# Spatial and temporal distribution of organic matter and molecules in the sediments of the City of Paris sewerage system. Link with practices and uses during the Anthropocene using a multi-proxy approach.

Camille Asselin, Jérémy Jacob, Thomas Thiebault, Gauthier Bernier-Turpin

<figure><img src="image_1.png" /></figure>

## To cite this version:

Camille Asselin, Jérémy Jacob, Thomas Thiebault, Gauthier Bernier-Turpin. Spatial and temporal distribution of organic matter and molecules in the sediments of the City of Paris sewerage system. Link with practices and uses during the Anthropocene using a multi-proxy approach. ICUD 2024 - Internation Conference of Urban Drainage 2024, Jun 2024, Delft, Netherlands. hal-04623181

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Submitted on 25 Jun 2024

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Distributed under a Creative Commons Attribution 4.0 International License
# Spatial and temporal distribution of organic matter and molecules in the sediments of the City of Paris sewerage system. Link with practices and uses during the Anthropocene using a multi-proxy approach.

Camille Asselin, Jérémy Jacob, Thomas Thiebault, Gauthier Bernier-Turpin

<figure><img src="image_1.png" /></figure>

## ► To cite this version:

Camille Asselin, Jérémy Jacob, Thomas Thiebault, Gauthier Bernier-Turpin. Spatial and temporal distribution of organic matter and molecules in the sediments of the City of Paris sewerage system. Link with practices and uses during the Anthropocene using a multi-proxy approach. ICUD 2024 - Internation Conference of Urban Drainage 2024, Jun 2024, Delft, Netherlands. hal-04623181

HAL Id: hal-04623181

https://hal.science/hal-04623181v1

Submitted on 25 Jun 2024

HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers.

L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

<figure><img src="image_2.png" /></figure>

Distributed under a Creative Commons Attribution 4.0 International License
# Spatial and temporal distribution of organic matter and molecules in the sediments of the City of Paris sewerage system. Link with practices and uses during the Anthropocene using a multi-proxy approach.

C. Asselin<fnref n="1" />*, J. Jacob<fnref n="1" />, T. Thiebault<fnref n="2" />, G. Bernier-Turpin<fnref n="3" /> & R. Moilleron<fnref n="3" />

## Highlights

* Delineation of the sewershed of silt trap to be able to precisely trace the sources of particles.

* Comparison of pharmaceutical products recorded in sediment and consumer populations.

* Spatial and temporal distribution of pharmaceuticals in Paris sewer sediments.

## Introduction

For 5 000 years, cities have been the universal centres of society, concentrating the functions of authority, exchange and the production of wealth. Despite these foundations, all cities are different in terms of demography, size, morphology, cultural diversity and landscape (Humain-Lamoure and Laporte, 2022). These differences give rise to numerous heterogeneities between cities, but also within cities (Bellidenty and Martinez, 2015; Madoré, 2015, 2005; Sabatini, 2006). The exponential growth of urbanisation since the beginning of the 20th century will lead to more than two thirds of the population living in urban centres by 2050, at the expense of rural areas (Carneiro Freire et al., 2019). This rapid urbanisation leads to problems of poverty, urban congestion, pollution, access to services, mental stress and adaptation to climate change, all of which manifest themselves in different ways within a single city. This growing urbanisation and the heterogeneity within cities pose major challenges that require effective urban planning for sustainable urban management.

### Silt

How can we account for these heterogeneities in the urban environment and their changes? The sediments that transit in the sewerage system store relevant information on the recent evolution of urban socio-ecosystems through the molecules they carry (Jacob et al., 2020). In Paris, previous studies have focused on the identification/location of pollution sources or the determination of their spatio-temporal distribution, on different types of pollution: plastic (Treilles et al., 2021a, 2021b) and chemical (PAHs (Gasperi et al., 2005; Rocher et al., 2004b), metals (Moilleron et al., 2005; Rocher et al., 2004a), biocides (Paijens et al., 2020), etc.).

The study of pollution in wastewater systems can be diverted from its initial objectives to define the state and study the trajectory of urban systems (Choi et al., 2020, 2019, 2018). This involves a paradigm shift by considering materials in transit or deposited not as pollutants, but as tracers, indicators and metrics that can be used to support public policy.

The ANR EGOUT project (Geochemical Observations of Urban Trajectories; egout.cnrs.fr) aims to identify the socio-economic and environmental factors that control the spatial and temporal distribution of materials in the Parisian sewer system, in order to propose innovative tools for managing the urban environment.

<footnote n="1">¹ Laboratoire des Sciences du Climat et de l'Environnement (LSCE-IPSL), UMR 8212 (CEA/CNRS/UVSQ), Université Paris-Saclay, Orme des merisiers, 91190 Saint Aubin, France</footnote>

<footnote n="2">² EPHE, PSL University, UMR 7619 METIS (SU/CNRS/EPHE), Jussieu, 75005 Paris, France</footnote>

<footnote n="3">³ LEESU, Ecole des Ponts, Université Paris Est Creteil, 61 avenue du Général de Gaulle, 94010 Créteil Cedex, France</footnote>

<footnote>*Corresponding author email: camille.asselin@lsce.ipsl.fr</footnote>
# Spatial and temporal distribution of organic matter and molecules in the sediments of the City of Paris sewerage system. Link with practices and uses during the Anthropocene using a multi-proxy approach.

C. Asselin<fnref n="1" />*, J. Jacob<fnref n="1" />, T. Thiebault<fnref n="2" />, G. Bernier-Turpin<fnref n="3" /> & R. Moilleron<fnref n="3" />

## Highlights

* Delineation of the sewershed of silt trap to be able to precisely trace the sources of particles.

* Comparison of pharmaceutical products recorded in sediment and consumer populations.

* Spatial and temporal distribution of pharmaceuticals in Paris sewer sediments.

## Introduction

For 5 000 years, cities have been the universal centres of society, concentrating the functions of authority, exchange and the production of wealth. Despite these foundations, all cities are different in terms of demography, size, morphology, cultural diversity and landscape (Humain-Lamoure and Laporte, 2022). These differences give rise to numerous heterogeneities between cities, but also within cities (Bellidenty and Martinez, 2015; Madoré, 2015, 2005; Sabatini, 2006). The exponential growth of urbanisation since the beginning of the 20th century will lead to more than two thirds of the population living in urban centres by 2050, at the expense of rural areas (Carneiro Freire et al., 2019). This rapid urbanisation leads to problems of poverty, urban congestion, pollution, access to services, mental stress and adaptation to climate change, all of which manifest themselves in different ways within a single city. This growing urbanisation and the heterogeneity within cities pose major challenges that require effective urban planning for sustainable urban management.

### Silt

How can we account for these heterogeneities in the urban environment and their changes? The sediments that transit in the sewerage system store relevant information on the recent evolution of urban socio-ecosystems through the molecules they carry (Jacob et al., 2020). In Paris, previous studies have focused on the identification/location of pollution sources or the determination of their spatio-temporal distribution, on different types of pollution: plastic (Treilles et al., 2021a, 2021b) and chemical (PAHs (Gasperi et al., 2005; Rocher et al., 2004b), metals (Moilleron et al., 2005; Rocher et al., 2004a), biocides (Paijens et al., 2020), etc.).

The study of pollution in wastewater systems can be diverted from its initial objectives to define the state and study the trajectory of urban systems (Choi et al., 2020, 2019, 2018). This involves a paradigm shift by considering materials in transit or deposited not as pollutants, but as tracers, indicators and metrics that can be used to support public policy.

The ANR EGOUT project (Geochemical Observations of Urban Trajectories; egout.cnrs.fr) aims to identify the socio-economic and environmental factors that control the spatial and temporal distribution of materials in the Parisian sewer system, in order to propose innovative tools for managing the urban environment.

<footnote n="1">¹ Laboratoire des Sciences du Climat et de l'Environnement (LSCE-IPSL), UMR 8212 (CEA/CNRS/UVSQ), Université Paris-Saclay, Orme des merisiers, 91190 Saint Aubin, France</footnote>

<footnote n="2">² EPHE, PSL University, UMR 7619 METIS (SU/CNRS/EPHE), Jussieu, 75005 Paris, France</footnote>

<footnote n="3">³ LEESU, Ecole des Ponts, Université Paris Est Creteil, 61 avenue du Général de Gaulle, 94010 Créteil Cedex, France</footnote>

<footnote>*Corresponding author email: camille.asselin@lsce.ipsl.fr</footnote>
# Methodology

## Delimitation and selection of sewersheds

The Paris sewerage network is criss-crossed by 159 silt trap (ST), which collect sediment to prevent the network from becoming saturated. Each ST is cleaned every 1 to 3 years and collects the sediment that passes through the combined sewer system (domestic sewage and rainwater). In order to relate the results of the geochemical analysis of the sediments to the corresponding sewershed (individual connection to individual addresses and cadastral parcels), it was first necessary to define the sewershed of each ST on the basis of the drainage networks, taking into account two drainage scales (wet weather and dry weather) and highlighting a sediment cascade system (Asselin et al., submitted).

Of the 159 ST, 6 were selected on the basis of a clear definition of the sewershed, the possibility to compare geochemical data (at the sewershed scale) with socio-economic data (at the IRIS grid scale) and socio-economic diversity (INSEE data; (Asselin et al., in prep).

## Samples and analyses

In June 2023, 24 sediment cores were collected from these 6 ST. The sediments are stratified with two different facies: a light, coarse, mineral facies and a dark, fine, organic facies. The cores were sampled according to these different facies. Total organic matter parameters (COT, IH, IO, Tmax, C/N, δ¹³C et δ¹⁵N) were determined using Rock-Eval pyrolysis and an elemental analyser coupled to an isotope ratio mass spectrometer. At the same time, around sixty organic molecules (pharmaceuticals, legal and illegal drugs and food tracers) were identified and quantified in the sediments after extraction and analysed with high performance liquid chromatography coupled to two tandem mass spectrometers.

# Case study

The 6 core samples are located in contrasting areas of Paris (Figure 1). Two ST (Boissy d'Anglas and Guynemer) are in well-to-do areas, two ST (Islettes and Voltaire) are in neighbourhoods with socially mixed populations and the last two (Pantin and Domrémy) are in vulnerable areas.

<figure><img src="image_3.png" /><figcaption>**Figure 1.** Sewershed of the 6 ST selected according to the socio-economic classes of the neighbourhoods.</figcaption></figure>
# Methodology

## Delimitation and selection of sewersheds

The Paris sewerage network is criss-crossed by 159 silt trap (ST), which collect sediment to prevent the network from becoming saturated. Each ST is cleaned every 1 to 3 years and collects the sediment that passes through the combined sewer system (domestic sewage and rainwater). In order to relate the results of the geochemical analysis of the sediments to the corresponding sewershed (individual connection to individual addresses and cadastral parcels), it was first necessary to define the sewershed of each ST on the basis of the drainage networks, taking into account two drainage scales (wet weather and dry weather) and highlighting a sediment cascade system (Asselin et al., submitted).

Of the 159 ST, 6 were selected on the basis of a clear definition of the sewershed, the possibility to compare geochemical data (at the sewershed scale) with socio-economic data (at the IRIS grid scale) and socio-economic diversity (INSEE data; (Asselin et al., in prep).

## Samples and analyses

In June 2023, 24 sediment cores were collected from these 6 ST. The sediments are stratified with two different facies: a light, coarse, mineral facies and a dark, fine, organic facies. The cores were sampled according to these different facies. Total organic matter parameters (COT, IH, IO, Tmax, C/N, δ¹³C et δ¹⁵N) were determined using Rock-Eval pyrolysis and an elemental analyser coupled to an isotope ratio mass spectrometer. At the same time, around sixty organic molecules (pharmaceuticals, legal and illegal drugs and food tracers) were identified and quantified in the sediments after extraction and analysed with high performance liquid chromatography coupled to two tandem mass spectrometers.

# Case study

The 6 core samples are located in contrasting areas of Paris (Figure 1). Two ST (Boissy d'Anglas and Guynemer) are in well-to-do areas, two ST (Islettes and Voltaire) are in neighbourhoods with socially mixed populations and the last two (Pantin and Domrémy) are in vulnerable areas.

<figure><img src="image_3.png" /><figcaption>Figure 1. Sewershed of the 6 ST selected according to the socio-economic classes of the neighbourhoods.</figcaption></figure>
The socio-economic diversity between the different study sites is important in order to compare geochemical results with socio-economic parameters, while maintaining a representation of intra-urban heterogeneity.

## Results and discussion

These results make it possible to discuss the spatial distribution (differences between cores) and temporal distribution (vertical evolution) of matter and organic molecules in relation to the socio-economic specificities of each input zone. Our results also provide essential information on how these molecules are archived in the sediments, depending on the facies and speciation of these molecules.

It seems possible to formulate two working hypotheses, the first being that we can expect to observe a heterogeneous spatial distribution of licit and illicit drug consumption, and the second indicating that antihistamine consumption evolves over time according to the seasons.

## Conclusions and future work

As the analyses are still in their early stages, it is impossible to draw any conclusions at the moment, but by June 2024 the work will have progressed.

## References

Asselin, C., Jacob, J., Moilleron, R., Rican, S., submitted. Méthode de délimitation des zones d'apport de bassins de dessablement : exemple des égouts de Paris. Techniques Sciences Méthodes.

Asselin, C., Jacob, J., Moilleron, R., Rican, S., in prep. Sélection des zones d'intérêt selon le prisme des données socio-économiques : exemple des égouts parisiens. Techniques Sciences Méthodes.

Bellidenty, J., Martinez, C., 2015. Des disparités de niveaux de vie fortes à Paris et dans les Hauts-de-Seine. Insee Flash 2.

Carneiro Freire, S.M., Corban, C., Ehrlich, D., Florczyk, A., Kemper, T., Maffenini, L., Melchiorri, M., Pesaresi, M., Schiavina, M., Tommasi, P., 2019. Atlas of the Human Planet 2019. https://doi.org/10.2760/014159

Choi, P.M., O'Brien, J.W., Tscharke, B.J., Mueller, J.F., Thomas, K.V., Samanipour, S., 2020. Population Socioeconomics Predicted Using Wastewater. Environ. Sci. Technol. Lett. 7, 567-572. https://doi.org/10.1021/acs.estlett.0c00392

Choi, P.M., Tscharke, B., Samanipour, S., Hall, W.D., Gartner, C.E., Mueller, J.F., Thomas, K.V., O'Brien, J.W., 2019. Social, demographic, and economic correlates of food and chemical consumption measured by wastewater-based epidemiology. PNAS 116, 21864-21873. https://doi.org/10.1073/pnas.1910242116

Choi, P.M., Tscharke, B.J., Donner, E., O'Brien, J.W., Grant, S.C., Kaserzon, S.L., Mackie, R., O'Malley, E., Crosbie, N.D., Thomas, K.V., Mueller, J.F., 2018. Wastewater-based epidemiology biomarkers: Past, present and future. TrAC Trends in Analytical Chemistry 105, 453-469. https://doi.org/10.1016/j.trac.2018.06.004

Gasperi, J., Moilleron, R., Chebbo, G., 2005. Variabilité spatiale de la pollution en HAP transitant dans le réseau d'assainissement parisien lors d'événements pluvieux. La Houille Blanche 35-40. https://doi.org/10.1051/lhb:200505004

Humain-Lamoure, A.-L., Laporte, A., 2022. Introduction à la géographie urbaine - 2e éd. Armand Colin.

Jacob, J., Thibault, A., Simonneau, A., Sabatier, P., Le Milbeau, C., Gautret, P., Ardito, L., Morio, C., 2020. High-resolution sedimentary record of anthropogenic deposits accumulated in a sewer decantation tank. Anthropocene 30, 100238. https://doi.org/10.1016/j.ancene.2020.100238

Madoré, F., 2015. Approche comparative de la ségrégation socio-spatiale dans les aires urbaines françaises. Annales de géographie 706, 653-680. https://doi.org/10.3917/ag.706.0653

Madoré, F., 2005. La ségrégation sociale dans les villes françaises : réflexion épistémologique et méthodologique. cgq 49, 45-60. https://doi.org/10.7202/012108ar

Moilleron, R., Perez, J., Garnaud, S., 2005. Grain size distribution of metals and polycyclic aromatic hydrocarbons in silt trap sediments from the combined sewer network of Paris (France). Water Science and Technology 52, 111-118. https://doi.org/10.2166/wst.2005.0067

Paijens, C., Frère, B., Caupos, E., Moilleron, R., Bressy, A., 2020. Determination of 18 Biocides in Both the Dissolved and Particulate Fractions of Urban and Surface Waters by HPLC-MS/MS. Water Air Soil Pollut 231, 210. https://doi.org/10.1007/s11270-020-04546-6

Rocher, V., Azimi, S., Moilleron, R., Chebbo, G., 2004a. Hydrocarbons and heavy metals in the different sewer deposits in the 'Le Marais' catchment (Paris, France): stocks, distributions and origins. Science of The Total Environment 323, 107-122. https://doi.org/10.1016/j.scitotenv.2003.10.010

Rocher, V., Garnaud, S., Moilleron, R., Chebbo, G., 2004b. Hydrocarbon pollution fixed to combined sewer sediment: a case study in Paris. Chemosphere 54, 795-804. https://doi.org/10.1016/j.chemosphere.2003.10.011

Sabatini, F., 2006. The Social Spatial Segregation in the Cities of Latin America. Inter-American Development Bank 1-44.

Treilles, R., Gasperi, J., Gallard, A., Saad, M., Dris, R., Partibane, C., Breton, J., Tassin, B., 2021a. Microplastics and microfibers in urban runoff from a suburban catchment of Greater Paris. Environmental Pollution 287, 117352. https://doi.org/10.1016/j.envpol.2021.117352
The socio-economic diversity between the different study sites is important in order to compare geochemical results with socio-economic parameters, while maintaining a representation of intra-urban heterogeneity.

## Results and discussion

These results make it possible to discuss the spatial distribution (differences between cores) and temporal distribution (vertical evolution) of matter and organic molecules in relation to the socio-economic specificities of each input zone. Our results also provide essential information on how these molecules are archived in the sediments, depending on the facies and speciation of these molecules.

It seems possible to formulate two working hypotheses, the first being that we can expect to observe a heterogeneous spatial distribution of licit and illicit drug consumption, and the second indicating that antihistamine consumption evolves over time according to the seasons.

## Conclusions and future work

As the analyses are still in their early stages, it is impossible to draw any conclusions at the moment, but by June 2024 the work will have progressed.

## References

Asselin, C., Jacob, J., Moilleron, R., Rican, S., submitted. Méthode de délimitation des zones d'apport de bassins de dessablement : exemple des égouts de Paris. Techniques Sciences Méthodes.

Asselin, C., Jacob, J., Moilleron, R., Rican, S., in prep. Sélection des zones d'intérêt selon le prisme des données socio-économiques : exemple des égouts parisiens. Techniques Sciences Méthodes.

Bellidenty, J., Martinez, C., 2015. Des disparités de niveaux de vie fortes à Paris et dans les Hauts-de-Seine. Insee Flash 2.

Carneiro Freire, S.M., Corban, C., Ehrlich, D., Florczyk, A., Kemper, T., Maffenini, L., Melchiorri, M., Pesaresi, M., Schiavina, M., Tommasi, P., 2019. Atlas of the Human Planet 2019. https://doi.org/10.2760/014159

Choi, P.M., O'Brien, J.W., Tscharke, B.J., Mueller, J.F., Thomas, K.V., Samanipour, S., 2020. Population Socioeconomics Predicted Using Wastewater. Environ. Sci. Technol. Lett. 7, 567-572. https://doi.org/10.1021/acs.estlett.0c00392

Choi, P.M., Tscharke, B., Samanipour, S., Hall, W.D., Gartner, C.E., Mueller, J.F., Thomas, K.V., O'Brien, J.W., 2019. Social, demographic, and economic correlates of food and chemical consumption measured by wastewater-based epidemiology. PNAS 116, 21864-21873. https://doi.org/10.1073/pnas.1910242116

Choi, P.M., Tscharke, B.J., Donner, E., O'Brien, J.W., Grant, S.C., Kaserzon, S.L., Mackie, R., O'Malley, E., Crosbie, N.D., Thomas, K.V., Mueller, J.F., 2018. Wastewater-based epidemiology biomarkers: Past, present and future. TrAC Trends in Analytical Chemistry 105, 453-469. https://doi.org/10.1016/j.trac.2018.06.004

Gasperi, J., Moilleron, R., Chebbo, G., 2005. Variabilité spatiale de la pollution en HAP transitant dans le réseau d'assainissement parisien lors d'événements pluvieux. La Houille Blanche 35-40. https://doi.org/10.1051/lhb:200505004

Humain-Lamoure, A.-L., Laporte, A., 2022. Introduction à la géographie urbaine - 2e éd. Armand Colin.

Jacob, J., Thibault, A., Simonneau, A., Sabatier, P., Le Milbeau, C., Gautret, P., Ardito, L., Morio, C., 2020. High-resolution sedimentary record of anthropogenic deposits accumulated in a sewer decantation tank. Anthropocene 30, 100238. https://doi.org/10.1016/j.ancene.2020.100238

Madoré, F., 2015. Approche comparative de la ségrégation socio-spatiale dans les aires urbaines françaises. Annales de géographie 706, 653-680. https://doi.org/10.3917/ag.706.0653

Madoré, F., 2005. La ségrégation sociale dans les villes françaises : réflexion épistémologique et méthodologique. cgq 49, 45-60. https://doi.org/10.7202/012108ar

Moilleron, R., Perez, J., Garnaud, S., 2005. Grain size distribution of metals and polycyclic aromatic hydrocarbons in silt trap sediments from the combined sewer network of Paris (France). Water Science and Technology 52, 111-118. https://doi.org/10.2166/wst.2005.0067

Paijens, C., Frère, B., Caupos, E., Moilleron, R., Bressy, A., 2020. Determination of 18 Biocides in Both the Dissolved and Particulate Fractions of Urban and Surface Waters by HPLC-MS/MS. Water Air Soil Pollut 231, 210. https://doi.org/10.1007/s11270-020-04546-6

Rocher, V., Azimi, S., Moilleron, R., Chebbo, G., 2004a. Hydrocarbons and heavy metals in the different sewer deposits in the 'Le Marais' catchment (Paris, France): stocks, distributions and origins. Science of The Total Environment 323, 107-122. https://doi.org/10.1016/j.scitotenv.2003.10.010

Rocher, V., Garnaud, S., Moilleron, R., Chebbo, G., 2004b. Hydrocarbon pollution fixed to combined sewer sediment: a case study in Paris. Chemosphere 54, 795-804. https://doi.org/10.1016/j.chemosphere.2003.10.011

Sabatini, F., 2006. The Social Spatial Segregation in the Cities of Latin America. Inter-American Development Bank 1-44.

Treilles, R., Gasperi, J., Gallard, A., Saad, M., Dris, R., Partibane, C., Breton, J., Tassin, B., 2021a. Microplastics and microfibers in urban runoff from a suburban catchment of Greater Paris. Environmental Pollution 287, 117352. https://doi.org/10.1016/j.envpol.2021.117352
Treilles, R., Gasperi, J., Saad, M., Tramoy, R., Breton, J., Rabier, A., Tassin, B., 2021b. Abundance, composition and fluxes of plastic debris and other macrolitter in urban runoff in a suburban catchment of Greater Paris. Water research 192, 116847.
Treilles, R., Gasperi, J., Saad, M., Tramoy, R., Breton, J., Rabier, A., Tassin, B., 2021b. Abundance, composition and fluxes of plastic debris and other macrolitter in urban runoff in a suburban catchment of Greater Paris. Water research 192, 116847.