number of rain events in roof, yard, street runoff, as well as in dry and wet weather flows at the catchment outlet. Mass entry-exit totals, at the scale of the catchment, were calculated over 31 rain events in order to evaluate the contribution of different types of runoff, of sanitary sewage and of sewer sediments to the total wet weather pollutant loads at the catchment outlet. The erosion of in-sewer pollutant stocks was found to be the main source of particles and of organic matter in wet weather flows, whereas heavy metal loads mainly originated from roof runoff due to the corrosion of metallic roofs. Particles eroded inside the sewer during rain events were found to be quite different from the particles constituting the main part of sewer sediments: they are organic and biodegradable, with rather important settling velocities and seem to accumulate during dry weather periods. A change of the chemical form of heavy metals was noticed during the transport in the sewer and it is suspected that a fraction of the dissolved metals from the runoff is adsorbed on sewer sediments. (C) 2000 Elsevier Science Ltd. All rights reserved