The U.S. Federal Energy Regulatory Commission released final guidance for natural gas project developers on the use of horizontal directional drilling in pipeline projects and plans for addressing drilling fluid releases.
FERC said it designed the guidance to help the industry improve its drilling plans, which should increase the effectiveness and efficiency of the commission's environmental reviews and reduce the need for additional data requests. The guidance has the potential to impact the timing of reviews of projects that would move natural gas to market.
Horizontal directional drilling, or HDD, is often used in pipeline construction to avoid cutting through rivers, streams and other obstacles or environmentally sensitive areas. In some cases where the technique was used, drilling fluids have migrated to the surface of the ground and put natural resources at risk.
A focus on the environmental risks of HDD increased after construction problems on the Energy Transfer LP-led Rover Pipeline LLC in 2017. Among other incidents, a major release of drilling mud during an HDD crossing of the Tuscarawas River in Ohio affected a state wetland. FERC halted some project construction, slowing the pace of a pipeline that would eventually be a major outlet for Marcellus Shale gas.
Following the troubles on the Rover project, FERC released draft guidance in October 2018 for HDD plans, with recommendations for inspection and monitoring and addressing fluid releases. (FERC docket AD19-6)
Timing of files, plans
According to FERC, the final document has been tweaked to address numerous comments on the draft. The pipeline sector had urged that the guidance be commensurate with the complexity of each HDD design, its location and the environmental conditions. Others had called for a greater emphasis on earlier geotechnical studies to avoid problems.
The guidance released Oct. 9 added details on the timing of developers' plans. It recommended that plans filed prior to the final National Environmental Policy Act report include site-specific geotechnical information; profiles showing the feasibility of an HDD crossing; and evaluations of the risk of hydrofracture and inadvertent returns of drilling releases, along with details about source water identification.
"Omissions can cause delays in our processing of applications and increase the need for supplemental data requests," the guidance said.
FERC recommended that geotechnical studies be conducted as early as practicable to determine if HDD is suitable for specific crossings and to help develop plans. The scope of those plans should be scaled to the length of the HDD, complexity of subsurface conditions and sensitive resources in the vicinity, FERC said.
The guidance expressed FERC's preferred approach to HDD. The commission said that because each project is unique, it is not possible for the guidance to apply to all scenarios. The commission continued to maintain that site-specific HDD plans should be used for each crossing.
A new section suggested that certain resources or conditions — such as springs, water supply wells, cultural resources or existing contamination — may warrant special measures. The guidance set distances around such resources for such measures, such as within 150 feet of a well or within 1,000 feet of karst terrain.
FERC said the guidance applies to trenchless construction methods that use drilling fluids under pressure. The Interstate Natural Gas Association of America had sought a clarification that the guidance would not apply to all trenchless construction.
Consistent with the draft version, the final guidance recommended that developers follow detailed plans to monitor for releases of fluids, retain documents, and identify conditions that might increase the risk of problems. It emphasized pre-construction training, monitoring of drilling fluid circulation, and watching for signs of releases or environmental impacts, such as the formation of sinkholes.
The guidance also required developers to have plans to notify regulators in the event of spills and plans for containing and cleaning up spills to avoid impacts to water resources.
Maya Weber is a reporter with S&P Global Platts. S&P Global Market Intelligence and S&P Global Platts are owned by S&P Global Inc.