The presence of microplastics in Catalan rivers It has gone from being an almost abstract issue to becoming a very concrete concern for governments. These tiny fragments of plastic have become established in both the sea and inland waters and, over time, can end up reaching the wetlands, reservoirs, and the human body itself through water and the food chain.
With the idea of having for the first time a clear and detailed x-ray To address this type of pollution in waterways, the Catalan Water Agency (ACA) has launched a specific project to measuring microplastics in the main rivers of Catalonia. This is a wide-ranging study that will combine fieldwork, laboratory analysis, and evaluation of results in order to find out What plastic particles are circulating in rivers and in what quantities.
A pioneering study with almost two years of work
The ACA has decided to promote a microplastic census through a public contract that has been put out to tender and which has an investment of just over 291.000 EurosThe Generalitat presents this action as a pioneering initiative within the community, which will allow a shift from general perceptions to data measured systematically at specific points in the Catalan hydrographic network.
The procedure sets a deadline for interested companies to submit their bids and, once awarded and the contract formalized, the selected company will have a total of 23 months to complete the orderFrom this time, 14 months will be dedicated to sampling On the ground, three months will be reserved for the analysis of the samples in the laboratory and another three months will be allocated to the preparation and validation of the final results.
The idea is not to limit one specific campaign, but to obtain a solid and comparable image of the situation, covering different times of the year and different hydrological scenarios. That is why the project is structured in three sampling campaigns which will allow us to observe how the presence of microplastics in rivers evolves over time.
According to the Catalan administration, this commission has been designed to ensure it doesn't simply become a technical report gathering dust in a drawer. The stated objective is for all the information gathered to serve as a basis for... define policies and specific actions in the area of water sanitation, spill control and reduction of plastic waste, both in Catalonia and, potentially, in other areas of Spain and Europe with similar problems.
54 checkpoints in the main river basins
The work plan establishes the creation of a network of 54 sampling points distributed throughout the most important river basins of the territory. Among the rivers included are the Llobregat, Ter, Muga, Tordera, Fluvià, Besòs, Foix, Anoia and Segre, in addition to several streams such as those of Rubí and Bisbal, which, although smaller, also play a prominent role in the transport of pollutants to other ecosystems.
The selection of these points aims to offer a representative view of the entire hydrographic networkThat is why sections subject to strong urban and industrial pressures have been chosen. areas near wastewater treatment plants and also river headwaters with less human impactIn this way, it will be possible to compare how microplastic concentrations vary between relatively well-preserved areas and others more affected by human activity.
In terms of distribution, it is planned to carry out 23 surface water samples directly in the riverbeds, 26 checkpoints at the entrance and exit of wastewater treatment plants and five points located at river headwaters. This design will make it possible to distinguish what part of the microplastic load reaches the rivers by diffuse contributions (for example, urban or agricultural runoff) and which is most directly linked to the functioning of sanitation infrastructure.
In total, over the three campaigns, the following will be collected 123 samples distributed among all the monitoring points. This amount of data will make it easier to detect whether the presence of microplastics remains stable or changes according to the season, rainfall intensity, or the incidence of drought episodes, something especially relevant in Mediterranean basins under water stress.
Continental freshwater bodies are considered one of the ecosystems most affected by human activity. Rivers act as true “highways of pollution” that transport particles from urban and industrial environments to reservoirs, wetlands, and ultimately, the coastline. In this context, having reliable measurements is key to assessing the ecological status of Catalan rivers and their capacity to continue providing essential services.
What type of microplastics will be analyzed
One of the central points of the project is to determine not only how many microplastics there are, but also What characteristics do the particles have? present in the water. The study will focus on synthetic and insoluble polymers with sizes ranging between 0,1 micrometers and 1,5 millimetersa range that encompasses everything from almost microscopic fragments to small visible pieces.
In addition to these fractions, the following will be taken into account fibers up to about 15 millimeters in lengthwhich can come from synthetic fabrics, ropes, industrial materials, or everyday products. The combination of fragments and fibers will allow for a fairly complete profile to be drawn. plastic waste traveling through rivers.
The contract plans to focus particularly on three widespread families of plastics: polyethylene, polypropylene and polystyreneWidely used in bags, films, packaging, and foams, these materials are part of everyday life in any home and, when not managed properly, end up fragmenting and entering aquatic environments.
Working with such small particles, especially those on the order of tenths of a micrometer, requires advanced laboratory equipment and very strict sampling protocolsIt is necessary to avoid external contamination, to control the sample collection and treatment process as much as possible, and to apply analytical methods capable of clearly differentiating the different types of polymers.
Environmental authorities believe that Detecting and quantifying these microplastics in rivers is essential to assess the potential risks. On the one hand, because this freshwater can connect with supply systems, agricultural uses, or industrial applications; on the other, because the particles can be ingested by aquatic organisms, accumulate in the food chain, and ultimately reach humans indirectly. This problem raises concerns about water quality and how it may ultimately affect human consumption, as the analysis on bottled water and the ingestion of particles.
The role of wastewater treatment plants and the new demands in sanitation
Much of the studio's design has been done with the wastewater treatment plantsKey pieces for understanding how microplastics behave in the urban water cycle. By including sampling at both the inlet and outlet of 26 Catalan wastewater treatment plantsThe ACA wants to know how many particles reach these facilities and how many are retained by the current treatment systems.
The results of these analyses will be cross-referenced with the current regulatory framework, marked by a state decree on wastewater and by various European directives that mandate improved sanitation. The goal is that, in the coming years, a very large proportion of wastewater treatment plants will have advanced tertiary treatments, capable of leaving the water in a practically “prepotable"before returning it to the river."
In Catalonia, the implementation of these advanced systems is still far from widespread, but some have already taken place. initial steps to strengthen the quality of treated waterThe microplastics census will provide useful information for deciding where to prioritize investments and what types of technologies (such as) Advanced filtration, membranes, or other complementary processes) may be more effective at capturing these particles.
Improved sanitation would not only result in a better ecological state of rivers and streams, but would also open the door to expand the reuse of treated wastewater as an alternative resource, something especially important in a context of recurring droughts across much of the Iberian Peninsula. Water with fewer microplastics is safer for agricultural, industrial, and even certain indirect urban uses.
This approach fits with the strategies of circular economy and reduction of pollutants promoted by the European Union. Retaining more microplastics in wastewater treatment plants not only means better protecting aquatic ecosystems, but also minimizing the arrival of these particles in soils and crops when treated wastewater is reused.
Connection with waste management and possible future measures
The ACA project is not conceived in isolation, but in coordination with the policies of waste and single-use plastics which the Generalitat is developing. The Government is working on a new regulation focused on reduce the generation of plastic waste and to promote more sustainable materials, a course of action that fits with European initiatives to reduce dependence on plastic.
The data obtained from the 123 samples could become a key tool for adjust these policiesIf particularly high concentrations of microplastics are detected in certain sections or basins, the administration considers the possibility of specific landfills or infrastructures that could be contributing a large part of the polluting load.
Detailed analysis of the territory will allow us to identify pollution “hotspots” linked to industrial parks, densely populated urban areas, or specific economic activities. Having this map will help design highly targeted measures, avoiding generic responses that do not take into account the particularities of each river or sub-basin.
In parallel, the information generated can be used to strengthen public awareness campaignsThe study emphasizes the importance of proper waste management, reducing the use of unnecessary packaging, and improving recycling. Although the study is technical in nature, the administration acknowledges that part of the solution involves changes in the consumption habits, recycling and use of plastics by the population.
For now, the specific measures that could result from the census are not yet finalized and will depend on the results. The intention is that any new obligations or additional investments will be based on... verified data, not just generic estimatesso that decisions are made with the highest possible technical rigor.
With this project, Catalonia joins the group of European regions that have begun to to rigorously measure microplastic pollution in rivers and wastewater treatment plants. The 54 planned monitoring points, 123 planned samples, and almost two years of continuous work aim to provide an accurate picture of the magnitude of the problem and pave the way for improvements in sanitation, waste management, and the protection of river ecosystems, with a potential impact not only on environmental health but also on the safety of the water we use daily.
