Life Cycle Assessment for the environmental impact assessment of a city' cleaning system. The case of Cracow (Poland)

In large urban agglomerations, the composition and amount of municipal waste are diversified and depend on the level of wealth, season, number of tourists, etc. In city strategies, there is a visible search for solutions that minimize the impact on the environment and optimize costs incurred by residents. One of the municipal waste streams is street sweepings, i.e. waste generated as a result of street cleaning processes, classified under the code 200303 and is not treated as hazardous waste. Their quantity, quality, and seasonal variability have an impact on the natural environment, including air quality. Their removal reduces the amount of PM10 and PM 2.5. They are usually disposed of the landfills. In Cracow, where air emissions have been successfully reduced in recent years via different actions, experimental studies were carried out on the impact of mechanical street cleaning on air quality, and methods of their management were discussed. The article analyzes various technological solutions based on the LCA (Life Cycle Assessment) methodology for assessing the environmental impact of technologies and waste generated in the processes of street cleaning in urbanized areas. It is used to assess the impact of individual products, technologies, strategies or systems on the environment, taking into account emissions "from the cradle to the grave". In the latest documents of the European Commission, the LCA method is recommended for the analysis of environmental performance measurement in the life cycle of products and organizations. The presented calculations in the SimaPro software showed that for the adopted assumptions, on the example of a selected street section, it is possible to reduce the impact by 5 times, as a result of city cleaning processes. The calculations take into account the consumption of water, fuel, and the operation of the machinery as well as the management of sweeping waste and wastewater treatment. The process of managing this type of waste reduces emissions related mainly to toxic effects for humans (carcinogenic and non-carcinogenic effects), reduction of solid particles and ecotoxicity for freshwater. Comparing the analyzed scenarios (scenario 1 -after cleaning the city and scenario 0 -before), scenario 1 is characterized by a much lower impact on the environment. Although there are loads in this scenario 1 in each impact category of EF 3.0, the overall result is still lower than in all scenarios 0 options. In scenario 1, the environmental impact mainly relates to the freshwater ecotoxicity, ionizing radiation and climate change categories, which are qualitatively different. From scenario 0, where the greatest environmental impact is in the particulate matter category.