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                                   EXHIBIT 15


                    Letter Re Unaudited Financial Information


Board of Directors and Shareholders
OHM Corporation

We are aware of the incorporation by reference into the Registration Statements
(Form S-8 No. 33-12099, Form S-8 No. 33-28025, Form S-8 No. 33-24953, Form S-8
No. 33-55371, Form S-8 No. 33-55373, Form S-8 No. 33-63233, Form S-8 No.
333-15141 and Form S-8 No. 333-21227) of OHM Corporation of our report dated
October 29, 1997, relating to the unaudited consolidated interim financial
statements of OHM Corporation which are included in its Form 10-Q for the
quarter ended September 30, 1997.

Pursuant to Rule 436(c) of the Securities Act of 1933, our report is not a part
of the registration statement prepared or certified by accountants within the
meaning of Section 7 or 11 of the Securities Act of 1933.



Ernst & Young LLP

Columbus, Ohio
October 29, 1997