X0306 4 2020-01-10 0001783400 US Ecology, Inc. ECOL 0001409319 Gerratt Eric L 101 S. CAPITOL BLVD. SUITE 1000 BOISE ID 83702 1 EVP and CFO Common Stock 2020-01-10 4 M 0 1182 0 A 33135 D Common Stock 2020-01-10 4 F 0 3529 57.49 D 29606 D Performance Stock Units 0 2020-01-10 4 M 0 1182 0 D 2019-12-31 Common Stock 1182 0 D The number of shares reported represents the shares earned during the three year performance period ending December 31, 2019 (as calculated on January 10, 2020) based on US Ecology Inc.'s total shareholder return relative to the S&P 600 (weighted at 50%) and a peer group of certain companies in the environmental and facilities industry (weighted at 50%). The target number of shares available was 2,000 and the maximum number of shares available was 4,000 or 200% of target. Date on which the number of shares to be withheld was determined upon election of the reporting person. Number of shares withheld was determined based on the closing price of US Ecology, Inc. common stock on December 31, 2019 and January 10, 2020 . Price indicated is a weighted average of the closing price of stock; 2,878 shares at $57.91 per share and 651 shares at $55.65 per share. /s/ Wayne Ipsen, power of attorney 2020-01-14