SEC FORM 3

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^*

Ross MariaElena

(Last)

(First)

(Middle)

C/O ENERGY RECOVERY, INC.

1908 DOOLITTLE DR.

(Street)

SAN LEANDRO

94577

(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	10% Owner
X	Officer (give title below)	Other (specify below)
VP of Admin & Human Resources

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)

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)
1. Title of Derivative Security (Instr. 4)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	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)
Employee Stock Option (Right to Buy)	⁽¹⁾	04/04/2015	Common Stock	40,000	1	D
Employee Stock Option (Right to Buy)	⁽²⁾	12/14/2015	Common Stock	45,000	1	D
Employee Stock Option (Right to Buy)	⁽³⁾	12/08/2016	Common Stock	30,000	2.65	D

Explanation of Responses:

1. All shares vest 1/4th on the 1 year anniversary of the vesting commencement date of 04/05/05 and 1/36th monthly thereafter.

2. All shares vest 1/4th on the 1 year anniversary of the vesting commencement date of 12/15/05 and 1/36th monthly thereafter.

3. All shares vest 1/4th on the 1 year anniversary of the vesting commencement date of 12/09/06 and 1/36th monthly thereafter.

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 MariaElena Ross	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).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
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