A team of Punjab Pollution Control Board officials collected samples of water mixed with ash and draining out from Guru Gobind Singh Super Thermal Plant, Ropar towards Sutlej river here today. The team led by Executive Engineer Joginder Singh from Mohali reached the site this morning and collected the samples from different places. It was on Monday that an ash disposal pipe in the plant burst, leading to Sutlej river water getting polluted. On Friday, four ash disposal pipes carrying ash slurry to dykes from units 5 and 6 of the thermal plant had burst. Revealing the cause of bursting of the pipes in the plant, sources said particles of ash had started damaging the inside of the pipes and to guard against this damage, these pipes are required to be rotated at 90 degree in the intervals of few months. However, these pipes had not been rotated for long, leading to the problem, said sources. Pollution of river had raised concern among environmentalists as well. Ropar-based bird-watcher Jaspreet Singh said the pollution will pose a risk to the flora and fauna in the region. It will even affect the arrival of migratory birds, he said. Thermal Plant Chief Engineer K Lall said such leakages take place occasionally and the management was in the know of the problem. Measures were being taken to minimise such incidents, said Lall. Pollution board officials collected six samples from channel four leading to Ghanauli drain and area of Ghanauli drain leading towards Sutlej. It will take some time to ascertain the quantum of pollution increased due to incident in the river, said Executive Engineer Joginder Singh.