POLICE, five firecrews and Environment Agency officers were called to deal with an incident involving petrol fumes in the centre of Tavistock last Wednesday. The alarm was raised by staff at Brown?s in West Street, who reported an overpowering smell of petrol coming from the cellar of the building. One woman was given oxygen by firecrews, the fumes were so strong. Tavistock?s fire chief Tim Smith said firefighters from Camel?s Head in Plymouth, plus Yelverton and Bere Alston, were called to assist in the operation. Mr Smith said: ?It was certainly an explosive level of fumes, which, by the end of the afternoon, had spread to the cellars of most of the shops in West Street, we were getting calls from the offices in Plymouth Road and even some houses up in Glanville Road.? Firefighters tackled the cellars with a positive pressure ventilation system and flooded the storm drains and sewers with thousands of gallons of water to try and flush the contaminant away. ?For the amount of fumes there were, an enormous amount of fuel must have leaked in from somewhere,? said Mr Smith. Firefighters did not leave the scene until Thursday morning. A spokesman for the Environment Agency said: ?We were called to Tavistock by the fire and rescue services. ?It quickly became clear there was no evidence of pollution in the water ? there was no discharge into either the river or the canal, it was contained within the drainage system, so we alerted South West Water. Stephen Swain, spokesman for South West Water, said: ?One of our crews did attend the incident, but after inspection and investigation there was found to be no effect on the public sewerage system. ?Our only part in this was to check in case there was an impact on the sewerage, like loads of petrol pouring in and going to the sewage works, but on the Richter scale, it didn?t register.? So far, it is not known how the petrol was released into the drainage system.