Major Donegal water plant overhaul planned as deficiencies identified
The proposed works aim to address deficiencies at the existing plant while strengthening water supply resilience across Inishowen and Letterkenny.
Uisce Éireann is seeking planning permission for a significant upgrade of the Illies Water Treatment Plant in Inishowen.
The State utility is seeking a 10-year planning permission for works at the existing plant in the townland of Illies, which include the construction of new buildings, structures and tanks, the demolition and replacement of an existing workshop, upgrades to existing treatment infrastructure and the installation of solar photovoltaic panels.
The proposed works are aimed at addressing deficiencies identified at the existing treatment plant while improving health and safety, security of supply and the operational resilience of the public water network.
In a supporting letter submitted with the application, Nicholas O’Dwyer Ltd, acting on behalf of Uisce Éireann, said the upgrade would strengthen and integrate the existing water supply infrastructure.
“By strengthening and integrating existing water supply infrastructure, the proposed development will support a resilient and adaptable public water supply network capable of meeting the needs of Inishowen and Letterkenny,” the consulting engineering firm stated.
Among the main elements of the proposed development is a new Dissolved Air Flotation building, which will be used for a fourth Dissolved Air Flotation treatment stream. The new building will be located beside the existing facility and will be of a similar height, but have a smaller footprint.
Dissolved Air Flotation (DAF) is a water and wastewater treatment process that clarifies liquid by removing suspended solids, oils, greases, and algae using microscopic air bubbles.
Two additional first-stage rapid gravity filters are also proposed as an extension to the existing six filters, while the existing second-stage rapid gravity filters will be upgraded to a dual-media configuration.
The plans also include a new 258 cubic metre sludge concentrator tank and an upgrade of the existing sludge dewatering system. This will include a high-capacity filter press, an automated conveyor system and a covered trailer loading bay.
The existing workshop is to be demolished and replaced with a new workshop at an alternative location within the site.
The application also provides for two new external aluminium sulphate, or alum, storage tanks, each with a capacity of 86 cubic metres.
The existing alum storage building is to be modified to accommodate a new soda ash silo, with the height of the building increased to match the adjacent structure containing the existing soda ash silos.
Several internal modifications are also planned within the existing treatment buildings to facilitate new and upgraded equipment, including dosing arrangements, backwash pumps and air blowers.
The project would also see extensive upgrades to the plant's electrical, instrumentation, control and automation systems, including a new Supervisory Control and Data Acquisition system, new electrical panels and modifications to input and output signals.
Solar photovoltaic panels are also proposed on the roofs of buildings and structures at the plant as part of measures to improve energy efficiency and support renewable energy targets.
The plans also include improvements to the internal road layout and access routes to facilitate site deliveries and operational efficiency.
New fencing and gates, up to a maximum height of 2.4 metres, are outlined where required, along with landscaping, screening planting and biodiversity improvement measures.
Illies Water Treatment Plant treats water from the Eddie Fullerton Pollan Dam and Reservoir, with treated water then distributed through a network of pipelines, pumping stations and storage reservoirs to homes and businesses across Inishowen and Letterkenny.
Uisce Éireann previously invested €8 million in the Illies Water Treatment Plant in 2023.
The investment was aimed at improving drinking water quality and increasing capacity at the plant, while ensuring compliance with the current Drinking Water Regulations.
The works included the modernisation of existing water treatment processes, including disinfection systems, sludge handling and treatment systems, monitoring and instrumentation systems, as well as the construction of new kiosks.
The latest application is the second major planning proposal involving the Illies water supply infrastructure to emerge in recent months.
Uisce Éireann previously submitted plans for the Letterkenny and Inishowen Water Supply Upgrade Project, which included the replacement of almost 13 kilometres of strategic watermain between Buncrana and Burt.
The wider project included several measures designed to improve the resilience and capacity of the water network serving South and East Inishowen, Letterkenny and surrounding areas.
However, the previous application was deemed invalid by Donegal County Council after the planning authority found shortcomings in the submitted documentation.
The council stated that the site location map did not comply with the requirements of the Planning and Development Regulations 2001, including requirements relating to the identification of the site boundaries and the location of site notices.
The planning authority also advised that a planning application cannot be made for separate sites within a single application where this would result in separate legal planning units being included under the one application.
A decision on the latest application for the Illies Water Treatment Plant upgrade is expected to be made by Donegal County Council in early November.