Sewermen

In North Wales, engineer Luke and his team of plumbers are midway through a project to replace a problematic 2km section of pipe that has a history of large bursts.

Engineers go underground in Liverpool city centre to shift a massive concrete slab that is reducing the sewer flow. Rookie waste-water engineer Bunty unblocks a stinking drain.

Engineers race against time to find and fix a massive leak on the busy A6 road in Stockport, which has left thousands of customers with little or no water. Steve and Oz unblock an overflowing drain in a customer's garden, while Luke and his dogs try to sniff out a leak in a field in Cumbria.

Two miles off the coast of Blackpool, specialist divers are on an underwater mission to clean a massive submerged outfall pipe that disperses treated wastewater deep into the sea. Water tester Annette is out in harsh Cumbrian weather to perform vital checks on the water quality in her area and sewage supremos Mick and Ash race to the aid of a family whose backyard is swimming with sewage from a bunged-up manhole.