This legislation empowers private owners and operators of critical infrastructure facilities to independently detect, track, and mitigate threats from unmanned aircraft systems (UAS). It addresses a current gap where only federal agencies and trained law enforcement possess such authority, despite growing UAS threats to vital sectors like the electric grid. The bill amends the Homeland Security Act of 2002 to allow designated security personnel or contractors to take necessary actions against credible UAS threats to covered facilities, which include high-risk sites like nuclear generating stations and key bulk power system components. To exercise this authority, personnel must undergo rigorous training and certification by the Secretary of Homeland Security, in coordination with other agencies. A national certification program will establish standards for legal, operational, and technical proficiency, mandate the use of authorized counter-UAS technologies, and require coordination with the Federal Aviation Administration. The bill also establishes a grant program to help critical infrastructure owners purchase and operate approved counter-UAS systems, and provides liability protection for authorized actions, except in cases of gross negligence or willful misconduct. This authority is set to terminate on September 30, 2031.