Our Rehabilitation Team was on site recently in Shankill, Dublin tasked with removing roots before relining on 180 metres of Sewer Trunk main line on behalf of Irish Water. This particular road is lined with trees which lie above the sewer pipe and which run parallel for its entire length. Unsurprisingly one would expect to have a huge risk of root ingress.
Alongside deposits, the ingress of roots into sewer systems creates flow obstacles and can over time cause significant damage to the integrity of the pipes. This problem occurs almost exclusively in sewer pipes which are permanently or partly lie above groundwater or in soil with a limited amount of water. Why? Sewage exfiltrating (leakage) from the pipe will stimulate the outer ends of the roots (a process called hydrotropism) causing them to form new cells in order to grow towards the source of this stimulation. These cells are minute allowing them to easily enter through the smallest cracks, joints and holes in the sewer pipe. Once inside the roots will grow until they block the sewer pipe with lengths of up to several metres. There is a danger that the expanding roots will destroy the immediate area surrounding the original entry point.
Our Rehabilitation Team working on site reported significant root ingress necessitating the use of both the IBG Chain cutting tool and the Group’s robotic cutting equipment. Once the roots were cleared, our team installed 28 CIPP patches and relined 180m of 525mm diameter pipe.