The number of attempted attacks on the U.S. power system has risen to between 3,000 and 4,000 per month, according to the former head of the nation's largest electricity operator.

PJM Interconnection's former CEO, Terry Boston, discussed the challenges of the electric grid at President Trump's National Infrastructure Advisory Council quarterly meeting Tuesday, led by the Department of Homeland Security. "At PJM, we had 3 to 4,000 attempts per month at our firewalls to get into our system," he said at the meeting.

He wants Energy Department personnel with security clearances to be trained to work alongside employees of the electric grid operator to better coordinate with the federal government during a cyberattack. "I would suggest ... that we add cross training federal [Department of Energy] contractors on industry control systems to have a stronger response team with appropriate clearance when under attack," Boston said.

He said security clearances are denied to private-sector employees most often because the federal government cannot disclose who is attacking. But he told the advisory council that PJM and the utility industry don't need that information to understand the threat and coordinate with the federal government. "Industry needs to know when, how and what to protect under the threat. Not who or why," he said. "Generally, the reason something is classified is because [of] who the threat is from. And we don't need to know that to mitigate the threat on the system."

Boston was the CEO of PJM Interconnection until December 2015, where he ushered in a number of key changes to the 13-state market that PJM oversees. He is intimately familiar with the challenges the grid faces from the risk of cyber and physical attacks.

A PJM spokeswoman said Boston was not speaking on behalf of the grid operator. She had no comment on his assertions of the number of attempted hacks on the grid operator.

Boston now is director of the Chicago-based Gridliance, which describes itself as the nation's first independent transmission-only company that is focused on working with publicly owned utilities and rural cooperatives to solve transmission challenges and cost issues. In 2014, he was elected to the National Academy of Engineering for his work on electric grid management and planning.

The president's advisory group held Tuesday's meeting to discuss draft recommendations to better coordinate with the private sector to respond to attacks. It recommends bringing the electricity sector together with Wall Street and the financial and telecommunications sectors to better coordinate their preparations for an attack.

Administration officials at the meeting said Trump supports the idea and is endorsing the involvement of Wall Street and the telecom sector in an electric grid attack exercise slated for November called Grid-X. Industry officials at the meeting expressed concern that without a coordinated and proactive government response to the threat of a cyberattack on the energy grid and other sectors, the nation is at risk of an attack akin to the Sept. 11, 2001, terrorist attacks.