UPDATE 1-Regulators investigate "unsafe" NY natural gas line
* Millennium natgas pipe may be unsafe, regulators say
* Potentially faulty welds could affect line safety
* Company and regulators assessing the line
(Adds company reaction)
NEW YORK, Aug 5 (Reuters) - A key natural gas pipeline which crosses southern New York state is in danger of rupturing and could pose a safety threat, according to a recent report from regulators.
An investigation by the New York State Department of Public Service into a leak on the Millennium Pipeline in January found that uninspected faulty welds were responsible for the accident.
Now the Pipeline and Hazardous Materials Safety Administration is conducting its own investigation along a large stretch of the pipe between Corning and Ramapo, concerned that similar problems are likely to occur at other points on the line.
"It appears that the continued operation of the affected pipeline without corrective measures would pose a pipeline integrity risk to public safety, property, or the environment," the PHMSA said in a letter to the pipeline operator, Columbia Gas Transmission, on July 6.
The company had thirty days to respond to the PHMSA.
PHMSA, which is part of the Department of Transportation, requested that Millennium operate the pipeline at a reduced pressure last month, and the reduction remains in place until further notice, according to the Millennium website.
Colombia Gas Transmission is making a weld assessment on the line, which is expected to be completed in two weeks, a company spokeswoman said on Friday.
"We would not operate a pipeline if we did not believe that it could be done so safely," she said. A PHMSA spokesman said that PHMSA and the company are undergoing "informal consultation" about the pipeline.
The Millennium Pipeline is a 182-mile system extending from Independence in Steuben County, New York to Buena Vista in Rockland County, New York. It can deliver up to 525 million cubic feet per day of supply.
Millennium is jointly owned by NiSource Inc (NI.N) business unit NiSource Gas Transmission & Storage, and affiliates of National Grid (NG.L) and DTE Energy (DTE.N). (Reporting by Edward McAllister and Eileen Moustakis; Editing by Alden Bentley and Sofina Mirza-Reid)