Roadstone retained VESI Environmental to design and oversee the development of an Integrated Constructed Wetland (ICW).

Site Suitability

The quality and quantity of the quarry’s drainage, as well as its location, landscape, geology, soils and hydrology, along with necessary economic, social and biodiversity considerations were essential to the ICW’s design and construction.

Land survey showed an area to the southwest of the quarry to be most suitable for the ICW. Desk-studies and field investigation to determine ground conditions (lithology and hydrogeology) were made.

These showed the proposed site to be suitable, affording natural protection of ground water and soils suitable for the ICW’s construction and operation.

The origins of Roadstone go back to the early 1930’s when two young Dublin brothers Tom and Donal Roche started a sand and gravel haulage business with a Bedford truck operating from a small yard at Inchicore in the suburbs of West Dublin. 

Initially called Roche Brothers it later became the Castle Sand Company and developed steadily during the 30’s and 40’s. The brothers launched a new company, Roadstone, on the Irish Stock Exchange in 1949. 

They were supported in this venture by John A. Wood who had his own sand, gravel and quarrying business in County Cork and which later joined with the Roadstone Company.


Construction of the ICW at the Roadstone Belgard Quarry commenced in March and was completed in May 2017. The time scale set for the works was 11 weeks and included:

  1. Construction of two shallow treatment cells with a combined surface area of 10,700m2 with an operational water depth of less than 150mm and a base level set at 1 meter below the top of the retaining embankment.
  2. An open water channel to carry water from the first receiving cell to the second cell along the south-western boundary of the site.
  3. Construction of access roadways to all sections of the wetlands
  4. Installation of 3 parallel 300mm diameter interconnecting pipes between ponds.
  5. Installation of 3 parallel 300mm diameter pipes at the inlet and outlet with manholes and sampling chambers.
  6. Installation of a manhole and sampling chamber between the cells.
  7. Planting of a range of tall-emergent plant (helophyte) species of known performance for treating through-flowing water.
  8. Landscape works that included tree, shrub and grass-seeding.

ICW Design

Critical considerations for the ICW’s design was the need to address all sustainable functional and aesthetic requirements, with regard to sitespecific inflows and their vectored constituents, including:

  1. Flows from all pumped quarry drainage to the proposed ICW,
  2. Physical, chemical, and biological properties of the pumped influent,
  3. Local climate including average annual rainfall.


Taking into account these factors and the land area available, a functional area 10,700m2 was considered optimum. Two treatment cells, 3,950m2 and 6,750m2 respectively, were designed.

Inter-connecting pipework and channels allow inflowing water to flow in sequence through each cell, minimising priority flow, with a final discharge to the Kingswood Stream tributary.

Vegetation Establishment

Planting was carried out by the contractor Killeen Civil Engineering Ltd. upon completion of earthworks in May 2017. 

Plants were supplied by VESI Environmental Ltd. from its nursery facilities and were delivered on site for each wetland cell as suitable planting conditions allowed. 

The ICW design focusses on the use of native plants in order to enhance the biodiversity of any given site and does not attempt to introduce non-native species for vegetation cover. The primary species list for planting was as follows: 

  • Glyceria maxima, Sweet water grass
  • Typha latifolia, Common bullrush
  • Typha angustifolia, Narrow leaved bullrush
  • Iris pseudacorus, Common iris
  • Schoenoplectus lacustris, Clubrush
  • Carex riparia, Common river sedge

Additional marginal native plant species were planted along the margins of each cell in keeping with the establishment of complementary biodiversity and aesthetics. 

Small quantities of aquatic vegetation were planted along the channel between Cell 1 and Cell 2. The southern boundary of the site was planted with native tree and shrub species to further increase the biodiversity and aesthetic value. 


The ICW at Roadstone’s Belgard Quarry and associated lands was constructed in 2017 to handle the quarry’s drainage waters before their discharge to an adjacent stream. The available land at the facility has been transformed from a disused state to a highly aesthetic and diverse natural habitat. 

It demonstrates how effective treatment with optimum outcomes for the wider environment can be achieved in an economical manner. This ecologically engineered approach to water treatment is not only cost effective, but provides potential habitat for local wildlife within the conurbation of Dublin. 

Designed to yield optimum outcomes intercepting and treating water through the reanimation of a wetland ecosystem, its social, economic and environmental impacts deliver new perspectives for the comprehensive management of water and Roadstone’s sustainable environmental commitments.

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