X0508 4 2025-12-04 0 0001421517 Energy Recovery, Inc. ERII 0001430122 Hanstveit Arve C/O ENERGY RECOVERY, INC. 1717 DOOLITTLE DRIVE SAN LEANDRO CA 94577 1 0 0 0 0 Common Stock 2025-12-04 4 S 0 15000 14.967 D 640220 D Common Stock 2025-12-05 4 S 0 15000 14.707 D 625220 D Common Stock 60000 I Sophie Hanstveit Irrevocable Trust Common Stock 60000 I Natasha Hanstveit Irrevocable Trust This amount represents the weighted average sales price of multiple trades ranging from $14.96 to $14.972 per share. The reporting person undertakes to provide the SEC Staff, Energy Recovery, Inc. or a shareholder of Energy Recovery, Inc. full information about the number of shares sold at each separate price upon request. This amount represents the weighted average sales price of multiple trades ranging from $14.64 to $14.753 per share. The reporting person undertakes to provide the SEC Staff, Energy Recovery, Inc. or a shareholder of Energy Recovery, Inc. full information about the number of shares sold at each separate price upon request. Mr. Hanstveit is sole trustee and exercises sole voting and investment power. Exhibit 24 /s/ William Yeung Attorney-in-fact for Arve Hanstveit 2025-12-08