Dublin faces serious and ongoing problems with sewage and wastewater infrastructure.
The Ringsend Wastewater Treatment Plant is running beyond its design capacity and frequently fails to fully treat the volume of waste, especially during heavy rain.
Due to limited sewage capacity, new housing developments in some parts of Dublin are on hold or under threat.
Uisce Éireann has warned that without key upgrades, there is a risk that no new homes can be built after 2028 in some areas due to sewage overload.
Environment Correspondent George Lee takes a closer look at the battle to keep the capital's sewage pipes clean.
Paul McVeigh of GMC utilities group says that if he saved every piece of gold he found in Dublin's sewers, he’d be a rich man by now.
Mr McVeigh has been cleaning, renovating, repairing, and upgrading sewers in Ireland for the past 25 years.
"There are rings, chains, watches, telephones, whatever you can name. It’s in the sewers."
Mr McVeigh is directing a team of workmen in Buckingham Street in Dublin’s north inner city when I meet him.
A big opening in the road, four and a half metres deep beside a manhole, have been opened up to access the brick-lined Victorian sewers below.
It's late in the evening, which is the best time of day for his kind of work because there is far less traffic about. Fewer people on the city street means the pipes below are easier to access.
"The bad stuff is baby wipes and grease. It builds up and combines with the normal material in the sewers, and it forms into something close to concrete. When it becomes really strong, it's very hard to break.
"It's very difficult to clean it out unless you physically go down with compressor guns or whatever else you need to break it up," he says.
"When the sewer is basically full of rubble, full of salt, full of grease. the material will not flow through it. Everything just stagnates and builds up. Nobody sees it till it happens and becomes a problem."
He says the old Victorian brick-lined sewers are everywhere in Dublin, but all head to the one point - the Ringsend Wastewater Treatment plant where the sewage gets cleaned up and discharged.
Uisce Éireann’s Programme Manager for Wastewater Ger Brady is on site too.
He says the men and women who work with him sometimes think they work on a forgotten utility because it is out of sight.
"Sewers are not often noticed. They are underground. But I think sewers are one of the most important things we've done in the developed world. Other than vaccines, sewerage systems save the most lives. They take pollution away from the water sources we drink. It's a very important resource," he says.
Mr Brady points out, however, that the biggest issue in Dublin is the age of the sewer network.
"It's a very old network, particularly in the city centre. Sewers anywhere between the canals, are probably 150 to 200 years old. They weren't designed for our industrial loads or modern flows. It needs a bit of love and care," he adds.
The age of the sewer network in Dublin may well be a significant and ongoing issue, but it is not the biggest problem at all. The real problem is capacity.
Built to cater for a population of about half a million people the Dublin wastewater system is now catering for three times that number of people.
Uisce Éireann is extremely worried that it will soon be unable to cope.
Every time the Government announces increased targets for new home building, anxiety levels at the wastewater utility company increase.
With the best will in the world it is going to be impossible for Uisce Éireann to provide wastewater connections to all the extra homes and businesses that are planned unless it gets a new facility.
That new facility is called the Greater Dublin Drainage Project. There are three main elements.
The biggest is a new wastewater treatment plant and sludge hub centre to be built on a 30-hectare site at Clonshaugh on the north side of Dublin.
This is to be a very large facility, equipped to deal with the sewage and wastewater of half a million people.
There will also be two big new pieces of pipeline infrastructure. One is to connect the new facility back into the existing wastewater network at Blanchardstown.
The other will take treated wastewater from Clonshaugh and pump it six kilometres offshore into the Irish Sea where it will be discharged safely.
The successful delivery of this project is critical for growth in the greater Dublin area.
Currently, there are eight large wastewater treatment plants in the Greater Dublin Area. Between them, they process 49% of the national wastewater load.
Most of it, however, 40% of the national load, is treated at the Ringsend Wastewater Treatment Plant.
Already one of the largest wastewater treatment plants in Europe, Ringsend is being upgraded to its ultimate capacity at the moment.
The cost of the upgrade is €500m.
When finished, which should be before the end of this year, it will be able to cater for a population of 2.4 million, up from 2.1 million in 2023.
The problem, however, is that the amount of wastewater generated in the Greater Dublin Area including parts of Wicklow, Kildare and Meath, is projected to increase by over 50% in the next 30 years.
Greater Dublin Drainage Project needed to expand housing
Physically, there is no room to further develop the Ringsend facility to cater for any of that. That is why the new Greater Dublin Drainage Project is so urgent.
Eoin Ahern, Senior Portfolio Manager in the Infrastructure Delivery Directorate at Uisce Éireann, says: "From a business and housing perspective the Greater Dublin Drainage Project is the key to facilitating expansion. All new growth needs a toilet and a tap.
"So, it must be able to discharge into our wastewater network. We are running out of capacity. We must have that new facility to be able to treat the extra wastewater in order to accommodate growth."
Uisce Éireann says it has no "Plan B" and that the crunch point could come as soon as 2028.
After that it will be forced to restrict the number of new houses and businesses allowed to connect to the sewage network in the northern and western environs of the Greater Dublin Area.
That would be a disaster, especially given the Government’s latest housing target of 150,000 new homes in the greater Dublin area by 2030.
It's hardly any wonder then that the long timelines and uncertainty involved in securing planning and consents for critical infrastructure is such a huge concern for Uisce Éireann.
The company’s Senior Planning Manager, Olwyn James, explained that Uisce Éireann’s projects like the Wastewater treatment plant at Clonshaugh can be moved along very speedily once they get on site.
The problem is that it is taking them years to get that far.
"There's a lot of discussion at the moment around planning and planning permission, but for us, that's just one part of the consent process. We have to engage and get consents from local authorities, An Coimisiún Pleanála, the Environmental Protection Agency, and the Marine Area Regulatory Authority if we want to do site investigations in the marine environment. We also need licences to operate our plants, and all of those consents happen individually," she said.
"They happen one after the other. They don't happen at the same time. That consultation engagement is complex, coming from complicated legislation. Some of those consents might need their own individual environmental assessments as well.
"And then what happens is, once those consents are made, they could be subject to their own judicial review. So, all of that takes an extraordinarily long time. There are no mandatory timelines for any of them, and there's great uncertainty.
"Then for all of our projects, we need land to carry out our development. That could involve linear projects, like long pipelines. We need to engage with landowners for that, sometimes multiple landowners. Sometimes you might end up in a compulsory purchase order process as well. That adds another layer of complexity and uncertainty.
"All of that adds up to a very long time and great uncertainty about when we can actually get on to a site to deliver our projects."
Delays cost big money
These delays cost money. Big money, according to Mr Ahern.
He says that construction inflation has pushed the cost of the Greater Dublin Drainage project from somewhere in the region of €700m when planning permission was first sought in 2018, to between €1.1bn and €1.4bn now.
In general, it is taking five to seven years for water and wastewater projects to get through all consents for a "straightforward" project, seven to ten years for more complex projects and more than ten years for very complex projects.
Legal challenges, or threatened legal challenges, have been brought against consents for Uisce Éireann’s water services infrastructure, throughout the country, from Donegal to Cork.
Judicial Reviews often come on top of that adding another 12-24 months with varying impact on the timelines for delivery of projects.
Uisce Éireann is looking for improvements in the planning and consenting processes if it is to be able to deliver critical infrastructure and upgrades in a timely manner.
It is particularly keen to see appropriate planning exemptions in the proposed new regulations that would help it to deliver schemes faster.
