Questar Pipeline Co. has filed an application with the Federal Energy regulatory Commission for a certificate authorizing it to provide open-access natural-gas storage service at its Clay Basin storage field in northeastern Utah beginning May 1.

If the commission is unable to issue an open-access certificate by May 15, Questar Pipeline is requesting interim authorization that would allow the company to proceed with its plan to offer firm and interruptible self-implementing storage service at Clay Basin in the coming year.Operated by the pipeline company since 1976, Clay Basin has provided contract storage service to Northwest Pipeline Corp. in addition to storage service for Questar Pipeline system operations.

It has a current injection capacity of 30 billion cubic feet, about a third of which would be marketed to new customers under the requested open-access storage certificate.

Questar Pipeline officials said they will hold an open season March 16-31 when they will accept requests for both firm and interruptible storage service at Clay Basin.

Firm service priority will be determined by calculating the present value of each buyer's service request based on the rates buyers are willing to pay and the term of service requested.