FERC granted one variance request by Impulsora Pipeline LLC, but denied a second one, as the pipeline that is to carry natural gas produced in the Eagle Ford Shale to markets in Mexico moves forward.

In a letter order Tuesday, the Federal Energy Regulatory Commission granted the pipeline permission to conduct certain maintenance activities along a 0.51-mile stretch of access road leading to the company's horizontal directional drilling (HDD) site in Webb County, TX [CP14-513 and CP16-70].

But Amanda Mardiney, an environmental project manager for FERC, said she could not approve Impulsora's request to keep vegetation within a 30-by-900 foot corridor cut to a height of six inches or less. The corridor functions as a workspace between a 1.6-acre temporary work site on the U.S. side of the international border and the Rio Grande River. Impulsora said the cut to vegetation would help facilitate installing, operating and monitoring a survey system designed to ensure that underground pipe remains in the authorized area.

"I cannot approve Impulsora's request...until adequate justification is provided," Mardiney wrote.

According to Mardiney, when Impulsora requested the variances last Thursday it had clarified to FERC that HDD drilling would begin on the U.S. side of the border, and that pigging and metering equipment would not be placed on the U.S. side. She acknowledged that the company had also notified FERC of a minor change to the location of the HDD site on the Mexican side of the border. Construction of the cross-border facilities began in October, four months after FERC approved several amendments to the project.

The 36-inch diameter Impulsora Pipeline would originate in Texas at the Howard Energy Partners (HEP) Webb County Hub to transport gas to the border crossing in Webb County and in Mexico near Colombia in the State of Nuevo Leon.

A separate pipeline, Midstream de Mexico, is planned to originate at the border crossing and extend to measurement stations near Monterrey, Nuevo Leon. Nueva Era, a joint venture of HEP and Grupo Clisa, would provide service to shippers for transport on both pipelines. Impulsora received its presidential permit in May 2015 for the facilities.