Watermen: A Dirty Business

Episode one sees the workers of United Utilities face the effects of Britain's hottest summer in seven years. Local residents in Salford want to cool down and they've decided that illegally opening fire hydrants is the best way to do it - they pay for the water so why shouldn't they enjoy it?! But the hundreds of thousands of litres of water wasted by hydrant abuse affect the supply to a huge number of homes in the area and the local network inspectors deal with a staggering ten hydrant call outs in just one day. As temperatures rise so do the often smelly and revolting jobs that customer service technicians Adrian and Wes have to handle. It takes a strong stomach to do what these boys do and as long people continue to flush wet wipes and nappies there will always be a drain to unblock. However, it's the out of town reservoirs, where sun seekers put their lives at risk by not paying attention to warning signs, that are one of the biggest worries during the heat wave. We see the devastating impact that death can have on the team charged with patrolling the area.

Focusing on the men and women who take our calls, come to unblock the drains and keep the sewage flowing. This episode is all about fat. From a clogged lift shaft in a nursing home to the sewers under Manchester's city centre - hundreds of litres of this greasy and gross substance is poured down the drains each week in the north west and this programme looks at just how messy things can get when the fat gets backed up. Manchester's waste water treatment centre treats 714 million litres of sewage a day, from false teeth to lumps of fat the size of a small car. It can take up to a week removing the leftover grease and fat from the gigantic tanks. But it's not all rancid waste. We also meet the leak detectives, visit households affected by leaking pipes, come across a housing development being illegally supplied with water, and meet Stuart, who travels the region testing the pH and chlorine levels in customers' homes. And over in Liverpool, we wait patiently on the docks for a 1,000-foot pipe, costing half a million pounds, to arrive from Norway for the local treatment plant.

In the world of water there is never a dull day, from broken sewers contaminating water supplies in hundreds of homes, to raw sewage polluting a river. This episode sees the men and women of United Utilities keep calm and carry on in the face of potential disaster. On the front line, the company's only all-female waste water A-team Vic and Babs are happy to unblock customers' drains and see off sewage in Liverpool - even in the face of some customers who feel drains are no place for the fairer sex. A stomach-churning blockage in Oldham sees apprentice manager Faz just about managing to keep it down. Unhappy customers voice their concerns about a new six-mile water pipeline near Blackburn, and the disconnection team come face to face with some tricky customers as they try to recover an eye-watering £64,000 in unpaid bills.

From collapsed Victorian sewers to 1970s pipes giving way under increased demand, this episode is a lesson in history as the United Utilities workforce try to cope with an ageing grid of 40,000 miles of sewers and 25,000 miles of water mains. In Blackpool, Andy and Terry deal with an ancient collapsed sewer which has caused a pavement to subside before tackling a rather pungent blocked sewer. A 40-year-old water main in Cheshire bursts, leaving two thousand irate villagers without water. Meanwhile in Rochdale, waste water team Adrian and Wes investigate a blocked Victorian sewer which is overflowing onto a main road. However, these problems are a learning curve for some, as the aqueduct which supplies Manchester's water supply is turned off for the first time in 60 years to check for repairs. It is a jaw-dropping thought that the 4,000 men who originally built the tunnel had none of the technology team have nowadays, a testament to the skill and engineering still relied upon today

From a collapsed sewer under a lucrative holiday home in Blackpool, to a rain-soaked team in Preston, this episode sees the watermen dive underground and under water as they do all they can to prevent upheaval for customers, come rain or come shine. Residents in Manchester face a year of noise and chaos as storm tanks are put in place to deal with excess waste caused by heavy rain, and despite three months' worth of notice and a chance to voice concerns ahead of the work starting, locals are less than pleased when the work eventually starts. Whilst a team in south east Manchester are tackling 30,000 litres of concrete that's been poured down a sewer, a specialist diving team face a technical job at a reservoir as well as a stomach churning waste water task. It's not a job for the faint-hearted.

Chris and Mark maintain Lennox Gate Pumping Station in Blackpool and are shocked when they find a pair of designer underwear. In Davyhulme, Scott and Melvin have to face a fatberg.