Bazalgette was born at Hill Lodge, Clay Hill, Enfield, London, the son of Joseph William Bazalgette (1783-1849), a retired Royal Navy captain, and Theresa Philo, born Pilton (1796-1850), and was the grandson of a French Protestant immigrant.
While he was recovering, London's short-lived Metropolitan Commission of Sewers ordered that all cesspits should be closed and that house drains should connect to sewers and empty into the Thames.