INTERNATIONAL TECHNOLOGY CORP, SC 13D/A, 1998-02-09

INTERNATIONAL TECHNOLOGY CORP
SC 13D/A, 1998-02-09
HAZARDOUS WASTE MANAGEMENT

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<PAGE>

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

-------------------------------

SCHEDULE 13D
Under the Securities Exchange Act of 1934

(AMENDMENT NO. 1)

INTERNATIONAL TECHNOLOGY CORPORATION
-------------------------------------
(Name of Issuer)

Common Stock, Par Value $.01 Per Share
--------------------------------------
(Title of Class of Securities)

CUSIP NUMBER
460465107
---------
(CUSIP Number)

Daniel A. D'Aniello
The Carlyle Group
1001 Pennsylvania Avenue, N.W.
Suite 220 South
Washington, D.C. 20004
(202) 347-2626
-------------------------------
(Name, Address and Telephone Number of Person
Authorized to Receive Notices and Communications)

Copies to:
Bruce E. Rosenblum, Esq.
Latham & Watkins
1001 Pennsylvania Avenue, N.W.
Suite 1300
Washington, D.C. 20004
(202) 637-2200

January 15, 1998
-------------------------------------------------------
(Date of Event which Requires Filing of this Statement)

If the filing person has previously filed a statement on Schedule 13G to report
the acquisition which is the subject of this Schedule 13D, and is filing this
statement because of Rule 13d-1(b)(3) or (4), check the following box: [ ]
<PAGE>

AMENDMENT NO. 1 TO SCHEDULE 13D

CUSIP NO. 460465107

1. NAME OF REPORTING PERSONS:

Carlyle Partners II, L.P.

IRS IDENTIFICATION NUMBER OF ABOVE PERSON:

51-1357731

2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) [ ]
(b) [X]
3. SEC USE ONLY

4. SOURCE OF FUNDS

5. CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS
REQUIRED PURSUANT TO ITEMS 2(d) OR 2(e) [ ]

6. CITIZENSHIP OR PLACE OF ORGANIZATION

Delaware

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH:

7. SOLE VOTING POWER: 0
---------
8. SHARED VOTING POWER: 6,430,334/1/
---------
9. SOLE DISPOSITIVE POWER: 0
---------
10. SHARED DISPOSITIVE POWER: (See Item 5(a)) 1,781,965
---------
11. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON:
6,430,334
---------
12. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11)
EXCLUDES CERTAIN SHARES [ ]

13. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 38.02%/2/
---------
14. TYPE OF REPORTING PERSON:

- -----------------------
/1/ Including (i) 1,471,673 shares receivable upon conversion of 11,170 Shares
of Cumulative Convertible Participating Preferred Stock, (ii) 310,292
shares receivable upon exercise of certain warrants, and (iii) shares
which may be deemed beneficially owned pursuant to the Agreements Among
Partnerships entered into by and among certain Reporting Persons. (See
item 5 and the previously-filed Schedule 13D.)

/2/ Percentage calculated based on 16,912,141 shares which are calculated as
described in Items 5(a).

1
<PAGE>

AMENDMENT NO. 1 TO SCHEDULE 13D

CUSIP NO. 460465107

1. NAME OF REPORTING PERSONS:

Carlyle Partners III, L.P.

IRS IDENTIFICATION NUMBER OF ABOVE PERSON:

51-0369721

2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) [ ]
(b) [X]
3. SEC USE ONLY

4. SOURCE OF FUNDS

5. CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS
REQUIRED PURSUANT TO ITEMS 2(d) OR 2(e) [ ]

6. CITIZENSHIP OR PLACE OF ORGANIZATION

Delaware

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH:

7. SOLE VOTING POWER: 0
---------
8. SHARED VOTING POWER: 6,430,334/1/
---------
9. SOLE DISPOSITIVE POWER: 0
---------
10. SHARED DISPOSITIVE POWER: (See Item 5(a)) 81,357
---------
11. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON:
6,430,334/1/
---------
12. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11)
EXCLUDES CERTAIN SHARES [ ]

13. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 38.02%/2/
---------
14. TYPE OF REPORTING PERSON:

- -----------------------
/1/ Including (i) 67,194 shares receivable upon conversion of 510 Shares of
Cumulative Convertible Participating Preferred Stock, (ii) 14,163 shares
receivable upon exercise of certain warrants, and (iii) shares which may
be deemed beneficially owned pursuant to the Agreements Among Partnerships
entered into by and among certain Reporting Persons. (See item 5 and the
previously-filed Schedule 13D.)

/2/ Percentage calculated based on 16,912,141 shares which are calculated as
described in Items 5(a).

2
<PAGE>

AMENDMENT NO. 1 TO SCHEDULE 13D

CUSIP NO. 460465107

1. NAME OF REPORTING PERSONS:

Carlyle International Partners II, L.P.

IRS IDENTIFICATION NUMBER OF ABOVE PERSON:

N/A

2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) [ ]
(b) [X]
3. SEC USE ONLY

4. SOURCE OF FUNDS

5. CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS
REQUIRED PURSUANT TO ITEMS 2(d) OR 2(e) [ ]

6. CITIZENSHIP OR PLACE OF ORGANIZATION

Cayman Islands

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH:

7. SOLE VOTING POWER: 0
---------
8. SHARED VOTING POWER: 1,504,210/1/
---------
9. SOLE DISPOSITIVE POWER: 0
---------
10. SHARED DISPOSITIVE POWER: (See Item 5(a)) 1,504,210
---------
11. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON:
1,504,210/1/
---------
12. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11)
EXCLUDES CERTAIN SHARES [ ]

13. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 8.89%/2/
---------
14. TYPE OF REPORTING PERSON:

- -----------------------
/1/ Including (i) 1,242,292 shares receivable upon conversion of 9,429 Shares
of Cumulative Convertible Participating Preferred Stock, and (ii) 261,918
shares receivable upon exercise of certain warrants. (See item 5 and the
previously-filed Schedule 13D.)

/2/ Percentage calculated based on 16,912,141 shares which are calculated as
described in Items 5(a).

3
<PAGE>

AMENDMENT NO. 1 TO SCHEDULE 13D

CUSIP NO. 460465107

1. NAME OF REPORTING PERSONS:

Carlyle International Partners III, L.P.

IRS IDENTIFICATION NUMBER OF ABOVE PERSON:

N/A

2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) [ ]
(b) [X]
3. SEC USE ONLY

4. SOURCE OF FUNDS

5. CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS
REQUIRED PURSUANT TO ITEMS 2(d) OR 2(e) [ ]

6. CITIZENSHIP OR PLACE OF ORGANIZATION

Cayman Islands

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH:

7. SOLE VOTING POWER: 0
---------
8. SHARED VOTING POWER: 81,042/1/
---------
9. SOLE DISPOSITIVE POWER: 0
---------
10. SHARED DISPOSITIVE POWER: (See Item 5(a)) 81,042
---------
11. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON:
81,042/1/
---------
12. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11)
EXCLUDES CERTAIN SHARES [ ]

13. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) .48%/2/
---------
14. TYPE OF REPORTING PERSON:

- -----------------------
/1/ Including (i) 66,930 shares receivable upon conversion of 508 Shares of
Cumulative Convertible Participating Preferred Stock, and (ii) 14,112
shares receivable upon exercise of certain warrants. (See item 5 and the
previously-filed Schedule 13D.)

/2/ Percentage calculated based on 16,912,141 shares which are calculated as
described in Items 5(a).

4
<PAGE>

AMENDMENT NO. 1 TO SCHEDULE 13D

CUSIP NO. 460465107

1. NAME OF REPORTING PERSONS:

C/S International Partners

IRS IDENTIFICATION NUMBER OF ABOVE PERSON:

N/A

2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) [ ]
(b) [X]
3. SEC USE ONLY

4. SOURCE OF FUNDS

5. CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS
REQUIRED PURSUANT TO ITEMS 2(d) OR 2(e) [ ]

6. CITIZENSHIP OR PLACE OF ORGANIZATION

Cayman Islands

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH:

7. SOLE VOTING POWER: 0
---------
8. SHARED VOTING POWER: 338,682/1/
---------
9. SOLE DISPOSITIVE POWER: 0
---------
10. SHARED DISPOSITIVE POWER: (See Item 5(a)) 338,682
---------
11. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON:
338,682/1/
---------
12. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11)
EXCLUDES CERTAIN SHARES [ ]

13. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 2.00%/2/
---------
14. TYPE OF REPORTING PERSON:

- -----------------------
/1/ Including (i) 279,710 shares receivable upon conversion of 2,123 Shares of
Cumulative Convertible Participating Preferred Stock and (ii) 58,972
shares receivable upon exercise of certain warrants. (See item 5 and the
previously-filed Schedule 13D.)

/2/ Percentage calculated based on 16,912,141 shares which are calculated as
described in Items 5(a).

5
<PAGE>

AMENDMENT NO. 1 TO SCHEDULE 13D

CUSIP NO. 460465107

1. NAME OF REPORTING PERSONS:

Carlyle Investment Group, L.P.

IRS IDENTIFICATION NUMBER OF ABOVE PERSON:

51-0357730

2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) [ ]
(b) [X]
3. SEC USE ONLY

4. SOURCE OF FUNDS

5. CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS
REQUIRED PURSUANT TO ITEMS 2(d) OR 2(e) [ ]

6. CITIZENSHIP OR PLACE OF ORGANIZATION

Delaware

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH:

7. SOLE VOTING POWER: 0
---------
8. SHARED VOTING POWER: 1,907/1/
---------
9. SOLE DISPOSITIVE POWER: 0
---------
10. SHARED DISPOSITIVE POWER: (See Item 5(a)) 1,907
---------
11. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON:
1,907/1/
---------
12. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11)
EXCLUDES CERTAIN SHARES [ ]

13. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 0.01%/2/
---------
14. TYPE OF REPORTING PERSON:

- -----------------------
/1/ Including (i) 1,581 shares receivable upon conversion of 12 Shares of
Cumulative Convertible Participating Preferred Stock and (ii) 326 shares
receivable upon exercise of certain warrants. (See item 5 and the
previously-filed Schedule 13D.)

/2/ Percentage calculated based on 16,912,141 shares which are calculated as
described in Items 5(a).

6
<PAGE>

AMENDMENT NO. 1 TO SCHEDULE 13D

CUSIP NO. 460465107

1. NAME OF REPORTING PERSONS:

Carlyle-IT Partners, L.P.

IRS IDENTIFICATION NUMBER OF ABOVE PERSON:

Application Pending

2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) [ ]
(b) [X]
3. SEC USE ONLY

4. SOURCE OF FUNDS

5. CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS
REQUIRED PURSUANT TO ITEMS 2(d) OR 2(e) [ ]

6. CITIZENSHIP OR PLACE OF ORGANIZATION

Delaware

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH:

7. SOLE VOTING POWER: 0
---------
8. SHARED VOTING POWER: 6,430,334/1/
---------
9. SOLE DISPOSITIVE POWER: 0
---------
10. SHARED DISPOSITIVE POWER: (See Item 5(a)) 195,107
---------
11. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON:
6,430,334/1/
---------
12. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11)
EXCLUDES CERTAIN SHARES [ ]

13. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 38.02%/2/
---------
14. TYPE OF REPORTING PERSON:

- -----------------------
/1/ Including (i) 161,133 shares receivable upon conversion of 1,223 Shares of
Cumulative Convertible Participating Preferred Stock, (ii) 33,974 shares
receivable upon exercise of certain warrants and (iii) shares which may be
deemed beneficially owned pursuant to the Agreements Among Partners
entered into by and among certain Reporting Persons. (See item 5 and the
previously-filed Schedule 13D.)

/2/ Percentage calculated based on 16,912,141 shares which are calculated as
described in Items 5(a).

7
<PAGE>

AMENDMENT NO. 1 TO SCHEDULE 13D

CUSIP NO. 460465107

1. NAME OF REPORTING PERSONS:

Carlyle-IT International Partners, L.P.

IRS IDENTIFICATION NUMBER OF ABOVE PERSON:

N/A

2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) [ ]
(b) [X]
3. SEC USE ONLY

4. SOURCE OF FUNDS

5. CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS
REQUIRED PURSUANT TO ITEMS 2(d) OR 2(e) [ ]

6. CITIZENSHIP OR PLACE OF ORGANIZATION

Cayman Islands

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH:

7. SOLE VOTING POWER: 0
---------
8. SHARED VOTING POWER: 2,366,299/1/
---------
9. SOLE DISPOSITIVE POWER: 0
---------
10. SHARED DISPOSITIVE POWER: (See Item 5(a)) 2,366,299
---------
11. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON:
2,366,299/1/
---------
12. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11)
EXCLUDES CERTAIN SHARES [ ]

13. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 13.99%/2/
---------
14. TYPE OF REPORTING PERSON:

- -----------------------
/1/ Including (i) 1,954,282 shares receivable upon conversion of 14,833 Shares
of Cumulative Convertible Participating Preferred Stock and (ii) 412,017
shares receivable upon exercise of certain warrants. (See item 5 and the
previously-filed Schedule 13D.)

/2/ Percentage calculated based on 16,912,141 shares which are calculated as
described in Items 5(a).

8
<PAGE>

AMENDMENT NO. 1 TO SCHEDULE 13D

CUSIP NO. 460465107

1. NAME OF REPORTING PERSONS:

Carlyle-IT International Partners II, L.P.

IRS IDENTIFICATION NUMBER OF ABOVE PERSON:

N/A

2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) [ ]
(b) [X]
3. SEC USE ONLY

4. SOURCE OF FUNDS

5. CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS
REQUIRED PURSUANT TO ITEMS 2(d) OR 2(e) [ ]

6. CITIZENSHIP OR PLACE OF ORGANIZATION

Cayman Islands

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH:

7. SOLE VOTING POWER: 0
---------
8. SHARED VOTING POWER: 79,765/1/
---------
9. SOLE DISPOSITIVE POWER: 0
---------
10. SHARED DISPOSITIVE POWER: (See Item 5(a)) 79,765
---------
11. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON:
79,765/1/
---------
12. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11)
EXCLUDES CERTAIN SHARES [ ]

13. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) .47%/2/
---------
14. TYPE OF REPORTING PERSON:

- -----------------------
/1/ Including (i) 65,876 shares receivable upon conversion of 500 Shares of
Cumulative Convertible Participating Preferred Stock (ii) 13,889 shares
receivable upon exercise of certain warrants. (See item 5 and the
previously-filed Schedule 13D.)

/2/ Percentage calculated based on 16,912,141 shares which are calculated as
described in Items 5(a).

9
<PAGE>

AMENDMENT NO. 1 TO SCHEDULE 13D

CUSIP NO. 460465107

1. NAME OF REPORTING PERSONS:

TC Group, L.L.C. (d/b/a The Carlyle Group)

IRS IDENTIFICATION NUMBER OF ABOVE PERSON:

54-1686957

2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) [ ]
(b) [X]
3. SEC USE ONLY

4. SOURCE OF FUNDS

5. CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS
REQUIRED PURSUANT TO ITEMS 2(d) OR 2(e) [ ]

6. CITIZENSHIP OR PLACE OF ORGANIZATION

Delaware

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH:

7. SOLE VOTING POWER: 0
---------
8. SHARED VOTING POWER: 6,430,334/1/
---------
9. SOLE DISPOSITIVE POWER: 0
---------
10. SHARED DISPOSITIVE POWER: (See Item 5(a)) 6,430,334/1/
---------
11. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON:
6,430,334/1/
---------
12. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11)
EXCLUDES CERTAIN SHARES [ ]

13. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 38.02%/2/
---------
14. TYPE OF REPORTING PERSON:

OO (Limited Liability Company)

- -----------------------
/1/ Including 5,310,671 shares receivable by the Fund Partnerships (as defined
in Item 2) upon conversion of 40,308 Shares of Cumulative Convertible
Participating Preferred Stock and 1,119,662 shares receivable by the Fund
Partnerships upon exercise of certain warrants, such shares which may be
deemed beneficially owned by the Reporting Person as the general partner
of each Fund Partnership. (See item 5 and the previously-filed Schedule
13D.)

/2/ Percentage calculated based on 16,912,141 shares which are calculated as
described in Items 5(a).

10
<PAGE>

AMENDMENT NO, 1 TO SCHEDULE 13D

CUSIP NO. 460465107

1. NAME OF REPORTING PERSONS:

TCG Holdings, L.L.C.

IRS IDENTIFICATION NUMBER OF ABOVE PERSON:

54-1686011

2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) [ ]
(b) [X]
3. SEC USE ONLY

4. SOURCE OF FUNDS

5. CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS
REQUIRED PURSUANT TO ITEMS 2(d) OR 2(e) [ ]

6. CITIZENSHIP OR PLACE OF ORGANIZATION

Delaware

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH:

13. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 38.02%/2/
---------
14. TYPE OF REPORTING PERSON:

OO (Limited Liability Company)

- -----------------------
/1/ Including 5,310,671 shares receivable by the Fund Partnerships upon
conversion of 40,308 Shares of Cumulative Convertible Participating
Preferred Stock and 1,119,662 shares receivable by the Fund Partnerships
upon exercise of certain warrants, such shares which may be deemed
beneficially owned by the Reporting Person as a member of TC Group, the
general partner of the Fund Partnerships. (See item 5 and the previously-
filed Schedule 13D.)

/2/ Percentage calculated based on 16,912,141 shares which are calculated as
described in Items 5(a).

11
<PAGE>

AMENDMENT NO. 1 TO SCHEDULE 13D

CUSIP NO. 460465107

1. NAME OF REPORTING PERSONS:

Carlyle Investment Management, L.L.C.

IRS IDENTIFICATION NUMBER OF ABOVE PERSON:

52-1988385

2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) [ ]
(b) [X]
3. SEC USE ONLY

4. SOURCE OF FUNDS

5. CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS
REQUIRED PURSUANT TO ITEMS 2(d) OR 2(e) [ ]

6. CITIZENSHIP OR PLACE OF ORGANIZATION

Delaware

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH:

7. SOLE VOTING POWER: 748,520/1/
---------
8. SHARED VOTING POWER: 0
---------
9. SOLE DISPOSITIVE POWER: (See Item 5(a)) 748,520
---------
0
10. SHARED DISPOSITIVE POWER: ---------

11. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON:
748,520/1/
---------
12. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11)
EXCLUDES CERTAIN SHARES [ ]

13. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 4.43%/2/
---------
14. TYPE OF REPORTING PERSON:

OO* (Limited Liability Company)

- -----------------------
/1/ Including 618,182 shares receivable upon conversion of 4,692 Shares of
Cumulative Convertible Participating Preferred Stock 130,338 shares
receivable upon exercise of certain warrants over which the Reporting
Person possesses sole power of disposition and voting as investment
advisor. (See also item 5 and the previously-filed Schedule 13D.)

/2/ Percentage calculated based on 16,912,141 shares which are calculated as
described in Items 5(a).

12
<PAGE>

This Amendment No. 1 to Schedule 13D ("Amendment No. 1") amends the
Schedule 13D dated November 27, 1996 filed by Carlyle Partners II, L.P., Carlyle
Partners III, L.P., Carlyle International Partners II, L.P., Carlyle
International Partners III, L.P., C/S International Partners, Carlyle Investment
Group, L.P., Carlyle-IT Partners, L.P., Carlyle-IT International Partners, L.P.,
Carlyle-IT Partners II, L.P., TC Group, L.L.C. (d/b/a The Carlyle Group), TCG
Holdings, L.L.C. and Carlyle Investment Management, L.L.C. (the "Reporting
Persons"), relating to the common stock, par value, $.01 per share (the "Common
Stock") of International Technology Corporation, a Delaware corporation (the
"Company").

Terms used but not defined herein have the meaning ascribed to such term
in the Schedule 13D.

ITEM 5. INTEREST IN SECURITIES OF THE ISSUER.

Item 5 is hereby amended in pertinent part as follows:

(a) Shares of Common Stock held of record or beneficially owned as of
February 9, 1998:

<TABLE>
<CAPTION>
RIGHT TO COMMON STOCK
UPON CONVERSION OF WARRANTS: RIGHT TO
CONVERTIBLE PREFERRED PURCHASE COMMON STOCK TOTAL BENEFICIAL
STOCK FROM THE COMPANY OWNERSHIP
- ---------------------------------------------------------------------------------------------
<S> <C> <C> <C>
CPII/1/ 1,471,673 310,292 1,781,965
- ---------------------------------------------------------------------------------------------
CPIII/1/ 67,194 14,163 81,357
- ---------------------------------------------------------------------------------------------
CIPII 1,242,292 261,918 1,504,210
- ---------------------------------------------------------------------------------------------
CIPIII 66,930 14,112 81,042
- ---------------------------------------------------------------------------------------------
C/SIP 279,710 58,972 338,682
- ---------------------------------------------------------------------------------------------
CIG 1,581 326 1,907
- ---------------------------------------------------------------------------------------------
CIT/1/ 161,133 33,974 195,107
- ---------------------------------------------------------------------------------------------
CITI 1,954,282 412,017 2,366,299
- ---------------------------------------------------------------------------------------------
CITII 65,876 13,889 79,765
- ---------------------------------------------------------------------------------------------
</TABLE>

- -------------------

/1/ See Item 5(b) and the previously-filed Schedule 13D for a discussion of the
beneficial ownerships of CPII, CPIII and CIT as parties to the CPII
Agreement, the CPIII Agreement and the CIT Agreement, respectively.

13
<PAGE>

14
<PAGE>

(a) (continued) Approximate Percentage of Common Stock of the Company held of
record of beneficially owned./1/

<TABLE>
<CAPTION>
RIGHT TO COMMON STOCK
UPON CONVERSION OF WARRANTS: RIGHT TO
CONVERTIBLE PREFERRED PURCHASE COMMON STOCK TOTAL BENEFICIAL
STOCK FROM THE COMPANY OWNERSHIP
- ---------------------------------------------------------------------------------------------
<S> <C> <C> <C>
CPII/1/ 8.70% 1.83% 10.54%
- ---------------------------------------------------------------------------------------------
CPIII/2/ .40% .084% .48%
- ---------------------------------------------------------------------------------------------
CIPII 7.35% 1.55% 8.89%
- ---------------------------------------------------------------------------------------------
CIPIII .40% .08% .48%
- ---------------------------------------------------------------------------------------------
C/SIP 1.65% .35% 2.00%
- ---------------------------------------------------------------------------------------------
CIG .01% .00% .01%
- ---------------------------------------------------------------------------------------------
CIT/2/ .95% .20% 1.15%
- ---------------------------------------------------------------------------------------------
CITI 11.56% 2.44% 13.99%
- ---------------------------------------------------------------------------------------------
CITII .39% .08% .47%
- ---------------------------------------------------------------------------------------------
TC GROUP 31.40% 6.62% 38.02%
- ---------------------------------------------------------------------------------------------
TCG 31.40% 6.62% 38.02%
- ---------------------------------------------------------------------------------------------
CIM 3.66% .77% 4.43%
- ---------------------------------------------------------------------------------------------
REPORTING PERSONS 35.06% 7.39% 42.45%
- ---------------------------------------------------------------------------------------------
</TABLE>

The increased number of shares of Common Stock, and corresponding
decrease in the percentage of the outstanding Common Stock, beneficially owned
by the Reporting Persons as reported in this Amendment No. 1, as compared to the
shares of Common Stock and corresponding percentage of the outstanding Common
Stock as reported in the Schedule 13D

- -------------------
/1/ All percentages calculated based on 9,733,288 shares which equals the
total shares of Common Stock reported by the Company as presently issued
and outstanding plus 5,928,853 shares of Common Stock issuable upon
conversion of the Preferred Stock and 1,250,000 shares of Common Stock
that will be issued upon exercise of the Purchaser's Warrants. Includes
5,310,671 shares receivable by the Fund Partnerships upon conversion of
40,308 shares of Cumulative Convertible Participating Preferred Stock and
1,119,662 shares receivable by the Funds Partnerships upon exercise of
certain warrants, such shares may be deemed beneficially owned by TC Group
as general partner of the Fund Partnerships and by TCG Holdings as a
member of TC Group.

/2/ See Item 5(b) and the previously-filed Schedule 13D for a discussion of
the beneficial ownerships of CPII, CPIII and CIT as parties to the CPII
Agreement, the CPIII Agreement and the CIT Agreement, respectively.

15
<PAGE>

results from the combinations of (i) the anti-dilution adjustment of the
conversion price at which each share of Preferred Stock converts into shares of
Common Stock as a result of the conversion to Common Stock of shares of 7%
Cumulative Convertible Exchangeable Preferred Stock, $100 par value per share,
of the Company (the "7% Preferred Stock") and (ii) the corresponding increase to
the Company's issued and outstanding shares of Common Stock due to the issuance
of shares of Common Stock upon conversion of shares of 7% Preferred Stock to
Common Stock.

(b) CPII is currently the record owner of 11,170 shares of Preferred
Stock (which converts into 1,471,673 shares of Common Stock) and Warrants to
purchase 310,292 shares of Common Stock. CPII has the power to vote and dispose
of all such shares. CPII shares the power to vote and the power to dispose of
these shares with TC Group, its general partner. Pursuant to the CPIII
Agreement and the CIT Agreement, described in the previously-filed Schedule 13D,
CPII shares the power to vote these shares with CPIII and CIT. Pursuant to the
CPII Agreement, described in the previously-filed Schedule 13D, CPII has shared
power to vote the 6,430,334 shares owned by the Fund Partnerships.

CPIII is currently the record owner of 510 shares of Preferred Stock
(which converts into 67,194 shares of Common Stock) and Warrants to purchase
14,163 shares of Common Stock. CPIII has the power to vote and dispose of such
shares, totaling 81,357. CPIII shares the power to vote and the power to
dispose of these shares with TC Group, its general partner. Pursuant to the
CPII Agreement and the CIT Agreement, described in the previously-filed Schedule
13D, CPIII shares the power to vote these shares with CPII and CIT. Pursuant to
the CPIII Agreement, described in the previously-filed Schedule 13D, CPIII has
shared power to vote the 6,430,334 shares owned by the other Fund Partnerships.

CIPII is currently the record owner of 9,429 shares of Preferred Stock
(which converts into 1,242,292 shares of Common Stock) and Warrants to purchase
261,198 shares of Common Stock. CIPII has the power to vote and dispose of all
such shares, totaling 1,504,210. CIPII shares the power to vote and the power
to dispose of these shares with TC Group, its managing general partner.
Pursuant to the Agreements Among Partnerships described in the previously-filed
Schedule 13D, CIPII shares the power to vote these shares with CPII, CPIII, and
CIT.

CIPIII is currently the record owner of 508 shares of Preferred Stock
(which converts into 66,930 shares of Common Stock) and Warrants to purchase
14,112 shares of Common Stock. CIPIII has the power to vote and dispose of all
such shares, totaling 81,042. CIPIII shares the power to vote and the power to
dispose of these shares with TC Group, its managing general partner. Pursuant
to the Agreements Among Partnerships described in the previously-filed Schedule
13D, CIPIII shares the power to vote these shares with CPII, CPIII, and CIT.

C/SIP is currently the record owner of 2,123 shares of Preferred Stock
(which converts into 279,710 shares of Common Stock) and Warrants to purchase
58,972 shares of Common Stock. C/SIP has the power to vote and dispose of all
such shares, totaling 338,682. C/SIP shares the power to vote and the power to
dispose of these shares with TC Group, its

16
<PAGE>

managing general partner. Pursuant to the Agreements Among Partnerships
described in the previously-filed Schedule 13D, C/SIP shares the power to vote
these shares with CPII, CPIII, and CIT.

CIG is currently the record owner of 12 shares of Preferred Stock
(which converts into 1,581 shares of Common Stock) and Warrants to purchase 326
shares of Common Stock. CIG has the power to vote and dispose of all such
shares, totaling 1,907. CIG shares the power to vote and the power to dispose
of these shares with TC Group, its general partner. Pursuant to the Agreements
Among Partnerships described in the previously-filed Scheduled 13D, CIG shares
the power to vote these shares with CPII, CPIII, and CIT.

CIT is currently the record owner of 1,223 shares of Preferred Stock
(which converts into 161,133 shares of Common Stock) and Warrants to purchase
33,974 shares of Common Stock. CIT has the power to vote and dispose of all
such shares, totaling 195,107. CIT shares the power to vote and the power to
dispose of these shares with TC Group, its general partner. Pursuant to the
CPII Agreement and the CPIII Agreement described in the previously-filed
Schedule 13D, CIT shares the power to vote these shares with CPII and CPIII.
Pursuant to the CIT Agreement described in the previously-filed Schedule 13D,
CIT has shared power to vote the 6,430,334 shares beneficially owned by the
other Fund Partnerships.

CITI is currently the record owner of 14,833 shares of Preferred Stock
(which converts into 1,954,282 shares of Common Stock) and Warrants to purchase
412,017 shares of Common Stock. CITI has the power to vote and dispose of all
such shares, totaling 2,366,299. CITI shares the power to vote and the power to
dispose of these shares with TC Group, its managing general partner. Pursuant
to the Agreements Among Partnerships described in the previously-filed Schedule
13D, CITI shares the power to vote these shares with CPII, CPIII, and CIT.

CITII is currently the record owner of 500 shares of Preferred Stock
(which converts into 65,876 shares of Common Stock) and Warrants to purchase
13,889 shares of Common Stock. CITII has the power to vote and dispose of all
such shares, totaling 79,765. CITII shares the power to vote and the power to
dispose of these shares with TC Group, its managing general partner. Pursuant
to the Agreements Among Partnerships described in the previously-filed Schedule
13D, CITII shares the power to vote these shares with CPII, CPIII, and CIT.

TC Group may be deemed to be the beneficial owner of 40,308 shares of
Preferred Stock (which converts into 5,310,671 shares of Common Stock) and
Warrants to purchase 1,119,662 shares of Common Stock as the general partner of
CPII, CPIII, CIG, and CIT, as the managing general partner of CIPII, CIPIII,
C/SIP, CITI, and CITII. TC Group may be deemed to share voting and disposal
rights of all such shares, totaling 6,430,334 as the general partner of CPII,
CPIII, CIG, and CIT, as the managing general partner of CIPII, CIPIII, C/SIP,
CITI, and CITII. TCG, as a member holding a controlling interest in TC Group,
may be deemed to share all rights herein described belonging to TC Group.

17
<PAGE>

As investment advisor to SBA, CIM may be deemed to be the beneficial
owner of 4,692 shares of Preferred Stock (which converts into 618,182 shares of
Common Stock) and Warrants to purchase 130,338 shares of Common Stock. CIM has
the power to vote and disposed all such shares, totaling 748,520. Because
certain TCG Principals are also CIM Principals, CIM may be deemed to share
beneficial ownership of any shares of Common Stock owned by the other Reporting
Persons.

Reporting Persons are the beneficial owner of 45,000 shares of
Preferred Stock (which converts into 5,928,853 shares of Common Stock) and
1,250,000 Warrants to purchase 1,250,000 shares of Common Stock. Reporting
Persons thus have voting rights and disposal rights of all such shares, totaling
7,178,854.

William E. Conway, Jr., Frank C. Carlucci, III, Daniel A. D'Aniello,
Richard G. Darman, David M. Rubenstein and James A. Baker, III are managing
members of TCG, and, in such capacity, such individuals may be deemed to share
beneficial ownership of any shares of Common Stock owned by TCG. Such
individuals expressly disclaim any such beneficial ownership.

(d) No person other than the Reporting Persons is known to the
Reporting Persons to have the right to receive or the power to direct the
receipt of dividends from, or the proceeds from the sale of, the shares of Stock
of the Company owned by the Reporting Persons.

(e) Not applicable.

ITEM 6. CONTRACTS, ARRANGEMENTS, UNDERSTANDINGS OR RELATIONSHIPS WITH
RESPECT TO SECURITIES OF THE ISSUER.

Item 6 has been amended in pertinent part as follows:

On January 15, 1998, each of the Reporting Persons entered into that
certain Parent Voting Agreement by and among such Reporting Persons, the Company
and OHM Corporation ("OHM"), and Ohio corporation (the "Voting Agreement").
Pursuant to the Voting Agreement, each Reporting Person has agreed to vote all
shares of Preferred Stock held by such Reporting Person in favor of the issuance
of shares of Common Stock by the Company in connection with the Company's
potential acquisition of OHM pursuant to that certain Agreement and Plan of
Merger (the "Merger Agreement") among the Company, OHM and IT-Ohio, Inc., an
Ohio corporation and wholly owned subsidiary of the Company and the election of
OHM's nominees to the Company's Board of Directors, and to not take certain
actions, or encourage or assist any other party in taking any action, which
would compete with, impede, interfere with or attempt to discourage such
transactions or inhibit the timely consummation of such transaction and to
deliver to OHM, upon its request, an irrevocable proxy to vote all shares of
Preferred Stock held by such Reporting Person and any other shares of capital
stock of the Company acquired by such Reporting Person prior to the effective
time of the Merger in a manner consistent with the provisions of the Voting
Agreement. The Voting Agreement shall terminate

18
<PAGE>

automatically upon the termination of the Merger Agreement or upon the effective
time of the Merger. A copy of the Voting Agreement is attached hereto as
Exhibit 2.

ITEM 7. MATERIAL TO BE FILED AS EXHIBITS.

Item 7 is amended and restated as follows:

Exhibit 1.* Joint Filing Agreement dated as of November 27, 1996, by and among
CPII, CPIII, CIPII, CIPIII, C/SIP, CIG, CIM, CIT, CITI, CITII, TC
Group, and TCG.

Exhibit 2. Parent Voting Agreement, dated as of January 15, 1998, among
International Technology Corporation, certain stockholders of
International Technology Corporation signatories thereto and OHM
Corporation, an Ohio Corporation.

- ------------------
* Incorporated by reference to Exhibit 1. to the Schedule 13D.

19
<PAGE>

SIGNATURE
---------

After reasonable inquiry and to the best of the knowledge and belief
of the undersigned, the undersigned certify that the information set forth in
this statement is true, complete and correct.

Dated: February 9, 1998
CARLYLE PARTNERS II, L.P.

By: TC Group, L.L.C., its General Partner

By: TCG Holdings, L.L.C., its Managing
Member

By: /s/ Daniel A. D'Aniello
-----------------------
Name: Daniel A. D'Aniello
-------------------
Title: Managing Director
-----------------

CARLYLE PARTNERS III L.P.

By: TC Group, L.L.C., its General Partner

By: TCG Holdings, L.L.C., its Managing
Member

By: /s/ Daniel A. D'Aniello
-----------------------
Name: Daniel A. D'Aniello
-------------------
Title: Managing Director
-----------------

CARLYLE INTERNATIONAL PARTNERS II, L.P.

By: TC Group, L.L.C., its General Partner

By: TCG Holdings, L.L.C., its Managing
Member

By: /s/ Daniel A. D'Aniello
-----------------------
Name: Daniel A. D'Aniello
-------------------
Title: Managing Director
-----------------

20
<PAGE>

CARLYLE INTERNATIONAL PARTNERS III, L.P.

By: TC Group, L.L.C., its General Partner

By: TCG Holdings, L.L.C., its Managing
Member

By: /s/ Daniel A. D'Aniello
-----------------------
Name: Daniel A. D'Aniello
-------------------
Title: Managing Director
-----------------

C/S INTERNATIONAL PARTNERS

By: TC Group, L.L.C., its General Partner

By: TCG Holdings, L.L.C., its Managing
Member

By: /s/ Daniel A. D'Aniello
-----------------------
Name: Daniel A. D'Aniello
-------------------
Title: Managing Director
-----------------

CARLYLE INVESTMENT GROUP, L.P.

By: TC Group, L.L.C., its General Partner

By: TCG Holdings, L.L.C., its Managing
Member

By: /s/ Daniel A. D'Aniello
-----------------------
Name: Daniel A. D'Aniello
-------------------
Title: Managing Director
-----------------

21
<PAGE>

CARLYLE-IT PARTNERS, L.P.

By: TC Group, L.L.C., its General Partner

By: TCG Holdings, L.L.C., its Managing
Member

By: /s/ Daniel A. D'Aniello
-----------------------
Name: Daniel A. D'Aniello
-------------------
Title: Managing Director
-----------------

CARLYLE-IT INTERNATIONAL PARTNERS, L.P.

By: TC Group, L.L.C., its General Partner

By: TCG Holdings, L.L.C., its Managing
Member

By: /s/ Daniel A. D'Aniello
-----------------------
Name: Daniel A. D'Aniello
-------------------
Title: Managing Director
-----------------

22
<PAGE>

CARLYLE-IT INTERNATIONAL PARTNERS II, L.P.

By: TC Group, L.L.C., its General Partner

By: TCG Holdings, L.L.C., its Managing
Member

By: /s/ Daniel A. D'Aniello
-----------------------
Name: Daniel A. D'Aniello
-------------------
Title: Managing Director
-----------------

State Board of Administration of Florida separate
account maintained pursuant to an Investment
Management Agreement dated as of September 6, 1996
by and between the State Board of Administration
of Florida, Carlyle Investment Group, L.P. and
Carlyle Investment Management, L.L.C.

By: Carlyle Investment Management, L.L.C.

By: /s/ Daniel A. D'Aniello
-----------------------
Name: Daniel A. D'Aniello
-------------------
Title: Managing Director
-----------------

23
<PAGE>

EXHIBIT INDEX
-------------

Exhibit * 1. Joint Filing Agreement dated as of November 27, 1996, by and
among CPII, CPIII, CIPII, CIPIII, C/SIP, CIG, CIM, CIT, CITI,
CITII, TC Group, and TCG.

Exhibit 2. Parent Voting Agreement, dated as of January 15, 1998, among
International Technology, Corporation, certain stockholders of
International Technology Corporation signatories thereto and OHM
Corporation, an Ohio Corporation.

- ----------------
* Incorporated by reference to Exhibit 1. to the Schedule 13D.

<PAGE>

EXHIBIT 2

PARENT VOTING AGREEMENT

PARENT VOTING AGREEMENT (this "Agreement"), dated as of January 15,
1998, among International Technology Corporation, a Delaware corporation
("Parent"), the undersigned stockholders (the "Stockholders") of Parent and OHM
Corporation, an Ohio corporation (the "Company").

WHEREAS, concurrently with the execution of this Agreement, the
Company, Parent and IT-Ohio, Inc., an Ohio Corporation and a wholly owned
subsidiary of Parent ("Merger Sub"), have entered into an Agreement and Plan of
Merger (as it may be hereafter amended from time to time, the "Merger
Agreement"), which provides that Merger Sub shall make a tender offer (the
"Offer") for 13,933,000 shares of common stock of the Company and that Merger
Sub shall thereafter merge (the "Merger") with and into the Company pursuant to
the terms and conditions of the Merger Agreement, and sets forth certain
representations, warranties, covenants and agreements of the parties thereto in
connection with the Offer, the Merger and the other transactions contemplated
therein (the "Merger Transactions"); and

WHEREAS, upon consummation the Merger, the holders of outstanding
shares of common stock of the Company at the Effective Time (as defined in the
Merger Agreement) will receive the merger Consideration (as defined in the
Merger Agreement), which will consist (at least in part) of shares of Common
Stock, par value $0.1 per share, of Parent ("Parent Common Stock") for each
share of common stock of the Company; and

WHEREAS, Section 6.4 of the Merger Agreement provides that if
stockholder approval of the issuance of shares of Parent Common Stock is
required under the rules of the New York Stock Exchange, Inc., Parent will take
all action necessary to convene a meeting of its stockholders as promptly as
practicable to consider and vote upon such issuance; and

WHEREAS, the Stockholders are the record holders of an aggregate of
45,000 shares of Cumulative Convertible Participating Preferred Stock, par value
$100 per share, of Parent (the "Preferred Shares") and warrants (the "Warrants")
to purchase 1,250,000 shares of Parent Common Stock; and

WHEREAS, in order to induce the Company, Parent and Merger Sub to
enter into the Merger Agreement, the Stockholders wish to agree (i) to vote the
Preferred Shares and any other shares of capital stock of Parent held by them so
as to facilitate the consummation of the Merger Transactions, (ii) except as
provided in this Agreement, not to transfer or otherwise dispose of any of the
Preferred Shares or, any other shares of capital stock held by them, or any
other shares of capital stock of Parent acquired by them hereafter and prior to
the Effective Time (as defined in the Merger Agreement), and (iii) to deliver to
the Company an irrevocable proxy to vote the Preferred Shares and any other
shares of capital stock held by them, and any other shares of capital stock of
Parent acquired by them hereafter and prior to the Effective Time, all in manner
set forth herein.
<PAGE>

NOW, THEREFORE, for good and valuable consideration, the receipt,
sufficiency and adequacy of which is hereby acknowledged, the parties hereto
agree as follows:

1. Representations of Stockholders. Each of the stockholders
-------------------------------
represents and warrants to the Company, Parent and Merger Sub that (a) such
Stockholder lawfully owns beneficially (as such term is defined in the
Securities Exchange Act of 1934, as amended (the 1934 Act")), and of record the
number of Preferred Shares set forth opposite such Stockholder's name on Exhibit
A (such Stockholder's "Shares") free and clear of all liens, claims, charges,
security interests or other encumbrances and, except for this Agreement and the
Merger Agreement, there are no options, warrants or other rights, agreements,
arrangements or commitments of any character to which such Stockholder is a
party relating to the pledge, disposition or voting of any shares of capital
stock of Parent and there are no voting trusts or voting agreements with respect
to such Shares, (b) such Stockholder does not beneficially own any shares of
Parent Common Stock or ` any other shares of capital stock of Parent other than
such Shares and, except for such Shares, does not have any options, warrants or
other rights to acquire any additional shares of capital stock of Parent or any
security exercisable for or convertible into shares of capital stock of Parent,
other than the Warrants, (c) such Stockholder has full power and authority to
enter into, execute and deliver this Agreement and to perform fully such
Stockholder's obligations hereunder, and (d) this Agreement has been duly
executed and delivered by such Stockholder, constitutes the legal, valid and
binding obligation of such Stockholder, and is enforceable against such
Stockholder in accordance with its terms.

2. Agreement to Vote Shares. Each of the Stockholders agrees that
------------------------
during the term of this Agreement it will vote such Stockholder's Shares and any
new Shares (as defined in Section 6 hereof), and will cause any holder of record
of such Shares or New Shares to vote such Stockholder's Shares and New Shares:
(a) in favor of the Merger Transactions and the issuance of shares of Parent
Common Stock in connection with the Merger at every meeting of the stockholders
of Parent at which such matters are considered and at every adjournment thereof,
and in connection with any written consent of the stockholders of Parent (b) in
favor of each of the Nominees (as defined in Section 6.11(c) of the Merger
Agreement) to Parent's Board of Directors, (c) against any action or agreement
that would compete with, impede, interfere with or attempt to discourage the
Merger Transactions, or inhibit the timely consummation of the Merger
Transactions, (d) against any action or agreement that would result in a breach
in any material respect of any covenant, representation or warranty or any other
obligation of Parent or Merger Sub under the Merger Agreement and (e) against
any merger, consolidation, business combination, reorganization,
recapitalization, liquidation or sale or transfer of any material assets of
Parent, Merger Sub or their respective subsidiaries that could compete with,
impede, interfere with or attempt to discourage the Merger Transactions or
inhibit the timely consummation of the Merger Transactions. Each Stockholder
agrees to deliver to the Company upon request a proxy substantially in the form
attached hereto as Exhibit B, which proxy shall be irrevocable during the term
of this Agreement to the fullest extent permitted under Delaware law.

3. No Voting Trusts. Each of the Stockholders agrees that they will
----------------
not, nor will they permit any entity under their control to, deposit any of
their Shares or any New Shares held by them in a voting trust or subject any of
their Shares or any New Shares held by them to any arrangement with respect to
the voting of such Shares or New Shares that would result in a

2
<PAGE>

stockholder's vote or action by consent of the stockholders of Parent in
opposition to or in competition with the consummation of the Merger
Transactions.

4. No Proxy Solicitations. Each of the Stockholders agrees that such
----------------------
Stockholder will not, nor will such Stockholder permit any entity under such
Stockholder's control to, (a) solicit proxies or become a "participant" in a
"solicitation" (as such terms are defined in Regulation 14A under the 1934 Act)
in opposition to or competition with the consummation of the Merger Transactions
or otherwise encourage or assist any party in taking or planning any action
which would compete with, impede, interfere with or attempt to discourage the
Merger Transactions or inhibit the timely consummation of the Merger
Transactions, (b) directly or indirectly encourage, initiate or cooperate in a
stockholders' vote or action by consent of Parent's stockholders in opposition
to or in competition with the consummation of the Merger Transactions, or (c)
become a member of a "group" (as such term is used in Section 13(d) of the 1934
Act) with respect to any voting securities of Parent for the purpose of opposing
or competing with the consummation of the Merger Transactions.

5. Transfer and Encumbrance. On or after the date hereof and during
------------------------
the term of this Agreement, each of the Stockholders agrees not to transfer,
sell, offer, exchange, pledge or otherwise dispose of or encumber any of such
Stockholder's Shares or New Shares, unless the transferee agrees in written form
satisfactory to the Company to be bound by the terms of this Agreement.

6. Additional Purchases. Each of the Stockholders agrees that such
--------------------
Stockholder will not purchase or otherwise acquire beneficial ownership of any
shares of Parent Common Stock, Preferred Shares, 7% Cumulative Convertible
Exchangeable Preferred Stock, par value $100 per share (the 7% Preferred Stock")
or any other capital stock of Parent after the execution of this Agreement ("New
Shares"), nor will any Stockholder voluntarily acquire the right to vote or
share in the voting of any shares of Parent Common Stock, Preferred Shares, 7%
Preferred Stock or any other capital stock of Parent other than the Shares,
unless such Stockholder agrees to deliver to the Company immediately after such
purchase or acquisition an irrevocable proxy in the form attached hereto as
Exhibit B with respect to such shares. Each of the Stockholders also severally
agrees that any New Shares acquired or purchased by such Stockholder shall be
subject to the terms of this Agreement to the same extent as if they constituted
Shares.

7. Specific Performance. Each party hereto acknowledges that it will
--------------------
be impossible to measure in money the damage to the other party if a party
hereto fails to comply with any of the obligations imposed by this Agreement,
that every such obligation is material and that, in the event of any such
failure, the other party will not have an adequate remedy at law or damages.
Accordingly, each party hereto agrees that injunctive relief or other equitable
remedy, in addition to remedies at law or damages, is the appropriate remedy for
any such failure and will not oppose the granting of such relief on the basis
that the other party has an adequate remedy at law. Each party hereto agrees
that it will not seek, and agrees to waive any requirement for, the securing or
posting of a bond in connection with any other party's seeking or obtaining such
equitable relief.

3
<PAGE>

8. Entire Agreement. This Agreement supersedes all prior agreements,
----------------
written or oral, among the parties hereto with respect to the subject matter
hereof and contains the entire agreement among the parties with-respect to the
subject matter hereof. This Agreement may not be amended, supplemented or
modified, and no provisions hereof may be modified or waived, except by an
instrument in writing signed by all the parties hereto. No waiver of any
provisions hereof by any party shall be deemed a waiver of any other provisions
hereof by any such party, nor shall any such waiver be deemed a continuing
waiver of any provision hereof by such party.

9. Notices. Any notice, request, instruction or other document to be
-------
given hereunder by any party to the others shall be in writing and delivered
personally or sent by registered or certified mail, postage prepaid, or by
facsimile:

if to any Stockholder:
----------------------

Daniel A. D'Aniello
Managing Director
The Carlyle Group
1001 Pennsylvania Avenue, N.W.
Suite 220 South
Washington, DC 20004-2505

if to Parent or Merger Sub:
--------------------------

James G. Kirk
International Technology Corporation
2790 Mosside Boulevard
Monroeville, PA 15146-2792
Telecopier: (412) 858-3978

4
<PAGE>

with a copy to:

Peter F. Ziegler
Gibson, Dunn & Crutcher LLP
333 South Grand Avenue
Los Angeles, California 90071
Telecopier: (213) 229-7520

if to the Company:
------------------

Steven E. Harbour
OHM Corporation
5445 Triangle Parkway, Suite 400
Norcross, Georgia 30092

with a copy to:

Joseph B. Frumkin
Sulllvan & Cromwell
125 Broad Street
New York, New York 10004
Telecopier: (212) 558-3588

and a copy to:

Thomas C. Daniels
Jones Day Reavis & Pogue
North Point
901 Lakeside Avenue
Cleveland, Ohio 44114
Telecopier: (216) 579-0212

or to such other persons or addresses as may be designated in writing
by the party to receive such notice as provided above.

10. Miscellaneous
-------------

(a) This Agreement shall be deemed a contract made under, and for
all purposes shall be construed in accordance with, the laws of the State of
Delaware applicable to agreements executed in and solely to be performed within
such state:

(b) If any provision of this Agreement or the application of such
provision to any person or circumstances shall be held invalid or unenforceable
by a court of competent jurisdiction, such provision or application shall be
unenforceable only to the extent of such invalidity or unenforceability and the
remainder of the provision held invalid or unenforceable and the application of
such provision to persons or circumstances, other than the party as to which it
is held invalid, and the remainder of this Agreement, shall not be affected.

5
<PAGE>

(c) This Agreement may be executed in one or more counterparts,
each of which shall be deemed to be an original but all of which together shall
constitute one and the same instrument.

(d) This Agreement shall terminate automatically upon the
termination of the Merger Agreement or upon the Effective Time of the Merger.
This Agreement shall not otherwise be terminable.

(e) Each party hereto shall execute and deliver such additional
documents as may be necessary or desirable to effect the transactions
contemplated by this Agreement.

(f) All Section headings herein are for convenience of reference
only and are not part of this Agreement, and no construction or reference shall
be derived therefrom.

1. The obligations of the Stockholders set forth in this Agreement
shall not be effective or binding upon any Stockholder until after such time as
the Merger Agreement is executed and delivered by the Company, Parent and Merger
Sub, and the parties agree that there is not and has not been any other
agreement, arrangement or understanding between the parties hereto with respect
to the matters set forth herein.

6
<PAGE>

IN WITNESS WHEREOF, the parties hereto have executed and delivered
this Agreement as of the date first written above.

International Technology
Corporation

By:
------------------------------------
Name:
Title:

OHM Corporation

By:
------------------------------------
Name:
Title:
Carlyle Partners II, L.P.

By: its General Partner, TC
Group, L.L.C.

By:
------------------------------------
Name: Daniel A. D'Aniello
Title: Managing Director

Carlyle Partners III, L.P.

By: its General Partner, TC
Group, L.L.C.

By:
------------------------------------
Name: Daniel A. D'Aniello
Title: Managing Director

Carlyle International Partners II, L.P.
By: its General Partner, TC Group, L.L.C.

By:
------------------------------------
Name: Daniel A. D'Aniello
Title: Managing Director

7
<PAGE>

Carlyle International Partners III, L.P.
By: its General Partner, TC Group, L.L.C.

By:
------------------------------------
Name: Daniel A. D'Aniello
Title: Managing Director

C/S International Partners
By: its General Partner, TC Group, L.L.C.

By:
------------------------------------
Name: Daniel A. D'Aniello
Title: Managing Director

Carlyle Investment Group, L.P.
By: its General Partner, TC Group, L.L.C.

By:
------------------------------------
Name: Daniel A. D'Aniello
Title: Managing Director

Carlyle -IT International Partners, L.P.
By: its General Partner, TC Group, L.L.C.

By:
------------------------------------
Name: Daniel A. D'Aniello
Title: Managing Director

Carlyle-IT International Partners II, L.P.
By: its General Partner, TC Group, L.L.C.

By:
------------------------------------
Name: Daniel A. D'Aniello
Title: Managing Director

Carlyle-IT Partners, L.P.
By: its General Partner, TC Group, L.L.C.

By:
------------------------------------
Name: Daniel A. D'Aniello
Title: Managing Director

8
<PAGE>

State Board of Administration of Florida separate
account maintained pursuant to an Investment
Management Agreement dated as of September 6, 1996
between the State Board of Administration of
Florida, Carlyle Investment Group, L.P. and
Carlyle Investment Management L.L.C.

By: Carlyle Investment Management, L.L.C.,
as Investment Manager

By:
-----------------------------------

Its:
-----------------------------------

9
<PAGE>

(EXHIBIT A)

<TABLE>
<CAPTION>
Number of Shares
of Cumulative Convertible
Name of Stockholder Participating Preferred Stock
- -------------------------------------------- -----------------------------
<S> <C>
Carlyle Partners II, L.P. 1,781,965
Carlyle Partners III, L.P. 81,357
Carlyle International Partners II, L.P. 1,504,210
Carlyle International III, L.P. 81,042
C/S International Partners 338,682
Carlyle Investment Group, L.P. 1,907
Carlyle-IT International Partners, L.P. 2,366,299
Carlyle-IT International Partners II, L.P. 79,765
The State Board of Administration of the 748,520
State of Florida
Carlyle-IT Partners, L.P. 195,107
</TABLE>

10
<PAGE>

(EXHIBIT B)

FORM OF PROXY

The undersigned, for consideration received, hereby appoints [insert
names of Company designees] and each of them my proxies, with power of
substitution and resubstitution, to vote all shares of Cumulative Convertible
Participating Preferred Stock, par value $100 per share, of International
Technology Corporation, a Delaware corporation, ("Parent"), [and [insert any
other Shares (as defined in the Voting Agreement) owned by Stockholder]] owned
by the undersigned at the Special Meeting of Stockholders of Parent to be held
[insert date, time and place] and at any adjournment thereof IN FAVOR OF
consummation of the Offer, the Merger and the other transactions (the "Merger
Transactions") contemplated by the Merger Agreement, dated as of January 15,
1998 (the "Merger Agreement"), among OHM Corporation (the "Company"), Parent and
IT-Ohio, Inc. ("Merger Sub"), IN FAVOR OF the issuance of shares of common stock
of Parent in connection with the merger of Merger Sub with and into the Company,
IN FAVOR OF each of the Nominees (as defined in Section 6.11(c) of the Merger
Agreement) to Parent's Board of Directors and AGAINST [insert description of any
action or agreement that would compete with, impede, interfere with or attempt
to discourage the Merger Transactions or inhibit the timely consummation of the
Merger Transactions or any action or agreement that would result in a breach in
any material respect of any covenant, representation or warranty or any other
obligation of Parent under the Merger Agreement or any merger, consolidation,
business combination, reorganization, recapitalization, liquidation or sale or
transfer of any material assets of Parent or its subsidiaries]. This proxy is
coupled with an interest, revokes all prior proxies granted by the undersigned
and is irrevocable until such time as the Voting Agreement, dated as of January
15, 1998 among certain stockholders of Parent, including the undersigned,
Parent, Merger Sub and the Company terminates in accordance with its terms.

Dated ______, 1998

[NAME OF STOCKHOLDER]

By:
-------------------------------------