Energy Recovery (ERII) director sells 25,000 shares in open market

Rhea-AI Filing Summary

Energy Recovery, Inc. director Arve Hanstveit reported an open‑market sale of 25,000 shares of common stock on March 10, 2026 at a weighted average price of $10.959 per share, with trades ranging from $10.83 to $11.11.

After the sale, he holds 550,220 shares directly. He also has indirect holdings of 60,000 shares in the Sophie Hanstveit Irrevocable Trust and 60,000 shares in the Natasha Hanstveit Irrevocable Trust, where he serves as sole trustee with sole voting and investment power.

Insights

Equity ownership & governance analyst

Director executes modest open‑market sale while retaining substantial stake.

Director Arve Hanstveit sold 25,000 shares of Energy Recovery, Inc. common stock on March 10, 2026 in an open‑market transaction at a weighted average price of $10.959 per share, based on multiple trades between $10.83 and $11.11.

Following the sale, he still directly owns 550,220 shares. In addition, there are indirect holdings of 60,000 shares for each of two irrevocable trusts, for which he is sole trustee with sole voting and investment power. This indicates he maintains a sizable overall position despite the net share reduction.

The filing shows no derivative positions and characterizes the activity as an open‑market sale rather than option exercises or tax‑related dispositions. Subsequent ownership reports may further clarify any changes in his direct and trust holdings over time.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
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hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Hanstveit Arve

(Last) (First) (Middle)

C/O ENERGY RECOVERY, INC.

1717 DOOLITTLE DRIVE

(Street)

SAN LEANDRO CA 94577

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Energy Recovery, Inc. [ ERII ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
	Officer (give title below)		Other (specify below)

3. Date of Earliest Transaction (Month/Day/Year)
03/10/2026

4. 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 Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	03/10/2026		S		25,000	D	$10.959(1)	550,220	D
Common Stock								60,000	I	Sophie Hanstveit Irrevocable Trust(2)
Common Stock								60,000	I	Natasha Hanstveit Irrevocable Trust(2)

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. This amount represents the weighted average sales price of multiple trades ranging from $10.83 to $11.11 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.

2. Mr. Hanstveit is sole trustee and exercises sole voting and investment power.

Remarks:

Exhibit 24

	/s/ William Yeung Attorney-in-fact for Arve Hanstveit	03/11/2026
	** 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 4 (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.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What did Energy Recovery (ERII) director Arve Hanstveit report in this Form 4?

Director Arve Hanstveit reported selling 25,000 shares of Energy Recovery common stock in an open‑market transaction. The sale occurred on March 10, 2026, at a weighted average price of $10.959 per share, based on multiple trades within a disclosed price range.

At what price did Arve Hanstveit sell Energy Recovery (ERII) shares?

The shares were sold at a weighted average price of $10.959 per share. The filing notes that individual trades occurred between $10.83 and $11.11 per share, and detailed trade‑by‑trade information is available from the reporting person upon request.

How many Energy Recovery (ERII) shares does Arve Hanstveit own after the sale?

After the sale, Arve Hanstveit directly owns 550,220 shares of Energy Recovery common stock. He also has indirect interests in 60,000 shares held by the Sophie Hanstveit Irrevocable Trust and 60,000 shares held by the Natasha Hanstveit Irrevocable Trust, as sole trustee for both.

What type of transaction was reported in this Energy Recovery (ERII) Form 4?

The Form 4 reports an open‑market sale of common stock, coded as “S” for a sale in an open market or private transaction. There were no option exercises, gifts, or tax‑withholding dispositions disclosed alongside this transaction in the filing data provided.

What authority does Arve Hanstveit have over the Energy Recovery (ERII) shares held in the trusts?

The filing states that Mr. Hanstveit is the sole trustee of the Sophie and Natasha Hanstveit Irrevocable Trusts. He exercises sole voting and investment power over the shares held in these trusts, giving him control over how those trust shares are voted and managed.

Does this Energy Recovery (ERII) Form 4 mention any derivative or option positions?

The filing data provided does not list any derivative or option transactions for this date. The derivative summary is empty, and the only reported activity is the sale of 25,000 shares of common stock, along with updated direct and indirect share ownership totals.