Schedule 13G Filing by Daniel Kaufman

Daniel Kaufman has acquired a 5.12% stake in Arq, representing 2,191,278 shares. This filing, dated March 12, 2026, with an event date of March 11, 2026, indicates that Kaufman holds sole voting and dispositive power over these shares. The principal business office for Kaufman is located in San Juan, Puerto Rico, while Arq's principal executive office is in Greenwood Village, Colorado. Kaufman certifies that these shares were not acquired for the purpose of influencing the control of Arq.