X0306 4 2019-03-01 0000742126 US ECOLOGY, INC. ECOL 0001369458 Feeler Jeffrey R 101 S. CAPITOL BLVD. SUITE 1000 BOISE ID 83702 1 1 President & CEO Performance Stock Units 2019-03-01 4 A 0 6592 0 A 2021-12-31 Common Stock 6592 6592 D Each performance stock unit ("PSU") represents a contingent right to receive 1 share of US Ecology, Inc. Common Stock. The number of shares reported represents the target number of shares underlying the PSUs. The actual number of shares to be delivered in settlement of the PSUs earned during the performance period will be based on achievement of established targets with respect to the Company's Adjusted Earnings Per Share and Return on Invested Capital, each weighted at 50% of the target PSUs. After the payout under the PSUs is determined, the number of shares to be provided is subject to modification based on the percentage change in the price of the Company's common stock from January 1, 2019 to December 31, 2021, relative to the percentage change in the price of the common stock of certain peer group companies. The PSUs will settle as soon as practicable after December 31, 2021. /s/ Jeffrey R. Feeler 2019-03-05