Empirically, there’s no impact to an attack on the grid
James Lewis, 2020 – Senior Vice President and Director, Strategic Technologies Program at the Center for Strategic and International Studies, “Dismissing Cyber Catastrophe” https://www.csis.org/analysis/dismissing-cyber-catastrophe //DH
It is easier to imagine a catastrophe than to produce it. The 2003 East Coast blackout is the archetype for an attack on the U.S. electrical grid. No one died in this blackout, and services were restored in a few days. As electric production is digitized, vulnerability increases, but many electrical companies have made cybersecurity a priority. Similarly, at water treatment plants, the chemicals used to purify water are controlled in ways that make mass releases difficult. In any case, it would take a massive amount of chemicals to poison large rivers or lakes, more than most companies keep on hand, and any release would quickly be diluted.