0001437749-20-010824 4 1 20200512 20200514 20200514 Lorentzen Ole Peter 0001429459 4 34 001-34112 20879867 POSTBOKS A, BYGD0Y OSLO Q8 0211 Energy Recovery, Inc. 0001421517 3559 010616867 DE 1231 1717 DOOLITTLE DRIVE SAN LEANDRO CA 94577 (510) 483-7370 1717 DOOLITTLE DRIVE SAN LEANDRO CA 94577 4 1 rdgdoc.xml FORM 4 X0306 4 2020-05-12 0001421517 Energy Recovery, Inc. ERII 0001429459 Lorentzen Ole Peter C/O ENERGY RECOVERY, INC. 1717 DOOLITTLE DRIVE SAN LEANDRO CA 94577 1 Common Stock 2020-05-12 4 S 0 1500000 7.52 D 6840334 I See Note The filing persons of this Form 4 are Ole Peter Lorentzen and Ludvig Lorentzen AS. Mr. Lorentzen is the controlling shareholder of Ludvig Lorentzen AS. The sale reported on this Form 4 was made pursuant to a registration statement on Form S-3 (File No. 333-233730). After giving effect to the sale reported on this Form 4, the shares of common stock beneficially owned by Mr. Lorentzen include 6,400,000 shares of common stock held by Ludvig Lorentzen AS and 440,334 shares of common stock held in other accounts controlled by Mr. Lorentzen. The filing persons disclaim beneficial ownership of the securities reported on this Form 4 except to the extent of their pecuniary interest therein. /s/ Ole Peter Lorentzen 2020-05-14