Carrigans Shared Waters Enhancement and Loughs Legacy (SWELL) project

Irish Water has recently commenced upgrade works at Carrigans wastewater treatment plant, improving water quality in Lough Foyle.

Irish Water has recently commenced upgrade works at Carrigans Wastewater Treatment Plant. The works will be delivered as part of the Shared Waters Enhancement & Loughs Legacy (SWELL) project. A €35m EU-funded project which aims to improve the quality of water in Carlingford Lough and Lough Foyle through the upgrade of wastewater assets on both sides of the border.

BSG Civil Engineering Ltd. is working in behalf of Irish Water to deliver the project. The main construction works commenced in late June 2021 and are expected to be finished in January 2022, with commissioning works to continue until summer 2022.

Carrigans Wastewater Treatment Plant currently provides primary treatment. The plant was originally designed to cater for a population equivalent (PE) of 280PE however it is estimated that the current wastewater load being received at the plant is approximately 330PE. The plant currently discharges via an outfall pipeline directly into the Carrigans River, which is part of the River Foyle (a Special Area of Conservation). There are currently no storm water holding facilities on site and as a result excess flows overflow to the outlet chamber and discharge via the discharge pipe into Carrigans River.

The SWELL project is being funded under the European Regional Development Fund (ERDF). This project has been supported by the European Union’s INTERREG VA Programme, managed by the Special EU Programmes Body (SEUPB).

In Progress

Why is this project needed?

The existing plant is currently operating above capacity and needs to be upgraded to meet the needs of the village and protect the environment by ensuring that receiving waters are not impacted.

Upon completion the project will:

  • Bring benefits to the village by meeting the current needs of the area and allowing for future growth.
  • Reduce the impact of storm water overflows.
  • Improve water quality in Lough Foyle and nearby coastal areas.
  • Ensure wastewater is treated and discharged in compliance with EU regulations.

What is involved as part of this project?

In order to overcome these deficiencies, it is proposed to pump the untreated wastewater to St. Johnston Wastewater Treatment Plant. The upgrade at Carrigans Wastewater Treatment Plant will involve:

  • Decommissioning of the existing Carrigans Wastewater Treatment Plant septic tank, converting this to a storm tank and constructing a new pumping station at the site.
  • Construction of a new rising main over a distance of 3,500m to transfer the wastewater for treatment at the St. Johnston Wastewater Treatment Plant.