MODIFICATION IN TERMS AGREEMENT

EXHIBIT 10(t)

MODIFICATION IN TERMS AGREEMENT

THIS MODIFICATION IN TERMS AGREEMENT (the “Modification”), dated as of April 27, 2004 (the “Effective Date”), is entered into by and among MPW Industrial Services Group, Inc. (“MPW Group”), each of the other Subsidiaries of MPW Group listed on the Schedule of Subsidiary Borrowers attached hereto, the Lenders listed on the signature pages of this Modification, and Bank One, NA, [Main Office Columbus], as Administrative Agent and LC Issuer.

Background Information

A. Borrowers, Lenders, Administrative Agent and LC Issuer entered into a certain Credit Agreement, dated as of June 18, 2002 (the “Agreement”).

B. Lenders have agreed to extend Revolving Loans to Borrowers in the maximum principal amount of $35,000,000, including a sublimit for LC Obligations in the maximum amount of $5,000,000 (the “Facility LC Sublimit”), pursuant to the Agreement.

C. Borrowers have requested that the LC Issuer issue a Facility LC in the amount of $1,0500,000 to Zurich North America (the “ZNA Facility LC”), but there currently is not sufficient availability under the Facility LC Sublimit for the issuance of the ZNA Facility LC.

D. Borrowers have requested that the Facility LC Sublimit be increased temporary to $5,833,006.00 in order to allow for the issuance of the ZNA Facility LC, and the Lenders are willing to consent to the same, pursuant to the terms and conditions as set forth herein.

Provisions

NOW, THEREFORE, in consideration of their mutual agreements hereunder and under the Agreement, and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, Borrowers, Lenders and LC Issuer hereby agree as follows:

1. Capitalized Terms. Except as otherwise defined herein, the capitalized terms used herein shall have the same meanings as set forth in the Agreement.

2. Modification of Terms. (a) The Facility LC Sublimit shall be increased temporarily from $5,000,000 to $ 5,833,006 in order to allow for the issuance of the ZNA Facility LC, and the LC Issuer is authorized to issue the ZNA Facility LC which shall otherwise be subject to all provisions of the Agreement with respect to the issuance of Facility LCs.

(b) In connection with the issuance of the ZNA Facility LC, the aggregate amount of the outstanding LC Obligations shall not exceed $ 5,833,006.00.

(c) The maximum of the Aggregate Outstanding Revolving Credit Exposure, including the Facility LC Sublimit as so increased temporarily, shall remain at $35,000,000.00.

(d) Upon the first to occur of the following events: (i) the ZNA Facility LC is terminated, cancelled or otherwise returned to the LC Issuer without having been drawn upon, (ii) the stated amount of the ZNA Facility LC is reduced to the extent that the then outstanding LC Obligations do not exceed $5,000,000, or (iii) the outstanding LC Obligations do not then otherwise exceed $5,000,000, the temporary increase in the Facility LC Sublimit provided by subsection (a) and (b) of this Section 2 shall terminate, the Facility LC Sublimit shall again not exceed $5,000,000 and outstanding LC Obligations thereafter shall not exceed $5,000,000.00.

3. Conditions to Lender’s Obligations. The agreement of Lenders and LC Issuer to enter into this Modification, and for Lenders and LC Issuer to be bound by the terms hereof, are subject to the satisfaction of the following conditions precedent:

(a) Delivery of Documents. On or prior to the Effective Date, Administrative Agent shall have received such certificates, documents and other items as Administrative Agent, in its reasonable discretion, deems necessary or desirable.

(b) Representations and Warranties. The representations and warranties made by Borrowers in this Modification shall be true and correct in all material respects as of the date of this Modification.

4. Exhibits and Schedules. Each Borrower confirms and warrants that the information set forth in all schedules and exhibits to the Agreement is true, accurate and complete as of the date hereof.

5. Representations and Warranties; No Defaults. Each Borrower hereby represents and warrants to Lenders, LC Issuer and Administrative Agent that the following are true and correct as of the date of this Modification:

(a) the representations and warranties of each Borrower contained in the Agreement are true and correct on and as of the date of this Modification as if made on and as of such date, unless stated to relate to a specific earlier date, in which case they were true, correct and complete in all material respects on and as of such earlier date;

(b) all financial statements and information of Borrowers provided to Administrative Agent and Lenders are true, accurate and complete in all material respects as of the date of, and for the periods covered by, such financial statements and information;

(c) neither this Modification nor any other document, certificate or written statement furnished to Administrative Agent and/or Lenders or to special counsel to Administrative Agent by or on behalf of any Borrower in connection with the transactions contemplated hereby contains any untrue statement of a material fact or omits to state a material fact necessary in order to make the statements contained herein and therein not misleading;

(d) each Borrower has full power and authority (i) to execute, deliver and perform this Modification, and (ii) to incur the obligations provided for herein and therein, all of which have been duly authorized by all necessary and proper action by each Borrower;

(e) no consent, waiver or authorization of, or filing with, any person, entity or governmental authority is required to be made or obtained by any Borrower in connection with the execution, delivery, performance, validity or enforceability of this Modification;

(f) this Modification constitutes the legal, valid and binding obligation of Borrowers, enforceable against Borrowers in accordance with its terms;

(g) giving effect to the changes to the Agreement contemplated by this Modification, no Unmatured Default nor Default has occurred and is continuing;

(h) no event has occurred which would have a Material Adverse Effect; and

&n