<PAGE>


                                                                 EXHIBIT 10.12.2

                               SECOND AMENDMENT TO
              FIRST AMENDED AND RESTATED REVOLVING CREDIT AGREEMENT


         THIS SECOND AMENDMENT TO FIRST AMENDED AND RESTATED REVOLVING CREDIT
AGREEMENT, dated effective as of August 10, 2000 (the "Second Amendment"), is
entered into between and among HERITAGE SERVICE CORP., a Delaware corporation
(the "Borrower") and BANK OF OKLAHOMA, NATIONAL ASSOCIATION ("BOk"), FIRSTAR
BANK, N.A., formerly Mercantile Bank National Association ("Firstar"), LOCAL
OKLAHOMA BANK, N. A. ("Local") and HARRIS TRUST AND SAVINGS BANK ("Harris")
(BOk, Firstar, Local and Harris collectively referred to herein as the "Banks"),
BOk, as administrative agent for the Banks (in such capacity, the
"Administrative Agent") and Firstar, as co-agent for the Banks (in such
capacity, the "Co-Agent").

         WHEREAS, the Borrower, the Banks, (other than Harris), the
Administrative Agent and the Co-Agent entered into that certain First Amended
and Restated Credit Agreement dated as of May 31, 1999, as amended by the First
Amendment thereto dated as of October 15, 1999 (the "Credit Agreement"); and

         WHEREAS, due to certain modifications and amendments to the Operating
Partnership Credit Agreement (as defined in the Credit Agreement), including an
increase in the maximum outstanding amount of the Working Capital Loan pursuant
to the Working Capital Facility from $35,000,000.00 to $50,000,000.00, and
reallocation of the Percentage Interests of the respective Banks, the Borrower,
the Banks (including Harris), the Administrative Agent and the Co-Agent desire
to amend and modify certain provisions of the Credit Agreement concerning such
matters.

         NOW THEREFORE, the Credit Agreement is hereby amended and modified as
follows:

         1. The definition of "Operating Partnership Credit Agreement" in the
Credit Agreement is deleted in its entirety and replaced with the following:

                  "Operating Partnership Credit Agreement" means the First
         Amended and Restated Credit Agreement dated as of May 31, 1999, between
         and among Heritage Operating, L. P., a Delaware limited partnership,
         BOk, Firstar and Local, and BOk, as Administrative Agent, and Firstar,
         as Co-Agent, as amended by the First Amendment thereto dated as of
         October 15, 1999, as further amended by the Second Amendment thereto
         dated as of May 31, 2000, as further amended by the Third Amendment
         thereto dated as of August 10, 2000,between and among the Operating
         Partnership, the Banks, the Administrative Agent and the Co-Agent, and
         as further amended and modified from time to time hereafter.

         2. Section 2.1.2(ii) of the Credit Agreement is amended by deleting
"$35,000,000" and inserting in lieu thereof "$50,000,000." The form of Exhibit
2.1.4 (Revolver Notes) annexed to the Credit Agreement is replaced with the form
of Exhibit 2.1.4 annexed to this First Amendment.


<PAGE>



         3. Article III of the Credit Agreement is amended by deleting "October
31, 1999" and inserting in lieu thereof "August 31, 2000."

         4. Section 7B.1(i) of the Existing Credit Agreement is amended by
deleting "$35,000,000" and inserting in lieu thereof "$50,000,000."

         5. Section 10.1 of the Existing Credit Agreement is deleted in its
entirety and replaced by the following:

                  10.1 Interests in Loans/Commitments. The percentage interest
         of each Bank in the Loans and the Commitments, shall be computed based
         on the maximum principal amount for each Bank as follows:

<Table>
<Caption>
                          MAXIMUM REVOLVER
                          LOAN COMMITMENT     PERCENTAGE
       BANK                    AMOUNT          INTEREST
       ----               ----------------  --------------
<S>                       <C>               <C>
        BOk                $   450,000.00            45.00%
      Firstar                  250,000.00            25.00%
       Local                   150,000.00            15.00%
      Harris                   150,000.00            15.00%
                           --------------   --------------
       Total               $ 1,000,000.00         100.0000%
                           ==============   ==============
</Table>

                  The foregoing percentage interests, as from time to time in
         effect and reflected in the Register, are referred to as the
         "Percentage Interests" with respect to all or any portion of the Loans
         and Letters of Credit, and the Commitments.

         6. Credit Agreement/Counterparts. All of the remaining terms,
provisions and conditions of the Credit Agreement, except as otherwise expressly
amended and modified by this Second Amendment, shall continue in full force and
effect in all respects. This Second Amendment may be executed in multiple
counterparts, each of which shall be deemed an original and all of which shall
constitute a single Second Amendment. Delivery of an executed counterpart of a
signature page to this Second Amendment by telecopier shall be as effective as
delivery of a manually executed counterpart of this Second Amendment.

         7. Further Assurances. The Borrower will, upon the request of the
Administrative Agent from time to time, promptly execute, acknowledge and
deliver, and file and record, all such instruments and notices, and take all
such action, as the Administrative Agent deems necessary or advisable to carry
out the intent and purposes of this Second Amendment and the Credit Agreement.

         8. General. The Credit Agreement and all of the other Loan Documents
are each confirmed as being in full force and effect. This Second Amendment, the
Credit Agreement and the other Loan Documents (including that certain Second
Restated Security Agreement and Assignment from Borrower, as debtor, dated as of
even date herewith) referred to herein or therein constitute the entire
understanding of the parties with respect to the subject matter hereof




                                       2
<PAGE>


and thereof and supersede all prior and current understandings and agreements,
whether written or oral, with respect to such subject matter. The invalidity or
unenforceability of any provision hereof shall not affect the validity and
enforceability of any other term or provision hereof. The headings in this
Second Amendment are for convenience of reference only and shall not alter,
limit or otherwise affect the meaning hereof. Each of this Second Amendment and
the Credit Agreement is a Loan Document and may be executed in any number of
counterparts, which together shall constitute one instrument, and shall bind and
inure to the benefit of the parties and their respective successors and assigns
including as such successors and assigns all holders of any Note. This Second
Amendment shall be governed by and construed in accordance with the laws (other
than the conflict of law rules) of the State of Oklahoma.

         IN WITNESS WHEREOF, the parties hereto have caused this Second
Amendment to Amended and Restated Credit Agreement to be duly executed and
delivered in Tulsa, Oklahoma, effective as of the tenth (10th) day of August,
2000, by the undersigned duly authorized officers thereof.


                                                "Borrower"

                                                HERITAGE SERVICE CORP.,
                                                a Delaware corporation


                                                By
                                                  ------------------------------
                                                  H. Michael Krimbill,
                                                  President



                                       3
<PAGE>




                                                "Banks"

                                                BANK OF OKLAHOMA, NATIONAL
                                                ASSOCIATION


                                                By
                                                  ------------------------------
                                                  Denise L. Maltby,
                                                  Senior Vice President




<PAGE>




                                                FIRSTAR BANK, N.A.


                                                By
                                                  ------------------------------
                                                                          (name)
                                                    ----------------------
                                                                         (title)
                                                    ---------------------


<PAGE>



                                             LOCAL OKLAHOMA BANK, N.A.


                                             By
                                               ---------------------------------
                                               Elisabeth F. Blue,
                                               Senior Vice President



<PAGE>



                                            HARRIS TRUST AND SAVINGS BANK


                                            By
                                               ---------------------------------
                                               Timothy E. Broccolo,
                                               Managing Director








<PAGE>



                                         "Administrative Agent"

                                         BANK OF OKLAHOMA, NATIONAL
                                         ASSOCIATION


                                         By
                                           -------------------------------------
                                           Denise L. Maltby,
                                           Senior Vice President


<PAGE>



                                         "Co-Agent"

                                         FIRSTAR BANK N.A.


                                         By
                                           -------------------------------------
                                                                          (name)
                                             -----------------------------
                                                                         (title)
                                             ----------------------------