Welsh Water is urging customers to be “vigilant for signs of pollution” as the recent prolonged dry weather has increased the risk of blockages in the sewer system.
It has warned of the problems flushing “inappropriate” items can have on the network and has appealed to customers to report any signs of pollution in rivers and streams directly to Welsh Water, so it can investigate quickly.
The water company said a “significant cause of pollution” comes from blockages, most commonly caused by the inappropriate disposal of wet wipes, which are often wrongly-labelled as “flushable”.
When these combine with fat, oil and grease it causes fatbergs, which can lead to flooding in communities and customer properties.
The warning comes after a sustained period of dry weather stretching from the hottest June on record in Wales, with little rain in the weeks that followed.
With considerably less water entering the sewer system to dilute wastewater that is flushed, there is a bigger risk of blockages, the company warned.
Steve Wilson, Welsh Water’s managing director of wastewater services, said: “The recent dry weather means there is a bigger chance of blockages in our sewers – with less water flowing through our pipes, the objects that cause blockages can’t flow through as easily, and the wastewater is less diluted.
“Blockages are mostly caused by the wrong things being flushed down the toilet and washed down the sink – around three-quarters of all our blockages. And when this goes wrong, it can cause very upsetting damage to customers’ properties.
“We always ask customers to be careful about what they’re disposing down the drain and the toilet, and we would ask they are especially cautious now as we recover from the prolonged period of dry weather we’ve experienced – and we would also ask all customers who discover a blockage, or what they think is pollution, to get in contact with us as soon as possible so we can investigate.”
Last year four out of five incidents of pollution brought to the company’s attention or the environmental regulator National Resources Wales was reported by a member of the public.
Welsh Water deals with around 2,000 sewer blockages a month, which costs approximately £7 million a year to put right.
Meanwhile United Utilities said it faces a “constant battle” to deal with increased levels of fibre entering the sewer network, such as wet wipes.
Keeping sewers flowing and free from blockages is an “ever-increasing challenge”, the company said.
Its engineers recently stopped a “monster structure” of congealed wipes (pictured) from entering its wastewater treatment works in Fazakerley.
Bob Turner from United Utilities said: “It took a team several hours to remove the gigantic rag roll and it was really fortunate we managed to do this before it entered into our treatment works.
“Across all our wastewater treatment works, approximately half the breakdowns on sites are caused by unflushable items. At Fazakerley wastewater treatment works alone, we remove approximately 170 tonnes of wet wipe litter a year.”
Each year United Utilities tackles on average 28,000 blockages on the sewers which serve the North West, costing around £10 million.