UNITED Utilities is warning residents to be careful when disposing of household waste following a blockage in the public sewerage system in town earlier this year.

Sewer blockages can remain undetected for some time and are often caused by dropping fatty food waste, including fat, oils and grease, down the kitchen sink, claims wastewater network manager Laura Mills.

She added: "People often think by using washing up liquid and hot water it's OK to dispose of fat and grease down the plughole.

“You can make it disappears that way. But the trouble is once it cools down in the sewer pipes outside it solidifies again, and over time this can lead to blockages and sewer flooding.

The warning comes after a huge build-up of grease - named the Fatberg - was discovered in London's sewer system last year.

Blockage problems can arise anywhere but tend to be most commonly on high streets where there are a lot of restaurants and takeaways.