Bazalgette's capacity for hard work was remarkable; every connection to the sewerage system by the various Vestry Councils had to be checked and Bazalgette did this himself and the records contain thousands of linen plans with handwritten comments in Indian ink on them "Approved JWB", "I do not like 6""" used here and 9""" should be used. JWB", and so on. It is perhaps not surprising that his health suffered as a result. The records are held by Thames Water in large blue binders gold-blocked reading "Metropolitan Board of Works" and then dated, usually two per year.