A BOUT OF heavy rainfall in Dublin city yesterday caused sewer debris to seep into the River Liffey. 

In a statement to TheJournal.ie, an Irish Water spokesperson said that it is “not uncommon for stormwater overflows to occur from the wastewater network”. 

“This is to ensure that the network does not overflow and cause a flood of raw sewage into homes and businesses,” the spokesperson said. 

Yesterday’s rain in the capital caused spot flooding, the National Gallery’s roof to leak and a delay to train services after lightning struck. 

Wastewater discharge into the Liffey and Dublin bay area is a relatively common occurrence, in part due to the Victorian design dating back to 1851.

At the time, a Dublin city engineer was tasked with redeveloping Dublin’s inadequate drainage system. Originally designed for a population of 325,000, Dublin’s wastewater treatment facility was first built at Pigeon House Harbour, Ringsend. 

Legacy issues from this original Victorian network persist to this day. If future city planners wanted to prevent storm water overflowing and mixing with sewage, separate collection systems would be built, a spokesperson for the EPA has said.

Figures seen by TheJournal.ie show that billions of litres of untreated waste water have overflowed into Dublin Bay from the Ringsend Wastewater Treatment Plant (WWTP), with more than 100 incidents since the beginning of 2015.

Such an occurrence after heavy rain is not uncommon.

On the most recent overflow into the Liffey yesterday, Irish Water said: “In general these network overflows are not screened and whereas this stormwater is mainly rainwater, it also includes wastewater and debris from the sewer network which can include sanitary items that should not be flushed.”

The spokesperson added that the problem is exacerbated by the kinds of items flushed down toilets, such as “wipes, cotton buds, plasters, sanitary towels and tampons, cotton buds and nappies”.

With reporting from Stephen McDermott, Cónal Thomas, Gráinne Ní Aodha