UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13G

Under the Securities Exchange Act of 1934
(Amendment No. ___)*

Energy Recovery, Inc.

(Name of Issuer)

Common Stock, $0.001 par value

(Title of Class of Securities)

29270J100

(CUSIP Number)

October 18, 2021

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

[ ]       Rule 13d-1(b)

[X]       Rule 13d-1(c)

[ ]       Rule 13d-1(d)

* The remainder of this cover page shall be filled out for a reporting person's initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter the disclosures provided in a prior cover page.

The information required in the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

Potential persons who are to respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number.

3. SEC Use Only

3. SEC Use Only

Item 1.

Item 2.

The Filers are filing this Schedule 13G jointly but not as members of a group, and each disclaims membership in a group. Each of the Filers disclaims beneficial ownership of the Stock (as defined in section (d) below), except to the extent of that person’s pecuniary interest therein.

Prior to October 18, 2021, Mr. Skaugen was included as a joint filer on a Schedule 13G filed by Arvarius AS to report beneficial ownership of Stock of the Issuer. On October 18, 2021, Arvarius AS distributed all Stock of the Issuer held by it to its investors, including Haut Brion AS, for no consideration. As a result, Arvarius AS filed an amendment to its Schedule 13G to report that it is no longer a beneficial owner of the Issuer’s Stock, and Mr. Skaugen and Haut Brion AS are separately filing this Schedule 13G to report their beneficial ownership of the Issuer’s Stock.

On October 18, 2021, the Filers acquired 4,421,974 shares of the Stock, representing 7.8% of the outstanding Stock. The Filers subsequently disposed of shares of the Stock and have ceased to own more than 5% of the Stock. In addition, Haut Brion has distributed its remaining shares of the Stock to its investors, including Mr. Skaugen. This Schedule 13G reports the Filers’ ownership of the Stock as of the date of filing.

If filing as a non-U.S. institution in accordance with §240.13d-1(b)(1)(ii)(J), please specify the type of institution _______________________________________________________________.

See Items 5-9 and 11 of the cover page.

The percentages reported in this Schedule 13G are based on 56,718,626 shares of the Issuer’s common stock outstanding as of October 29, 2021, as reported in the Issuer’s Form 10-Q filed on November 5, 2021.

If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than five percent of the class of securities, check the following [ X ].

Not applicable.

Not applicable.

Not applicable

Not applicable.

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under § 240.14a-11.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Dated: December 9, 2021

EXHIBIT A

AGREEMENT REGARDING JOINT FILING

OF STATEMENT ON SCHEDULE 13D OR 13G

The undersigned agree to file jointly with the Securities and Exchange Commission (the "SEC") any and all statements on Schedule 13D or Schedule 13G and Forms 3, 4 or 5 (and any amendments or supplements thereto) required under section 13(d) or 16(a) of the Securities Exchange Act of 1934, as amended, in connection with purchases by the undersigned of the securities of any issuer. For that purpose, the undersigned hereby constitute and appoint Marius Skaugen as their true and lawful agent and attorney-in-fact, with full power and authority for and on behalf of the undersigned to prepare or cause to be prepared, sign, file with the SEC and furnish to any other person all certificates, instruments, agreements and documents necessary to comply with section 13(d) and section 16(a) of the Securities Exchange Act of 1934, as amended, in connection with said purchases, and to do and perform every act necessary and proper to be done incident to the exercise of the foregoing power, as fully as the undersigned might or could do if personally present.

Dated: December 9, 2021