The U.S. Department of Homeland Security (DHS) on Thursday issued cybersecurity requirements for natural gas and oil pipeline owners and operators in response to the ransomware attack on Colonial Pipeline Co. earlier this month.

The directive requires critical pipeline owners and operators to report confirmed and potential cybersecurity incidents to the DHS Cybersecurity and Infrastructure Security Agency (CISA). It also requires a cybersecurity coordinator be designated and available 24 hours a day, seven days a week.

“The cybersecurity landscape is constantly evolving and we must adapt to address new and emerging threats,” said DHS Secretary Alejandro Mayorkas.

The attack on Colonial, the country’s largest refined products pipeline, “demonstrates that the cybersecurity of pipeline systems is critical to our homeland security,” Mayorkas said. “DHS will continue to work closely with our private sector partners to support their operations and increase the resilience of our nation’s critical infrastructure.”

The directive also requires critical pipeline owners and operators “to review their current practices as well as to identify any gaps and related remediation measures to address cyber-related risks,” DHS said. Companies must report the results to DHS’s Transportation Security Administration and CISA within 30 days.

“TSA is also considering follow-on mandatory measures that will further support the pipeline industry in enhancing its cybersecurity and that strengthen the public-private partnership so critical to the cybersecurity of our homeland,” DHS said.

The directive will enable DHS “to better identify, protect against, and respond to threats to critical companies in the pipeline sector.”

After learning on May 7 it had been victimized by hackers, Colonial shut down its 5,500-mile system, which transports more than 100 million gallons gasoline, diesel and jet fuel to markets throughout the southern and eastern United States.

The shutdown led to fuel shortages and panic buying across the region, as Colonial did not fully restart operations until May 13.

While the impacts of the Colonial hack were limited to transportation fuels, a similar attack on natural gas infrastructure could have more dire impacts, given the fuel’s widespread use in electricity and heating.

In reference to the Colonial incident, North American Electric Reliability Corporation CEO Jim Robb said this month that, “If this had happened to a major natural gas line serving electricity generators under extreme cold weather conditions, the results could have been catastrophic.”

He added, “It is time for policymakers to refocus on ensuring that gas infrastructure is as secure as the grid it supplies.”