Water quality of urban surface freshwater in Kolkata, India, June 2018 to December 2019

Some of the data was collected in the field at the sampling locations, whilst other analysis was conducted on samples collected at the sampling time. Field equipment was calibrated as necessary, with handheld meters being calibrated with the correct reagents weekly. The fluorimeters were calibrated before the field surveys by the manufacturer and checks were carried out before each sampling day to ensure baseline values were as expected (0 QSU or 0 FNU in DI water). Data here is provided as an average with a standard deviation to represent 1 minute (n =-60) of sampling time. The survey conducted in December 2019 provides fluorescence data as a single value due to errors in data logging. Microbiological analysis was conducted within 6 hours of the sample collection, whilst some of the nutrient analysis was conducted up to 3 weeks after samples were collected in India. These were analysed in the UK but standard preparation, storage and transportation procedures were followed.