South China Morning Post All residents of a Wong Tai Sin public housing block with 731 flats will be required to undergo mandatory Covid-19 testing after Hong Kong’s sewage monitoring programme detected coronavirus in waste samples taken across four days. The news emerged as the city expected more than 60 cases on Monday, according to a medical source. Local health authorities said a testing order had been issued covering all residents as well as recent visitors to Fung Chak House in Choi Wan (II) Estate. “We hope the results [of the sewage testing] can provide early signals before we identify confirmed cases,” said Professor Zhang Tong of the University of Hong Kong’s department of civil engineering, the man in charge of the monitoring scheme backed by the Food and Health Bureau and the Environment Bureau.