For a Planning Application by Aughinish Alumina Limited for development at existing alumina facility

Note: this is a large (749 page) EIA report

The proposed development comprises of:

• An expansion of the Bauxite Residue Disposal Area (BRDA) to increase its disposal capacity in order to accommodate additional bauxite residue resulting in a proposed increase in height of c.12m (to c. 44m OD) above the currently permitted levels. No increase to the existing footprint of the BRDA is proposed.
• An extension to the existing Salt Cake Disposal Cell (SCDC) to accommodate further disposal of salt cake resulting in an increase in height of the cell by c.2.25m. The SCDC is located within the BRDA area.

• An extension of the permitted borrow pit2, located to the east of the BRDA, is also proposed. This extension proposes to increase the footprint of the borrow pit from c.4.5ha to c.8.4ha. This extension will provide an additional 380,000m3 of rock fill material which is needed to satisfy the requirements of the construction and operation of the BRDA.
• The continued use of an existing stockpile area at the south east of the subject site to store topsoil in order to satisfy the additional restoration requirements of the extended BRDA.
• Upgrades to the existing water management infrastructure to accommodate the BRDA development to Stage 16 which will also allow for greater Inflow Design Flood (IDF) capacity for the entirety of the BRDA.

Raise of the Bauxite Residue Disposal Area (BRDA)

The currently permitted BRDA (planning ref. Limerick County Council Reg. Ref. 05/1836; ABP Ref. PL13.217976) has capacity to provide a disposal area for bauxite residue until c.2030, for the current rate of alumina production (1.95 million tonnes per annum).

The proposed increase in disposal capacity to the BRDA will result in a height increase of c.12m above the currently permitted stage 10 level (c. 32m OD) to a final stage 16 level (c. 44m OD).

This additional disposal capacity will extend the lifetime of the currently permitted BRDA from c.2030 to c.2039 – an extension of approximately 9 no. years.

No increase to the existing footprint of the BRDA is proposed.

The existing BRDA can facilitate an increase in height to Stage 16 (currently permitted to Stage 10), which would provide a perimeter elevation of 36mOD and a maximum dome crown elevation of 44m OD.

The proposed development will provide for the deposition of circa 0.9 million m3 / year of bauxite residue and total of circa 8.0 million m3 over the lifetime of the development.

The proposed method of raising the BRDA from Stage 10 to Stage 16 is the upstream method (identified by the European Commission as the ‘Best Available Technique’1), consistent with the construction methodology for the current BRDA and involves the construction of rock fill embankments (Stages), offset internally and founded on the previously deposited and farmed bauxite residue, in 2m high vertical lifts.

The overall stack is raised systematically as the Stages are filled with bauxite residue, farmed, carbonated and compacted, prior to deposition of the next layer.

Raise of Saltcake Disposal Cell (SCDC)

The proposed development comprises the vertical extension of the existing SCDC to a crest height of c. 31.25m OD, which will have a maximum overall height of c. 35.50mOD when capped at cell closure.

The extension of the SCDC will accommodate disposal for an additional c. 22,500 m³ of salt cake in total. No increase to the existing footprint of the saltcake cell is proposed.

The construction of the SCDC extension will be undertaken in one step as opposed to the staged BRDA construction. Approximately 27,000m3 of processed rock fill material will be required to construct the perimeter wall of the SCDC raise. It is proposed that this rock material will be sourced from AAL’s borrow pit (see also Section 3). The composite lining, which will be placed inside the raised SCDC will comprise 4,500m2 of a mixture of geosynthetic materials.

No change in emissions or emission limit values are proposed associated with the raise of the saltcake cell.

In parallel, AAL have developed a process modification to avoid the generation of saltcake as a waste stream.

Extension of Rock Extraction Area

An existing permitted borrow pit was granted planning permission from An Bord Pleanala (ABP Ref. 301011-18) and was the subject of an Industrial Emissions Licence review for which Licence P0035-07 was issued in September 2021. This permitted borrow pit has an extraction area of circa 4.5 hectares to extract 374,000 m3 of rock over a 10 year period. This will provide sufficient rock for the lifetime of the permitted BRDA. This rock is required for construction of embankment walls at the Licenced BRDA facility.

The proposed development will increase the extraction area of the borrow pit, increasing the footprint of the borrow pit from c.4.5ha to c.8.4ha. This extension will provide an additional 385,000m3 of rock fill material, which is needed to satisfy the requirements of the construction and operation of the proposed raised BRDA.

As per the existing permitted borrow pit, the extraction area is sought up to a maximum depth of 8.5m O.D., at which depth there is no interaction with groundwater.

The proposed development seeks to extract rock from within the confines of the AAL landholding (and licence site boundary) to reduce the dependence of the construction of the BRDA on rock sourced from commercial quarries in the local area.