SEC Form 3

FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person* Arvarius AS (Last) (First) (Middle) C/O ENERGY RECOVERY, INC. 1908 DOOLITTLE DR. (Street) SAN LEANDRO CA 94557 (City) (State) (Zip)	2. Date of Event Requiring Statement (Month/Day/Year) 07/01/2008	3. Issuer Name and Ticker or Trading Symbol Energy Recovery, Inc. [ ERII ]
		4. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director X 10% Owner Officer (give title below) Other (specify below)	5. If Amendment, Date of Original Filed (Month/Day/Year)
			6. Individual or Joint/Group Filing (Check Applicable Line) X Form filed by One Reporting Person Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)
Common Stock	10,122,411	D

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Warrant (Right to Buy)	(1)	05/15/2012	Common Stock	400,000	0.2	D
Warrant (Right to Buy)	(2)	09/27/2012	Common Stock	70,000	0.2	D
Warrant (Right to Buy)	(3)	11/08/2012	Common Stock	130,000	0.2	D
Warrant (Right to Buy)	(4)	12/15/2012	Common Stock	208,000	0.2	D
Warrant (Right to Buy)	(5)	12/06/2012	Common Stock	90,000	0.2	D
Warrant (Right to Buy)	(6)	12/16/2012	Common Stock	170,000	0.2	D
Warrant (Right to Buy)	(7)	03/11/2013	Common Stock	36,122	0.2	D
Warrant (Right to Buy)	(8)	12/05/2013	Common Stock	200,000	0.5	D
Warrant (Right to Buy)	(9)	07/31/2014	Common Stock	400,000	1	D
Warrant (Right to Buy)	(10)	07/31/2015	Common Stock	200,000	1	D

Explanation of Responses:

1. All shares exercisable as of the warrant date of 05/15/02.

2. All shares exercisable as of the warrant date of 09/27/02.

3. All shares exercisable as of the warrant date of 11/08/02.

4. All shares exercisable as of the warrant date of 12/15/02.

5. All shares exercisable as of the warrant date of 12/06/02.

6. All shares exercisable as of the warrant date of 12/16/02.

7. All shares exercisable as of the warrant date of 03/11/03.

8. All shares exercisable as of the warrant date of 12/05/03.

9. All shares exercisable as of the warrant date of 07/31/04

10. All shares exercisable as of the warrant date of 07/31/05.

Remarks:

The Date of Event is based upon the date of effectiveness of the Issuer's Registration Statement on Form S-1 filed in connection with the Issuer's initial public offering, estimated to be on or about July 1, 2008.

	/s/ Thomas Willardson Attorney-in-Fact for Arvarius AS	07/01/2008
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 5 (b)(v).
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