The UK led the way in this field of science until recently - but now other countries have overtaken. So, how can that lead be recovered?

Yorkshire Water asks people not to pour Christmas cooking fats down the sink to avoid blockages.

The company said more than 6,400 blockages had to be cleared in the region in 2023.

Yorkshire Water is offering waste disposal of oils which are turned into bio diesel for vehicles.

Southern Water says the blockage could have led to manholes overflowing or flooding.

South West Water claims it is seeing fewer incidents across Devon and Cornwall because of its campaign.

Yorkshire Water's display at Trinity Leeds showcases the "disgusting" things found blocking sewers.

Southern Water says it is the time of year when "gruesome" blockages clog up the sewers.