Sewer misuse, flooding and pollution
The problem of blockages in sewer pipes, through misuse of the wastewater disposal network, costs the industry tens of millions of pounds each year.
Internal sewer flooding is the most unpleasant aspect of a blocked or overloaded foul sewer, and brings customer misery.
At local level, behaviour linked to sewer misuse is addressed through water company campaigns. These explain the importance of not treating the kitchen sink as a bin for food waste or fats, oils and greases, which solidify in the pipes and build up blockages, and not putting non-flushable products into the toilet.
Many so-called flushable products do not break down in the water in the way that toilet paper does. Instead the waste attaches to the fatty build-up in the pipes and reduces or stops movement in the pipes.
Food macerators also increase the risk of sewer blockages and other malfunctions of the wastewater network and treatment plants.
Working with the Environment Agency, water companies are addressing the widespread problem of pipe misconnections in domestic plumbing - where rainwater and foul sewage wastepipes are linked to the wrong wastewater pipes in the ground.
These cause two separate problems: rainwater is mistakenly emptied into and overloads the foul sewers, causing flooding at times of extreme rainfall; and sewage is discharged direct to local water courses via pipes that are meant to carry rainwater.