Sir, I write in response to the recent article by Suresh et al. on water and the Green Impact Toolkit in reducing the carbon footprint of dental practices.1 While the article discusses important measures such as procurement, waste management, and water conservation, I believe there is an additional aspect of sustainability in dental practice that warrants consideration: wastewater management.

Traditionally, dental unit wastewater has been categorised as domestic wastewater and disposed of into urban sewer systems. However, recent legal rulings, such as the ‘Corte di Cassazione Penale, sez III, sentenza 17 gennaio 2013, n˚2340' in Italy, have reclassified dental unit wastewater as industrial wastewater.2 This reclassification has significant implications for wastewater treatment and regulatory compliance.

Conventional wastewater treatment processes, particularly those employed in wastewater treatment plants, are known to be carbon-intensive. The energy requirements for processes such as aerobic activated sludge and anaerobic digestion contribute to CO2 emissions, posing challenges to achieving sustainability goals.

However, there are opportunities to mitigate these challenges through the adoption of energy-extracting wastewater technologies. For example, biogas produced from anaerobic digestion can be utilised for combined heat and power, reducing energy consumption and CO2 emissions. Integrating water, energy, sanitation, and carbon considerations into wastewater treatment pathways offers a promising approach to achieving a net-zero-carbon water sector.3

In conclusion, while the study highlights the effectiveness of certain changes recommended by the Green Impact Toolkit in reducing the carbon footprint of dental practices, it is essential to consider holistic approaches to sustainability, including wastewater management. By raising awareness and promoting innovative solutions, we can work towards more sustainable and eco-friendly healthcare practices.