ON SITE pumped down to the water recycling dams , and from there it is transferred to a water / oil separation system , where it is further filtered for reuse in other applications .” A portion of the dams is concretelined towards the drainage end because of the sumps and manholes in that section . The rest of the dams are HDPE-lined and were installed by specialist company Aquatan . The volume of the dams is 50m × 40m by about 6 – 8m deep . The highlight of the project , however , was the wetland crossing , Keevy says with obvious pride . The piping system crossing the wetland transfers water to the ash dams . “ This entailed a suspended piping system across the wetland , on pilings . When it comes to wetlands , because of their importance to the ecology , there is a mountain of red tape around any project in which one is involved . Nevertheless , within a really limited timespan , we were able to complete a really attractive section of pipe over a wetland and rehabilitate the area , without damaging the ecological system . It was quite an achievement from an environmental point of view , but also from a quality and programming perspective . Very few people thought it was achievable , given the intricacies of working in a wetland , the delicate balance that has to be achieved , and the risk of contamination ,” he beams . The challenges on this project included controlling the construction process to minimise contamination of the wetland , while adhering to deadlines and completing the project on time , before the onset of the rainy season .
The wetland crossing
A wetland is an area that is inundated or saturated by surface or underground water , which is usually small and limited as a result of the topography
Alex Keevy , contracts director at Esor Construction .
The biggest challenge of the operation was the tight schedule of five months within which to complete the construction works before completing the rehabilitation of the wetland , and avoid the rainy season .