WATER firm Welsh Water Dwr Cymru last year released sewage into rivers and the sea around Wales on hundreds of occasions at multiple locations. 

Figures from the not-for-profit firm show that throughout 2020 sewage was discharged by the company more than 100,000 times for nearly 900,000 hours. 

The issue has come under renewed focus this week after MPs rejected an amendment by the Lords which would have required water firms to end the practice. 

After a social media campaign highlighted Conservative MPs who voted against the amendment the government, which had citied the cost of a new regulations on water companies and existing mitigation measures, said it would impose a legal duty for firms to “progressively reduce” such discharges. 

Though regulation of water companies and water quailty are devolved issues the Welsh Government had agreed the UK Parliament could bring forward the environmental legislation impacting Wales – under a process known as Legislative Consent. The Welsh Government can still set its own regulations in the area.

Dwr Cymru, in line with other water firms in the UK, say such discharges are necessary to avoid sewers – which carry household water waste and rainwater in one pipe to treatment plants – from overloading. However the European Court of Justice has ruled such discharges are permitted only in “exceptional circumstances” such as extreme rainfall. 

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Campaign group Barry and Vale Friends of the Earth said it disputes that the amount of releases by Dwr Cymru is in line with “exceptional circumstances” such as severe weather events. 

Max Wallis, from the campaign group, said: “The law says they can only discharge during exceptional rainfall but some sites are discharging sewage over 100 times, almost 200 times, a year.” 

The group says it has compared the information released by Dwr Cymru for the Cog Moors Wastewater Treatment Plant, near Dinas Powys, in the Vale of Glamorgan which receives and treats wastewater from Barry, Penarth and the west of Cardiff with weather data. 

The group says that shows the plant was releasing waste water in December last year before a period of heavy rainfall and during dry days. 

It says the date shows there was intense rainfall on December 23, 2020 but the Cog Moors plant had been releasing sewage from three days before that and it continued through to December 30 including two dry days on December 24 and 25. 

Dwr Cymru said it was unable to respond to requests for further information on a specific location at short notice. 

Figures released by the company on its website show that during 2020 the Cog Moors site pumped out sewage for 845 hours from 74 releases. 

Barry and Vale Friends of the Earth believe the Cog Moors plant is discharging sewage as it is unable to cope with demand, rather than in exceptional circumstances, and the group fears new developments in Cardiff and the Vale will place a further strain on the drainage system and they should be prevented. 

Dwr Cymru said the operation of storm overflow at Cog Moors is in full compliance with its permit and the site receives an annual review from regulator Natural Resources Wales which has been “fully satisfactory”.  

It added: “All spills from Cog Moors are treated and during bathing season receive additional disinfection using UV technology.  It should be noted that the works serves a large geographic area which means it can take many hours for the water to drain from the furthest reaches of the catchment - up on the western ends of Cardiff - to reach the treatment works.” 

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The treatment plant however is far from being the site in the firm’s network that has released sewage on the most occasions. 

Water can be discharged from more than 830 treatment stations or through overflow pipes along its 37,000 kms of sewers.  

Elsewhere in the firm’s south east operations area sewage was released for more than 1,200 hours (during 109 releases) and for more than 1,100 hours in 127 releases at Clydach and Maesygwartha, near Gilwern in Monmouthshire, respectively. 

In the mid Wales network sewage was released for more than 2,754 hours during 241 releases at Pontneddfechan in the Brecon Beacons with sewage also released for more than 2,000 hours each at the Brecon Wastewater Treatment Plant and at Beulah, Llanwrtyd Wells and nearby Abernant Lake all west of Builth Wells. 

The Clawddnewydd plant in the north east had 93 sewage releases over 1,727 hours and 15 minutes while in the north west Rhos Cottages at Capel Curig, the Llanbrynmair and Llithfaen plants, Cwm Penmachno, Dolwyddelan Conwy and Aberch all released sewage for more than 4,000 hours each. 

In south west Wales the Ferwig Wastewater Treatment Plant made 226 releases lasting 5,045 hours and 30 minutes. The company also operates in Herefordshire were it also released sewage into rivers. 

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Dwr Cymru says using combined storm overflows (CSOs) to release sewage is essential in stopping sewage from backing up into customers’ properties during periods of heavy rain and the sewage released into rivers or the sea is usually highly diluted and their operation is highly regulated and closely monitored by Natural Resources Wales. 

A spokeswoman for the firm said: “Whilst CSOs are mainly operating as designed and permitted, we recognise that with environmental legislation tightening and customer expectations changing, more needs to be done.  

“However, this requires significant additional funding and will take many years to deliver. This storm water is coming from roads, roofs and driveways and as more and more impermeable surface such as patios, driveways and car parks are laid down this extra water is entering the sewer. 

“We have invested £8.1 million in improving the monitoring of the CSOs since 2015, and now have spill monitors on over 90% of all of our CSOs – more than any other water company. 

“These monitors record the number and duration of spills and this data is published on our website allowing us to develop investment cases to make further improvements and also to provide real time spill information for key bathing waters to interested bodies, including Surfers Against Sewage. 

“As our profits don’t go to shareholders but instead are reinvested to improve our services, over the past 20 years we have invested over £1billion in our entire wastewater network.  We know however that there is still further work to be undertaken and that is why we are investing £765 million between now and 2025 on further improvements to our wastewater system.” 

The company said it believes that as Wales has 45 Blue Flag beaches and marinas, recgonised for their water quaility, while making up only 16 per cent of the UK coastline it is a testament to its investment in the wastewater network. 

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