United States securities and exchange commission logo September 6, 2022 Joshua Ballard Chief Financial Officer Energy Recovery, Inc. 1717 Doolittle Drive San Leandro, CA 94577 Re: Energy Recovery, Inc. Form 10-K for the Year Ended December 31, 2021 Form 8-K filed August 3, 2022 File No. 001-34112 Dear Mr. Ballard: We have completed our review of your filings. We remind you that the company and its management are responsible for the accuracy and adequacy of their disclosures, notwithstanding any review, comments, action or absence of action by the staff. Sincerely, Division of Corporation Finance Office of Real Estate & Construction