Document:

<PAGE>   1

                                                                    EXHIBIT 10.1
                           FOURTH AMENDMENT AND WAIVER
                                       TO
                                CREDIT AGREEMENT

                  THIS FOURTH AMENDMENT AND WAIVER TO CREDIT AGREEMENT (the
"Agreement") is being executed and delivered as of August 14, 2001, by and among
EarthCare Company, a Delaware corporation (the "Borrower"), the Borrower's
Subsidiaries named as signatories hereto, Mr. Raymond M. Cash ("Mr. Cash"), and
Mr. Donald F. Moorehead, Jr. ("Mr. Moorehead" and, together with Mr. Cash and
such Subsidiary signatories, collectively, the "Guarantors"), the financial
institutions from time to time party to such Credit Agreement referred to and
defined below (collectively, the "Banks"), and Bank of America, N.A., as
representative of the Banks (in such capacity, the "Administrative Agent").
Undefined capitalized terms used herein shall have the meanings ascribed to such
terms in such Credit Agreement referred to below.

                                   WITNESSETH:

                  WHEREAS, the Borrower, the Banks, the Administrative Agent
have entered into that certain Amended and Restated Credit Agreement dated as of
February 15, 2000 (as heretofore amended pursuant to amendment agreements dated
as of April 14, 2000, October 31, 2000 and April 16, 2001, the "Credit
Agreement"), pursuant to which, among other things, the Banks have agreed to
provide, subject to the terms and conditions contained therein, certain loans to
the Borrower;

                  WHEREAS, in connection with the Credit Agreement, the Borrower
and certain of the Guarantors have executed and delivered in favor of the
Administrative Agent and the Banks certain Loan Documents pursuant to which such
Guarantors have guaranteed the Borrower's Obligations under the Credit Agreement
and the Borrower and such Guarantors have granted liens and security interests
in certain of their properties as security for their respective obligations
under the Loan Documents;

                  WHEREAS, certain Events of Default have occurred as a result
of (collectively, the "Existing Defaults"): (i) the Borrower's failure to comply
with its minimum Adjusted EBITDA covenant set forth in Section 10.6.7 of the
Credit Agreement with respect to each of the periods ending as of the last day
of the months January 2001 through May 2001, (ii) the Borrower's failure to
comply with each of the financial covenants set forth in Sections 10.6.1 through
10.6.5 with respect to the Computation Period ended June 30, 2001, (iii) the
Borrower's failure to complete sales of the EarthLiquids Subsidiaries or the
EarthAmerica Subsidiaries in accordance with the requirements of Section 12.1.12
of the Credit Agreement, (iv) the Borrower's failure to pay the amendment fees
due on June 30, 2001 pursuant to Section 5.7 of the Third Amendment, Waiver and
Consent dated as of April 16, 2001 to the Credit Agreement (hereinafter, the
"Third Amendment"), (v) the Borrower's failure cause Mr. Moorehead to provide
certain lien perfection documentation to the Administrative Agreement pursuant
to Section 5.8 of the Third Amendment, (vi) the Borrower's breach of
representations and warranties set forth in Sections 9.15(a) and 9.15(c) of the
Credit Agreement, and compliance

<PAGE>   2

with Section 10.4 of the Credit Agreement, with respect to the matters described
in Exhibit A hereto, (vii) the Borrower's failure, prior to the effectiveness of
this Agreement, to timely comply with the requirements of Sections 10.1.7 and
10.13 of the Credit Agreement with respect to certain Subsidiaries of the
Borrower, or the requirements of Section 5.6 of the Second Amendment dated as of
February 15, 2000 to the Credit Agreement with respect to certain parcels of
real property, and (viii) the failure, prior to the effectiveness of this
Agreement, by Mr. Moorehead and Mr. Cash to comply with the requirement to
deliver to the Administrative Agent collateral security for their obligations
under the Individual Guaranty and that certain Additional Guaranty dated as of
October 31, 2000 executed by Mr. Moorehead in favor of the Administrative Agent
and the Banks (as heretofore amended, the "Additional Guaranty") or any security
documentation with respect thereto; and

                  WHEREAS, the Borrower and the Guarantors have requested that
the Banks waive, and subject to the terms and conditions of this Agreement the
Banks have agreed to waive, the Existing Defaults.

                  NOW, THEREFORE, in consideration of the foregoing premises,
the terms and conditions stated herein and other valuable consideration, the
receipt and sufficiency of which are hereby acknowledged, the Borrower, the
Guarantors, the Banks and the Administrative Agent hereby agree as follows:

                  1. Amendment to Credit Agreement. Subject to the satisfaction
of each of the conditions set forth in Paragraph 3 of this Agreement, the Credit
Agreement is hereby amended as follows (section and schedule references used
herein shall refer to sections and schedules of the Credit Agreement):

                  (a) Section 1.1 is amended to add the following new
definitions in their respective alphabetical locations:

                           "Adjusted EBITDA" means EBITDA calculated without
         including any financial results from ERMFI.

                           "EarthLiquids Payment Date" means the earlier of (i)
         September 30, 2001 and (ii) the consummation of the sale or other
         disposition of the EarthLiquids Subsidiaries.

                  (b) Section 1.1 is further amended to delete the definition of
"Floating Rate Margin" in its entirety and to replace such definition with the
following definition:

                           "Floating Rate Margin" means 3.00% per annum at all
         times from and after July 31, 2001.

                  (c) Section 2.2 is amended to add the following new subsection
to the end of such section:

                           2.2.4 Elimination of Eurodollar Option.
         Notwithstanding anything in this section or Agreement to the contrary,
         from and after the April 16, 2001, the

                                       2
<PAGE>   3

         Company shall have no right to borrow or continue, or to convert Loans
         into, Eurodollar Rate Loans.

                  (d) Section 4.2 is amended to delete in its entirety the first
sentence of such section and to replace such sentence with the following
sentence:

         Accrued interest on each Floating Rate Loan shall be payable in arrears
         on the last Business Day of each calendar month and at maturity;
         provided, however, that the payment of a portion of such interest
         accrued with respect to each Floating Rate Loan during the period
         commencing July 31, 2001 and ending on the EarthLiquids Payment Date in
         an amount calculated at the rate of 1.50% per annum on the daily
         outstanding principal balance of such Floating Rate Loan during such
         period shall be deferred during such period and become due and payable
         in full on the EarthLiquids Payment Date, with the remaining portion of
         such accrued interest with respect to such Floating Rate Loan payable
         in arrears on the last Business Date of each calendar month ending
         during such period.

                  (e) Section 5 is amended to add the following new subsection
to the end of such section:

                           5.4 Amendment Fees. The Company agrees to pay, on the
         EarthLiquids Payment Date, an amendment fee in the amount of $400,000
         to Bank of America and an amendment fee in the amount of $400,000 to
         Fleet National Bank. The Company shall have no further obligation to
         pay the amendment fees otherwise due and payable to such Banks pursuant
         to Section 5.5 of the Second Amendment dated as of October 31, 2000 to
         this Agreement.

                  (f) Section 6.2(b)(i) is deleted in its entirety and replaced
with the following provision:

         On each date on which the Commitment Amount is reduced pursuant to
         Section 6.1.3, the Company shall prepay the Loans in an amount equal to
         100% of the Net Cash Proceeds received by the Company or any Subsidiary
         from the Asset Sale or issuance of equity or Debt giving rise to such
         Commitment Amount reduction. The foregoing provisions shall be
         applicable notwithstanding the provisions of Section 5.5 of the Third
         Amendment dated as of April 16, 2001 to this Agreement, the latter of
         which provisions shall be of no further force or effect.

                  (g) Section 10.6.7 is amended to be deleted in its entirety
and to be replaced with the following:

                           10.6.7 Minimum EBITDA. Not permit Adjusted EBITDA for
         any of the following calendar months to be less than the corresponding
         amounts set forth below opposite such months:

                                       3
<PAGE>   4

<Table>
<Caption>

                           Calendar Month                     Minimum Amount
                           --------------                     --------------
<S>                                                           <C>
                           June 2001                            $350,000

                           July 2001                            $350,000

                           August 2001 and each
                           calendar month thereafter            $400,000;
</Table>

         provided, however, that, following the sale or other disposition of
         all, or each sale of any material part, of the EarthAmerica
         Subsidiaries, the foregoing minimum required amounts shall be reduced
         to amounts determined by Required Lenders, in their sole determination,
         as indicated by written notification thereof delivered to the Company
         by the Required Banks. Such determination shall be based upon the
         Required Lenders' estimate, as determined solely by such Lenders, of
         the portion of the minimum amounts of Adjusted EBITDA set forth above
         which were attributable to the Subsidiaries or portions thereof subject
         to such sale or disposition as of the date such minimum amounts were
         initially established pursuant to the Fourth Amendment and Waiver to
         this Agreement.

                  (h) Section 10.6 is further amended to add the following new
subsection to the end of such section:

                           10.6.7 Suspension of Financial Covenants.
         Notwithstanding the foregoing, the covenants set forth in Sections
         10.6.1 through 10.6.5 will not be applicable until the Computation
         Period ended December 31, 2001, except that such covenants shall
         continue to apply for purposes of (a) the definition of "Release Date"
         (other than the covenant contained in Section 10.6.3) and (b) Section
         10.11(c)(4).

                  (i) Section 10.11 is amended to delete the phrase "or sell,
transfer, convey or lease all or any substantial part of its assets" set forth
therein and to replace such phrase with the following phrase:

         or sell, transfer, convey or lease all or any of its property (other
         than the sale of its inventory in the ordinary course of business)

                  (j) Section 10.11 is further amended to delete in its entirety
clause (d) thereof and to replace such clause with the reference:
"[intentionally omitted]."

                  (k) Section 10.13 is amended to add the following provisions
to the end of such section:

         Without limiting the foregoing, (a) on or before September 15, 2001,
         the Company shall have provided to the Administrative Agent schedules
         describing the information described on Exhibit B to the Fourth
         Amendment and Waiver dated as of August 14, 2001 with respect to this
         Agreement (in each case in form and scope acceptable to the
         Administrative Agent in its reasonable discretion), accompanied by a
         certificate by an executive officer of the Company as to the accuracy
         and completeness in all material respects of such information as of a
         date no earlier than such Fourth Amendment and (b) as soon as
         practicable after its delivery of the information described in the
         immediately preceding clause (a), but in any event within fifteen (15)
         days following the Administrative Agent's request therefor, the Company
         shall execute, deliver and provide,

                                       4
<PAGE>   5

         or cause to be executed, delivered and provided (whether by a
         Subsidiary, Guarantor or otherwise), all documentation and instruments
         requested by the Administrative Agent with respect to the Loan
         Documents (including, without limitation, the Individual Guaranty or
         Additional Guaranty), and take such actions or cause such actions to be
         taken, in each case pursuant to the foregoing provisions of this
         section as a consequence of the information delivered to the
         Administrative Agent pursuant to the immediately preceding clause (a)
         hereof or otherwise requested by the Administrative Agent with respect
         to its counsel's legal review of the Loan Documents.

                  (l) Section 12.1.12 is deleted in its entirety and replaced
with the following provision:

                           12.1.12 Sale of Certain Business Units. The Company
         shall fail to consummate, pursuant to terms, conditions and definitive
         documentation acceptable to the Required Lenders: (i) the sale of the
         EarthLiquids Subsidiaries on or before September 30, 2001, (ii) the
         sale of the portable toilet business on or before October 15, 2001,
         (iii) the sale of EarthCare Company of New York or its operating assets
         and liabilities on or before October 31, 2001, (iv) the sale of all the
         assets and liabilities comprising the bulk hauling line of business of
         Reifsneider Transportation, Inc. on or before October 31, 2001, (v) the
         sale of the common stock or the operating assets and liabilities of the
         EarthAmerica restaurant grease trap, septic, confined space and
         ancillary lines of business on or before October 31, 2001, unless the
         sale described in the immediately following clause shall have occurred
         on or before such date pursuant to the provisions of such clause, or
         (vi) the sale of ERMFI on or before October 31, 2001, unless the sale
         described in the immediately preceding clause shall have occurred on or
         before such date pursuant to the provisions of such clause.

                  (m) Schedule 1.1 is amended to delete each reference therein
to "the Floating Rate Margin" and each corresponding percentage with respect to
such term in the table contained in such schedule.

                  2. Waiver. Subject to the satisfaction of each of the
conditions set forth in Paragraph 3 of this Agreement, the Required Banks hereby
waive (a) each of the Existing Defaults and (b) any failure, after the
effectiveness of this Agreement, by Mr. Moorehead or Mr. Cash to comply with the
requirements to deliver to the Administrative Agent collateral security for
their obligations under the Individual Guaranty and the Additional Guaranty in
addition to that theretofore so delivered by Mr. Moorehead and Mr. Cash;
provided, however, that, in the event there shall have occurred any Event of
Default, other than the Existing Defaults and other than any other Events of
Default which shall have been waived in writing prior to the date hereof, such
requirements shall thereupon once again become immediately effective pursuant to
the terms of the Individual Guaranty and Additional Guaranty and the other Loan
Documents to which Mr. Moorehead or Mr. Cash is a party (including, without
limitation, this Agreement) and such collateral shall be thereupon immediately
provided to the Administrative Agent by Mr. Moorehead and Mr. Cash pursuant to
documentation acceptable to the Administrative Agent.

                  3. Conditions Precedent to Effectiveness of Amendment and
Waiver. The provisions of Paragraphs 1 and 2 of this Agreement shall become
effective as of the date

                                       5
<PAGE>   6

hereof upon the Administrative Agent's receipt of each of the following
(provided, however, that the amendment to the definition of "Floating Rate
Margin" set forth in Paragraph 1 hereof shall be retroactively effective as of
July 31, 2001) originally-executed (or facsimilies of originally-executed)
counterparts of this Agreement executed and delivered by duly authorized
officers of the Company, each Guarantor and each of the Banks.

                  4. Representations, Warranties and Covenants.

                  (a) The Borrower hereby represents and warrants that this
Agreement, and the Credit Agreement as amended by this Agreement, constitute the
legal, valid and binding obligations of the Borrower enforceable against the
Borrower in accordance with their terms. Each Guarantor hereby represents and
warrants that each Loan Document to which it is a party (as amended,
supplemented, reaffirmed, restated or otherwise modified) constitutes the legal,
valid and binding obligations of such Guarantor enforceable against such
Guarantor in accordance with its terms.

                  (b) Each of the Borrower and the Guarantors hereby represents
and warrants that its execution, delivery and performance of this Agreement and
other Loan Documents to which it is a party have been duly authorized by all
proper organization action, do not violate any provision of its organization
documents (if applicable), will not violate any law, regulation, court order or
writ applicable to it, and will not require the approval or consent of any
governmental agency, or of any other third party under the terms of any contract
or agreement to which the Borrower or any of the Borrower's Subsidiaries is
bound (which has not been previously obtained).

                  (c) The Borrower hereby represents and warrants that, after
giving effect to the provisions of this Agreement, (i) no Default or Event of
Default has occurred and is continuing or will have occurred and be continuing
and (ii) all of the representations and warranties of the Borrower contained in
the Credit Agreement and in each other Loan Document (other than representations
and warranties which, in accordance with their express terms, are made only as
of an earlier specified date) are, and will be, true and correct as of the date
of the Borrower's execution and delivery hereof or thereof in all material
respects as though made on and as of such date.

                  5. Reaffirmation, Ratification and Acknowledgment;
Reservation. (a) The Borrower and each Guarantor hereby (i) ratifies and
reaffirms all of its payment and performance obligations, contingent or
otherwise, and each grant of security interests and liens in favor of the
Administrative Agent, under each Loan Document (as amended, supplemented or
otherwise modified by, among other things, this Agreement) to which it is a
party, (ii) agrees and acknowledges that such ratification and reaffirmation is
not a condition to the continued effectiveness of such Loan Documents and (iii)
agrees that neither such ratification and reaffirmation, nor the Administrative
Agent's, or any Bank's solicitation of such ratification and reaffirmation,
constitutes a course of dealing giving rise to any obligation or condition
requiring a similar or any other ratification or reaffirmation from the Borrower
or such Guarantors with respect to any subsequent modifications to the Credit
Agreement or the other Loan Documents. As modified hereby, the Credit Agreement
is in all respects ratified and confirmed, and the

                                       6
<PAGE>   7

Credit Agreement as so modified by this Agreement shall be read, taken and so
construed as one and the same instrument. Each of the Loan Documents shall
remain in full force and effect and are hereby ratified and confirmed. Except as
expressly set forth in this Agreement, neither the execution, delivery nor
effectiveness of this Agreement shall operate as a waiver of any right, power or
remedy of the Administrative Agent or the Banks, or of any Default or Event of
Default, under any of the Loan Documents, all of which rights, powers and
remedies, with respect to any such Default or Event of Default or otherwise, are
hereby expressly reserved by the Administrative Agent and the Lenders. This
Agreement shall constitute a Loan Document for purposes of the Credit Agreement.

                  (b) The Borrower, the Guarantors, the Banks and the
Administrative Agent hereby agree to and acknowledge each of the following with
respect to the Individual Guaranty and the Additional Guaranty, notwithstanding
anything in such Loan Documents, any other Loan Documents, or this Agreement, to
the contrary (with all other terms of such documents being hereby reaffirmed and
ratified):

                  (i) the maximum liability (exclusive of interest, costs and
         expenses) of Messrs. Moorehead and Cash pursuant to the Individual
         Guaranty, as provided in the third paragraph thereof, is $20,000,000,
         which liability is borne jointly and severally by such Guarantors;

                  (ii) it is agreed that the "Maximum Principal Liability
         Amount" of Mr. Moorehead under and as defined in the fifth paragraph of
         the Additional Guaranty, shall deemed to be currently $30,000,000
         (subject to further adjustment with respect to asset sales consummated
         after the date hereof, subject to the terms of the Additional
         Guaranty);

                  (iii) subject to Paragraph 2 of this Agreement, the aggregate
         minimum value of collateral required to be maintained by Messrs. Cash
         and Moorehead pursuant to the Individual Guaranty is $10,000,000 and
         the Banks' security interest in such collateral shall be perfected;

                  (iv) subject to Paragraph 2 of this Agreement, the aggregate
         minimum value of collateral required to be maintained by Mr. Moorehead
         pursuant to the Additional Guaranty is $11,400,000 and the Banks'
         security interest in such collateral shall be perfected;

                  (v) all collateral granted by Mr. Cash shall be allocated to
         the collateral required as security for the Individual Guaranty, the
         first $11,400,000 of collateral granted by Mr. Moorehead shall be
         allocated to the collateral required as security for the Additional
         Guaranty, and all other collateral granted by Mr. Moorehead shall be
         allocated to the collateral required as security for the Individual
         Guaranty;

                  (vi) Mr. Cash shall continue to maintain, in the Goldman Sachs
         brokerage account he pledged to the Administrative Agent pursuant to
         that certain Security Agreement dated as of November 30, 2000,
         marketable securities having an aggregate value in excess of $9,500,000
         as of the last day of each month; and

                                       7
<PAGE>   8

                  (vii) Mr. Moorehead shall continue to maintain, and cause to
         be maintained, in the Sanders Morris Harris brokerage accounts pledged
         to the Administrative Agent by Mr. Moorehead, Ms. Shelley B. Moorehead
         and Moorehead Property Company, Ltd., pursuant to those certain
         Security Agreements dated as of February, 2001, marketable securities
         having an aggregate value in excess of $4,000,000 as of the last day of
         each month (subject to Paragraph 2 of this Agreement), and agrees that,
         notwithstanding anything in such Security Agreements to the contrary,
         until such Security Agreements shall have been terminated, no such
         collateral (or proceeds, income, interest or dividends) shall be
         withdrawn or transferred from such account without the prior written
         consent of the Administrative Agreement.

                  6. Release and Indemnification. The Borrower and each of the
Guarantors hereby acknowledges and confirms that (i) it does not have any
grounds, and hereby agrees not to challenge (or to allege or to pursue any
matter, cause or claim arising under or with respect to), in any case based upon
acts or omissions of the Administrative Agent or any of the Banks occurring
prior to the date hereof or facts otherwise known to it as of the date hereof,
the effectiveness, genuiness, validity, collectibility or enforceability of the
Credit Agreement or any of the other Loan Documents, the obligations of the
Borrower or any Guarantor under the Loan Documents, the Liens securing such
obligations, or any of the terms or conditions of any Loan Document (it being
understood that such acknowledgement and confirmation does not preclude the
Borrower or the Guarantors from challenging the Administrative Agent's or any
Bank's interpretation of any term or provision of the Credit Agreement or other
Loan Document) and (ii) it does not possess (and hereby forever waives, remises,
releases, discharges and holds harmless the Banks, the Administrative Agent and
their respective affiliates, stockholders, directors, officers, employees,
attorneys, agents and representatives and each of their respective heirs,
executors, administrators, successors and assigns (collectively, the
"Indemnified Parties") from and against, and agrees not to allege or pursue) any
action, cause of action, suit, debt, claim, counterclaim, cross-claim, demand,
defense, offset, opposition, demand and other right of action whatsoever,
whether in law, equity or otherwise (which it, all those claiming by, through or
under it, or its successors or assigns, have or may have) against the
Indemnified Parties, or any of them, by reason of, any matter, cause or thing
whatsoever, with respect to events or omissions occurring or arising on or prior
to the date hereof and relating to the Credit Agreement or any of the other Loan
Documents (including, without limitation, with respect to the payment,
performance, validity or enforceability of the obligations of the Borrower or
any Guarantor under the Loan Documents, the Liens securing such obligations or
any or all of the terms or conditions of any Loan Document) or any transaction
relating thereto; provided, however, that neither the Borrower nor any Guarantor
hereby releases or holds harmless any Indemnified Party for actions or omissions
by any such Indemnified Party constituting, or losses or expenses directly
resulting from, the gross negligence or willful misconduct of such Indemnified
Party.

                  7. Governing Law. This Agreement shall be governed by and
construed in accordance with the laws and decisions of the State of Illinois
(but without giving effect to any other conflicts of law provisions).

                  8. Counterparts. This Agreement may be executed in
counterparts, each of which shall be an original and all of which together shall
constitute one and the same agreement among the parties.

                                       8
<PAGE>   9

                  9. Section Titles. The section titles contained in this
Agreement are and shall be without substance, meaning or content of any kind
whatsoever and are not a part of the agreement between the parties hereto.

                  10. Agent's Expense. The Company hereby agrees to reimburse
the Agent for all reasonable out-of-pocket expenses, including, without
limitation, attorneys' and paralegals fees, it has heretofore or hereafter
incurred or incurs in connection with the preparation, negotiation and execution
of this Agreement or any document, instrument, agreement delivered pursuant to
this Agreement, in each case on or before the earlier of the "EarthLiquids
Payment Date" (as proposed to be defined in Paragraph 1 hereof) or the
occurrence of any Event of Default, other than the Existing Defaults and other
than any other Events of Default which shall have been waived in writing prior
to the date hereof.

                                      ****

                                       9
<PAGE>   10

         IN WITNESS WHEREOF, this Agreement has been duly executed as of the day
and year first above written.

                                            EARTHCARE COMPANY, as Borrower

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

                                            BANK OF AMERICA, N.A., as
                                              Administrative Agent

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

                                            BANK OF AMERICA, N.A., as a Bank

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

                                            FLEET NATIONAL BANK, as a Bank

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

                                            RAYMOND M. CASH, as a Guarantor,

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

                                            DONALD F. MOOREHEAD, JR., as a
                                               Guarantor

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

                        Signature Page to Amendment No.4
<PAGE>   11

Agreed, Acknowledged and Consented to as of this 14th day of August, 2001:

ALL COUNTY RESOURCE MANAGEMENT CORP.
BONE-DRY ENTERPRISES, INC.
BREHMS CESSPOOL SERVICE INC.
EARTHAMERICA COMPANY
EARTHAMERICA DISTRIBUTORS, INC.
EARTHCARE COMPANY OF PENNSYLVANIA
EARTHCARE COMPANY OF NEW YORK
EARTHCARE COMPANY OF TEXAS
EARTHLIQUIDS COMPANY
EC ACQUISITIONS, INC.
INTERNATIONAL ENVIRONMENTAL SERVICES, INC.
INTERNATIONAL PETROLEUM CORPORATION
INTERNATIONAL PETROLEUM CORP. OF DELAWARE
INTERNATIONAL PETROLEUM CORP. OF GEORGIA
INTERNATIONAL PETROLEUM CORP. OF LA.
INTERNATIONAL PETROLEUM CORPORATION OF LAFAYETTE
INTERNATIONAL PETROLEUM CORP. OF MARYLAND
INTERNATIONAL PETROLEUM CORP. OF PA.
LIQUID WASTE CONTROL SYSTEMS, INC.
MAGNUM ENVIRONMENTAL SERVICES, INC.
MAGNUM PROPERTY DEVELOPMENT CORPORATION
REIFSNEIDER TRANSPORTATION, INC.
SUB-SURFACE LIQUID INJECTION COMPANY, INC.
MAGNUM EAST COAST PROPERTIES, LTD.
MAGNUM NORTHEAST PROPERTIES, LTD.
MAGNUM WEST COAST PROPERTIES, LTD.
MAGNUM WORLD ENTERPRISES, INC.]
each as a Guarantor,

By:
   -------------------------------
Name:
as authorized representative

                        Signature Page to Amendment No.4
<PAGE>   12

                                    EXHIBIT A
                                       TO
                           FOURTH AMENDMENT AND WAIVER

                        New Orleans Environmental Matters

         The New Orleans plant of EarthCare's EarthLiquids division is currently
conducting an internal audit to assess whether the New Orleans plant personnel
complied with environmental policies and procedures prescribed by EarthCare and
its EarthLiquids division. As of August 14, 2001, EarthCare is not able to
estimate the probability that it will incur any costs associated with any
environmental matters that may be discovered as part of this internal audit. In
addition, although EarthCare has estimated a range of costs associated with
certain corrective actions, EarthCare is not able to currently estimate the
actual costs that may be incurred.

         As of August 14, 2001, EarthCare has determined that the former general
manager of the New Orleans plant, Richard Lane, who is also the former President
of International Petroleum Corporation of Louisiana, Inc., did not comply with
the environmental policies and procedures prescribed by EarthCare and its
EarthLiquids division. Specifically, he directed New Orleans plant employees to
offload used oil and oily waste water from tanker trailers to storage tanks at
the New Orleans plant before a sample of the used oil and oily waste water was
tested and analyzed.

         As of August 14, 2001, EarthCare has also determined that the chemical
testing equipment used at the New Orleans plant was not properly calibrated or
functioning and may not have provided accurate test results for used oil and
oily waste water samples. EarthCare has corrected this deficiency through a
recalibration of the machines and, if needed, replacement of the machines or
parts thereto.

         As of August 14, 2001, EarthCare has notified the Louisiana Department
of Environmental Quality (LDEQ) of its internal audit. EarthCare plans to update
LDEQ on the results of its findings on or about August 16, 2001."

                                    Exhibits
<PAGE>   13

                                    EXHIBIT B
                                       TO
                           FOURTH AMENDMENT AND WAIVER

                              Due Diligence Request

                  The Borrower shall have provided to the Administrative Agent
         schedules describing the following information with respect to the
         Borrower and its Subsidiaries, accompanied by a certificate by an
         executive officer as to the accuracy and completeness in all material
         respects of such schedules as of a date no earlier than the August 14,
         2001 (in each case in form and scope acceptable to the Administrative
         Agent in its reasonable discretion):

                           (i) the legal names, forms of legal organization, and
                  jurisdictions of organization of each Subsidiary;

                           (ii) the number of authorized and outstanding units
                  of equity interests of each Subsidiary (including, without
                  limitation, all options, warrants and convertible interests
                  with respect thereto), and the names of each owner of such
                  units and number of units owned by each such owner;

                           (iii) the address of each location of inventory and
                  equipment (other than mobile goods) of the Borrower and each
                  Subsidiary, on an entity-by-entity basis, including, without
                  limitation, with respect to goods held by consignees, bailees
                  and other third parties, except in each case to the extent
                  that the book value of all inventory and equipment at any
                  single such location is less than $25,000 and the aggregate
                  book value of all inventory and equipment located at all such
                  de minimus locations is less than $250,000;

                           (iv) a description of all mobile goods owned by the
                  Borrower and each Subsidiary, on an entity-by-entity basis,
                  together with registration numbers thereof, if any, and
                  identifying the state of each of such registrations, except in
                  each case to the extent that the book value of any such item
                  is less than $25,000 and the aggregate book value of all such
                  de minimus items is less than $250,000;

                           (v) a description of all United States federally
                  registered (and applications therefor) patents, trademarks,
                  service marks and copyrights owned or licensed by the Borrower
                  and each Subsidiary, on an entity-by-entity basis, together
                  with registration numbers and dates of such registrations (or
                  applications);

                           (vi) the address of each location of real property
                  owned or leased by the Borrower and each Subsidiary, on an
                  entity-by-entity basis (and indicating as to whether each such
                  property is owned in fee simple or leased), together with the
                  names and addresses of each lessor and sublessor with respect
                  to each such leased location and the names and addresses of
                  each mortgagee with respect to each such owned location;

                                    Exhibits
<PAGE>   14

                           (vii) a listing of all deposit accounts and lockboxes
                  owned by the Borrower and each Subsidiary, on an
                  entity-by-entity basis, together with a brief description of
                  the type of account or lockbox (e.g. concentration,
                  disbursement or payroll), the name and address of the
                  financial institution at which each such deposit account or
                  lockbox is located or maintained and the account numbers
                  thereof; and

                           (viii) a listing of all promissory notes and other
                  instruments evidencing Debt or other obligations owing to the
                  Borrower and each Subsidiary, on an entity-by-entity basis,
                  together with a brief description of the instrument, the
                  amount outstanding with respect thereto, the name and address
                  of the payor thereunder, and the basic terms thereof.

                                      ****

                                    Exhibits<PAGE>   1

                                                                     EXHIBIT 4.1

<Table>
<S>                                        <C>                              <C>
 070867

          INCORPORATED UNDER THE LAWS                                                  COMMON STOCK
           OF THE STATE OF NEVADA
                                                     [PICTURE]                        PAR VALUE $.01

  THIS CERTIFICATE IS TRANSFERABLE                                                   CUSIP 961468 10 0
   IN NEW YORK, NY AND DENVER, CO                                            SEE REVERSE FOR CERTAIN DEFINITIONS

                                            WESTPORT RESOURCES CORPORATION

                 -----------------------------------------------------------------------------------
                     THIS CERTIFIES THAT

                  IN THE NAME OF
                 -----------------------------------------------------------------------------------

                       FULLY PAID AND NON-ASSESSABLE SHARES OF THE COMMON STOCK OF

                 Westport Resources Corporation, transferable on the books of the Corporation by the
                 holder hereof in person or by duly authorized attorney, upon surrender of this
                 Certificate properly endorsed. This Certificate is not valid until countersigned by
                 the Transfer Agent and registered by the Registrar.
                    Witness the facsimile corporate seal and the facsimile signatures of its duly
                 authorized officers.

                 DATED

                          /s/ DONALD D. WOLF              HOWARD L. BOIGON
                         CHAIRMAN OF THE BOARD            SECRETARY

          [SEAL]                                                                              [SEAL]
</Table>

<PAGE>   2
                         WESTPORT RESOURCES CORPORATION

     THE CORPORATION WILL FURNISH WITHOUT CHARGE TO EACH STOCKHOLDER WHO SO
REQUESTS THE POWERS, DESIGNATIONS, PREFERENCES AND RELATIVE PARTICIPATING,
OPTIONAL OR OTHER SPECIAL RIGHTS OF EACH CLASS OF STOCK OR SERIES THEREOF OF THE
CORPORATION, AND THE QUALIFICATIONS, LIMITATIONS OR RESTRICTIONS OF SUCH
PREFERENCES AND/OR RIGHTS.

     The following abbreviations when used in the inscription on the face of
this certificate shall be construed as though they were written out in full
according to applicable laws or regulations:

<Table>
<S>                                          <C>
TEN COM - as tenants in common               UNIF GIFT MIN ACT- _________ Custodian __________
TEN ENT - as tenants by the entireties                           (Cust)              (Minor)
JT TEN  - as joint tenants with right                          under Uniform Gifts to Minors
          of survivorship and not as                           Act __________
          tenants in common                                        (State)
</Table>

    Additional abbreviations may also be used though not in the above list.

     For value received, ___________________________________ hereby sell, assign
and transfer unto

PLEASE INSERT SOCIAL SECURITY OR OTHER
   IDENTIFYING NUMBER OF ASSIGNEE

________________________________________________________________________________

________________________________________________________________________________
Please print or typewrite name and address including postal zip code of assignee

________________________________________________________________________________

________________________________________________________________________________

_________________________________________________________________________ Shares
of the capital stock represented by the within Certificate, and do hereby
irrevocably constitute and appoint

_______________________________________________________________________ Attorney
to transfer the said stock on the books of the within-named Corporation with
full power of substitution in the premises.

Dated: __________

                     NOTICE:                   X
           THE SIGNATURE(S) TO THIS             --------------------------
           ASSIGNMENT MUST CORRESPOND                   (SIGNATURE)
           WITH THE NAME(S) AS WRITTEN
           UPON THE FACE OF THE CERTIFI-       X
           CATE IN EVERY PARTICULAR             ---------------------------
           WITHOUT ALTERATION OF ENLARGE-               (SIGNATURE)
           MENT OR ANY CHANGE WHATEVER

                                          THE SIGNATURE(S) MUST BE GUARANTEED
                                          BY AN ELIGIBLE GUARANTOR INSTITUTION
                                          (BANKS, STOCKBROKERS, SAVINGS AND LOAN
                                          ASSOCIATIONS AND CREDIT UNIONS WITH
                                          MEMBERSHIP IN AN APPROVED SIGNATURE
                                          GUARANTEE MEDALLION PROGRAM)
                                          PURSUANT TO SEC RULE 17A6 13
                                          ------------------------------------
                                          SIGNATURE(S) GUARANTEED BY:

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00029-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00029-of-00352.parquet"}]]