The sewer workers at West Midlands water company Severn Trent have an unenviable task on their hands. This two-part documentary follows them as they unblock thousands of toilets and drains and delve down sewers clogged with all sorts of waste. It's a dirty job but someone has to do it - and as it turns out, these sewage shovellers just love their work. Along the way, they lift the lid on Birmingham's toilet habits, while Severn Trent's chief executive goes into emergency mode to keep the taps flowing and sort out water leaks during the driest summer in decades.