Southern Water is investing almost £1.5m to improve the treatment processes at its Newhaven East Wastewater Treatment Works.
The works serve more than 60,000 homes, but an influx of wet wipes and non-biodegradable items such as sanitary products is causing blockages.
Along with solidified cooking oils, wet wipes contribute to about three quarters of all sewer blockages.
These cause toilets, sinks and baths to overflow inside homes, costing families hundreds of pounds to clear or environmental pollution if sewers flood outside.
At the treatment works, wet wipes can block screens and pumps, causing problems and interrupting the treatment process.
New screens, which are more efficient at removing these items, are being installed but customers can play a key role in helping prevent the problem.
Southern Water project manager James Rance said: “While the new screens will be better at removing wet wipes and other items, prevention is better than cure so we ask customers to help us by only flushing the three Ps – pee, poo and paper. Everything else should be put in the bin.
“This simple message is the focus of Southern Water’s Pain in the Drain campaign which aims to educate people about the causes of blockages and asks for their help in avoiding them.”
The screen installation project began in July and is expected to be completed by March next year.
Visit www.southernwater,co.uk for tips to avoid blocking your drain.