Highway stormwater (HSW) runoff is among the environment’s most important sources of microplastics. This study aimed to characterize via vibrational spectroscopy and quantify SMPs (small microplastics < 100 µm) in HSW runoff from a trafficked highway entering a facility equipped with a filtration system and in those flowing out to the receiving water body near agricultural activities. Samples of the inlet runoff (from the highway) and outlet runoff (the discharge into the environment) were collected in different periods to investigate potential seasonal and spatial differences. The sampling, methodology, and analysis were thoroughly carried out to quantify and simultaneously identify SMPs via Micro-FTIR to obtain a specific novel dataset to assess the environmental quality of highway pollution. A significant difference between inlet and outlet samples was reported; the highest abundance in inlet samples was 39813 ± 277 SMPs L.1 (SW10 IN; average length of 77 µm), while the highest one in outlet samples was 15173 ± 171 SMPs L−1 (SW10 OUT; SMPs’ average length of 63 µm). Polyamide 6 (PA 6) and High-Density Polyethylene (HDPE) were predominant. Our results show that these HSW treatment plants, designed for managing regulated pollutants, can intercept SMPs, improving the quality of HSW runoff discharged into the environment.

The study about how tyre-derived particles can potentially worsen the water quality and how traffic pollution markers can affect the environment is crucial for environmental management. Road emissions are known to contribute to pollution in various environments, and benzothiazoles and their derivates can be used to trace pollutant inputs related to surface runoff in the aquatic system. A total of eight benzothiazoles were determined in highway stormwater runoff and road dust collected from February to August 2022 near Venice (Casale sul Sile, Veneto Region, Italy). A new analytical method was validated, by using an UHPLC system coupled to a mass spectrometer (triple quadrupole). The target compounds were determined in both dissolved phase and suspended particulate matter of runoff, and the road dust samples were divided into seven fractions depending on particle diameters to understand the fraction partitioning. The results indicate that 2-SO 3 H-BTH was the most concentrated benzothiazole in all the analysed substrates, suggesting tyre debris as the main source because it is usually used in the vulcanization process. 2-SO 3 H-BTH reached a mean concentration of 115 ± 59 µg L −1 , 4 ± 3 µg L −1 , and 411 ± 441 µg Kg −1 for dissolved phase, suspended particulate matter, and road dust, respectively, while 2-OH-BTH and BTH showed values about an order of magnitude lower. The size distribution of most BTHs suggests that they are distributed in the finest fraction of road dust. An exception was given by 2-SCNMeS-BTH being present only in particles with a diameter > 1 mm.

Due to urbanization and industrialization, water pollution is now one of the major environmental challenges of the twenty-first century. Considering the increasing of agricultural and non-agricultural settings in the last decades, the investigation of the relationship between such pesticides and urban stormwater is critical to understand how urban, residential, and industrialized areas can affect environmental safety. Recently, scientific interest has grown in stormwater chemical characterization with the aim to define its impacts in the environment and possibly to make it potable water. In this context, glyphosate, glufosinate, and their degradation products have been identified as the key knowledge gap for the chemical characterization of stormwater. Research investments are needed for a better understanding of the highly polar pesticides to estimate their load, source, and dispersion of urban runoff due to residential use of herbicides. Furthermore, a more comprehensive study of wet and dry deposition and spray drift should be considered for a correct evaluation of source apportionment.

Highway stormwater runoff is influenced by various factors that result in significant unpredictability in terms of quantity, quality, and composition. Possible pollutants, resulting from anthropogenic activities and accidental spills as well, can cause significant effects (acute and chronic) on receiving water bodies. Increased urbanization increases the pollutant impacts as well as the probability of spills and other unique events. Fortunately, technological advances in real-time controls allows for the development of technology to address some of these issues. To satisfy environmental impact concerns, data were collected by monitoring stormwater runoff and other pollutant parameters, i.e. temperature, pH, turbidity, conductivity, and TPH to establish the relationships between events (rain, temperature, traffic conditions) and these parameters. Thus it has been possible to build a model using these correlations to determine an envelope of acceptance and a range of normality. Using this envelope, an automated spill containment and warning system was developed for parameters measured outside the envelope with water quality treatment for runoff inside the parameter envelope. This paper presents a case study of the how a water quality and spill containment system has been installed along 82 kilometers of 163 km toll road in the Veneto region of Italy using a web enabled monitoring, emergency response, and operations and maintenance.