An investigation has started into how foul-smelling raw sewage spilled into the Leeds-Liverpool canal after a mains pipe burst.

Yorkshire Water had to close the canal towpath when a stream of waste spilled from the pipe next to the treatment works in Esholt.

Emergency teams were quick to seal the metal pipe and only a “small amount” of sewage escaped into the canal, a Yorkshire Water spokesman said.

The Environment Agency has now started an investigation into how the spillage happened.

A spokesman said: “We want to make sure the chances of this ever happening again are minimised.”

Part of the path running beside the canal was closed yesterday[fri] while repairs to the pipe continued.

A spokesman for Yorkshire Water said: “We had a burst on a sewer main in the part of the pipe which runs over the canal. We had spillage into the canal path which was cleaned up.

“The Environment Agency say there has been no impact on the canal. The actual burst was brought under control and sealed very quickly.

“We have got contractors down there and we are trying to keep the towpath open as much as possible.”

Officials from the Environment Agency were quickly at the scene after the spillage, which happened at about 12pm on Thursday. Yorkshire Water put temporary pumping arrangements in place to deal with the sewage flow.

At first it was feared harmful bacteria may have contaminated the water but an agency spokesman said samples had shown that had not been the case.

British Waterways, which is responsible for canals, and Bradford Council’s Environmental Health department have been informed.

A spokesman for the Environment Agency said: “We are monitoring the situation and sampling the water in the canal and the River Aire, which runs next to it.

“It was a very small amount of sewage which has had minimal impact. We are happy with the steps Yorkshire Water has taken and we will be staying in touch with them.

“There will be bacteria in that general area anyway because of where the sewage works is and, if it is untreated it will be in higher concentrations, but from a public health point of view, it is not introducing any bacteria that are not there already.

“We are investigating what happened and want to make sure the chances of this happening again are minimised.”

A British Waterways spokesman said: “Because there has been quite a large volume of boat traffic, most of the sewage has been dispersed.”