PNC Bank, N.A.                              973 881 5478 Tel
Corporate Banking                           973 881 5288 Fax
1 Garret Mountain Plaza
West Paterson, NJ  07424








February 22, 2000                                                      PNCBANK


Mr. Frank Russomanno, CFO
Environmental Waste Management Associates, L.L.C.
100 Misty Lane
Parsippany, NJ 07054


Re:  Extension/Renewal of Expiration Date for Committed Line of Credit


Dear Mr. Russomanno:

         We are  writing  to inform you that your  committed  line of credit has
been  temporarily  extended.  The Expiration  Date, as set forth in that certain
Letter Agreement dated August 26, 1997, and in the Committed Line of Credit Note
executed and delivered pursuant to that Letter Agreement, has been extended from
October 31, 1999 to April 30,  2000,  effective  on November 1, 1999.  All other
terms  and  conditions  of the  Committed  Line of  Credit  Note and the  Letter
Agreement remain in full force and effect.

Please note that this extension  through 4/30/2000 is subject to the receipt and
satisfactory  review of the 1/31/2000  accounts  receivable  aging and Borrowing
Base Certificate.


Very truly yours,

PNC BANK, NATIONAL ASSOCIATION


By:    /s/ Thomas Slater
       -----------------

Name:  Thomas Slater
       -----------------
Title: Assistant Vice President
       ------------------------


CC:      Environmental Waste Management Associates, Inc.
         Integrated Analytical Laboratories, Inc.
         Integrated Analytical Laboratories, L.L.C.
         Menlo Acquisition Corporation
         Richard Greenberg


<PAGE>




PNC Bank, N.A.                              973 881 5478 Tel
Corporate Banking                           973 881 5288 Fax
1 Garret Mountain Plaza
West Paterson, NJ  07424








February 22, 2000                                                      PNCBANK


Environmental Waste Management Associates, LLC
100 Misty Lane
P. O. Box 5430
Parsippany, NJ 07054
Attention:  Frank Russomanno, Chief Financial Officer

Re: $750,000.00 Committed Line of Credit ("Line of Credit") to EWMA, LLC
    ("Borrower") expired 10/31/99/Treasury Management Services from PNC Bank

Dear Mr. Russomanno:

Per our  discussion  of Monday,  2/14/2000,  the Bank has agreed to extend  your
Committed  Line  of  Credit  through  4/30/2000.  The  document  evidencing  the
extension has been  executed and is attached for your records.  Please note that
extension  of the line is  subject  to  receipt  of the  January  2000  accounts
receivable aging and Borrowing Base Certificate, which I expect to receive on or
before  3/8/2000.  The terms and conditions of the Committed Line of Credit Note
and Letter  Agreement,  including the financial  reporting  requirements,  shall
remain unchanged for the duration of the extension.

As we also  discussed  on  2/14/2000,  the Bank is not  willing  to  extend  the
Committed  Line of Credit beyond  4/30/2000.  We intend to cancel the line as of
the expiration date, and we encourage you to make other lending  arrangements as
soon as possible.

Please also be advised that your Treasury Management Services,  including Direct
Deposit  Payroll,  will terminate at the same time as the Line of Credit.  Those
products are tied together because of incidental  extensions of unsecured credit
which are  inherent  in the  Direct  Deposit  Payroll  product.  Once  again,  I
encourage  you to seek  another  provider as soon as possible  because  there is
typically  several weeks lead time necessary to establish such a service with no
inadvertent interruptions.

Despite the short tenure of our  relationship,  I wish you continued  success in
your "new" position at EWMA. You are a strong addition to the management team.

Sincerely,



/s/ Thomas E. Slater
AVP/Relationship Manager

CC:      Environmental Waste Management Associates, Inc.
         Integrated Analytical Laboratories, Inc.
         Integrated Analytical Laboratories, L.L.C.
         Menlo Acquisition Corporation
         Richard Greenberg