Chevron's 2007 drilling mud spill benign: N.L

An offshore spill of drilling mud in 2007 involving Chevron Canada had no significant environmental impact, says the Newfoundland and Labrador government.

At the time of the incident in January 2007, the Canada-Newfoundland and Labrador Offshore Petroleum Board reported that 74,000 litres of drilling mud were spilled in the Orphan Basin area.

Natural Resources Minister Kathy Dunderdale commented on the spill in the house of assembly in St. John's on Tuesday after a York University professor complained on CBC Radio Monday that the public has not been told about the impact of the spill.

"Mr. Speaker, there was a terrible storm on that day. The drill rig had to disconnect because it was at very high risk and there was a spill," said Dunderdale.

"Mr. Speaker, it didn't rise to the surface, it had no effect on fish, and it had no effect on birds. The only organisms that it would have impacted are those that were crawling on the sea floor and not able to get away."

Dunderdale told the provincial legislature that drilling mud is used in the industry to prevent oil or gas from escaping during drilling operations.

Environmental sciences professor Gail Fraser told CBC Radio's The Current that she has repeatedly been denied information about the 2007 spill and others.

Petroleum board spokesman Sean Kelly said a spill of drilling mud is not as serious as an oil spill.

But studies have found that a common drilling mud additive, used as a thinner, can harm fish eggs and fry. Other mud additives have reported effects on marine organisms, including reduced fertility and higher mortality.

Chevron Canada did not respond to a request for an interview from a CBC radio's The Current.

Chevron began drilling a deepwater well in the Orphan Basin on May 9, weeks after the catastrophic BP oil blowout in the Gulf of Mexico on April 20 that continues to spill.

The ship Stena Carron was hired to drill Chevron's Lona O-55 prospect in the Orphan Basin, about 430 kilometres northeast of St. John's.

At more than 2.5 kilometres underwater, the exploratory well will set a depth record for Canadian offshore drilling, according to Chevron's website.