X0306 4 2020-03-13 0 0001136294 Williams Industrial Services Group Inc. WLMS 0001017043 OBUS NELSON 450 SEVENTH AVENUE SUITE 509 NEW YORK NY 10123 1 0 1 0 Common Stock, $0.01 par value per share 2020-03-13 4 A 0 73171 0 A 219838 D Common Stock, $0.01 par value per share 5768581 I See Footnote As of the date of this Form 4, Mr. Obus is (i) a principal executive officer of Wynnefield Capital, Inc., which is the sole investment manager of Wynnefield Small Cap Value Offshore Fund, Ltd., which beneficially owns 1,556,864 shares of the issuer's common stock; (ii) a co-managing member of Wynnefield Capital Management, LLC, which is the sole general partner of Wynnefield Partners Small Cap Value, L.P. I, which beneficially owns 2,099,160 shares of the issuer's common stock, and the sole general partner of Wynnefield Partners Small Cap Value, L.P., which beneficially owns 1,859,983 shares of the issuer's common stock; and (iii) a co-trustee of Wynnefield Capital, Inc. Profit Sharing & Money Purchase Plan, which beneficially owns 252,574 shares of the issuer's common stock. Mr. Obus disclaims beneficial ownership of the securities described in this footnote except to the extent of his pecuniary interest. Consists of restricted shares granted under the 2015 Equity Incentive Plan, as amended and restated, all of which will vest on March 13, 2021. The vesting of the grant disclosed herein is subject to continued service as a director through the vesting and accelerated vesting in the event of certain terminations. Any shares that do not vest will be forfeited. /s/ Charles E. Wheelock for Nelson Obus by Power of Attorney 2020-03-17