1
                                                              Exhibit 10(a)
                              AMENDMENT NUMBER ONE
                                     TO THE
                    OHM CORPORATION RETIREMENT SAVINGS PLAN
              (AS AMENDED AND RESTATED EFFECTIVE JANUARY 1, 1994)


                 WHEREAS, OHM Corporation (the "Company") previously adopted
the OHM Corporation Retirement Savings Plan (the "Plan"); and

                 WHEREAS, Article 15.1 of the Plan provides that the Company
may amend the Plan at any time.

                 NOW, THEREFORE, the Company hereby amends the Plan to read as
follows:

                                       I.

                 Effective June 1, 1995, Section 1.40 of the Plan is hereby
amended by adding the following sentence at the end thereof:

                 With the approval of the Plan Committee, Years of Service will
                 be credited to an Employee for service with an entity that is
                 acquired by the Employer to the extent and for the purposes
                 listed on Schedule A to the Plan.


                                      II.

                 Effective June 1, 1995, Section 3.11 of the Plan is hereby
amended to read as follows:

                          3.11    Elective Transfers.  The Plan may accept an
                 elective transfer of assets from another qualified plan if the
                 following provisions are satisfied.

                                  (a)      The person electing the transfer
                 must become an Employee as the result of a corporate
                 transaction for which the Committee deems this provision
                 should be applicable.

                                  (b)      The plan from which the benefits are
                 transferred must provide that the transfer is conditioned upon
                 a voluntary, fully informed election by the participant to
                 transfer such participant's benefit to this Plan.

                                  (c)      The plan from which the benefits are
                 transferred must either offer the participant the opportunity
                 to leave his or her assets in that plan or must terminate and
                 make a distribution of all appropriate benefits.





   2
                                  (d)      Any spousal consent requirements or
                 notice requirements imposed on the elective transfer by the
                 Code must be satisfied.

                                  (e)      The Employee who elects the transfer
                 must be eligible under the terms of the transferor plan to
                 receive an immediate distribution from that plan.

                                  (f)      The amount of the benefit
                 transferred must equal the entire nonforfeitable accrued
                 benefit under the plan of the participant whose benefit is
                 transferred and the Employee shall be fully vested in the
                 transferred benefit under this Plan.

                                      III.

                 Effective June 1, 1995, Section 4.1 of the Plan is hereby
amended by adding the following sentence to the end thereof:

                 Matching Employer Contributions may be made, at the discretion
                 of the Company, in the form of Company Stock.

                                      IV.

                 Effective June 1, 1995, Section 5.5 of the Plan is hereby
amended to read as follows:

                          5.5     Investment Options.  All Profit Sharing
                 Contributions will be invested by the Trustee at the direction
                 of the Committee.  All Matching Employer Contributions made in
                 the form of Company Stock will be initially invested in the
                 Company Stock Fund.  Each Participant will, by written
                 direction to the Committee, direct that all Before-Tax
                 Contributions, After-Tax Contributions, Matching Employer
                 Contributions (other than Matching Employer Contributions made
                 in the form of Company Stock) and Rollover Contributions made
                 by or for the Participant be invested in one or more of the
                 Investment Funds in multiples of 5%.  An investment option
                 selected by a Participant will remain in effect and be
                 applicable to all subsequent Before-Tax Contributions,
                 After-Tax Contributions, Matching Employer Contributions
                 (other than Matching Employer Contributions made in the form
                 of Company Stock) and Rollover Contributions made by or for
                 the Participant unless and until an investment change is made
                 by the Participant and becomes effective pursuant to Section
                 5.6.  In the absence of an effective investment direction,
                 Before-Tax Contributions, After-Tax Contributions, Matching
                 Employer Contributions (other than Matching Employer



                                       2

   3
                 Contributions made in the form of Company Stock) and Rollover
                 Contributions made to the Trust by or for a Participant will
                 be invested in a fixed income fund or its equivalent
                 maintained pursuant to Section 5.1.

                                       V.

                 Effective June 1, 1995, Section 5.6 of the Plan is hereby
amended to read as follows:

                          5.6     Change of Investment Option.  Subject to any
                 limitation imposed by the terms of an Investment Fund, a
                 Participant may, as of any Enrollment Date, upon at least 15
                 days prior written notice filed with the Committee, change his
                 or her investment option to any other option specified in
                 Section 5.5 with respect to all subsequent Before-Tax
                 Contributions, After-Tax Contributions, Matching Employer
                 Contributions (other than Matching Employer Contributions made
                 in the form of Company Stock) and Rollover Contributions made
                 by or for the Participant.  In addition, subject to any
                 limitation imposed by the terms of an Investment Fund, a
                 Participant may, as of any Enrollment Date, upon at least 15
                 days prior written notice filed with the Committee, change his
                 or her investment option to any other option specified in
                 Section 5.5 with respect to all previous Before-Tax
                 Contributions, After-Tax Contributions, Matching Employer
                 Contributions (including Matching Employer Contributions made
                 in the form of Company Stock) and Rollover Contributions made
                 by or for the Participant.


                 Executed this 1st day of June, 1995.


                                             OHM Corporation


                                             /s/ RANDALL M. WALTERS
                                             -----------------------------------
                                             By: Randall M. Walters
                                                 Vice President, General Counsel
                                                 and Secretary


                                       3