Best practice for water management and saving for bus operators

LIFEH2OBUS, part of the European Commission LIFE program, innovatively assesses water consumption in the bus sector during vehicle washing, a neglected aspect in public transport. Unlike emissions and noise, no specific standards regulate water overuse at various governance levels. This study underlines the absence of guidelines for reducing water consumption and the significant impact of traditional bus washing practices, considering that each bus requiring around 300 litres of freshwater, totalling 43 million cubic meters annually for the European bus fleet. The energy-intensive nature of bus washing exacerbates environmental concerns. Moreover, the COVID-19 pandemic emphasised the significance of vehicle cleanliness in enhancing public transit appeal. LIFEH2OBUS implements three water-saving technologies (water reclamation, water reclamation with harvesting, and waxing) in bus garages across Europe, considering diverse climates and washing needs. A groundbreaking cost-benefit analysis, possibly the first for water conservation in bus cleaning, reveals an 84% reduction in average water consumption after one year, saving 37 million liters for the LIFEH2OBUS test fleet of 680 buses. Scaling up to cover 50% of the European transit fleet within five years could save eighteen-billion litres annually, marking a 42% reduction in the transport sector's total water usage. This achievement also leads to substantial decreases in energy consumption (1,151 GWh) and greenhouse gas emissions (496 ktCO2eq), translating to a cost savings of 150 million Euros. The paper outlines the three technologies, the associated cost-benefit analysis, and their profound impact on water conservation. Ultimately, LIFEH2OBUS aspires to establish a new research field on water management in the transport sector, particularly among bus maintenance operators, contributing to scientific progress.