On January 15, the US Department of Transport’s Pipeline and Hazardous Materials Safety Administration (PHMSA) announced new comprehensive proposed requirements for carbon dioxide (CO₂) and hazardous liquid pipelines.

According to the official statement released by PHMSA, the Notice of Proposed Rulemaking (NPRM) will strengthen existing standards for hazardous liquid and CO₂ pipelines (including CO₂  transported in a supercritical fluid state). For the first time, new standards will also be established for transporting carbon dioxide in a gaseous state via pipeline.

The new requirements are partly informed by “lessons learned” from PHMSA’s comprehensive investigation into the February 2020 Denbury pipeline failure in Satartia, Mississippi, which resulted in the evacuation of some 200 individuals. Some who succumbed to the effects of the migrating CO₂ vapour cloud required emergency medical assistance to be able to leave the area. A total of 45 people sought assistance at local hospitals.

The pipeline was returned to service late in October 2020.

The Department of Energy has forecast a significant expansion of the US carbon dioxide pipeline network. There are 5,000 miles of pipeline currently in operation. This figure could increase tenfold.

Read the full PHMSA statement here.