**5. Conclusions**

In conclusion, the analysis of the evolution of Saint Martin's metabolism following the impact of hurricane Irma shows a strong variation in its three short-term dimensions. Faced with the intensity of waste flows, a new spatial structure and a new system of actors reinforced by external resources was set up in order to control the waste streams. This change led to a transformation in the system's operation when compared to the way it operated previously. Once the crisis period was over, the waste managemen<sup>t</sup> system did not return to its initial mode of operation. The intensity of the waste flows that continued to be generated remained much higher than before Irma. The capacities of existing o fficial infrastructures proved to be insu fficient for absorbing all the new waste flows, and this resulted in their spatial dissipation to illegal dumps or via informal streams. As a result, the metabolism evolved on the three dimensions under study: intensity, spatial dimension and actors and techniques.

These evolutions led to a lasting transformation of waste stocks. Most of the waste generated by Irma was buried, particularly furniture and electrical/electronic waste collected together during the crisis period. The condition for having this waste recovered by an eco-organization is that it is sorted and clean, an operation that is extremely di fficult to set up during a crisis period if it has not been planned beforehand. Under these conditions, according to the manager of Verde SXM company, the Grandes Cayes landfill lost three years of its life as a result of Irma [41]. Three years after the crisis, new post-Irma waste flows continue to be generated by operations for cleaning, demolishing or reconstructing abandoned houses—operations that have only been 50% completed at present. These operations were essentially focused on building and public works.

On the other hand, the permanent transformation of the waste flow's circulation is less certain, a phenomenon that can be partly attributed to informal streams. The waste flows from the ELV (End-of-Life Vehicles) and BPHU (Out-of-Service Pleasure Boats) sector are the only ones whose structuring was supported by the authorities, through the assistance of DEAL Guadeloupe. The managemen<sup>t</sup> of hazardous waste is the state's responsibility. After Irma, a DEAL territorial unit was created in Saint Martin with a risk and pollution officer, an evolution that has represented a lasting transformation in the managemen<sup>t</sup> of hazardous waste flows. Two extra garages were installed on the territory for handling ELVs and accelerating their decontamination, crushing and compacting operations. Thanks to these measures, the collection rate went up from 40 ELV per month to around 200 ELV per month during 2018, but it did not reach the target imposed by the DEAL of 400 ELV per month. In 2019, one of these two garages was closed following controls due to non-compliance with pollution regulations, but the garage at Grandes Cayes is still in operation. Hence, by March 2019, 2900 ELV out of a total stock of 50,000 were evacuated from the territory (2000 before Irma). In 2019, a number of ELVs were identified on public land that had not ye<sup>t</sup> been collected, and there were also a number of ELVs stored on private property that the population had kept for selling their spare parts. Concerning out-of-service pleasure boats, public tenders have been issued to find an operator capable of decontaminating and dismantling them. By 2019, 170 wrecks have been mapped and located, but they were still awaiting processing due to lengthy administrative procedures [41]. On the other hand, and despite the support of the Saint Martin prefecture, which recognizes the importance of structuring this type of activity, building and public works waste stream still operates under unofficial conditions. Even so, the system of actors in this sector has undergone a transformation, caused by the appearance of new actors or by the consolidation of a certain number of pre-existing actors. The managemen<sup>t</sup> of the sector is under the responsibility of the collectivity. As far as managemen<sup>t</sup> of household waste is concerned, it has returned to its initial mode of operation.

The lack of structured streams in Saint Martin before Irma and the di fficulty in incorporating them into the structure of the o fficial system after the crisis have given rise to di fficulties in monitoring and accounting for these waste flows and to a low recycling rate. Some exports of waste were reported by the Verde SXM company. Up to 2019, two ships of 3700 tons each of crushed scrap metal and one container of 300 tons were shipped to the north of France [41]. Two years later, the Grandes Cayes ecosite had still not returned to normal operation, as it was still processing waste caused by Irma.

The Saint Martin case study highlights a metabolism that remains largely internalized. Despite its transformation following the disaster and the appearance of a few new recycling or re-use streams, waste flows remain relatively linear. This observation underlines the importance of working firstly on the circularity of these flows internally, and secondly on the scale of the Caribbean region, thereby tending toward outsourcing.

**Author Contributions:** Conceptualization, R.P., H.B. and B.B.; data curation, R.P.; funding acquisition, B.B.; investigation, R.P.; methodology, R.P. and H.B.; writing—original draft, R.P., H.B. and B.B.; writing—review & editing, H.B. and B.B. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by the National Research Agency, which supports the research project Post Hurricane Waste (ANR-18-OURA-0003).

**Acknowledgments:** The authors thank to all the local public, private stakeholders as well as the civil society and the citizens of Saint Martin that offered us valuable information and support during the field research mission. The authors are also grateful to all the partners of the ANR DéPOs project: Gustave Eiffel University, Le Mans University, Avignon University, IFSTTAR, Robin des Bois Association and University of Mons (associated international partner).

**Conflicts of Interest:** The authors declare no conflict of interest.
