In work package 1 of the LIVES interreg-EMR project, Rijkswaterstaat is working together with partners from the Netherlands, Belgium and Germany to build up a representative picture of the problem of litter, especially plastics, in the Meuse basin. All partners have their own assignments within the project. One of the contributions to the project to be produced by Rijkswaterstaat is the implementation of a monitorings pilot with a sampling technique in 2021. In August 2021, Rijkswaterstaat has ordered the realization of this pilot.
Data collection by standardized sampling
Rijkswaterstaat has commissioned 2bProjects from Maastricht to carry out the pilot, says Lea Crijns, project manager from Rijkswaterstaat. “Together with performance contract contractor IdVerde, who perform management and maintenance in this region for Rijkswaterstaat Zuid Nederland, 2bProjects will collect and analyze litter in the water column. The pilot focuses on representative hotspots and on data from macro- and mesoplastic (>0.5 mm)”.
In the autumn of 2021, monitoring will take place using a sampling technique that has been tested elsewhere. Point-shaped hoop nets that hang above each other in the water column are used for this research. For example, it can be determined per measuring point within the water column which plastic floats and what the amount of plastic is. The nets are emptied at agreed times, after which the analysis can take place. The Rijkswaterstaat Meetpunt in Eijsden was chosen as the test location.
Monitorings pilot: sorting, counting and weighing
“The hoop nets will be placed first at the test location in Eijsden”, says Paul Vriend, supervisor of this assignment. “After this, a number of representative measurement locations will be sought in the EMR area, the Meuse from the Liège/Wallonia region to the Grensmaas in the Netherlands/Flanders. At the locations where the sampling takes place, visible and immediately recognizable larger items of macro plastic are separated on site, dried, counted and registered in accordance with OSPAR-based riverine monitoring. The remaining sample material is sieved into fractions and separated into categories (natural organic fractions, anthropogenic wood, metal, glass, natural mineral parts, plastic items). The separated plastic items >2.5 cm (and also metal cans) are photographed, counted and weighed, the residual fraction with items <2.5 cm (including meso- and microplastics) are categorized.
By using the OSPAR method, this research fits within the international collaboration of LIVES, where the recognizable plastic on the banks is counted in a similar way”.
Valuable information to further embroider on
In addition to the data set for LIVES, the end result of this assignment also includes a further developed technique and a feasible measurement plan. The pilot carried out by Rijkswaterstaat forms the basis for an application in a multi-year (follow-up) monitoring experiment, which can be carried out LIVES after completion.