1 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 1)* Clean Harbors, Inc. ______________________________________________________________________ (Name of Issuer) Common Stock, $.01 Par Value ______________________________________________________________________ (Title of Class of Securities) 184496107 ______________________________________________________________________ (CUSIP Number) August 1, 2003 ______________________________________________________________________ (Date of Event Which Requires Filing of This Statement) Check the appropriate box to designate the rule pursuant to which this Schedule is filed: [x] Rule 13d-1(b) [ ] 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). Page 1 of 8 Pages

2 CUSIP No. 184496107 13G Page 2 of 8 Pages 1 NAME OF REPORTING PERSON S.S. or I.R.S. IDENTIFICATION NO. OF ABOVE PERSON William D. Witter, Inc. F13-2879276 _____________________________________________________________________ 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* (a) [ ] (b) [ ] _____________________________________________________________________ 3 SEC USE ONLY _____________________________________________________________________ 4 CITIZENSHIP OR PLACE OF ORGANIZATION One Citicorp Center 153 East 53rd Street New York, New York 10022-4611 NUMBER OF 5 SOLE VOTING POWER SHARES 551,300 ------------------------------------------------ BENEFICIALLY 6 SHARED VOTING POWER OWNED BY 0 ------------------------------------------------ EACH 7 SOLE DISPOSITIVE POWER REPORTING 601,500 ------------------------------------------------ PERSON WITH 8 SHARED DISPOSITIVE POWER 0 _____________________________________________________________________ 9 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 601,500 _____________________________________________________________________ 10 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* [ ] _____________________________________________________________________ 11 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9 4.5% _____________________________________________________________________ 12 TYPE OF REPORTING PERSON IA

3 CUSIP No. 184496107 13G Page 3 of 8 Pages 1 NAME OF REPORTING PERSON S.S. or I.R.S. IDENTIFICATION NO. OF ABOVE PERSON Mary R. Donnelly F13-2879276 _____________________________________________________________________ 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* (a) [ ] (b) [X] _____________________________________________________________________ 3 SEC USE ONLY _____________________________________________________________________ 4 CITIZENSHIP OR PLACE OF ORGANIZATION One Citicorp Center 153 East 53rd Street New York, New York 10022-4611 _____________________________________________________________________ NUMBER OF 5 SOLE VOTING POWER SHARES 551,300 ------------------------------------------------ BENEFICIALLY 6 SHARED VOTING POWER OWNED BY 0 ------------------------------------------------ EACH 7 SOLE DISPOSITIVE POWER REPORTING 601,500 ------------------------------------------------ PERSON WITH 8 SHARED DISPOSITIVE POWER 0 _____________________________________________________________________ 9 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 601,500 _____________________________________________________________________ 10 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* [ ] _____________________________________________________________________ 11 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9 4.5% _____________________________________________________________________ 12 TYPE OF REPORTING PERSON IN

4 SCHEDULE 13G Page 4 of 8 Pages Item 1(a) Name of Issuer: Clean Harbors,Inc. Item 1(b) Address of Issuer's Principal Executive Offices: 1501 Washington Street Braintree, Massachusetts 02184 Item 2(a) Names of Persons Filing: William D. Witter, Inc. Mary R. Donnelly Item 2(b) Address of Principal Business Office: 153 East 53rd Street 51st Floor New York, New York 10022 Item 2(c) Citizenship: New York Item 2(d) Title of Class of Securities: Common Stock Item 2(e) CUSIP Number: 184496107

5 SCHEDULE 13G Page 5 of 8 Pages Item 3 If This Statement is Filed Pursuant to Rule 13d-1(b), or 13d-2(b) or (c), Check Whether the Person Filing is a: (a) [ ] Broker or dealer registered under Section 15 of the Exchange Act. (b) [ ] Bank as defined in Section 3(a)(6) of the Exchange Act. (c) [ ] Insurance company as defined in Section 3(a)(19) of the Exchange Act. (d) [ ] Investment company registered under Section 8 of the Investment Company Act. (e) [X] An investment adviser in accordance with Rule 13d-1(b)(1)(ii)(E); (f) [ ] An employee benefit plan or endowment fund in accordance with Rule 13d-1(b)(1)(ii)(F); (g) [ ] A parent holding company or control person in accordance with Rule 13d-1(b)(1)(ii)(G); (h) [ ] A savings association as defined in Section 3(b) of the Federal Deposit Insurance Act; (i) [ ] A church plan that is excluded from the definition of an investment company under Section 3(c)(14) of the Investment Company Act; (j) [ ] Group,in accordance with Rule 13d-1(b)(1)(ii)(J). If this statement is filed pursuant to rule 13d-1(c), check this box [ ] See Exhibit A attached hereto.

6 SCHEDULE 13G Page 6 of 8 Pages Item 4 Ownership: Provide the following information regarding the aggregate number and percentage of the class of securities of the issuer identified in Item 1. (a) Amount Beneficially Owned: 601,500 (b) Percent of Class: 4.5% (c) Number of Shares as to Which such Person has: (i) Sole power to vote or direct the vote 551,300 (ii) Shared power to vote or to direct the vote 0 (iii) Sole power to dispose or to direct the disposition of 601,500 (iv) Shared power to dispose or to direct the disposition of 0 Item 5 Ownership of Five Percent or Less of a Class: 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] Item 6 Ownership of More than Five Percent on Behalf of Another Person: The shares owned directly by Witter, Inc. are held on behalf of various clients of the firm. These clients have the right to receive or power to direct the receipt of dividends from, or the proceeds, from the sale of, such securities. Item 7 Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company: See Exhibit A attached hereto. Item 8 Identification and Classification of Members of a Group: Not applicable Item 9 Notice of Dissolution of Group: Not applicable

7 SCHEDULE 13G Page 7 of 8 Pages Item 10 Certification: By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and 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 such securities and were not acquired and are not held in connection with or as a participant in any transaction having such purpose or effect. 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. Date: August 5, 2003 WILLIAM D. WITTER, INC. By:/s/ MARY R. DONNELLY Mary R. Donnelly Secretary

8 SCHEDULE 13G Page 8 of 8 Pages EXHIBIT A This Exhibit explains the relationship between the Reporting Persons. William D. Witter, Inc. is a New York corporation registered as an investment adviser under the Advisers Act. Witter, Inc. serves as an investment adviser for individuals and institutions. Mary R. Donnelly is the Secretary of William D. Witter, Inc.