Summer downpours and Dublin Bay

It's 8th August 2019, and we've had some heavy downpours in the last few days. Dublin City Council has spoken with HSE and EPA and is saying don't swim in Dublin Bay. That's good advice. For the moment don't swim. The Bay flushes out fairly quickly, so the next couple of days should see cleaner water, but there may be more downpours on 9th August 2019, so don't put on your togs just yet. 

The current Ringsend Treatment Plant was commissioned in 2003 to serve a population of 1.65 million. It currently treats wastewater for the equivalent of 1.9 million people, that's 15% over-capacity. Just twenty years ago since the infamous ‘ship of shame’ MV Sir Joseph Bazalgette was taken out of service. It shipped our, eh shit to Howth.  Here’s an article by journalist Frank McDonald from 1999. Why Sir Joseph Bazalgette? One of my Victorian heroes, here, take a read…  

It's worth noting that the European Commission has taken an infringement case against Ireland in relation to the Urban Wastewater Treatment Directive  Looking ahead, a big upgrade €400 million upgrade is on the way for the Ringsend Sewage Treatment Plant. The plans got the green light from Bord Pleanála back in April of this year. This means less no swim notices in the future and the works should be completed by end of 2021. A previous proposal would have involved a 9km pipeline out into Dublin bay. That’s where I got the notion of building a new island with the spoil, but I digress.

The current proposed upgrade will use a technology called Aerobic Granular Sludge. This is a new process (invented around 2005) that gobbles up the pollutants more quickly than the old plant. It means faster and less costly sewage treatment. Aerobic granules are a type of sludge that can self-immobilize flocs and microorganisms into spherical and strong compact structures. Sorry you asked? But these type of summer downpours represent a real challenge and can overwhelm any Sewage Plant. Will they be more likely with climate change? I suspect so. 

We also need to separate out the storm sewers (rain water) from the ordinary sewers (poo) as currently in the inner city they both go into the same pipe, and that’s another challenge for @irishwater. As you can see this stuff interests me, I used to lecture in it at @WeAreTUDublin. Want to find out more? Check out two fascinating books by former Dublin City Council engineers Michael Corcoran and Clair Sweeney: 'Our Good Health' and 'The Rivers of Dublin'.

An update on Dublin's water

Took a trip to Wicklow yesterday for the opening of a water pipe, a €30m water pipe at Roundwood Reservoir. 

One of my heroes in the world of water is Sir John Grey. He has a statue on O'Connell Street, and this one here at Roundwood. 

He chaired Dublin Corporation's Drainage Committee in the 1860s, and knowing a reservoir would be needed in Wicklow he bought the lands in advance, and then sold them back to the city at cost to avoid speculation, a man of honour.

He also owned the Freeman's Journal, trained as a physician and was a Protestant Nationalist who sought the repeal of the Act of Union.

Fun Fact: his grandson Edmund John Chisholm Dwyer-Gray was 29th Premier of Tasmania in the 1930s.

Prior to Roundwood Reservoir's completion the Blessington Basin supplied water from 1814 to Dubliners, as well as the Jameson Distillery, but as Dublin expanded more water was needed.

Here's a picture at the Blessington Basin in Dublin's North Inner City with my @WeAreTUDublin students of environment and planning

In James Joyce’s Ulysses Leopold Bloom turns the tap to prepare a cup of cocoa for Stephan Dedalus. He makes the mistake of asking “Did it flow?” Bloom describes the entire Vartry scheme in his reply. 

Members of the Dublin Corporation enjoyed a picnic during their inspection of the Vartry waterworks in 1892. £51 16s 8d was spent, including luncheon and refreshments: a dozen bottles of Chateau Margaux, a dozen bottles of fine old Dublin whiskey and a box of cigars. 

Thankfully the local government auditor disallowed this expenditure and the Lord Chief Justice affirmed his decision. (on yesterday's trip Irish Water gave us tea and scones.)

In 1923 Alderman Staines and his colleagues from the Corporation headed down to Roundwood for an extension of the waterworks. This wonderful black and white Pathé film shows Dublin's flag being raised at the dam.

Yesterday marked the opening of a new €30m pipe and pumping station to replace the Vartry to Callowhill Link tunnel which was in danger of collapse after 150 years of use. Hopefully the old tunnel can now be rehabilitated to spare us the cost of pumping. 

There's other works in progress at Roundwood, including new slow filter beds where the water is cleaned by trickling down through fine layers of sand. 

Climate change may be reducing output as Summer droughts mean less water, and alga growth that reduce the filter capacity.

We've also got to ensure we maintain flow to the River Vartry that keeps Mount Usher gardens and farms supplied with water.

If you're interested in finding out more look out for Michael Corcoran's book 'Our Good Health' which maps out the 100 year history of Dublin's water supply. Here's a paper he gave a few years ago to Engineers Ireland.

I welcomed the launch, but said we must focus more efforts on water harvesting and conservation, as a new water supply from the Shannon will cost over a billion Euro , and use a lot of energy for pumping. Here's my few words...

Here's a link to Irish Water's information on yesterday's launch. 

And finally thanks to Ned Fleming, the engineer and waterworks superintendent who gave me a fantastic tour of the waterworks and the old valve rooms at Roundwood. Much appreciated!