World War Z: Brad Pitt films in Essex water plant A water treatment plant in Essex has been given a Hollywood makeover for Brad Pitt's zombie blockbuster World War Z. The Essex and Suffolk Water's site, in East Hanningfield, near Chelmsford, was was turned into a South Korean prison for the film, based on a book by Max Brooks. Although the two weeks of filming took place in September 2011, a confidentiality agreement meant staff could not talk about their experiences until now. Pitt plays Gerry Lane, a UN inspector chosen to investigate the source of a viral outbreak that has turned three billion people into zombies. Brad Pitt shock for Essex and Suffolk water firm workers Muse to perform at film premiere Pitt in Scotland for zombie film