Comment on essd-2021-214 Anonymous Referee # 1 Referee comment on " Distribution and characteristics of wastewater treatment plants within the global river network " by Heloisa Ehalt

The study combines multiple existing wastewater treatment plant (WWTP) datasets, supplementing available information with additional (inferred) plant characteristics, to produce a consistent and coherent global dataset of wastewater treatment plants. Information captured within the dataset includes both geographical location and important plant characteristics such as flow rates and treatment level. The authors calculate an average wastewater treatment plant dilution factor, and link WWTP outfall locations to the river network, to calculate the length of the stream network downstream of WWTPs as a basic indicator for identifying areas of potential environmental concern.