Balbane Landfill Remediation

We provided consultancy services for the restoration of the Balbane landfill site after its waste licence was granted by the Environmental Protection Agency (EPA). Balbane is an old, three hectares, unengineered site that closed in 2004.

The works included the placement of a reduced depth geosynthetic cap and restoration soils, landscaping works, construction of access roads and hardstanding, installation of a leachate abstraction system, installation of landfill gas management measures and all associated civil engineering works.

Challenge

A primary issue requiring management at the site was the impact of leachate from the unlined site, which appeared to be impacting surface waters immediately downstream from the landfill. This occurred predominantly via surface water discharges from leachate breakout from the waste body and subsequent overland and shallow groundwater flow.

The primary receptor considered at risk from the site is the Balbane River and Lough Aderry River further downstream. The river is located down the gradient of the waste body and connected to the waste body by a series of small unnamed streams.

The Appropriate Assessment Screening considered all Natura Sites within the development's vicinity and identified those that can be screened out of the Appropriate Assessment where there was no potential for impact or pathway to the sensitive receptor.

Solution

We negotiated an alternative capping detail with EPA using locally available soils and prepared and submitted the Specified Engineering Works for approval. As part of the scheme, we prepared a design to incorporate the use of Integrated Constructed Wetlands (ICW) for a low-cost sustainable method of treating leachate generated on-site with a direct discharge to the surface water of the treated leachate permitted.

Acting as the Employer’s Representative for Donegal County Council, we were responsible for preparing the suitability assessment documents, and prepared tender documents under the Public Works Contract for issue to shortlisted contractors.

During construction works, it was critical that the Contractor managed emissions such as odour, landfill gas, leachate, noise, vibration and groundwater. The works included reprofiling waste body across the site, which is needed to achieve the required levels and surfaces for the permanent landfill capping works.

Ultimately, we fulfilled the role of construction quality assurance (CQA) supervision and project management for the project.