The Castle Archdale Integrated Constructed Wetlands (ICW) contains just over 13,000m2 (3.25 acres) of wetland ponds.
Wastewater flows from the settlement pond through the densely planted treatment ponds under gravity flow. As the water progresses through each pond it becomes cleaner as pollutants are removed by natural biological processes.
Altogether the wetland planting comprises around 20,000 plants of emergent species within the treatment ponds and settlement ponds; native trees along the perimeter of the site and grass seeding, the most prominent plant species within the ponds are Iris pseudacorus (yellow iris), Glyceria maxima (reed sweetgrass), Typha latifolia (cattail) and Carex riparia (greater pond sedge).
The Castle Archdale site is the second ICW to be constructed by NI Water and represents an eco-friendly fully sustainable approach to wastewater treatment in the area. The wetland will now be available for the public to be at one with nature, enjoying the flora and fauna as part of the beautiful surroundings.
ICWs are designed, built and operated by man but are based on processes that occur naturally within indigenous wetlands providing an environment where the interaction of the wetland and the plants cleanse the wastewater. The investment has seen the construction of a series of shallow treatment ponds, the careful selection of plants providing the retention time and the capacity to treat wastewater from the Castle Archdale area.
The new wetland can accommodate seasonal fluctuations in flow and is therefore ideally suited to the Castle Archdale area. The ICW method has an established record in Europe of providing a low cost, low energy and low maintenance alternative to mechanical wastewater treatment. NI Water believes that this natural environmentally-friendly solution will accommodate the future development needs of the Castle Archdale area, while promoting a natural ecosystem.