Dublin Drainage in the 18th Century
During the late 18th Century, open drains were provided in Dublin streets, which were often unpaved, into which chamber pots were emptied. Many properties relied on cesspools, dug in gardens from which the contents seeped into the ground or simply overflowed given the dense boulder clays in the City.
With the development of the city of Dublin at the confluence of the River Liffey with the sea, wastewater collection and discharge became an important consideration affecting the social conditions and, more particularly, the public health of its citizens. These original open drains and cesspools gave rise to foul smells, contamination of drinking water and related disease, and the consequent need for improved drainage works. The combination of poor drainage and polluted drinking water gave rise to regular epidemics of cholera and other waterborne diseases.
Towards the end of the 18th Century, legislation provided for the establishment of an Authority with responsibility for paving streets and regulating sewage discharges in the City. This led to the provision of covered sewers discharging to the River Liffey, thus gradually eliminating the use of cesspools. The City’s population expanded rapidly from around 1850 with the onset of industrial development and also as a result of poverty and famine in rural areas, with the associated rural peasantry crowding into the City. This led to expansion of the drainage system and greatly increased pollution of the River Liffey and other rivers.
Dublin Drainage in the 19th Century
In April 1851, Parke Neville was appointed as Dublin’s first full-time City Surveyor and was faced with addressing the wholly inadequate drainage arrangements that existed in the City. At the same time, there was a growing public recognition of the relationship between contaminated water and poor hygiene and the frequency of disease epidemics in urban areas that proved fatal to large numbers of people, especially the elderly and children. Much of the early covered sewers were of poor quality and cesspools continued in use. The first priority, therefore, was the provision of a suitable sewerage network for the City.
The period between 1851 and 1880 saw the construction of a substantial network of new sewers, mainly void brick conduits. At the same time, Parke Neville recognised the need for ‘interceptor’ sewers on the North and South quays of the River Liffey to cope with the increasingly foul nature of this river. A Government Royal Commission was established to study the proposals and the needs of Dublin and substantially endorsed the proposals of Parke Neville in 1879. The proposals, which evolved over time, were to build these major interceptor sewers to join each other downstream (East Wall) where a tidal storage basin would be built to discharge the flows on the ebb tide to Dublin Bay. This concept mirrored very closely what was happening in London and though it took nearly 50 years to agree, it eventually led to the Dublin Main Drainage Scheme, completed in 1906.
Dublin Main Drainage Scheme and Wastewater Treatment Plant at Ringsend, 1906
This scheme was originally designed for a population of 325,000 and comprised the interceptor sewers collecting the large number of outfalls to the River Liffey, retaining overflows to discharge excess stormwater during wet weather. The foul flows were conveyed to a wastewater treatment plant (primary settlement) and outfall at Pigeon House Harbour in Ringsend. The scheme brought enormous benefits to the City, greatly improving water quality in the River Liffey, while the tidal exchange in Dublin Bay removed the pollution load to be dispersed into the Irish Sea. The waste sewage sludge was exposed of at sea.
Prior to this major City centre scheme, a scheme had been constructed to serve the wealthy Rathmines and Pembroke townships. Frustrated by delays in the City scheme and by gross pollution in the River Dodder, they succeeded in getting the Rathmines and Pembroke Drainage Bill passed in 1877 and a substantial trunk sewer network was built to serve the area, to an outfall to the River Liffey at Whitebanks on the South Bull Wall. This scheme operated for over 100 years until it was connected to the treatment plant in Ringsend.
Wastewater Infrastructural Developments from 1906 to present
The treatment plant at Ringsend has been developed and expanded many times to cater for the needs of the Dublin Region since 1906. As well as the City centre, other major schemes implemented for this purpose were the:
- Dodder Valley sewer to Ringsend, constructed in the early 1970s, serves the southern suburbs, including Dundrum, Templeogue, and Tallaght;
- Grand Canal Tunnel sewer, together with the Lucan / Clondalkin and Blanchardstown / Mulhuddart areas, was commissioned in the early 1980s. This greatly extended the Ringsend catchment to these new suburbs;
- Dún Laoghaire scheme, constructed in the early 1990s, diverted the sewage from that catchment to Ringsend through a sub-sea pipeline from the original tidal tank and outfall at West Pier; and
- In the 1950s, a separate sewerage scheme had been constructed to serve the North Dublin catchment (Finglas to Baldoyle / Howth) discharging to an outfall off Howth. This intercepted local outfalls to Dublin Bay from Clontarf, Kilbarrack, and Sutton. In 2003, this catchment was diverted to Ringsend for treatment through a subsea pipeline from Sutton to Ringsend.
In 2003, as an aspect of the Dublin Bay Project, the Ringsend wastewater treatment plant was upgraded from 950,000 to 1.64 million population equivalent, with full secondary treatment for flows from the entire catchment, bringing the discharge into compliance with the 1991 EU Urban Wastewater Treatment Directive and associated National Regulations, adopted in 1994. The method of disposing of sewage sludge at sea ceased at this time and the sludge is now processed and used as an agricultural fertiliser.
It is useful to note the history of legislation governing wastewater management. In the 19th Century, the Corporation and Town Councils were empowered by legislation to provide infrastructural services after much local debate, especially on how to raise and divide between them the revenue to pay for it. The Public Health Acts (1878 to 1896) provided a general legal framework for development and operation of sanitary schemes in Ireland by Local Authorities and this legislation was only recently fully replaced by the Water Services Act, 2007.
The EU Council Directive 91/271/EEC implemented in Ireland through the Urban Water Treatment Regulations, 1994 required full secondary treatment of wastewater from agglomerations with a population of more than 15,000 by December, 2000. This was the driver for the most recent upgrading of the Ringsend plant and the North Dublin catchment transfer from Howth to Ringsend. Under the EU Water Framework Directive, higher standards of effluent treatment may now be required to achieve “good” water quality by 2015.
The Greater Dublin Strategic Drainage Study (GDSDS) was adopted in 2005, having regard to the major economic development of the Greater Dublin Area (GDA), the need to provide for the future socio-economic development in the region, and to comply with the latest environmental legislation. The study recognised the limiting capacity of the Ringsend plant and of the major arterial sewers draining to it.
The study, which was the subject of a Strategic Environmental Assessment (SEA) carried out by Fingal County Council in 2008, concluded that in addition to maximising the capacity of the existing wastewater treatment plants in the GDA, a new regional wastewater treatment facility, including a new orbital sewer to intercept flows from the Ringsend catchment, is required to be located in north Dublin, with an outfall to the Irish Sea. The implementation of this scheme, in parallel with upgrading of the Ringsend works to its sustainable limit, would secure the drainage need of the Dublin metropolitan region into the future, protecting public health and the environment and providing for essential social and economic needs. The SEA recommended that the site of a new wastewater treatment plant, outfall, and the routes of new sewers should be identified following rigorous Alternative Site Assessment (ASA) process. This recommendation is now being implemented through the Greater Dublin Drainage project.