<PAGE>   1









                               INDENTURE OF TRUST


                                     BETWEEN


                              CARBON COUNTY, UTAH,
                                    AS ISSUER


                                       AND


                              WEST ONE BANK, UTAH,
                                   AS TRUSTEE




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

                          Dated as of February 1, 1995

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




                               Carbon County, Utah
                  Solid Waste Disposal Refunding Revenue Bonds
                 (Laidlaw Inc./ECDC Environmental, L.C. Project)







<PAGE>   2







                                TABLE OF CONTENTS

        (THIS TABLE OF CONTENTS IS NOT A PART OF THIS INDENTURE OF TRUST
                   AND IS FOR CONVENIENCE OF REFERENCE ONLY.)


<TABLE>
<S>                                                                                                     <C>
ARTICLE I

DEFINITIONS ...........................................................................................  5
                  SECTION 101.      DEFINITIONS........................................................  5
                  SECTION 102.      RULES OF CONSTRUCTION.............................................. 13

ARTICLE II

THE BONDS.............................................................................................. 14
                  SECTION 201.      AUTHORIZED AMOUNT OF BONDS......................................... 14
                  SECTION 202.      ISSUANCE OF THE SERIES 1995A BONDS; CERTAIN TERMS.................. 14
                  SECTION 203.      INTEREST ON THE BONDS.............................................. 15
                  SECTION 204.      FORM OF BONDS AND TEMPORARY BONDS.................................. 15
                  SECTION 205.      EXECUTION; SPECIAL LIMITED OBLIGATION.............................. 16
                  SECTION 206.      AUTHENTICATION..................................................... 16
                  SECTION 207.      DELIVERY OF THE SERIES 1995A BONDS................................. 16
                  SECTION 208.      ISSUANCE OF ADDITIONAL BONDS....................................... 17
                  SECTION 209.      MUTILATED, LOST, STOLEN OR DESTROYED BONDS......................... 19
                  SECTION 210.      BOND REGISTER; TRANSFER AND EXCHANGE OF BONDS; PERSONS
                                    TREATED AS OWNERS.................................................. 19
                  SECTION 211.      BOOK ENTRY PROVISIONS.............................................. 20
                  SECTION 212.      CANCELLATION....................................................... 22

ARTICLE III

REDEMPTION OF BONDS.................................................................................... 24
                  SECTION 301.      OPTIONAL REDEMPTION OF SERIES 1995A BONDS.......................... 24
                  SECTION 302.      EXTRAORDINARY OPTIONAL REDEMPTION.................................. 24
                  SECTION 303.      SPECIAL MANDATORY REDEMPTION....................................... 25
                  SECTION 304.      NOTICE OF REDEMPTION............................................... 26
                  SECTION 305.      BONDS PAYABLE ON REDEMPTION DATE................................... 27
                  SECTION 306.      BONDS REDEEMED IN PART............................................. 27
                  SECTION 307.      ELECTION TO REDEEM; NOTICE TO TRUSTEE AND ISSUER................... 27
                  SECTION 308.      SELECTION OF BONDS TO BE REDEEMED.................................. 27
                  SECTION 309.      DEPOSIT OF REDEMPTION PRICE........................................ 28

ARTICLE IV

FUNDS AND ACCOUNTS..................................................................................... 29
                  SECTION 401.      ESTABLISHMENT OF FUNDS AND ACCOUNTS................................ 29
                  SECTION 402.      DISPOSITION OF PROCEEDS OF SALE OF SERIES 1995A BONDS.............. 29
                  SECTION 403.      BOND FUND.......................................................... 29
                  SECTION 404.      CONSTRUCTION FUND.................................................. 30
                  SECTION 405.      REBATE FUND........................................................ 31
</TABLE>


                                       i



<PAGE>   3







<TABLE>
<S>                                                                                                     <C>
ARTICLE V

INVESTMENT OF MONEYS................................................................................... 33

ARTICLE VI

SATISFACTION OF THE INDENTURE.......................................................................... 34
                  SECTION 601.      DISCHARGE OF INDENTURE............................................. 34
                  SECTION 602.      BONDS DEEMED PAID.................................................. 34

ARTICLE VII

GENERAL COVENANTS...................................................................................... 36
                  SECTION 701.      PAYMENT OF PRINCIPAL, PREMIUM, IF ANY, AND INTEREST; NO
                                    GENERAL OBLIGATION................................................. 36
                  SECTION 702.      PERFORMANCE OF COVENANTS; LEGAL AUTHORIZATION...................... 36
                  SECTION 703.      FURTHER ASSURANCES................................................. 36
                  SECTION 704.      IMMUNITIES AND LIMITATIONS OF RESPONSIBILITY OF ISSUER............. 36
                  SECTION 705.      RECORDING AND FILING............................................... 37
                  SECTION 706.      BOOKS AND RECORDS.................................................. 37
                  SECTION 707.      DEFENSE OF ISSUER'S RIGHTS......................................... 37
                  SECTION 708.      ARBITRAGE; COMPLIANCE WITH PROCEEDS CERTIFICATE.................... 37

ARTICLE VIII

EVENTS OF DEFAULT...................................................................................... 38
                  SECTION 801.      EVENTS OF DEFAULT.................................................. 38
                  SECTION 802.      ACCELERATION....................................................... 39
                  SECTION 803.      REMEDIES; RIGHTS OF BONDHOLDERS.................................... 39
                  SECTION 804.      TRUSTEE MAY FILE PROOFS OF CLAIM................................... 40
                  SECTION 805.      DIRECTION OF PROCEEDINGS BY BONDHOLDERS............................ 40
                  SECTION 806.      APPOINTMENT OF RECEIVERS........................................... 41
                  SECTION 807.      APPLICATION OF MONEYS.............................................. 41
                  SECTION 808.      REMEDIES VESTED IN TRUSTEE......................................... 42
                  SECTION 809.      RIGHTS AND REMEDIES OF BONDHOLDERS................................. 42
                  SECTION 810.      TERMINATION OF PROCEEDINGS......................................... 43
                  SECTION 811.      WAIVERS OF EVENTS OF DEFAULT....................................... 43
                  SECTION 812.      NOTICE OF DEFAULT.................................................. 43
                  SECTION 813.      DEMAND UNDER GUARANTY.............................................. 43
                  SECTION 814.      LIMITATION OF LIABILITY............................................ 43

ARTICLE IX

TRUSTEE................................................................................................ 44
                  SECTION 901.      ACCEPTANCE OF TRUSTS............................................... 44
                  SECTION 902.      COMPENSATION AND EXPENSES OF TRUSTEE............................... 46
                  SECTION 903.      NOTICE TO BONDHOLDERS IF DEFAULT OCCURS............................ 46
                  SECTION 904.      GOOD FAITH RELIANCE................................................ 47
                  SECTION 905.      DEALINGS IN BONDS.................................................. 47
                  SECTION 906.      INTERVENTION BY TRUSTEE............................................ 47
                  SECTION 907.      SUCCESSOR TRUSTEE BY MERGER OR CONSOLIDATION....................... 47
</TABLE>


                                       ii





<PAGE>   4






<TABLE>
<S>               <C>               <C>                                                                 <C>

                  SECTION 908.      TRUSTEE REQUIRED; ELIGIBILITY...................................... 47
                  SECTION 909.      RESIGNATION BY THE TRUSTEE......................................... 48
                  SECTION 910.      REMOVAL OF THE TRUSTEE............................................. 48
                  SECTION 911.      APPOINTMENT OF SUCCESSOR TRUSTEE BY THE BONDHOLDERS;
                                    TEMPORARY TRUSTEE.................................................. 48
                  SECTION 912.      JUDICIAL APPOINTMENT OF SUCCESSOR TRUSTEE.......................... 48
                  SECTION 913.      CONCERNING ANY SUCCESSOR TRUSTEES.................................. 49
                  SECTION 914.      SUCCESSOR TRUSTEE AS TRUSTEE OF FUNDS.............................. 49

ARTICLE X

SUPPLEMENTAL INDENTURES................................................................................ 50
                  SECTION 1001.     SUPPLEMENTAL INDENTURES NOT REQUIRING CONSENT OF
                                    BONDHOLDERS........................................................ 50
                  SECTION 1002.     SUPPLEMENTAL INDENTURES REQUIRING CONSENT OF BONDHOLDERS........... 51

ARTICLE XI

AMENDMENTS TO THE LOAN AGREEMENT....................................................................... 54
                  SECTION 1101.     AMENDMENTS, ETC. TO LOAN AGREEMENT NOT REQUIRING CONSENT........... 54
                  SECTION 1102.     AMENDMENTS, ETC. TO LOAN AGREEMENT REQUIRING CONSENT OF
                                    BONDHOLDERS........................................................ 54

ARTICLE XII

MISCELLANEOUS.......................................................................................... 56
                  SECTION 1201.     PARTIES IN INTEREST................................................ 56
                  SECTION 1202.     SEVERABILITY....................................................... 56
                  SECTION 1203.     DELIVERY OF NOTICES; DELIVERY OF BONDS............................. 56
                  SECTION 1204.     COUNTERPARTS....................................................... 57
                  SECTION 1205.     GOVERNING LAW...................................................... 57
                  SECTION 1206.     IMMUNITY OF OFFICERS AND EMPLOYEES OF ISSUER....................... 57
                  SECTION 1207.     BONDS OWNED BY THE ISSUER, THE GUARANTOR OR THE COMPANY............ 57
                  SECTION 1208.     PLEDGE AND UNDERTAKING OF THE STATE................................ 57
</TABLE>



                                      iii






<PAGE>   5







      THIS INDENTURE OF TRUST, dated as of February 1, 1995 (the "Indenture"),
between CARBON COUNTY, UTAH (the "Issuer"), a duly organized and existing
political subdivision of the State of Utah, whose mailing address is 120 East
Main Street, Price, Utah 84501, and WEST ONE BANK, UTAH (the "Trustee"), a
banking institution duly established, existing and authorized to accept and
execute trusts of the character herein set out under and by virtue of the laws
of the State of Utah, whose principal corporate trust office, domicile and
mailing address is 107 South Main Street, Salt Lake City, Utah 84111, Attention:
Corporate Trust Department:

                                   WITNESSETH:

      WHEREAS, the Legislature of the State of Utah has enacted the Utah
Industrial Facilities and Development Act, Title 11, Chapter 17, Utah Code
Annotated 1953, as amended (the "Act"), for the purpose of achieving greater
industrial development in the State of Utah and protecting and promoting the
health, welfare and safety of the citizens of the State of Utah; and

      WHEREAS, the Act authorizes counties of the State of Utah to issue revenue
bonds for the purpose, among other things, of defraying the cost of financing,
acquiring, constructing, improving, equipping, furnishing or maintaining any
project or projects suitable for, among other things, industrial purposes, for
the reduction, abatement or prevention of pollution and for any other business
purpose, such project or projects to consist of any land, interest in land,
building, structure, facility, system, fixture, improvement, appurtenance,
machinery or equipment; and

      WHEREAS, the Issuer is a county of the State of Utah within the meaning of
the Act; and

      WHEREAS, the Issuer has previously issued its Unit Priced Demand
Adjustable Solid Waste Disposal Refunding Revenue Bonds (Union Pacific
Corporation/ECDC Environmental, L.C. Project), Series 1993A in an aggregate
principal amount of $15,000,000 (the "Series 1993A Bonds") and its Solid Waste
Disposal Refunding Revenue Bonds (East Carbon Landfill Project-- Short-Term
Series 1994) (the "Series 1994 Bonds") in the outstanding principal amount of
$35,242,500 (the Series 1993A Bonds and Series 1994 Bonds are collectively
referred to herein as the "Prior Bonds") for the purpose of paying a portion of
the costs of financing, acquiring, constructing, improving, equipping, and
furnishing certain facilities for ECDC Environmental, L.C., a Utah limited
liability company (the "Company"), consisting of land, interests in land,
buildings, structures, facilities, systems, fixtures, improvements,
appurtenances, machinery, rail cars, vehicles, containers, and equipment to be
located and/or utilized within the boundaries of the Issuer, and suitable for
use as a solid waste disposal facility (the "Project") or to refund bonds issued
for such purposes; and

      WHEREAS, the Issuer is authorized by the provisions of the Act to issue
its revenue refunding bonds to refund all or a portion of the Prior Bonds and
the issuance of such bonds to refund the Prior Bonds will provide financing for
the cost of the Project to be financed by the Prior Bonds; and

      WHEREAS, the Company has requested that the Issuer issue bonds to finance
the refunding of all of the Series 1993A Bonds and a portion of the Series 1994
Bonds; and

      WHEREAS, upon the issuance of the Series 1995A Bonds (defined below), an
amount equal to $15,000,000 of the proceeds of said Series 1995A Bonds shall be
used to refund and retire the Series 1993A Bonds and an amount equal to
$8,000,000 of the proceeds of said Series 1995A Bonds shall be used to refund
and retire $8,000,000 principal amount of the




                                       1
<PAGE>   6

Series 1994 Bonds which, in turn, will cause $8,000,000 from proceeds of the
Series 1994 Bonds to be deposited with the Trustee to be used (1) to pay certain
costs of financing, acquiring, constructing, improving, equipping, and
furnishing the Project, and (2) to pay costs and expenses incurred in connection
with the issuance of the Series 1995A Bonds, all as permitted under the Act; and

      WHEREAS, pursuant to the Act, in connection with the issuance of the
Series 1995A Bonds under the Act, the Issuer is entitled to provide for and
enter into agreements incident to the financing of the Project to accomplish the
purposes of the Act and the performance of the Issuer's obligations relative to
the Series 1995A Bonds, including but not limited to the specification of the
terms and conditions under which the Series 1995A Bonds may be issued, the
officer of the Issuer responsible for the issuance, execution and delivery of
the Series 1995A Bonds, the source of payment on the Series 1995A Bonds and all
other details necessary or appropriate for the issuance of the Series 1995A
Bonds not inconsistent with the Act, it being the intention of the Issuer that
the provisions of this Indenture are determined and established in compliance
with and in furtherance of the authority granted the Issuer under the Act to
accomplish the foregoing purposes; and

      WHEREAS, pursuant to and in accordance with the provisions of the Act, by
resolution duly adopted (the "Resolution"), and in furtherance of the intent and
purposes of the Act, the Issuer has authorized the issuance of its Solid Waste
Disposal Refunding Revenue Bonds (Laidlaw Inc./ECDC Environmental, L.C.
Project), 1995 Series A, in an aggregate principal amount not to exceed
$23,000,000 (the "Series 1995A Bonds") and the execution and delivery of an
indenture providing for the issuance of such Series 1995A Bonds and for their
security; and

      WHEREAS, the Issuer will loan the proceeds of the Series 1995A Bonds to
the Company pursuant to a Loan Agreement, dated as of February 1, 1995 (the
"Loan Agreement"), by and between the Company and the Issuer, pursuant to which
the Company will covenant, among other things, to make payments at such times
and in such amounts so as to provide for payment of (i) the principal of,
premium, if any, and interest on the Series 1995A Bonds outstanding under this
Indenture, and (ii) all other amounts payable under this Indenture; and

      WHEREAS, Laidlaw Inc., a Canadian corporation (the "Guarantor") is the
indirect owner of approximately 80% of the membership interest of the Company
and the Guarantor desires to execute and deliver a Guaranty (the "Guaranty")
whereby the Guarantor will guaranty payment of all obligations of the Company
with respect to the Series 1995A Bonds; and

      WHEREAS, the Issuer is authorized under the Act to issue its revenue bonds
for the aforesaid purposes and the Issuer has determined that the public
interest will be best served and that the purposes of the Act can be
advantageously achieved by the Issuer's issuance of the Series 1995A Bonds in
order to obtain funds to loan to the Company for the foregoing purposes; and

      WHEREAS, provision is made herein for the issuance of additional bonds
from time to time which will rank on a parity with the Series 1995A Bonds for
the purposes, upon the terms and subject to the conditions provided for herein;
and

      WHEREAS, all things necessary to make the Series 1995A Bonds, when
authenticated by the Trustee and issued as in this Indenture provided, the
valid, binding and legal obligations of the Issuer according to the import
thereof, and to constitute this Indenture a valid assignment



                                       2
<PAGE>   7

and pledge of the payments and prepayments under the Loan Agreement to be
applied to the payment of the principal of, premium, if any, and interest on the
Bonds (as hereinafter defined) and to the payment of certain other amounts, and
a valid assignment of the right, title and interest of the Issuer under the Loan
Agreement and amounts payable to the Issuer under the Loan Agreement (except
fees and expenses payable to the Issuer and the Issuer's rights relating to
indemnification and notice), have been done and performed, and the creation,
execution and delivery of this Indenture, and the creation, execution and
issuance of the Series 1995A Bonds, subject to the terms hereof, have in all
respects been duly authorized:

      NOW, THEREFORE, THIS INDENTURE WITNESSETH:

      That the Issuer, in consideration of the premises and the acceptance by
the Trustee of the trusts hereby created and of the purchase and acceptance of
the Bonds by the owners thereof, and of other good and lawful consideration, the
receipt of which is hereby acknowledged, and to secure the payment of the
principal of, premium, if any, and interest on the Bonds according to their
tenor and effect and the payment of certain other amounts and to secure the
performance and observance by the Issuer of all of the covenants and conditions
herein or therein contained, by these presents does hereby convey, assign,
transfer, pledge, set over and confirm and grant a security interest in, unto
the Trustee, its successor or successors and its or their assigns forever, with
power of sale, all and singular the property hereinafter described (said
property being herein sometimes referred to as the "Trust Estate"), to wit:

                                GRANTING CLAUSES

                                   DIVISION I

      All right, title and interest of the Issuer in and to the Loan Agreement
and the amounts payable to the Issuer under the Loan Agreement (excluding the
Issuer's rights relating to the payment of fees, the reimbursement of expenses,
indemnification and notice);

                                   DIVISION II

      The Bond Fund and the Construction Fund (as each such term is hereinafter
defined), including moneys and obligations therein, held by the Trustee (except
moneys or obligations deposited with or paid to the Trustee for payment or
redemption of Bonds that are deemed no longer to be outstanding hereunder)
pursuant to the terms of this Indenture;

                                  DIVISION III

      Any and all other property of every kind and nature from time to time
hereafter, by delivery or by writing of any kind, conveyed, pledged, assigned or
transferred as and for additional security hereunder by the Issuer or the
Company or by anyone on their behalf to the Trustee, subject to the terms
thereof, including without limitation debt service reserve or similar funds,
letters or lines of credit, bond insurance policies, guaranties, or other forms
of credit enhancement or funds of the Company held by the Trustee as security
for the Bonds.



                                       3
<PAGE>   8


                                EXCEPTED PROPERTY

      There is, however, expressly excepted and excluded from the lien and
operation of this Indenture amounts to be transferred pursuant to this Indenture
to, or held by the Trustee in, the Rebate Fund established hereunder;

      TO HAVE AND TO HOLD, all and singular, the properties and the rights and
privileges hereby conveyed, assigned and pledged by the Issuer or intended so to
be, unto the Trustee and its successors and assigns forever, in trust,
nevertheless, with power of sale for the equal and pro rata benefit and security
of each and every owner of the Bonds issued and to be issued hereunder, without
preference, priority or distinction as to participation in the lien, benefit and
protection hereof of one Bond over or from the others, by reason of priority in
the issue or negotiation or maturity thereof, or for any other reason
whatsoever, except as herein otherwise expressly provided, so that each and all
of such Bonds shall have the same right, lien and privilege under this Indenture
and shall be equally secured hereby with the same effect as if the same had all
been made, issued and negotiated simultaneously with the delivery hereof and
were expressed to mature on one and the same date;

      PROVIDED, NEVERTHELESS, and these presents are upon the express condition
that if the Issuer or its successors or assigns shall well and truly pay or
cause to be paid the principal of the Bonds, with interest according to the
provisions set forth in the Bonds, or shall provide for the payment or
redemption of the Bonds by depositing or causing to be deposited with the
Trustee the entire amount of funds or securities required for payment or
redemption thereof when and as authorized by the provisions hereof, or shall
provide, as permitted hereby, for the payment thereof in accordance with Article
VI hereof, and shall also pay or cause to be paid all other sums payable
hereunder by the Issuer, then these presents and the estate and rights hereby
granted shall cease, determine and become void, and thereupon the Trustee, on
payment of its lawful charges and disbursements then unpaid, on demand of the
Issuer and upon the payment of the costs and expenses thereof, shall duly
execute, acknowledge and deliver to the Issuer and the Company such instruments
of satisfaction or release as may be necessary or proper to discharge this
Indenture, including, if appropriate, any required discharge of record, and if
necessary shall grant, reassign and deliver to the Issuer, its successors or
assigns, all and singular the property, rights, privileges and interests by it
hereby granted, conveyed and assigned, and all substitutes therefor, or any part
thereof, not previously disposed of or released as herein provided; otherwise
this Indenture shall be and remain in full force and effect.

      AND IT IS HEREBY COVENANTED, DECLARED AND AGREED by and between the
parties hereto that all Bonds are to be issued, authenticated and delivered, and
that all the Trust Estate is to be held and applied, subject to the further
covenants, conditions, releases, uses and trusts hereinafter set forth, and the
Issuer, for itself and its successors, does hereby covenant and agree to and
with the Trustee and its respective successors in said trust, for the benefit of
those who shall hold the Bonds, or any of them, as follows:





                                       4
<PAGE>   9




                                    ARTICLE I

                                   DEFINITIONS

      SECTION 101. DEFINITIONS. To the extent not defined herein, capitalized
terms used in this Indenture shall have the same meanings as set forth in the
Loan Agreement. In addition to the capitalized words and terms used herein and
defined in the Loan Agreement or elsewhere in this Indenture, the following
words and terms as used in this Indenture shall have the following meanings
unless the context or use indicates another or different meaning or intent:

      "ACT" means the Utah Industrial Facilities and Development Act, Title 11,
Chapter 17, Utah Code Annotated 1953, as amended.

      "ACT OF BANKRUPTCY OF GUARANTOR" means that the Guarantor has become
insolvent or has failed to pay its debts generally as such debts become due or
has admitted in writing its inability to pay any of its indebtedness or has
consented to or has petitioned or applied to any authority for the appointment
of a receiver, liquidator, trustee, or similar official for itself or for all or
any substantial part of its properties or assets or that any such trustee,
receiver, liquidator, or similar official has otherwise been appointed or that
bankruptcy, insolvency, reorganization, arrangement, or liquidation proceedings
(or similar proceedings) have been instituted by or against the Guarantor, and,
in the case such proceedings are instituted against the Guarantor, such
proceedings continue undismissed in excess of 90 days.

      "ADDITIONAL BONDS" means the parity bonds authorized to be issued by the
Issuer pursuant to the terms and conditions of this Indenture in addition to the
Series 1995A Bonds.

      "AFFILIATE" means, with respect to the Company, any other Person which,
directly or indirectly, through one or more intermediaries, controls or is
controlled by, or is under common control with, the Company. For the purposes of
this definition, the term "control" means the possession, directly or
indirectly, of the power to direct or cause the direction of the management and
policies of the Company, whether through the ownership of voting securities, by
contract or otherwise; and the terms "controlling" and "controlled" have
meanings correlative to the foregoing.

      "AUTHORIZED COMPANY REPRESENTATIVE" means the person or persons at the
time and from time to time designated, by written certificate furnished to the
Issuer and the Trustee, as the person or persons authorized to act on behalf of
the Company. Such certificate shall contain the specimen signature of such
person or persons, shall be signed on behalf of the Company by the President,
any Vice President, a Treasurer or any Assistant Treasurer of the Company and
may designate alternate Authorized Company Representatives. The Authorized
Company Representative may, but need not, be an employee of the Company.

      "AUTHORIZED DENOMINATIONS" means $5,000 and any integral multiple thereof.

      "AUTHORIZED GUARANTOR REPRESENTATIVE" means the person or persons at the
time and from time to time designated, by written certificate furnished to the
Issuer and the Trustee, as the person or persons authorized to act on behalf of
the Guarantor. Such certificate shall contain the specimen signature of such
person or persons, shall be signed on behalf of the Guarantor by the President,
any Executive Vice President or Senior Vice President or the Treasurer of the
Guarantor and may designate alternate Authorized Guarantor Representatives. The
Authorized Guarantor Representative may, but need not, be an employee of the
Guarantor.



                                       5
<PAGE>   10



      "AUTHORIZED ISSUER REPRESENTATIVE" means the person or persons at the time
and from time to time designated, by written certificate furnished to the
Company and the Trustee, as the person or persons authorized to act on behalf of
the Issuer. Such certificate shall contain the specimen signature of such person
or persons, shall be signed on behalf of the Issuer by the Chairman of the
Governing Body and may designate alternate Authorized Issuer Representatives.
The Authorized Issuer Representative may, but need not, be an employee of the
Issuer.

      "BANKRUPTCY CODE" means Title 11 of the United States Code, as now or
hereafter constituted.

      "BOND COUNSEL" means the firm of Ballard Spahr Andrews & Ingersoll, or any
other law firm having a national reputation in the field of municipal law whose
opinions are generally accepted by purchasers of municipal bonds and appointed
by resolution of the Issuer.

      "BOND FUND" means the trust fund so designated which is created and
established with the Trustee pursuant to Section 401 hereof.

      "BONDHOLDER", "HOLDER", "OWNER" or "OWNER OF THE BONDS" means the
registered owner of any Bond.

      "BOND PURCHASE CONTRACT" means a bond purchase contract between the Issuer
and BA Securities, Inc., providing for its purchase from time to time of Series
1995A Bonds.

      "BOND REGISTER" means the registration books of the Issuer kept by the
Trustee to evidence the registration, transfer and exchange of Bonds.

      "BOND RESOLUTION" means the resolution of the Governing Body adopted
February 1, 1995 authorizing the issuance and sale of the Series 1995A Bonds.

      "BONDS" means the Series 1995A Bonds and any Additional Bonds,
collectively.

      "BUSINESS DAY" means any day other than (a) a Saturday, (b) a Sunday, (c)
a day on which (i) the Principal Office of the Trustee, or (ii) banking
institutions located in the City of New York, New York, are authorized or
required by law or executive order to be closed, or (d) a day on which the New
York Stock Exchange is closed.

      "CHAIRMAN" means the duly elected Chairman or Vice Chairman of the
Governing Body or any successor to the principal functions thereof or any other
member of the Governing Body temporarily designated by the Issuer to serve pro
tempore as Chairman.

      "CODE" means the Internal Revenue Code of 1986, as amended from time to
time. Each reference to a Section of the Code herein shall be deemed to include
the United States Treasury Regulations, including temporary and proposed
regulations, relating to such Section which are applicable to the Bonds or the
use of the proceeds thereof.

      "COMPANY" means ECDC Environmental, L.C., a Utah limited liability
company, its successors and assigns and any surviving, resulting or transferee
entity as permitted under the Loan Agreement.

      "COMPANY DOCUMENTS" means the Loan Agreement and the Proceeds Certificate.


                                       6
<PAGE>   11






      "COMPLETION CERTIFICATE" means the certificate delivered by the Company
pursuant to Section 3.4 of the Loan Agreement.

      "CONSTRUCTION" (and other forms of the word "construct"), when used with
reference to any portion of the Project, means acquisition, construction,
improvement, renovation, equipping, installation and furnishing.

      "CONSTRUCTION FUND" means the trust fund so designated which is created
and established pursuant to Section 401 hereof.

      "DEFAULT RATE" means the per annum rate of interest announced publicly by
the Trustee from time to time as its base rate.

      "DELIVERY DATE" means each date on which any of the Bonds are initially
authenticated and delivered hereunder.

      "DTC" means The Depository Trust Company, New York, New York, a
limited-purpose trust company organized under the laws of the State of New York.

      "ELIGIBLE SECURITIES" means, to the extent permitted by law, any of the
following securities, maturing (or redeemable at the option of the holder
thereof), at such time or times as to enable disbursements to be made from the
fund in which such investment is held in accordance with the terms hereof:

                  (a) Direct obligations of the United States of America or
            obligations to the full and prompt payment of which the full faith
            and credit of the United States of America is pledged or evidences
            of direct ownership in future interest and principal payments on
            such obligations held by a bank or trust company, as custodian,
            under which the owner of the investment is the real party in
            interest and has the right to proceed directly and individually
            against the obligor on such obligations, and which underlying
            obligations are not available to satisfy any claim of the custodian
            or any person claiming through the custodian or to whom the
            custodian may be obligated;

                  (b)

                        (i)  any obligation, the interest on which is excludable
                  from gross income of the owner thereof for federal income tax
                  purposes; and

                        (ii) stock of a corporation during any quarter of the
                  taxable year of the corporation that--

                             (1) the corporation is a regulated investment
                        company (as defined in Section 851(a) of the Code)
                        which, for the taxable year, meets the requirements of
                        Section 852(a) of the Code;

                             (2) the corporation has authorized and outstanding
                        only one class of stock;




                                       7
<PAGE>   12





                       (3)   the corporation to the extent practicable invests
                 all its assets in obligations described in subclause (i) of
                 this clause (b); and

                       (4)   at least 98 percent of--

                             (A)   the gross income of the corporation (without 

                       regard to the exclusion of interest from gross income
                       under Section 103 of the Code) is derived from interest
                       on or gains from the sale or other disposition of
                       obligations described in subclause (i) of this clause
                       (b); or

                             (B)   the weighted average value of the assets of 
                       the corporation is represented by investments in
                       obligations described in subclause (i) of this clause
                       (b); and

                 (iii) any other investment which qualifies as a tax-exempt
           bond for purposes of Section 148(b)(3)(A) of the Code and the
           applicable United States Treasury Regulations;

           provided that, at the time of purchase of any investment under this
           clause (b), such investment is rated in either of the two highest
           rating categories (without regard to pluses or minuses) of the
           Rating Services;

           (c)   Evidences of indebtedness issued by any of the following: Bank
     for Cooperatives; Export-Import Bank of the United States; Farmers Home
     Administration; Federal Financing Bank; Federal Home Loan Bank System;
     Federal Home Loan Mortgage Corporation (including participation
     certificates); Federal Housing Administration; Federal Intermediate Credit
     Banks; Federal Land Banks; Federal National Mortgage Association;
     Government National Mortgage Association; Small Business Administration;
     Student Loan Marketing Association; or any other agency or instrumentality
     of the United States of America created by an act of Congress which is
     substantially similar to the foregoing in its legal relationship to the
     United States of America, provided that at the time of their purchase such
     obligations of such other agency or instrumentality are guaranteed by the
     full faith and credit of the United States of America or are rated in
     either of the two highest rating categories (without regard to pluses or
     minuses) of the Rating Services;

           (d)   Obligations of any person, including the Trustee, provided
     that, at the time of their purchase, such obligations are rated in either
     of the two highest rating categories (without regard to pluses or minuses)
     of the Rating Services;

           (e)   Demand deposits or interest-bearing time deposits,
     certificates of deposit or other similar banking arrangements that are
     made with the Trustee or with any other bank having deposits insured by
     the Federal Deposit Insurance Corporation ("FDIC"), or any savings and
     loan association having deposits insured by the Resolution Trust
     Corporation ("RTC"), provided that


                                      8
<PAGE>   13





      such time deposits or certificates of deposit or other similar banking
      arrangements are: (i) fully insured by the FDIC or the RTC, (ii) made with
      any bank (including the Trustee) having undivided capital and surplus of
      at least $100,000,000, the debt obligations (or, in the case of the
      principal bank in a bank holding company, debt obligations of the bank
      holding company) of which are rated in either of the two highest rating
      categories (without regard to pluses or minuses) of the Rating Services,
      or (iii) continuously secured as to principal, to the extent not insured
      by the FDIC or the RTC, (A) by lodging with a bank or trust company other
      than the depository, as collateral security, and granting to the Trustee a
      perfected first security interest therein, obligations described in clause
      (a), (b) or (c) above or, with the approval of the Trustee, other
      marketable securities eligible as security for the deposit of trust funds
      under applicable regulations, having a market value (exclusive of accrued
      interest) not less than the amount of such deposit and not subject to the
      prior claims of any third parties, or (B) if the furnishing of security as
      provided in clause (A) of this clause is not permitted by applicable law,
      in such other manner as may then be required or permitted by applicable
      State or federal laws and regulations regarding the security for, or
      granting a preference in the case of the deposit of, trust funds;

            (f)   Investment agreements or repurchase agreements with any
      institution (including the Trustee), the long-term debt or claims paying
      ability of which is rated in either of the two highest rating categories
      (without regard to pluses or minuses) of the Rating Services;

            (g)   Repurchase agreements with a financial institution (including
      the Trustee) having deposits insured by the FDIC or the RTC, or any broker
      or dealer that is a dealer in government bonds and that is recognized by,
      trades with and reports to, a Federal Reserve Bank as a primary dealer in
      government securities, provided in any case: (i) the collateral for the
      repurchase agreement, at the last determination thereof, is described in
      clause (a), (b) or (c) above, (ii) the current market value of the
      collateral securing the repurchase agreement, at the last determination
      thereof, is at least equal to the amount of the repurchase agreement and
      is determined not less frequently than monthly, (iii) the collateral is
      held for the benefit of the Trustee by a Person other than the obligor on
      such repurchase agreement and (iv) the collateral is not subject to the
      prior claims of any third parties;

            (h)   Open market debt instruments (having an original maturity of
      365 days or less) that are rated in either of the two highest short-term
      debt rating categories (without regard to pluses or minuses) of the Rating
      Services;

            (i)   Investments in money market funds rated in either of the two
      highest rating categories (without regard to pluses or minuses) of the
      Rating Services; and

            (j)   Any fund or other pooling arrangement which exclusively
      purchases and holds one or more of the investments described in clauses
      (a) through (i), above.




                                       9
<PAGE>   14


      "EVENT OF DEFAULT" means (a) with respect to this Indenture, an "Event of
Default" as defined in Section 801 hereof and (b) with respect to the Loan
Agreement, an "Event of Default" as defined in Section 7.1 thereof.

      "FACILITY" means the solid waste landfill located in East Carbon City,
Utah consisting of (i) land and land improvements to be used as a site for
approximately 29 landfill cells for the disposal of nonhazardous solid waste;
(ii) the equipment, facilities, and improvements to be used in connection with
the operation of said landfill; and (iii) the rail cars, containers, and other
transportation equipment acquired by the Company to transport solid waste to the
landfill site.

      "GOVERNING BODY" means the Board of County Commissioners of the Issuer.

      "GOVERNMENT OBLIGATIONS" means obligations described in clause (a) of the
definition of Eligible Securities.

      "GUARANTOR" means Laidlaw Inc., a Canadian corporation and its successors
and assigns as permitted by the Guaranty.

      "GUARANTY" means the Guaranty from the Guarantor to the Trustee, dated as
of February 1, 1995, with respect to the Series 1995A Bonds.

      "IMMEDIATE NOTICE" means notice by telephone, telex or telecopier to such
address as the addressee shall have directed in writing, promptly followed by
written notice by first class mail, postage prepaid.

      "INDENTURE" means this Indenture of Trust, dated as of February 1, 1995,
between the Issuer and the Trustee, as the same may from time to time be amended
or supplemented in accordance with the terms hereof.

      "INTEREST PAYMENT DATE" means, with respect to any Bond each February 1
and August 1.

      "ISSUE DATE" means, with respect to the Series 1995A Bonds, their initial
Delivery Date.

      "ISSUER" means Carbon County, Utah.

      "ISSUER DOCUMENTS" means the Bond Resolution, the Loan Agreement, the
Indenture, and the Proceeds Certificate.

      "LOAN AGREEMENT" means the Loan Agreement dated as of February 1, 1995, by
and between the Company and the Issuer, as the same may from time to time be
amended or supplemented in accordance with the terms thereof and hereof.

      "MAXIMUM RATE" means the maximum interest rate per annum permitted under
Utah law to be borne by obligations similar to the Bonds.

      "OUTSTANDING", "BONDS OUTSTANDING" or "OUTSTANDING BONDS" means, as of any
given date, all Bonds which have been duly authenticated and delivered under
this Indenture, except:

                  (a) Bonds cancelled on or prior to such date or delivered to
            or acquired by the Trustee on or prior to such date for
            cancellation;


                                       10
<PAGE>   15


                  (b) Bonds deemed to be paid in accordance with Article VI of
            this Indenture; and

                  (c) Bonds in lieu of which other Bonds have been authenticated
            under Sections 204, 209, and 210 hereof.

      "PERSON" means any natural person, firm, joint venture, association,
partnership, business trust, corporation, public body, agency or political
subdivision thereof or any other similar entity.

      "PRINCIPAL OFFICE" means, when used with respect to the Issuer, the
Trustee, the Company and the Guarantor, each respective office of such Persons
designated in Section 1203 hereof. The Principal Office of any such Person may
be changed from time to time by delivering notice of such change to the Issuer,
the Trustee, the Company, and the Guarantor.

      "PRIOR BONDS" means the Issuer's Series 1993A Bonds and Series 1994 Bonds.
All of the Series 1993A Bonds and $8,000,000 in principal amount of the Series
1994 Bonds will be refunded pursuant to the Refunding with the proceeds of the
Series 1995A Bonds.

      "PROCEEDS CERTIFICATE" means that certain Proceeds Certificate, dated the
first Delivery Date, and executed by the Issuer and the Company, as amended from
time to time.

      "PROJECT" means the Project described in Exhibit A to the Loan Agreement
as the same may be amended from time to time in accordance with the provisions
of the Loan Agreement, including any other project undertaken by the Company and
financed through Additional Bonds issued under this Indenture.

      "PROJECT COSTS" OR "COSTS" means any cost of the Project or in respect of
the Project now or hereafter permitted under the Act. Without limiting the
generality of the foregoing, such costs may include: (i) amounts payable to
contractors and suppliers (including fees for designing the Project where the
designs are provided by the contractor or supplier); (ii) costs of labor,
services, materials, supplies and equipment furnished by the Borrower (including
shipping costs) plus the Borrower's standard overhead charge; (iii)
architectural, engineering, legal and other professional fees, marketing costs
and brokerage commissions; (iv) costs of funding a reserve to the extent
permitted by the Code; (v) interest on the Bonds to the extent permitted by the
Act; (vi) costs of financing including but not limited to bond discount,
printing expense, mortgage taxes and recording fees, Issuer and Trustee fees
accruing prior to completion of the Project, and legal and accounting fees.

      "QUALIFIED PROJECT COSTS" means the Project Costs, but only to the extent
such costs were paid or incurred by the Borrower after April 25, 1991 and only
to the extent that such costs are incurred for the acquisition, development,
construction, equipping and furnishing, or improvement of land or property of a
character subject to the allowance for depreciation provided in Section 167 of
the Code and are chargeable to the capital account of the Project or would be so
chargeable either with a proper election by the Borrower or but for a proper
election by the Borrower to deduct such costs, within the meaning of Treasury
Regulation Section 1.103-8(a)(1), as the same may be amended or supplemented
from time to time. "Qualified Project Costs" shall not include (i) working
capital and inventory costs, (ii) costs of issuance, and (iii) interest
following completion of construction of the Project. Interest during
construction of the Project shall be allocated proportionately between Qualified
Project Costs and other costs paid from Bond proceeds.



                                       11
<PAGE>   16




      "RATING SERVICES" means, collectively, Standard & Poor's Corporation, a
corporation organized and existing under the laws of the State of New York, and
its successors and assigns, and Moody's Investors Service, a corporation
organized and existing under the laws of the State of New York, and its
successors and assigns; provided that if such corporation shall be dissolved or
liquidated or shall no longer perform the functions of a securities rating
agency, "Rating Services" shall be deemed to refer to any other nationally
recognized securities rating agency designated by the Trustee, at the written
direction of the Company.

      "REBATABLE ARBITRAGE" shall mean, with respect to any Series of Bonds, the
amount (determined as of each Rebate Calculation Date) of rebatable arbitrage
payable to the United States at the times and in the amounts specified in
Section 148(f)(3) of the Code and Section 1.148-1 and 1.148-2 of the
Regulations.

      "REBATE CALCULATION DATE" means, with respect to each series of Bonds, the
interest payment date next preceding the fifth anniversary of the issue date of
such series of Bonds, each fifth anniversary of the initial Rebate Calculation
Date for such series of Bonds, and the date of retirement of the last Bond of
such series.

      "REBATE FUND" shall mean the fund established by Section 405 hereof.

      "RECORD DATE" means with respect to any Bond the fifteenth day of the
month preceding an Interest Payment Date with respect to such Bond.

      "REFUNDING" means the series of transactions whereby a portion of the
Prior Bonds are refunded and cancelled with the proceeds of the Series 1995A
Bonds authenticated and delivered on the first Delivery Date.

      "REGISTRAR" means the Trustee, when acting in accordance with Section 210
hereof.

      "REGULATIONS" and all references thereto shall mean and include applicable
final, proposed and temporary United States Treasury Regulations promulgated
with respect to Sections 103 and 141 through 150 of the Code, including all
amendments thereto made hereafter.

      "REQUIRED REBATE DEPOSIT" means with respect to any series of Bonds an
amount determinable as of each Rebate Calculation Date, which when added to
amounts then on deposit in the Rebate Fund with respect to such series of Bonds,
if any, equals the aggregate amount of Rebatable Arbitrage for such series of
Bonds less the amount of Rebatable Arbitrage theretofore paid to the United
States with respect to such series of Bonds, if any.

      "SERIES 1992 BONDS" means the Issuer's Solid Waste Disposal Refunding
Revenue Bonds, 1992 Series A (East Carbon Development Corporation Project)
issued pursuant to the Series 1992 Indenture.

      "SERIES 1992 INDENTURE" means that certain Indenture of Trust dated as of
May 1, 1992 between the Issuer and West One Bank, Utah.

      "SERIES 1992 LOAN AGREEMENT" means that certain Loan Agreement dated as of
May 1, 1992 between the Issuer and East Carbon Development Corporation, the
predecessor in interest of the Company, relating to the 1992 Bonds.




                                       12
<PAGE>   17






      "SERIES 1993A BONDS" means the Issuer's Unit Priced Demand Adjustable
Solid Waste Disposal Refunding Revenue Bonds (Union Pacific Corporation/ECDC
Environmental, L.C. Project) in the outstanding principal amount of $15,000,000.

      "SERIES 1993A INDENTURE" means that certain Indenture of Trust dated as of
June 1, 1993 between the Issuer and West One Bank, Utah, as Trustee.

      "SERIES 1994 BONDS" means the Issuer's Solid Waste Disposal Refunding
Revenue Bonds (East Carbon Landfill Project--Short Term Series 1994) in the
outstanding principal amount of $35,242,500.

      "SERIES 1994 LOAN AGREEMENT" means the Loan and Trust Agreement among the
Issuer, the Company and West One Bank, Utah, as Trustee, dated as of April 15,
1994.

      "SERIES 1995A BONDS" means the Issuer's Solid Waste Disposal Refunding
Revenue Bonds (Laidlaw Inc./ECDC Environmental, L.C. Project), 1995 Series A,
authorized by the Issuer to be authenticated and delivered from time to time
pursuant to the terms and conditions of this Indenture in an aggregate principal
amount not to exceed $23,000,000.

      "SPECIAL RECORD DATE" means the date fixed by the Trustee pursuant to
Section 202 of this Indenture for the payment of Defaulted Interest (as such
term is defined in Section 202 hereof).

      "STATE" means the State of Utah.

      "TRUST ESTATE" is defined in the Granting Clauses of this Indenture.

      "TRUSTEE" means West One Bank, Utah, Salt Lake City, Utah, and any
successor trustee under this Indenture.

      SECTION 102. RULES OF CONSTRUCTION. Unless the context shall otherwise
require,

                  (a) an accounting term not otherwise defined shall have the
            meaning assigned to it in accordance with generally accepted
            accounting principles as the same shall be in effect from time to
            time;

                  (b) references to Articles and Sections are to the Articles
            and Sections of this Indenture;

                  (c) words of the masculine gender shall be deemed and
            construed to include correlative words of the feminine and neuter
            genders;

                  (d) unless the context shall otherwise indicate, words
            importing the singular number shall include the plural and vice
            versa; and

                  (e) headings of Articles and Sections herein and the table of
            contents hereof are solely for convenience of reference, do not
            constitute a part hereof and shall not affect the meaning,
            construction or effect hereof.




                                       13
<PAGE>   18





                                   ARTICLE II

                                    THE BONDS

      SECTION 201. AUTHORIZED AMOUNT OF BONDS. No Bonds may be issued under the
provisions of this Indenture except in accordance with this Article. The total
principal amount of Bonds which may be issued hereunder is hereby expressly
limited (a) with respect to the Series 1995A Bonds authorized pursuant to
Section 202 hereof, to $23,000,000 and (b) with respect to any Additional Bonds
issued in accordance with Section 208 hereof, the amount permitted pursuant to
the provisions of Section 208 hereof and specified in any supplemental indenture
or supplemental indentures entered into pursuant to Section 208 and Article X
hereof.

      SECTION 202. ISSUANCE OF THE SERIES 1995A BONDS; CERTAIN TERMS. In order
to provide funds to refund a portion of the Prior Bonds and to finance a portion
of the Project Costs there is hereby authorized to be issued by the Issuer a
series of bonds which is hereby designated as the "Carbon County, Utah Solid
Waste Disposal Refunding Revenue Bonds (Laidlaw Inc./ ECDC Environmental, L.C.
Project), 1995 Series A". The Series 1995A Bonds may be authenticated and
delivered to the purchasers thereof at any time and from time to time as
provided in Section 207(b) hereof.

      The Series 1995A Bonds shall be issuable as fully registered bonds,
without coupons, in any Authorized Denomination, in substantially the form
described in Section 204 hereof. The Series 1995A Bonds shall be lettered "R"
and shall be numbered consecutively from one (1) upward. The Series 1995A Bonds
shall be dated the Issue Date, shall bear interest payable on each Interest
Payment Date beginning August 1, 1995, and shall mature, subject to prior
redemption, in the years and amounts as follows:

<TABLE>
<CAPTION>
================================================================================
        Year
    (February 1)           Principal Amount                 Interest Rate
--------------------------------------------------------------------------------
        <S>                   <C>                               <C> 
        2010                  $23,000,000                       7.5%
================================================================================
</TABLE>

      Each Bond authenticated prior to the first Interest Payment Date with
respect to such Bond shall bear interest from the Delivery Date thereof, as
evidenced by the Certificate of Authentication on such Bond. Each Bond
authenticated on or after the first Interest Payment Date with respect to such
Bond shall bear interest from the Interest Payment Date next preceding the date
of authentication thereof, unless the date of authentication shall be an
Interest Payment Date to which interest on such Bond has been paid in full or
duly provided for, in which case such Bond shall bear interest from the date of
authentication thereof; provided that if, as shown by the records of the
Trustee, interest on a Bond shall be in default, such Bond, or Bonds issued in
exchange for or upon the registration of transfer thereof, shall bear interest
from the date to which interest has been paid in full on the Bond or, if no
interest has been paid on the Bond with respect to which interest is in default,
the Delivery Date thereof.

      Interest on each Bond shall be payable on the Interest Payment Date
applicable thereto to the Person who, on the close of business on the Record
Date, is the registered holder thereof. Interest on any Bond shall be payable by
check mailed on the Interest Payment Date to the registered holder of such Bond
at the address of such registered holder set forth in the Bond Register.


                                       14
<PAGE>   19






      Interest on any Bond which is not punctually paid or duly provided for on
any Interest Payment Date (herein called "Defaulted Interest") shall forthwith
cease to be payable to the owner thereof on the relevant Record Date by virtue
of having been such owner, and such Defaulted Interest shall be paid to the
Person in whose name such Bond (or the respective predecessor Bond) is
registered at the close of business on a Special Record Date to be established
as hereinafter provided. The Trustee shall establish (a) the date on which the
Defaulted Interest shall be paid, (b) the amount of Defaulted Interest payable
on each Bond on such payment date and (c) a Special Record Date for the payment
of such Defaulted Interest, which Special Record Date shall be not more than
fifteen (15) nor less than ten (10) days prior to the payment date. Not less
than ten (10) days prior to the Special Record Date the Trustee shall cause
notice to be delivered to the Issuer, the Company, and each owner of Bonds as to
which Defaulted Interest is payable, which notice shall specify the proposed
payment date, the Special Record Date and, in the case of notice to the Company
and the Issuer, the total amount of Defaulted Interest payable with respect to
all Bonds payable on such proposed payment date, and in the case of notice to
each Bondholder, the amount of Defaulted Interest payable with respect to each
Bond held by such Bondholder. Such notice shall be mailed, first-class postage
prepaid, to the address of each Bondholder appearing in the Register. Upon
receipt of such notice, the Company shall, in accordance with the Loan
Agreement, deposit with the Trustee, as appropriate, an amount of money equal to
the aggregate amount of Defaulted Interest to be paid on the payment date, or
shall make arrangements satisfactory to the Trustee, as appropriate, for such
deposit prior to the proposed date of payment, such money when deposited to be
held in trust for the benefit of the persons entitled to such Defaulted Interest
as provided in this paragraph. Notice having been mailed as aforesaid, such
Defaulted Interest shall be paid to the Person in whose name the Bond (or the
respective predecessor Bond) is registered at the close of business on such
Special Record Date.

      The principal of (including the principal component of the redemption
price) and any applicable redemption premium on the Bonds are payable at the
Principal Office of the Trustee only upon presentation and surrender thereof.

      All payments of principal of, premium, if any, and interest on the Bonds
are payable in any coin or currency of the United States of America that is
legal tender for the payment of public and private debts on the respective dates
of payment thereof.

      SECTION 203. INTEREST ON THE BONDS.

                  (a) Calculation of Interest. Interest on the Bonds shall be
            calculated on the basis of a 360-day year composed of twelve 30-day
            months.

                  (b) Maximum Rate. None of the Bonds shall bear interest at a
            rate per annum in excess of the Maximum Rate.

      SECTION 204. FORM OF BONDS AND TEMPORARY BONDS. The Bonds issued under
this Indenture shall be in substantially the form set forth in Exhibit "A"
hereto, with such appropriate variations, omissions and insertions as are
permitted or required by this Indenture or deemed necessary by the Trustee and
the Issuer.

      Bonds of any series may be initially issued in temporary form exchangeable
for definitive Bonds of the same series when ready for delivery. The temporary
Bonds shall be in the form of registered Bonds without coupons in Authorized
Denominations, substantially in the form of Exhibit "A" hereto, with such
appropriate omissions, insertions and variations as may be


                                       15
<PAGE>   20






required with respect to such temporary Bonds and may contain such reference to
any of the provisions of this Indenture as may be appropriate. Every temporary
Bond shall be executed by the Issuer and be authenticated by the Trustee, upon
the same conditions and in substantially the same manner as the definitive
Bonds. If the Issuer issues temporary Bonds it will execute and furnish
definitive Bonds without delay and thereupon the temporary Bonds shall be
surrendered for cancellation in exchange therefor at the Principal Office of the
Trustee, and the Trustee shall authenticate and deliver in exchange for such
temporary Bonds an equal aggregate principal amount of definitive Bonds of the
same series and maturity in Authorized Denominations. Until so exchanged, the
temporary Bonds shall be entitled to the same benefits under this Indenture as
definitive Bonds authenticated and delivered hereunder.

      SECTION 205. EXECUTION; SPECIAL LIMITED OBLIGATION. The Bonds shall be
executed on behalf of the Issuer with the manual or facsimile signature of the
Chairman of the Governing Body and shall have impressed or imprinted thereon, by
facsimile or otherwise, the official seal of the Issuer and shall be attested
with the manual or facsimile signature of the Issuer's County Clerk. In case any
officer of the Issuer whose signature or whose facsimile signature shall appear
on the Bonds shall cease to be such officer before the delivery of such Bonds,
such signature or facsimile signature shall nevertheless be valid and sufficient
for all purposes, the same as if he had remained in office until delivery. The
Bonds are special, limited obligations of the Issuer, payable by the Issuer
solely from certain amounts received by the Issuer under, and secured by a
pledge of certain rights of the Issuer under and pursuant to, the Loan
Agreement, and, further, from the funds and accounts created hereunder (but not
including the Rebate Fund created hereunder) and investment earnings thereon,
all of which shall be used for no other purpose than to pay the principal of,
premium, if any, and interest on the Bonds, except as may be otherwise expressly
authorized in this Indenture. Neither the faith and credit nor the taxing power
of the State of Utah or any political subdivision thereof is pledged to the
payment of the principal of, premium, if any, or interest on the Bonds. The
Bonds and the interest thereon do not constitute or give rise to a general
obligation or liability of the Issuer or a charge against its general credit or
taxing powers and the Bonds do not constitute a loan of the credit of the Issuer
within the meaning of any constitutional restriction or statutory limitation of
the State of Utah.

      SECTION 206. AUTHENTICATION. No Bond shall be valid or obligatory for any
purpose or entitled to any security or benefit under this Indenture unless and
until the Certificate of Authentication on such Bond in substantially the form
set forth in Exhibit "A" hereto shall have been duly executed by the Trustee and
such execution shall be conclusive evidence that such Bond has been
authenticated and delivered under this Indenture and that the holder thereof is
entitled to the benefits of the trust hereby created. The Trustee shall insert
the authentication date on each Bond authenticated hereunder. The Certificate of
Authentication on any Bond shall be deemed to have been executed by it if
manually signed by an authorized officer or signatory of the Trustee, but it
shall not be necessary that the same officer or signatory sign the Certificate
of Authentication on all of the Bonds.

      SECTION 207. DELIVERY OF THE SERIES 1995A BONDS.

                  (a) Following the execution and delivery of this Indenture,
            the Issuer shall execute and deliver to the Trustee, and the Trustee
            shall authenticate, Series 1995A Bonds (in either temporary or
            definitive form), and shall deliver them to the purchasers thereof
            as directed by the Issuer as hereinafter in this Section provided.



                                       16
<PAGE>   21







                  (b)   Prior to the delivery by the Trustee on the Delivery 
      Date of any of the Series 1995A Bonds, there shall be delivered to the
      Trustee:

                        (i)    a copy, duly certified by the County Clerk of the
            Issuer, of all resolutions adopted and approved by the Issuer
            authorizing the issuance and sale of the Series 1995A Bonds and the
            execution and delivery of the Loan Agreement, the Proceeds
            Certificate, this Indenture and a Bond Purchase Contract relating to
            the Series 1995A Bonds being delivered on such Delivery Date;

                        (ii)   a copy, duly certified by a Vice President, the
            Secretary, an Assistant Secretary, the Treasurer or an Assistant
            Treasurer, as appropriate, of the Company, of all resolutions
            adopted and approved by the Company authorizing the execution and
            delivery of the Loan Agreement, the Proceeds Certificate, and
            approving this Indenture and the issuance and sale of the Series
            1995A Bonds and the terms thereof;

                        (iii)  an original executed counterpart of this
            Indenture, the Loan Agreement, and the Proceeds Certificate;

                        (iv)   a request and authorization to the Trustee on
            behalf of the Issuer and signed by the Chairman of the Governing
            Body, to authenticate and deliver Series 1995A Bonds in the
            aggregate principal amount specified therein to the purchasers
            specified therein upon payment to the Trustee, but for the account
            of the Issuer, of the net proceeds from the sale of such Series
            1995A Bonds;

                        (v)    the items required to be delivered prior to the
            issuance of such Series 1995A Bonds under the terms of the Bond
            Purchase Contract relating to such Series 1995A Bonds unless waived
            by the respective parties thereto;

                        (vi)   a certificate, signed by [a (Vice President) of
            the Company], with a copy to the Issuer, requesting the Trustee to
            cause Series 1995A Bonds in the amount specified in the request and
            authorization delivered pursuant to Clause (b)(v) of this Section to
            be authenticated and delivered, which certificate shall constitute
            conclusive evidence under Section 3.1 of the Loan Agreement of such
            request and approval;

                        (vii)  the original executed Guaranty, and a certificate
            signed by a duly authorized officer of the Guarantor and an opinion
            of counsel to the Guarantor in form and substance satisfactory to
            the original purchaser of the Series 1995A Bonds; and

                        (viii) such other closing documents and opinions of
            counsel (including Bond Counsel) as the Trustee, the Issuer or Bond
            Counsel may reasonably specify.

      SECTION 208. ISSUANCE OF ADDITIONAL BONDS. Additional Bonds (in addition
to the Series 1995A Bonds) may be issued by the Issuer on a parity with the
Series 1995A Bonds for any


                                       17
<PAGE>   22







one or more of the following purposes: (a) to refund any series of Outstanding
Bonds or portion thereof in a manner consistent with the provisions of Article
VI hereof; (b) to obtain funds to loan to the Company to complete the Facility;
(c) to obtain funds for any other purpose permitted under the Act; and (d) for
any combination of the foregoing purposes.

      The principal amount of such Additional Bonds may include an amount
sufficient to pay the costs and expenses of issuance as well as such capitalized
amounts as are permitted by the Act. Such Additional Bonds shall be issued on a
parity with the Series 1995A Bonds (subject, however, to the terms of Article VI
hereof) notwithstanding the fact that no additional security (except the
security provided by any supplements or amendments to the Loan Agreement) is
made subject to the lien of this Indenture. The foregoing notwithstanding, the
Trustee is authorized to accept additional security upon the issuance of any
series of Additional Bonds with respect to such series of Additional Bonds,
including but not limited to debt service reserve or similar funds, letters or
lines of credit, guaranties, bond insurance policies or other forms of credit
enhancement.

      Prior to the initial delivery of any Additional Bonds, there shall be
filed with the Trustee, among other items, all of the following:

                           (a) a written statement by the Company approving (i)
                  the issuance and delivery of such Additional Bonds and (ii)
                  any other matters to be approved by the Company pursuant to
                  the Loan Agreement and this Section 208;

                           (b) a copy, duly certified by the County Clerk of the
                  Issuer, of a resolution adopted and approved by the Governing
                  Body authorizing the execution and delivery of such
                  supplements or amendments to this Indenture and to the Loan
                  Agreement as may be necessary and authorizing the issuance of
                  such Additional Bonds;

                           (c) a copy, duly certified by a Vice President, the
                  Secretary, an Assistant Secretary, the Treasurer or an
                  Assistant Treasurer of the Company, of the resolutions adopted
                  and approved authorizing the execution and delivery of a
                  supplement or amendment to the Loan Agreement and such other
                  documents as may be required, and approving a supplement or
                  amendment to this Indenture and the issuance and sale of such
                  Additional Bonds;

                           (d) the original executed counterparts of the
                  supplements or amendments to this Indenture and the Loan
                  Agreement providing, among other things, for payments to be
                  made thereunder in amounts sufficient to cover payments of
                  principal, premium and interest to be made on the Additional
                  Bonds to be issued;

                           (e) a request and authorization to the Trustee,
                  signed by the Chairman of the Governing Body, to authenticate
                  and deliver such Additional Bonds (specifically stating the
                  principal amount to be issued and delivered to the purchasers
                  therein identified) upon payment to the Trustee, but for the
                  account of the Issuer, of a sum specified in such request and
                  authorization plus accrued interest, if any, thereon to the
                  date of delivery. The Trustee shall deposit the proceeds of
                  such Additional Bonds in the funds and accounts hereunder as
                  specified in the supplemental indenture relating to such
                  Additional Bonds;

                                       18
<PAGE>   23


                        (f) any required supplement or amendment to the Guaranty
                  or an additional guaranty and related opinions and
                  certificates; and


                        (g) such other closing documents and opinions of counsel
                  as the Issuer, the Trustee and Bond Counsel may reasonably
                  specify.

         SECTION 209. MUTILATED, LOST, STOLEN OR DESTROYED BONDS. In the event
any temporary or definitive Bond is mutilated, lost, stolen or destroyed, the
Issuer may execute and the Trustee may authenticate a new Bond of like form,
date, maturity and denomination as that mutilated, lost, stolen or destroyed and
bearing a number not contemporaneously Outstanding; provided that, in the case
of any mutilated Bond, such mutilated Bond shall first be surrendered to the
Issuer, and in the case of any lost, stolen or destroyed Bond, there shall be
first furnished to the Issuer and the Trustee evidence of such loss, theft or
destruction satisfactory to the Issuer and the Trustee, together with indemnity
satisfactory to them. In the event any such Bond shall have matured or is about
to mature or been called for redemption, instead of issuing a duplicate Bond the
Issuer may pay the same without surrender thereof upon compliance with the
foregoing. The Issuer and the Trustee may charge the holder or owner of such
Bond with their reasonable fees and expenses in this connection.

         All duplicate Bonds issued and authenticated pursuant to this Section
209 shall constitute original, contractual obligations of the Issuer (whether or
not, in the case of the first paragraph of this Section 209, lost or stolen
Bonds be at any time found by anyone) and shall be entitled to equal and
proportionate rights and benefits hereunder as all other Outstanding Bonds
issued hereunder.

         All Bonds shall be owned upon the express condition that the foregoing
provisions, to the extent permitted by law, are exclusive with respect to the
replacement or payment of mutilated, destroyed, lost, or stolen Bonds, and shall
preclude any and all other rights or remedies.

         SECTION 210. BOND REGISTER; TRANSFER AND EXCHANGE OF BONDS; PERSONS
TREATED AS OWNERS. The Issuer shall cause books for the registration and
transfer of the Bonds to be kept by the Trustee which is hereby constituted and
appointed the Registrar for purposes of this Indenture with respect to such
Bonds. The Trustee shall keep in the Bond Register the name and address of each
Bondholder, and the serial number of each Bond held by such Bondholder. This
Indenture shall constitute a "system of registration" for all purposes of the
Registered Public Obligations Act of the State. At reasonable times and under
reasonable regulations established by the Trustee, such books may be inspected
and copied by the Issuer, the Company, the Trustee, or the owners (or a
designated representative thereof) of 15% or more in aggregate principal amount
of the Bonds then Outstanding.

         Subject to the limitations contained in the next succeeding paragraph,
upon surrender for registration of transfer of any Bond at the Principal Office
of the Trustee, duly endorsed by, or accompanied by a written instrument or
instruments of transfer in form satisfactory to the Trustee and duly executed
by, the Bondholder or such Bondholder's attorney duly authorized in writing and
with such guarantee of signature as shall be satisfactory to the Trustee, the
Issuer shall execute and the Trustee shall authenticate and deliver in the name
of the transferee or transferees a new Bond or Bonds of the same series and of
Authorized Denominations, which shall be identical to the Bond being exchanged
with respect to interest rate and the stated maturity applicable to such Bond,
and bearing numbers not contemporaneously outstanding. Subject to the
limitations contained in the next succeeding paragraph, Bonds may be exchanged


                                       19
<PAGE>   24






at such Principal Office of the Trustee upon surrender thereof together with an
assignment duly executed by the registered owner thereof or such owner's
attorney or legal representative in such form and with guarantee of signature as
shall be satisfactory to the Trustee for an equal aggregate principal amount of
Bonds of any Authorized Denomination as the Bonds surrendered for exchange,
which Bonds shall be identical to the Bonds being exchanged with respect to
series, interest rate and stated maturity, bearing numbers not contemporaneously
outstanding. The execution by the Issuer of any Bond of any Authorized
Denomination shall constitute full and due authorization of such Bond and the
Trustee shall thereby be authorized to authenticate and deliver such registered
Bond.

         The Registrar shall not be required to exchange or register the
transfer of any Bond during the period commencing on the Record Date next
preceding any Interest Payment Date for such Bond and ending at the close of
business on the day next preceding such Interest Payment Date, nor to exchange
or register the transfer of such Bond after the mailing of notice calling such
Bond for redemption, nor during the period of fifteen days next preceding the
mailing of such notice of redemption.

         No service charge shall be imposed on any Bondholder for any exchange
or transfer of Bonds. The Issuer and the Trustee may, however, require payment
by the person requesting an exchange or transfer of Bonds of a sum sufficient to
cover any tax, fee or other governmental charge that may be imposed in relation
thereto, except in the case of the issuance of a Bond or Bonds for the
unredeemed portion of a Bond surrendered for redemption in part unless there is
a transfer in connection with such issuance.

         Bonds delivered upon any registration of transfer or exchange as
provided herein shall be valid limited obligations of the Issuer, evidencing the
same debt as the Bond surrendered, shall be secured by this Indenture and shall
be entitled to all of the security and benefits hereof to the same extent as the
Bond surrendered.

         The Issuer, the Trustee, and the Company may treat the registered owner
of any Bond as the absolute owner thereof for all purposes, whether or not such
Bond shall be overdue, and shall not be bound by any notice to the contrary. All
payments of or on account of the principal of and premium, if any, and interest
on any such Bond as herein provided shall be made only to or upon the written
order of the registered owner thereof or such owner's legal representative, but
such registration may be changed as herein provided. All such payments shall be
valid and effectual to satisfy and discharge the liability upon such Bond to the
extent of the sum or sums so paid.

         SECTION 211.      BOOK ENTRY PROVISIONS.

                           (a) The Series 1995A Bonds shall be initially issued
                  in the form of a separate single certificated fully registered
                  Series 1995A Bond for each of the maturities set forth in
                  Section 202 hereof. Upon initial issuance, the ownership of
                  each Series 1995A Bond shall be registered in the registration
                  books kept by the Bond Registrar in the name of Cede & Co.
                  ("Cede"), as nominee of DTC. Except as provided in Section 210
                  hereof, all of the Outstanding Bonds shall be registered in
                  the registration books kept by the Bond Registrar in the name
                  of Cede, as nominee of DTC.

                           (b) With respect to Series 1995A Bonds registered
                  in the registration books kept by the Bond Registrar in the
                  name of Cede, as nominee

                                       20
<PAGE>   25






                  of DTC, the Issuer, the Trustee and the Paying Agent shall
                  have no responsibility or obligation to any Participant or to
                  any person on behalf of which a Participant holds an interest
                  in the Series 1995A Bonds. Without limiting the immediately
                  preceding sentence, the Issuer, the Paying Agent and the
                  Trustee shall have no responsibility or obligation with
                  respect to (i) the accuracy of the records of DTC, Cede or any
                  Participant with respect to any ownership interest in the
                  Series 1995A Bonds, (ii) the delivery to any Participant or
                  any other person, other than a Registered Owner, as shown in
                  the registration books kept by the Bond Registrar, of any
                  notice with respect to the Series 1995A Bonds, including any
                  notice of redemption, or (iii) the payment to any Participant
                  or any other person, other than a Registered Owner, as shown
                  in the registration books kept by the Trustee, of any amount
                  with respect to principal of, premium, if any, or interest on
                  the Series 1995A Bonds. The Issuer, the Paying Agent and the
                  Trustee may treat and consider the person in whose name each
                  Series 1995A Bond is registered in the registration books kept
                  by the Trustee as the holder and absolute owner of such Series
                  1995A Bond for the purpose of payment of principal, premium
                  and interest with respect to such Series 1995A Bond, for the
                  purpose of giving notices of redemption and other matters with
                  respect to such Series 1995A Bond, for the purpose of
                  registering transfers with respect to such Series 1995A Bond,
                  and for all other purposes whatsoever. The Paying Agent shall
                  pay all principal of, premium, if any, the interest on the
                  Series 1995A Bonds only to or upon the order of the respective
                  Registered Owners, as shown in the registration books kept by
                  the Trustee, or their respective attorneys duly authorized in
                  writing, as provided in Section 202 hereof, and all such
                  payments shall be valid and effective to fully satisfy and
                  discharge the Issuer's obligations with respect to payment of
                  principal of, premium, if any, and interest on the Series
                  1995A Bonds to the extent of the sum or sums so paid. No
                  person other than a Registered Owner, as shown in the
                  registration books kept by the Trustee, shall receive a
                  certificated Series 1995A Bond evidencing the obligation of
                  the Issuer to make payments of principal, premium, if any, and
                  interest pursuant to this Indenture. Upon delivery by DTC to
                  the Bond Registrar of written notice to the effect that DTC
                  has determined to substitute a new nominee in place of Cede,
                  and subject to the provisions herein with respect to record
                  dates, the word "Cede" in this Indenture shall refer to such
                  new nominee of DTC; and upon receipt of such a notice the Bond
                  Registrar shall promptly deliver a copy of the same to the
                  Trustee, if the Trustee is other than himself.

                           (c) The Representation Letter in substantially the
                  form attached hereto as Exhibit "B", with such changes,
                  omissions, insertions and revisions as the Chairman shall
                  approve, is hereby authorized and the Chairman shall execute
                  and deliver such Representation Letter. The approval of the
                  Chairman of any such changes, omissions, insertions and
                  revisions shall be conclusively established by said Chairman's
                  execution and delivery of the Representation Letter which
                  shall not in any way limit the provisions of Section 211(b)
                  hereof or in any other way impose upon the Issuer any
                  obligation whatsoever with respect to persons having interests
                  in the Series 1995A Bonds other than the Registered Owners, as
                  shown on the registration books kept by the Bond Registrar.
                  The Trustee shall take all action necessary for all
                  representations of the Issuer in the Representation Letter
                  with respect to the Paying Agent to at all times be complied
                  with.


                                       21
<PAGE>   26



                           (d)     (i) DTC may determine to discontinue 
                  providing its services with respect to the Series 1995A Bonds
                  at any time by giving notice to the Issuer and the Trustee and
                  discharging its responsibilities with respect thereto under
                  applicable law.

                                   (i) The Issuer, in its sole discretion and
                           without the consent of any other person, may
                           terminate the services of DTC with respect to the
                           Series 1995A Bonds if the Issuer determines that:

                                       (A) DTC is unable to discharge its 
                                    responsibilities with respect to the Series 
                                    1995A Bonds, or

                                       (B) a continuation of the requirement
                                    that all of the Outstanding Bonds be
                                    registered in the registration books kept
                                    by the Bond Registrar in the name of Cede,
                                    or any other nominee of DTC, is not in the
                                    best interest of the beneficial owners of
                                    the Series 1995A Bonds.

                                    (ii) Upon the termination of the services of
                           DTC with respect to the Series 1995A Bonds pursuant
                           to subsection 211(d)(ii)(B) hereof, or upon the
                           discontinuance or termination of the services of DTC
                           with respect to the Series 1995A Bonds pursuant to
                           subsection 211(d)(i) or subsection 211(d)(ii)(A)
                           hereof after which no substitute securities
                           depository willing to undertake the functions of DTC
                           hereunder can be found which, in the opinion of the
                           Issuer, is willing and able to undertake such
                           functions upon reasonable and customary terms, the
                           Issuer is obligated to deliver Bond Certificates at
                           the expense of the beneficial owners of the Series
                           1995A Bonds, as described in this Indenture and the
                           Series 1995A Bonds shall no longer be restricted to
                           being registered in the registration books kept by
                           the Bond Registrar in the name of Cede as nominee of
                           DTC, but may be registered in whatever name or names
                           Registered Owners transferring or exchanging Series
                           1995A Bonds shall designate, in accordance with the
                           provisions of this Indenture.

                           (e)      Notwithstanding any other provision of this
                  Indenture to the contrary, so long as any Series 1995A Bond is
                  registered in the name of Cede, as nominee of DTC, all
                  payments with respect to principal of, premium, if any, and
                  interest on such Series 1995A Bond and all notices with
                  respect to such Series 1995A Bond shall be made and given,
                  respectively, in the manner provided in the Representation
                  Letter.

         SECTION 212. CANCELLATION. Upon payment of the principal of, premium,
if any, and interest on any Bond, or replacement of any Bond pursuant to Section
209 hereof or transfer or exchange pursuant to Section 210 hereof, any such Bond
shall be cancelled and destroyed by the Trustee. The Issuer or the Company may
at any time deliver to the Trustee for cancellation any Bonds previously
authenticated and delivered hereunder which the Issuer or the Company may have
acquired in any manner whatsoever, and all Bonds so delivered shall be promptly
cancelled and destroyed by the Trustee. No Bonds shall be authenticated in lieu
of or in exchange for any Bonds cancelled as provided in this Section, except as
expressly permitted by this Indenture. Counterparts of a certificate of
destruction evidencing the destruction and disposal of any Bond pursuant to this
Section 212 shall be furnished by the Trustee to the Company and the Issuer.



                                       22
<PAGE>   27






                                   ARTICLE III

                               REDEMPTION OF BONDS

      SECTION 301. OPTIONAL REDEMPTION OF SERIES 1995A BONDS. The Series 1995A
Bonds are subject to optional redemption prior to maturity by the Trustee at the
direction of the Company, in whole at any time or in part on any Interest
Payment Date, in inverse order of maturity and by lot within each maturity at
any time on or after February 1, 2005, at a redemption price expressed as a
percentage of principal amount of Series 1995A Bonds to be redeemed set forth in
the table below, together with accrued interest to the Redemption Date:

<TABLE>
<CAPTION>
              Redemption Date                          Redemption Price
              ---------------                          ----------------
<S>                                                          <C> 
February 1, 2005 - January 31, 2006                          102%
February 1, 2006 - January 31, 2007                          101%
February 1, 2007 and thereafter                              100%
</TABLE>

      SECTION 302. EXTRAORDINARY OPTIONAL REDEMPTION. The Series 1995A Bonds
shall be subject to extraordinary optional redemption prior to maturity by the
Trustee, at the direction of the Company, in whole or in part, on any date at a
redemption price equal to the principal amount of the Series 1995A Bonds to be
redeemed plus accrued interest to the redemption date, within 365 days following
the occurrence of any one of the following events (or, in the case of (a) and
(b) below, at the option of the Company, within sixty (60) days following the
receipt of any proceeds relating to such event):

                           (a) The Facility or a substantial portion thereof
                  shall have been damaged or destroyed by fire or other casualty
                  (i) to such extent that, in the opinion of the Company
                  expressed in a certificate signed by an Authorized Company
                  Representative and filed with the Issuer and the Trustee,
                  within a period of twelve consecutive months following such
                  damage or destruction it is not practicable or desirable to
                  rebuild, repair or restore the Facility, or (ii) to such
                  extent that, in the opinion of the Company expressed in a
                  certificate signed by an Authorized Company Representative and
                  filed with the Issuer and the Trustee, the Facility is or will
                  be prevented thereby from operating normally for a period of
                  twelve (12) consecutive months.

                           (b) Title to, or the temporary use of, all or
                  substantially all the Facility shall have been taken under the
                  exercise of the power of eminent domain (including such a
                  taking or takings which results or is likely to result, in the
                  opinion of the Company expressed in a certificate signed by an
                  Authorized Company Representative and filed with the Issuer
                  and the Trustee, in normal operations at the Facility being
                  interrupted for a period of twelve (12) consecutive months or
                  results or is likely to result in rendering the Facility, in
                  the opinion of the Company expressed in a certificate signed
                  by an Authorized Company Representative and filed with the
                  Issuer and the Trustee, unsuitable for use).

                           (c) As a result of any changes in the Constitution of
                  the State of Utah or the Constitution of the United States of
                  America or of legislative or administrative action (whether
                  state or federal) or by final decree, judgment or order of any
                  court or administrative body (whether state or federal)
                  entered



                                       23
<PAGE>   28


                  after the contest thereof by the Company in good faith, the
                  Loan Agreement shall have become void or unenforceable or
                  impossible of performance in accordance with the intent and
                  purposes of the parties as expressed in the Loan Agreement, or
                  unreasonable burdens or excessive liabilities shall have been
                  imposed on the Issuer or the Company, including without
                  limitation, federal, state or other ad valorem, property,
                  income or other taxes not being imposed on the date of the
                  Loan Agreement or changes since the date of initial issuance
                  of the Bonds in regulatory requirements, technology or the
                  economic availability of raw materials, operating supplies,
                  equipment or waste requiring treatment and disposal, which
                  condition cannot reasonably be expected to improve materially
                  within a period of twelve (12) consecutive months and causes
                  the Company to determine that the Facility should not be
                  completed or that operation of the Facility should be
                  discontinued.

         SECTION 303. SPECIAL MANDATORY REDEMPTION. The Series 1995A Bonds are
also subject to special mandatory redemption in whole by the Issuer on any date
prior to maturity at a redemption price of 100% of the principal amount thereof
together with accrued interest to the date of redemption, upon the occurrence of
a Determination of Taxability, as soon as practicable, but in no event later
than thirty (30) days after the occurrence of such Determination of Taxability.
Upon being notified of a Determination of Taxability, the Trustee shall give
immediate notice of redemption to the Company, to the Guarantor and to the
Registered Owners as provided in Section 304 herein.

         "Determination of Taxability" shall mean a determination that the
interest income on any Series 1995A Bond does not qualify as being excludable
from the gross income of the Registered Owner thereof ("exempt interest") for
any reason other than that such Registered Owner is a "substantial user" of the
Facility or a "related person" as such terms are defined in Section 103(b)(6) of
the Internal Revenue Code of 1954, which determination shall be deemed to have
been made upon the occurrence of the first to occur of the following:

                        (i)   the date on which the Company determines that the
                  interest income on any of the Series 1995A Bonds does not
                  qualify as exempt interest; or

                        (ii)  the date on which any change in law or regulation
                  becomes effective or on which the Internal Revenue Service has
                  issued any private ruling, technical advice or any other
                  written communication to the effect that the interest income
                  on any of the Series 1995A Bonds does not qualify as exempt
                  interest; or

                        (iii) the date on which the Company shall receive notice
                  from the Trustee in writing that the Trustee has been advised
                  in writing by any Registered Owner of any Series 1995A Bond
                  that the Internal Revenue Service has issued a thirty-day
                  letter or other notice which asserts that the interest on such
                  Series 1995A Bond does not qualify as exempt interest; or

                        (iv)  the date on which the Trustee receives written
                  notice that the Company or the Issuer has taken any action
                  inconsistent with, or has failed to act consistently with, the
                  tax exempt status of interest on the Series 1995A Bonds;

                                       24
<PAGE>   29







                  provided that no Determination of Taxability shall be deemed
                  to have occurred as a result of a determination by the Company
                  pursuant to Clause (i), (ii) or (iv) above unless such
                  determination is supported by a written opinion of nationally
                  recognized bond counsel satisfactory to the Trustee that the
                  interest income on the Series 1995A Bonds does not constitute
                  exempt interest. If, however, in the opinion of nationally
                  recognized bond counsel acceptable to the Trustee, redemption
                  of less than all of the Series 1995A Bonds will preserve the
                  exclusion from gross income of the Registered Owners thereof
                  of interest on the remaining Series 1995A Bonds, then only
                  such amount need be redeemed, the particular Series 1995A
                  Bonds to be redeemed to be selected by lot by the Trustee in
                  such manner as the Trustee in its discretion shall determine
                  or otherwise as specified in such final determination or
                  opinion. Such determination shall be referred to herein as a
                  "Determination of Taxability" and the event giving rise to
                  such Determination shall be referred to herein as an "Event of
                  Taxability". The Trustee shall receive and coordinate notices
                  from Registered Owners of the Series 1995A Bonds in connection
                  with such determination and to forward such notices to the
                  Company.

      SECTION 304. NOTICE OF REDEMPTION. Notice of redemption shall be given by
the Trustee, by first-class mail, postage prepaid, mailed not less than thirty
(30) nor more than sixty (60) days prior to the redemption date, to each owner
of Bonds to be redeemed, at his address appearing in the Bond Register;
provided, however, that in the event of a redemption pursuant to Section 303
hereof, the Trustee shall not later than 2:00 p.m. (Trustee's local time) on the
first Business Day following the Determination of Taxability (a) use its best
reasonable efforts to notify the Company, the Guarantor and the Issuer thereof
by telephone, telex or telecopier, and (b) send written notice thereof to the
Company, the Guarantor and the Issuer by personal delivery or by Federal Express
or other similar express mail service guaranteed for next-day delivery. Failure
to give such notice by mailing, or any defect therein, shall not affect the
validity of the proceedings for the redemption of any Bond or portion thereof
with respect to which no such failure has occurred. In addition, notice of
redemption shall be sent by first-class mail, postage prepaid, or by overnight
delivery service, not less than 35 days prior to the redemption date, (1) to at
least two or more information services of national recognition that disseminate
redemption information with respect to municipal bonds and (2) to any securities
depository registered as such pursuant to the Securities Exchange Act of 1934,
as amended, in whose name Bonds to be redeemed have been registered as nominee;
provided, however, that no defect in or failure to give the notice described in
this sentence shall in any manner defeat the effectiveness of a call for
redemption with respect to Bonds for which notice was properly given as
described in the preceding sentence.

      All notices of redemption shall state:

                        (a)   the redemption date,

                        (b)   the redemption price,

                        (c)   the identification of the Bonds to be redeemed,
                  including complete designation and issue date of the series of
                  Bonds of which such Bonds are a part and the CUSIP number (and
                  in the case of partial redemption, the certificate numbers of
                  the Bonds to be redeemed and the respective


                                       25
<PAGE>   30


                  principal amounts thereof), interest rates and maturity dates
                  of such Bonds, and any other descriptive information which may
                  be necessary to identify accurately the Bonds to be redeemed,

                        (d)   that on the redemption date the redemption price
                  will become due and payable upon each such Bond, and that
                  interest thereon shall cease to accrue from and after said
                  date, and

                        (e)   the name and address of the Trustee including the
                  name and telephone number of a contact person and the place
                  where such Bonds are to be surrendered for payment of the
                  redemption price.

      If at the time of mailing of notice of an optional redemption there shall
not have been deposited with the Trustee moneys sufficient to redeem all the
Bonds called for redemption, which moneys are or will be available for
redemption of Bonds, such notice will state that it is conditional, that is,
subject to the deposit of the redemption moneys with the Trustee not later than
the close of business of the fifth day prior to the Redemption Date, and such
notice shall be of no effect unless such moneys are so deposited.

      SECTION 305. BONDS PAYABLE ON REDEMPTION DATE. Notice of redemption having
been given as aforesaid, the Bonds so to be redeemed shall, on the redemption
date, become due and payable at the redemption price therein specified and from
and after such date (unless the Issuer shall default in the payment of the
redemption price) such Bonds shall cease to bear interest. Upon surrender of any
such Bond for redemption in accordance with said notice, the redemption price of
such Bond shall be paid by the Trustee. If any Bond called for redemption shall
not be so paid upon surrender thereof for redemption, the principal (and
premium, if any) shall, until paid, bear interest from the redemption date at
the rate last borne by the Bond.

      SECTION 306. BONDS REDEEMED IN PART. Any Bond which is to be redeemed in
part only shall be surrendered at the place of payment, duly endorsed by the
owner of such Bond, or accompanied by a written instrument of transfer in form
satisfactory to the Trustee, as appropriate, duly executed by the owner thereof
or his attorney duly authorized in writing and, upon such surrender, the Issuer
shall execute and the Trustee shall authenticate and deliver to the owner of
such Bond without service charge, a new Bond or Bonds in aggregate principal
amount equal to and in exchange for the unredeemed portion of the principal of
the Bond so surrendered which Bond or Bonds shall be in any Authorized
Denominations and shall be identical to the Bond being purchased or redeemed
with respect to stated maturity and interest rate, and bearing numbers not
contemporaneously outstanding.

      SECTION 307. ELECTION TO REDEEM; NOTICE TO TRUSTEE AND ISSUER. The
election of the Company to redeem any Bonds shall be evidenced by a written
notice, signed by an Authorized Company Representative, given to the Trustee and
the Issuer not less than 45 days (unless a shorter notice shall be satisfactory
to the Trustee and the Issuer) and not more than 90 days prior to the redemption
date specified by the Company therein, which notice shall specify the Section of
this Indenture pursuant to which the Bonds are being redeemed, the redemption
date, and the aggregate principal amount of Bonds to be redeemed.

      SECTION 308. SELECTION OF BONDS TO BE REDEEMED. If less than all the Bonds
are to be redeemed, the particular Bonds or portion thereof to be redeemed shall
be selected prior to the redemption date by the Trustee, by lot by such method
as the Trustee shall deem fair and appropriate and which may provide for the
selection for redemption of portions of the principal



                                       26

<PAGE>   31







of Bonds of a denomination larger than the minimum Authorized Denomination. The
unredeemed portion of a Bond selected for partial redemption must be equal to an
Authorized Denomination.

      SECTION 309. DEPOSIT OF REDEMPTION PRICE. Pursuant to Section 4.1(b)(iii)
of the Loan Agreement, the Company is required, prior to any redemption date, to
deposit with the Trustee an amount of money in immediately available funds
sufficient to pay the redemption price of all the Bonds which are to be redeemed
on such date.























                                       27

<PAGE>   32






                                   ARTICLE IV

                               FUNDS AND ACCOUNTS

      SECTION 401. ESTABLISHMENT OF FUNDS AND ACCOUNTS. There are hereby created
by the Issuer and ordered established with the Trustee the following irrevocable
trust funds and accounts:

                        (a)   A separate Bond Fund, to be designated "Carbon
                  County, Utah Solid Waste Disposal Refunding Revenue Bonds
                  (Laidlaw Inc./ECDC Environmental, L.C. Project) Bond Fund",
                  shall be used for the purposes and shall be administered in
                  the manner set forth in Section 403 hereof; and

                        (b)   A separate Construction Fund to be designated
                  "Carbon County, Utah Solid Waste Disposal Refunding Revenue
                  Bonds (Laidlaw Inc./ ECDC Environmental, L.C. Project)
                  Construction Fund", and within the Construction Fund separate
                  accounts relating to the series of Bonds authenticated and
                  delivered on each Delivery Date. Each of such accounts shall
                  be designated by the Trustee as the Trustee deems appropriate
                  and shall be administered in the manner set forth in Section
                  404 hereof.

      The Trustee may establish such other funds and accounts as it may deem
necessary and appropriate to carry out the trusts hereby created.

      SECTION 402. DISPOSITION OF PROCEEDS OF SALE OF SERIES 1995A BONDS. The
proceeds of the sale of the Series 1995A Bonds to be received by the Issuer on
the first Delivery Date shall be deposited by the Trustee upon receipt thereof
as follows:

                        (a)   $15,000,000 shall be deposited with the trustee
                  for the Series 1993A Bonds into the bond fund established
                  pursuant to the Series 1993A Indenture and applied in
                  accordance with the provisions thereof to redeem an equal
                  aggregate principal amount of the Series 1993A Bonds; and

                        (b)   $8,000,000 shall be deposited with the trustee for
                  the Series 1994 Bonds into the bond fund established pursuant
                  to the Series 1994 Loan Agreement and applied in accordance
                  with the provisions thereof to redeem an equal aggregate
                  principal amount of the Series 1994 Bonds.

      Upon the issuance of the Series 1995A Bonds, $8,000,000 from the proceeds
of the Series 1994 Bonds on deposit in the construction fund created under the
Series 1994 Loan Agreement shall be transferred to, and deposited into the
separate account of the Construction Fund established by, the Trustee on the
Delivery Date.

      SECTION 403. BOND FUND. There shall be deposited into the Bond Fund as and
when received all payments made by the Company pursuant to the Loan Agreement
with respect to the principal of, premium, if any, and interest on the Bonds,
including the redemption price of Bonds to be redeemed, and any other moneys
required by this Indenture or the Loan Agreement to be deposited into the Bond
Fund.

      Except as may otherwise be required by the Proceeds Certificate or Section
405 hereof, moneys in the Bond Fund shall be used solely for the payment of the
principal of and premium,




                                       28
<PAGE>   33



if any, on the Bonds as the same becomes due and payable (whether at stated
maturity, upon redemption or upon acceleration), and to pay interest on the
Bonds when due, all as provided in this Indenture.

      Upon delivery by the Company of a Completion Certificate pursuant to
Section 3.4 of the Loan Agreement, there shall be transferred from the
Construction Fund to a segregated account of the Bond Fund certain amounts on
deposit in the Construction Fund, as described in Section 404 hereof, which
amounts shall be used in the manner described in Section 3.4 of the Loan
Agreement. The Trustee is hereby authorized and directed to use the moneys
transferred to the Bond Fund as described in this paragraph for the purposes set
forth in Section 3.4 of the Loan Agreement.

      After the right, title and interest of the Trustee in and to the Trust
Estate and all covenants and agreements and other obligations of the Issuer to
the owners of the Bonds shall have ceased, terminated and become void and shall
have been satisfied and discharged in accordance with Article VI hereof, and the
fees, expenses and other amounts payable to the Trustee and the Issuer, pursuant
to any provisions hereof shall have been paid in full, any moneys remaining in
the Bond Fund shall be paid to the Company upon a written request therefor
signed by an Authorized Company Representative.

      SECTION 404. CONSTRUCTION FUND. There shall be deposited into the
Construction Fund the amounts specified in Section 402 hereof from the proceeds
to be received from time to time of the sale of the Series 1995A Bonds.

      Moneys in the Construction Fund shall be expended in accordance with the
applicable provisions of the Loan Agreement to pay Project Costs at any time
with respect to which no Event of Default has occurred and is continuing, upon
receipt by the Trustee of a written requisition signed by an Authorized Company
Representative, stating the name and address of the person to whom payment is to
be made and the amount to be paid and certifying that (a) none of the payments
for which the payment or reimbursement is proposed to be made has formed the
basis for any payment or reimbursement theretofore made from the Construction
Fund, (b) each item for which payment or reimbursement is proposed to be made is
or was necessary in connection with Construction of the Project, (c) all of the
proceeds of the Bonds (to and including such disbursement) have been or are
being used to provide for Project Costs and (d) such payment or reimbursement is
in accordance with all applicable provisions of the Loan Agreement. In making
any such payment, the Trustee may conclusively rely upon such written
requisition and the Trustee shall be relieved of all liability with respect to
making such payment in accordance with such written requisition. The Trustee
shall keep and maintain adequate records pertaining to the Construction Fund and
all disbursements therefrom. Notwithstanding the foregoing the Trustee is
directed to pay an amount equal to $160,000 from the Construction Fund for costs
of issuance of the Series 1995A Bonds upon receipt of a closing statement signed
by an Authorized Company Representative.

      In addition to the foregoing, there shall be withdrawn from the
Construction Fund (a) any moneys remaining on deposit in the Construction Fund
upon the delivery of a Completion Certificate pursuant to Section 3.4 of the
Loan Agreement (other than amounts to be retained by the Trustee in the
Construction Fund at the direction of the Company to pay Project Costs not then
due and payable or amounts with respect to which the liability for payment is in
dispute), to be deposited into a segregated account of the Bond Fund, and (b)
any moneys remaining on deposit in the Construction Fund upon the prepayment of
all installments payable pursuant to Article VIII of the Loan Agreement, to be
deposited into the Bond Fund.



                                       29

<PAGE>   34





There shall also be transferred to the Bond Fund from the Construction Fund any
moneys remaining on deposit in the Construction Fund at such time as the
principal of all Outstanding Bonds shall have become due and payable in
accordance with the provisions of Section 7.3(a) of the Loan Agreement, and (c)
no more than 2% of the proceeds of the Refunded Bonds (less costs of issuance
previously paid from proceeds of the Refunded Bonds) shall be used for costs of
issuance of the Bonds, including the Underwriter's discount, and (d) not less
than 95% of the Spendable Proceeds of the Bonds, as defined herein, shall be
used for Qualified Project Costs. The term "Spendable Proceeds" means the
proceeds from the sale of the Bonds, less amounts used to redeem the Refunded
Bonds, plus transferred proceeds of the Refunded Bonds, plus earnings from
investment of the foregoing.

      SECTION 405. REBATE FUND.

                  (a) There is hereby created and established with the Trustee a
            trust fund to be designated "Carbon County, Utah Solid Waste
            Disposal Refunding Revenue Rebate Fund". The Rebate Fund is not
            pledged and does not secure the Registered Owners of the Bonds. The
            Company shall on each applicable Rebate Calculation Date determine
            or cause to be determined, the amount of Rebatable Arbitrage and the
            corresponding Required Rebate Deposit with respect to the Bonds of
            each Series to be deposited into the Rebate Fund and shall give
            written notice to the Trustee of such determination. The Trustee
            shall retain records of all such determinations until six years
            after the requirement of the last Bond. In addition, the Company
            shall deposit into the Rebate Fund the Required Rebate Deposit, if
            any, within 30 days after each Rebate Calculation Date. Upon written
            direction of the Company, the Trustee shall withdraw from the Rebate
            Fund and pay over to the United States Government: (1) not less
            frequently than once each five years commencing no later than 30
            days after each Rebate Calculation Date, and upon each fifth
            anniversary of the first such payment date, an amount equal to 90%
            of the net aggregate amount of Rebatable Arbitrage less the amount,
            if any, of Rebatable Arbitrage theretofore paid to the United
            States, and (2) not later than 30 days after the retirement of the
            last Bond of such series 100% of the aggregate amount of Rebatable
            Arbitrage with respect to such series of Bonds.

                  (b) Withdrawals from the Rebate Fund may be made to the extent
            the Company determines with the written approval of the Trustee that
            amounts on deposit in such fund exceed amounts required to be on
            deposit therein pursuant to this Section 405. All such withdrawals
            shall be transferred to the Bond Fund.

                  (c) The provisions of this Section 405 may be amended or
            deleted from this Indenture upon receipt by the Issuer and the
            Trustee of an opinion of nationally recognized bond counsel that
            such amendment or deletion will not adversely affect the exclusion
            of the interest on the Bonds from gross income for purposes of
            federal income taxation. Any moneys on deposit in the Rebate Fund
            may be applied by the Trustee as permitted in such opinion.

                  (d) The Trustee shall at least 60 days prior to each Rebate
            Calculation Date notify the Company and the Issuer of the
            requirements of this Section. By agreeing to give this notice, the
            Trustee assumes no responsibility whatsoever for compliance by the
            Company with the requirements of Section 148 of the Code or any
            successor. Notwithstanding any other provision of the Indenture, any
            failure of the Trustee to give any such notice, for any reason
            whatsoever, shall not cause the Trustee to be responsible for any
            failure of the Company to comply with the requirements of said
            Section 148 or any successor thereof.


                                       30
<PAGE>   35




                                    ARTICLE V

                              INVESTMENT OF MONEYS

      Any moneys held pursuant to this Indenture as part of the Construction
Fund, the Bond Fund (other than moneys for the payment of Bonds which shall have
become payable at maturity, upon redemption or otherwise, or for the payment of
interest thereon which has become due) and the Rebate Fund shall be invested and
reinvested by the Trustee in Eligible Securities upon the written order of the
Company signed by an Authorized Company Representative, provided, however, that
all investments shall be made by the Trustee in compliance with the applicable
provisions of the Proceeds Certificate. The Trustee shall be entitled to rely on
each such written order and shall incur no liability for making any such
investment so designated or for any loss incurred in selling such investment.
The Trustee may make any and all such investments through or from its own bond
department, provided that such investments are on fair and reasonable terms no
less favorable than would be obtained in a comparable arm's-length transaction.

      Any investments pursuant to this Article V shall be held by or under the
control of the Trustee and shall be deemed at all times a part of the fund,
account or subaccount for which they were made, but the Trustee shall have no
liability with respect to any investment made pursuant to any such written
order. The interest accruing thereon and any profit realized from such
investments shall be credited, and any loss resulting from such investment shall
be charged, to such fund, account or subaccount. The Trustee shall sell and
reduce to cash a sufficient amount of such investments (a) of the Construction
Fund whenever the cash balance in the Construction Fund is insufficient to pay a
written requisition when presented, (b) of the Bond Fund whenever the cash
balance in the Bond Fund is insufficient to pay the principal of or premium, if
any, or interest on the Bonds when due, and (c) of the Rebate Fund as necessary
for the purposes thereof.








                                       31
<PAGE>   36



                                   ARTICLE VI

                          SATISFACTION OF THE INDENTURE

      SECTION 601. DISCHARGE OF INDENTURE. If the Issuer shall pay or cause to
be paid, or there shall be otherwise paid or deemed paid or provision for
payment made to or for the owners of the Bonds the principal, premium, if any,
and interest due or to become due thereon at the times and in the manner
stipulated therein and in this Indenture, and if the Issuer shall not then be in
default in any of the other covenants and promises in the Bonds and in this
Indenture expressed to be kept, performed and observed by it or on its part, and
shall pay or cause to be paid to the Trustee all sums of money due or to become
due according to the provisions hereof, then these presents and the estate and
rights hereby granted shall cease, determine and be void, whereupon the Trustee
shall cancel and discharge the lien of this Indenture and execute and deliver to
the Issuer such instruments in writing as shall be requisite to cancel and
discharge the lien of this Indenture, and reconvey, release, assign and deliver
unto the Issuer any and all estate, right, title and interest in and to any and
all property conveyed, assigned or pledged to the Trustee or otherwise subject
to this Indenture, except amounts in the Rebate Fund and amounts in the Bond
Fund required to be paid to the Company pursuant to any express provisions to
that effect contained herein and moneys or securities held by the Trustee for
the payment of the principal of, and premium, if any, and interest on, the
Bonds.

      SECTION 602. BONDS DEEMED PAID. Any Bond shall be deemed to have been paid
if:

                  (a) in case said Bond is to be redeemed on any date prior to
            its stated maturity, the Company shall have given to the Trustee in
            form satisfactory to the Trustee, irrevocable instructions to give
            notice of redemption of such Bond on said redemption date;

                  (b) payment of the principal of and premium, if any, on such
            Bond, plus interest thereon to the due date thereof (whether such
            due date be by reason of maturity or upon redemption as provided in
            this Indenture, or otherwise), either (i) shall have been made or
            caused to be made in accordance with the terms thereof, or (ii)
            shall have been provided for by depositing with the Trustee, in
            trust and irrevocably set aside exclusively for such payment, (1)
            moneys sufficient to make such payment or (2) Government Obligations
            maturing as to principal and interest in such amounts and at such
            times as will provide sufficient moneys to make such payment
            (provided that such deposit will not affect the excludability of
            interest on any of the Bonds from the gross income of the owners
            thereof for federal income tax purposes or cause any of the Bonds to
            be classified as "arbitrage bonds" within the meaning of Section 148
            of the Code), and all necessary and proper fees, compensation and
            expenses of the Issuer and the Trustee, pertaining to the Bond with
            respect to which such deposit is made and all other liabilities of
            the Company under the Loan Agreement pertaining to such Bond shall
            have been paid or the payment thereof provided for; and

                  (c) in the event said Bond is not by its terms subject to
            redemption within 60 days following the proposed date of deposit,
            the Company shall have given the Trustee in form satisfactory to it
            irrevocable instructions to give a notice to the holders of such
            Bonds that the deposit required by clause (b)



                                       32
<PAGE>   37







                  above has been made with the Trustee and that said Bonds are
                  deemed to have been paid in accordance with this Section and
                  stating such date upon which moneys are to be available for
                  payment of the principal of, premium, if any, and interest on
                  said Bonds.

         The Issuer or the Company may at any time surrender to the Trustee for
cancellation by it any Bonds previously authenticated and delivered, which the
Issuer or the Company may have acquired in any manner whatsoever, and such
Bonds, upon such surrender and cancellation, shall be deemed to be paid and
retired.



                                      33

<PAGE>   38






                                   ARTICLE VII

                                GENERAL COVENANTS

      SECTION 701. PAYMENT OF PRINCIPAL, PREMIUM, IF ANY, AND INTEREST; NO
GENERAL OBLIGATION. The Issuer covenants that it will promptly pay or cause to
be paid the principal of, premium, if any, and interest on every Bond issued
under this Indenture at the place or places, on the dates and in the manner
provided herein and in the Bonds, provided that such principal, premium, if any,
and interest are payable by the Issuer solely from the Trust Estate, and nothing
in the Bonds or this Indenture shall be considered as assigning or pledging any
other funds or assets of the Issuer other than the Trust Estate.

      Each and every covenant made herein by the Issuer is predicated upon the
condition that the Issuer shall not in any event be liable from any property or
source other than the Trust Estate for the payment of the principal of, premium,
if any, or interest on the Bonds, or the payment of any amounts payable under
the Loan Agreement, or the performance of any pledge, obligation or agreement
created by or arising under this Indenture, the Bonds or the Loan Agreement;
and, further, that neither the Bonds nor any such obligation or agreement of the
Issuer shall be construed to constitute an indebtedness of the Issuer within the
meaning of any constitutional or statutory provision whatsoever, or a pecuniary
liability of the Issuer or a charge against its general credit or taxing power.

      SECTION 702. PERFORMANCE OF COVENANTS; LEGAL AUTHORIZATION. The Issuer
covenants that it will faithfully perform at all times any and all covenants,
undertakings, stipulations and provisions contained in this Indenture, in any
and every Bond executed, authenticated and delivered hereunder and in all
proceedings of the Governing Body pertaining thereto. The Issuer represents that
it is duly authorized under the Constitution and laws of the State to issue the
Bonds authorized hereby, to execute this Indenture, to assign the Loan Agreement
and to pledge and assign the Trust Estate pledged to the payment of the Bonds
and payments thereon in the manner and to the extent herein set forth; that all
action on its part for the issuance of the Series 1995A Bonds and the execution
and delivery of this Indenture has been duly and effectively taken (or, if
Additional Bonds are issued pursuant to Section 208 hereof, will be duly taken
as provided therein); and that the Bonds in the hands of the owners thereof as
shown on the Bond Register are and will be valid and enforceable obligations of
the Issuer according to the import thereof.

      SECTION 703. FURTHER ASSURANCES. Except to the extent otherwise provided
in this Indenture, the Issuer shall not enter into any contract or take any
action by which the rights of the Trustee or the Bondholders may be impaired and
shall, from time to time, execute and deliver such further instruments and take
such further action as may be required to carry out the purposes of this
Indenture. The Issuer shall be entitled to reimbursement from the Company for
any action taken pursuant to this Section 703.

      SECTION 704. IMMUNITIES AND LIMITATIONS OF RESPONSIBILITY OF ISSUER. The
Issuer shall be entitled to the advice of counsel (who, except as otherwise
provided, may be counsel for any Bondholder), and the Issuer shall be wholly
protected as to action taken or omitted in good faith in reliance on such
advice. The Issuer may rely conclusively on any communication or other document
furnished to it hereunder and reasonably believed by it to be genuine. The
Issuer shall not be liable for any action (a) taken by it in good faith and
reasonably believed by it to be within its discretion or powers hereunder, or
(b) in good faith omitted to be taken by it because such action was reasonably
believed to be beyond its discretion or powers



                                       34
<PAGE>   39







hereunder, or (c) taken by it pursuant to any direction or instruction by which
it is governed hereunder, or (d) omitted to be taken by it by reason of the lack
of any direction or instruction required hereby for such action; nor shall it be
responsible for the consequences of any error of judgment reasonably made by it.
The Issuer shall in no event be liable for the application or misapplication of
funds or for other acts or defaults by any person, except its own officers and
employees. When any payment or consent or other action by it is called for
hereby, it may defer such action pending receipt of such evidence (if any) as it
may reasonably require in support thereof. The Issuer shall not be required to
take any remedial action (other than the giving of notice) unless reasonable
indemnity is furnished for any expense or liability to be incurred thereby,
other than liability for failure to meet the standards set forth in this
Section. As provided herein and in the Loan Agreement, the Issuer shall be
entitled to reimbursement for its expenses reasonably incurred or advances
reasonably made, with interest at the rate borne by the Bonds, in the exercise
of its rights or the performance of its obligations hereunder, to the extent
that it acts without previously obtaining indemnity. No permissive right or
power to act which it may have shall be construed as a requirement to act, and
no delay in the exercise of a right or power shall affect its subsequent
exercise of that right or power.

      SECTION 705. RECORDING AND FILING. The Issuer covenants that, solely from
additional amounts payable as provided in Section 4.3 of the Loan Agreement, it
will, if necessary, cause this Indenture and all supplements hereto and the Loan
Agreement and all supplements thereto, and all related financing statements, to
be kept, recorded and filed in such manner and in such places as may be required
by law in order to preserve and protect fully the security of the Bondholders
and the rights of the Trustee hereunder.

      SECTION 706. BOOKS AND RECORDS. The Issuer covenants that so long as any
Bonds are Outstanding and unpaid, it will keep, or cause to be kept, proper
books of record and account, relating to its financial dealings under this
Indenture and the Loan Agreement. Such books shall at all times be open for any
lawful purpose to the inspection of such accountants or other agents as the
Trustee may from time to time designate.

      SECTION 707. DEFENSE OF ISSUER'S RIGHTS. The Issuer agrees that the
Trustee may defend the Issuer's rights to the payments and other amounts due
under the Loan Agreement, for the benefit of the Bondholders, against the claims
and demands of all persons whomsoever. The Issuer covenants that it will do,
execute, acknowledge and deliver, or cause to be done, executed, acknowledged
and delivered, such indentures supplemental hereto and such further acts,
instruments and transfers as the Trustee may reasonably require for the better
assuring, transferring, pledging, assigning and confirming to the Trustee all
and singular the rights assigned hereby and the amounts pledged hereby to the
payment of the principal of, premium, if any, and interest on the Bonds. The
Issuer covenants and agrees that, except as herein and in the Loan Agreement
provided, it will not sell, convey, assign, pledge, encumber or otherwise
dispose of any part of the Trust Estate.

      SECTION 708. ARBITRAGE; COMPLIANCE WITH PROCEEDS CERTIFICATE. The Issuer
covenants and agrees that it will not take any action or fail to take any action
with respect to the investment of the proceeds of any Bonds issued under this
Indenture or with respect to the payments derived from the Loan Agreement, which
would result in constituting the Bonds "arbitrage bonds" within the meaning of
such term as used in Section 148(a) of the Code. The Issuer further covenants
and agrees that it will comply with and take all actions required by the
Proceeds Certificate.




                                       35
<PAGE>   40






                                  ARTICLE VIII

                                EVENTS OF DEFAULT

      SECTION 801. EVENTS OF DEFAULT. An "Event of Default," as used herein,
shall mean any of the following events, whatever the reason for such Event of
Default and whether it shall be voluntary or involuntary or come about or be
effected by operation of law or pursuant to or in compliance with any judgment,
decree or order of any court or any order, rule or regulation of any
administrative or governmental body:

                  (a) failure to pay any installment of interest payable on any
            of the Bonds when the same shall become due and payable; or

                  (b) failure to pay the principal of or the premium, if any, on
            any of the Bonds when the same shall become due and payable, whether
            at the stated maturity thereof, by proceedings for redemption, upon
            acceleration or otherwise; or

                  (c) failure by the Issuer or the Company to duly observe or
            perform any covenant or agreement (other than a covenant or
            agreement whose performance or observance is elsewhere in this
            Section 801 specifically dealt with) on the part of the Issuer or
            the Company, respectively, contained in this Indenture or the Loan
            Agreement, for a period of 30 days after the date on which written
            notice of such failure, requiring the same to be remedied, shall
            have been given to the Issuer and the Company by the Trustee, or to
            the Issuer, the Company and the Trustee by the owners of at least
            twenty-five percent (25%) in aggregate principal amount of Bonds
            then Outstanding; provided that if such default can be cured by the
            Issuer or the Company but cannot be cured within the 30-day curative
            period described above, it shall not constitute an Event of Default
            if corrective action is instituted by the Issuer or the Company
            within such 30-day period and such action is diligently pursued
            until the default is corrected; or

                  (d) a decree or order by a court having jurisdiction in the
            premises shall have been entered adjudging the Company bankrupt or
            insolvent, or approving as properly filed a petition seeking
            reorganization or arrangement of the Company under the federal
            Bankruptcy Code or any other similar applicable federal or state
            law, and such decree or order shall have continued undischarged and
            unstayed for a period of 90 days; or a decree or order of a court
            having jurisdiction in the premises for the appointment of a
            receiver or trustee or assignee in bankruptcy or insolvency of the
            Company or of the Company's property, or for the winding up or
            liquidation of the Company's affairs, shall have been entered, and
            such decree or order shall have remained in force undischarged and
            unstayed for a period of 90 days; or

                  (e) the Company shall institute proceedings to be adjudicated
            a voluntary bankrupt, or shall consent to the institution of a
            bankruptcy proceeding against it, or shall file a petition or answer
            or consent seeking reorganization or arrangement under the federal
            Bankruptcy Code or any other similar applicable federal or state
            law, or shall consent to the appointment of a receiver or trustee or
            assignee in bankruptcy or insolvency of it or of its



                                       36

<PAGE>   41






            property or shall make assignment for the benefit of creditors, or
            shall admit in writing its inability to pay its debts generally as
            they become due, or corporate action shall be taken by the Company
            in furtherance of any of the aforesaid purposes;

                  (f) the occurrence of an "Event of Default" under the Loan
            Agreement or the Guaranty; or

                  (g) the occurrence of an Act of Bankruptcy of Guarantor.

      SECTION 802. ACCELERATION. Upon the occurrence and continuation of an
Event of Default the Trustee may, and upon receipt of the written directions of
the owners of not less than twenty-five percent (25%) in principal amount of the
Bonds Outstanding shall, by written notice delivered to the Issuer and the
Company declare the entire principal amount of the Bonds then Outstanding, and
the interest accrued thereon, immediately due and payable and the entire
principal and interest shall thereupon become and be immediately due and
payable, subject, however, to the provisions of Section 811 hereof with respect
to waivers of Events of Default, and the Trustee shall give notice thereof by
first class mail, postage prepaid, to all owners of Outstanding Bonds.

      SECTION 803. REMEDIES; RIGHTS OF BONDHOLDERS. Upon the occurrence and
continuance of any Event of Default, the Trustee may, without any action on the
part of the Bondholders, and shall, at the written request of the owners of not
less than twenty-five percent (25%) in principal amount of the Bonds then
Outstanding, and in any case upon being indemnified to its satisfaction as
provided in Section 901(k) hereof:

                  (a) by mandamus, or other suit, action or proceeding at law or
            in equity, enforce all rights of the Bondholders under, and require
            the Issuer, the Company or the Guarantor to carry out any agreements
            with or for the benefit of the Bondholders and to perform its or
            their duties under, the Act, the Loan Agreement, the Guaranty, and
            this Indenture, provided that any such remedy may be taken only to
            the extent permitted under the applicable provisions of the Loan
            Agreement, the Guaranty or this Indenture, as the case may be;

                  (b) bring suit upon the Bonds; or

                  (c) by action or suit in equity enjoin any acts or things
            which may be unlawful or in violation of the rights of the
            Bondholders;

provided, however, that the Trustee shall have the right to decline to comply
with any such request or direction if the Trustee shall be advised by counsel
(who may be its own counsel) that the action so requested may not lawfully be
taken or the Trustee in good faith shall determine that such action would be
unjustly prejudicial to the Bondholders not parties to such request.

      No remedy by the terms of this Indenture conferred upon or reserved to
the Trustee (or to the Bondholders) is intended to be exclusive of any other
remedy, but each and every such remedy shall be cumulative and shall be in
addition to any other remedy given to the Trustee or to the Bondholders now or
hereafter existing at law or in equity or by statute; provided, however, that
any conditions set forth herein to the taking of any remedy to enforce the





                                       37
<PAGE>   42




provisions of this Indenture, the Bonds, the Guaranty or the Loan Agreement
shall also be conditions to seeking any remedies under any of the foregoing
pursuant to this Section 803.

      No delay or omission of the Trustee or any Bondholder to exercise any
right or power accruing upon any default or Event of Default shall impair any
such right or power or shall be construed to be a waiver of any such default or
Event of Default, or acquiescence therein; and every such right and power given
by this Article VIII to the Trustee and the Bondholders, respectively, may be
exercised from time to time and as often as may be deemed expedient.

      No waiver of any default or Event of Default hereunder, whether by the
Trustee or by the Bondholders, shall extend to or shall affect any subsequent
default or Event of Default or shall impair any rights or remedies consequent
thereon.

      SECTION 804. TRUSTEE MAY FILE PROOFS OF CLAIM. In case of the pendency of
any receivership, insolvency, liquidation, bankruptcy, reorganization,
arrangement, adjustment, composition or other judicial proceeding relative to
the Issuer, the Company, the Guarantor or any other obligor upon the Bonds or
their creditors, and whether or not an Event of Default hereunder shall have
occurred and be continuing, the Trustee (irrespective of whether the principal
of the Bonds shall then be due and payable as therein expressed or by
declaration or otherwise and irrespective of whether the Trustee shall have made
any demand on the Issuer for the payment of overdue principal or interest) may
be entitled and empowered, by intervention in such proceeding or otherwise,

                  (a) to file and prove a claim for the whole amount of
            principal (and premium, if any) and interest owing and unpaid with
            respect to the Bonds and to file such other papers or documents as
            may be necessary or advisable in order to have the claims of the
            Trustee (including any claim for the reasonable compensation,
            expenses, disbursements and advances of the Trustee, its agents and
            counsel) and of the Bondholders allowed in such judicial proceeding,
            and

                  (b) to collect and receive any moneys or other property
            payable or deliverable on any such claims and to distribute the
            same; and any receiver, assignee, trustee, liquidator, sequestrator
            (or other similar official) in any such judicial proceeding is
            hereby authorized by each Bondholder to make such payments to the
            Trustee, and in the event that the Trustee shall consent to the
            making of such payments directly to the Bondholders, to pay to the
            Trustee any amount due to it for the reasonable compensation,
            expenses, disbursements and advances of the Trustee, its agents and
            counsel, and any other amounts due the Trustee under this Indenture.

      Nothing herein contained shall be deemed to authorize the Trustee to
authorize or consent to or accept or adopt on behalf of any Bondholder any plan
of reorganization, arrangement, adjustment or composition affecting the Bonds or
the rights of any owner thereof, or to authorize the Trustee to vote with
respect to the claim of any Bondholder in any such proceeding.

      SECTION 805. DIRECTION OF PROCEEDINGS BY BONDHOLDERS. The owners of not
less than fifty-one percent (51%) in aggregate principal amount of Bonds then
Outstanding shall have the right, at any time, by an instrument or instruments
in writing executed and delivered to the Trustee, to direct the method and place
of conducting all proceedings to be taken in connection



                                       38
<PAGE>   43






with the enforcement of the terms and conditions of this Indenture, including
enforcement of the rights of the Issuer under the Loan Agreement or the
appointment of a receiver or any other proceedings hereunder; provided, that
such direction shall not be otherwise than in accordance with the provisions of
law and of this Indenture.

      SECTION 806. APPOINTMENT OF RECEIVERS. Upon the occurrence of an Event of
Default, and upon the filing of a suit or other commencement of judicial
proceedings to enforce the rights of the Trustee and the Bondholders under this
Indenture, the Trustee shall be entitled, as a matter of right, to the
appointment of a receiver or receivers of the rights and properties pledged
hereunder and of the revenues, issues, payments and profits thereof, pending
such proceedings, with such powers as the court making such appointment shall
confer.

      SECTION 807. APPLICATION OF MONEYS. Subject to the provisions of the
Proceeds Certificate, all moneys received by the Trustee, by any receiver or by
any Bondholder pursuant to any right given or action taken under the provisions
of this Article VIII shall, after payment of the costs and expenses of the
proceedings resulting in the collection of such moneys and of the expenses,
liabilities and advances incurred or made by the Trustee (provided that moneys
on deposit in the Bond Fund prior to the Event of Default and held for Bonds not
presented for payment and moneys deposited pursuant to Article VI hereof shall
not be used for purposes other than payment of such Bonds), be deposited into
the Bond Fund and all moneys so deposited during the continuance of an Event of
Default (other than moneys for the payment of Bonds which had matured or
otherwise become payable prior to such Event of Default or for the payment of
interest due prior to such Event of Default), together with all moneys in any
other fund or account maintained by the Trustee under this Indenture shall be
applied as follows:

                  (a) Unless the principal of all the Bonds shall have become or
            shall have been declared due and payable, all such moneys shall be
            applied:

                        First:  To the payment of amounts, if any, payable to
                  the United States Treasury pursuant to the Proceeds
                  Certificate and Section 405 hereof;

                        Second: To the payment to the Persons entitled thereto
                  of all installments of interest then due on the Bonds, with
                  interest on overdue installments of interest and principal, if
                  lawful, at the Default Rate in the order of the maturity of
                  the installments of such interest, and, if the amount
                  available shall not be sufficient to pay in full any
                  particular installment of interest, then to the payment
                  ratably, according to the amounts due on such installment, to
                  the Persons entitled thereto without any discrimination or
                  privilege; and

                        Third:  To the payment to the Persons entitled thereto
                  of the unpaid principal of any of the Bonds which shall have
                  become due (other than Bonds called for redemption for the
                  payment of which moneys are held pursuant to the provisions of
                  this Indenture), in the order of their due dates, and, if the
                  amount available shall not be sufficient to pay in full the
                  principal of Bonds due on any particular date, then to the
                  payment ratably, according to the amount of principal due on
                  such date, to the Persons entitled thereto without any
                  discrimination or privilege.




                                       39

<PAGE>   44







                           (b) If the principal of all the Bonds shall have
                  become due or shall have been declared due and payable, all
                  such moneys shall be applied to the payment of the principal
                  and interest then due and unpaid upon the Bonds, with interest
                  on overdue interest and principal, as aforesaid, without
                  preference or priority of principal over interest or of
                  interest over principal, or of any installment of interest
                  over any other installment of interest, or of any Bond over
                  any other Bond, ratably, according to the amounts due
                  respectively for principal and interest, to the Persons
                  entitled thereto without any discrimination or privilege.

      Whenever moneys are to be applied pursuant to the provisions of this
Section 807, such moneys shall be applied at such times, and from time to time,
as the Trustee shall determine, having due regard for the amount of such moneys
available for application and the likelihood of additional moneys becoming
available for such application in the future. Whenever the Trustee shall apply
such moneys, it shall fix the date upon which such application is to commence
and upon such date interest on the amounts of principal and interest to be paid
on such date shall cease to accrue. The Trustee shall give such notice as it may
deem appropriate of the deposit with it of any such moneys and of the fixing of
any such date by mailing a copy of such notice by first class mail postage
prepaid to the owners of the then Outstanding Bonds. The Trustee shall not be
required to make payment to the holder of any unpaid Bond until such Bond shall
be presented to the Trustee for appropriate endorsement or for cancellation if
fully paid.

      SECTION 808. REMEDIES VESTED IN TRUSTEE. All rights of action, including
the right to file proof of claims under this Indenture or under any of the
Bonds, may be enforced by the Trustee without the possession of any of the Bonds
or the production thereof in any trial or other proceedings relating thereto and
any such suit or proceeding instituted by the Trustee shall be brought in its
name as Trustee without the necessity of joining as plaintiffs or defendants any
holders of the Bonds, and any recovery of judgment shall be for the equal
benefit of the holders of the then Outstanding Bonds, subject to the provisions
of this Indenture.

      SECTION 809. RIGHTS AND REMEDIES OF BONDHOLDERS. No holder of any Bond
shall have any right to institute any suit, action or proceeding in equity or at
law for the enforcement of this Indenture or for the execution of any trust
hereof or for the appointment of a receiver or for the enforcement of any other
remedy hereunder, unless a default shall have become an Event of Default and the
holders of twenty-five percent (25%) in aggregate principal amount of Bonds then
Outstanding shall have made written request to the Trustee and shall have
offered the Trustee reasonable opportunity either to proceed to exercise the
powers hereinbefore granted or to institute such action, suit or proceeding in
its own name, and unless such Bondholders have also offered to the Trustee
indemnity as provided in Section 901(k) hereof, and unless the Trustee shall
thereafter fail or refuse to exercise the powers hereinbefore granted, or to
institute such action, suit or proceeding in its own name; and such
notification, request and offer of indemnity are hereby declared in every case
at the option of the Trustee to be conditions precedent to the execution of the
powers and trusts of this Indenture and to any action or cause of action for the
enforcement of this Indenture, or for the appointment of a receiver or for any
other remedy hereunder; it being understood and intended that no one or more
Bondholders shall have any right in any manner whatsoever to affect, disturb or
prejudice the lien of this Indenture by any action or to enforce any right
hereunder except in the manner herein provided, and that all proceedings at law
or in equity shall be instituted, had and maintained in the manner herein
provided and for the equal benefit of the holders of all Bonds



                                       40
<PAGE>   45






Outstanding. Nothing in this Indenture contained shall, however, (a) affect or
impair the right of any Bondholder to enforce the payment of the principal of
and interest on any Bond at and after the maturity thereof, or (b) affect or
impair the obligation of the Issuer to pay the principal of and interest on each
of the Bonds issued hereunder to the respective holders thereof at the time and
place, from the source and in the manner in said Bonds expressed.

      SECTION 810. TERMINATION OF PROCEEDINGS. In case the Trustee shall have
proceeded to enforce any right under this Indenture by the appointment of a
receiver, or otherwise, and such proceedings shall have been discontinued or
abandoned for any reason, or shall have been determined adversely to the
Trustee, then and in every case the Issuer and the Trustee shall, subject to any
determination in such proceeding, be restored to their former positions and
rights hereunder with respect to the property pledged and assigned hereunder,
and all rights, remedies and powers of the Trustee shall continue as if no such
proceedings had been taken.

      SECTION 811. WAIVERS OF EVENTS OF DEFAULT. The Trustee may, in its
discretion, without any action on the part of the Bondholders, waive any Event
of Default hereunder and its consequences and rescind any declaration that the
principal of and interest on the Bonds is immediately due and payable, if such
waiver or rescission is not, in the judgment of the Trustee, detrimental to the
Bondholders, and shall do so upon the written request of the holders of at least
fifty-one percent (51%) in aggregate principal amount of all Bonds Outstanding
which are affected by such default.

      SECTION 812. NOTICE OF DEFAULT. In the event of any default hereunder, the
Trustee will promptly give written notice thereof to the Issuer, the Guarantor
and the Company setting forth the nature of such default.

      SECTION 813. DEMAND UNDER GUARANTY. In the event that the Trustee fails to
receive any payment due from the Company, the Trustee shall take the actions
provided under Section 4.7 of the Loan Agreement and seek to enforce the rights
as otherwise provided in the Guaranty.

      SECTION 814. LIMITATION OF LIABILITY. In the event of a violation of the
tax covenants contained herein or in the Loan Agreement or the other Company
Documents, the Bondholders' remedy shall be limited to the payment of 100% of
the principal amount of the Bonds then outstanding, plus accrued interest, if
any, to the payment date, such that neither the Issuer nor the Company will be
liable for any premium or penalty.




                                       41
<PAGE>   46






                                   ARTICLE IX

                                     TRUSTEE

      SECTION 901. ACCEPTANCE OF TRUSTS. The Issuer initially appoints West One
Bank, Utah, Salt Lake City, Utah, as Trustee and Registrar. The Trustee hereby
accepts such appointment and agrees to execute the trusts imposed upon it by
this Indenture, but only upon the terms and conditions set forth herein, to all
of which the Issuer agrees and the respective owners of the Bonds agree by their
acceptance of delivery of any of the Bonds. The Trustee undertakes to perform
such duties and only such duties as are specifically set forth in this Indenture
and no implied covenants or obligations should be read into this Indenture
against the Trustee. The Trustee agrees to perform such trusts as an ordinarily
prudent trustee under a corporate indenture, but in any such event, only upon
and subject to the following expressed terms and conditions:

                  (a) The Trustee may execute any of the trusts or powers hereof
            and perform any of its duties by or through attorneys, agents or
            receivers and shall not be responsible for the misconduct or
            negligence of any such attorneys, agents or receivers appointed in
            the exercise of the care of an ordinarily prudent trustee, and shall
            be entitled to advice of counsel concerning all matters of trusts
            hereof and duties hereunder, and may in all cases pay such
            reasonable compensation to any attorney, agent, receiver or employee
            retained or employed by it in connection herewith. The Trustee may
            act upon the opinion or advice of an attorney, surveyor, engineer or
            accountant selected by it in the exercise of reasonable care or, if
            selected or retained by the Issuer, approved by the Trustee in the
            exercise of such care. The Trustee shall not be responsible for any
            loss or damage resulting from any action or nonaction based on its
            good faith reliance upon such opinion or advice.

                  (b) The Trustee shall not be responsible for any recital
            herein, or in the Bonds (except with respect to the Certificate of
            Authentication of the Trustee endorsed on the Bonds), or for the
            investment of moneys as herein permitted (except that no investment
            shall be made except in compliance with Article V hereof), or for
            the recording or re-recording, filing or re-filing of this
            Indenture, or any supplement or amendment thereto, or the filing of
            financing statements, or for the validity of the execution by the
            Issuer of this Indenture, or of any supplemental indentures or
            instruments of further assurance, or for the sufficiency of the
            security for the Bonds issued hereunder or intended to be secured
            hereby, or for the value or title of the property herein conveyed or
            otherwise as to the maintenance of the security hereof. The Trustee
            may (but shall be under no duty to) require of the Issuer and the
            Company full information and advice as to the performance of the
            covenants, conditions and agreements in the Loan Agreement and shall
            make its best efforts, but without any obligation, to advise the
            Issuer and the Company of any impending default known to the
            Trustee. Except as otherwise provided in Section 803 hereof, the
            Trustee shall have no obligation to perform any of the duties of the
            Issuer under the Loan Agreement.

                  (c) The Trustee shall not be accountable for the use or
            application by the Issuer or the Company of any of the Bonds or the
            proceeds thereof or


                                       42
<PAGE>   47


            for the use or application of any money paid over by the Trustee in
            accordance with the provisions of this Indenture.

                  (d) The Trustee shall be protected in acting upon any notice,
            order, requisition, request, consent, certificate, order, opinion
            (including an opinion of counsel), affidavit, letter, telegram or
            other paper or document in good faith deemed by it to be genuine and
            correct and to have been signed or sent by the proper person or
            persons. Any action taken by the Trustee pursuant to this Indenture
            upon the request or authority or consent of any person who at the
            time of making such request or giving such authority or consent is
            the owner of any Bond, shall be conclusive and binding upon all
            future owners of the same Bond and upon Bonds issued in exchange
            therefor or in place thereof.

                  (e) As to the existence or non-existence of any fact or as to
            the sufficiency or validity of any instrument, paper or proceeding,
            the Trustee shall be entitled to rely upon a certificate signed by
            an Authorized Issuer Representative, or an Authorized Company
            Representative, as the case may be, as sufficient evidence of the
            facts therein contained and prior to the occurrence of a default of
            which the Trustee has been notified as provided in subsection (g) of
            this Section, or of which by said subsection it is deemed to have
            notice, may accept a similar certificate to the effect that any
            particular dealing, transaction or action is necessary or expedient,
            but may at its discretion secure such further evidence deemed
            necessary or advisable, but shall in no case be bound to secure the
            same. The Trustee may accept a certificate of the County Clerk of
            the Issuer under its seal to the effect that a resolution in the
            form therein set forth has been adopted by the Issuer as conclusive
            evidence that such resolution has been duly adopted, and is in full
            force and effect.

                  (f) The permissive right of the Trustee to do things
            enumerated in this Indenture shall not be construed as a duty and
            the Trustee shall not be answerable for other than its negligence or
            willful default.

                  (g) The Trustee shall not be required to take notice or be
            deemed to have notice of any default hereunder, other than an Event
            of Default under clause (a), (b), and (c) of Section 801 hereof
            unless the Trustee shall be specifically notified in writing of such
            default by the Issuer, the Company, or the holders of at least
            twenty-five percent (25%) in aggregate principal amount of all Bonds
            then Outstanding, and all notices or other instruments required by
            this Indenture to be delivered to the Trustee must, in order to be
            effective, be delivered at the Principal Office of the Trustee, and
            in the absence of such notice so delivered the Trustee may
            conclusively assume there is no default except as aforesaid.

                  (h) At any and all reasonable times, the Trustee, and its duly
            authorized agents, attorneys, experts, engineers, accountants and
            representatives, shall have the right fully to inspect any and all
            of the property pledged hereunder, including all books, papers and
            records of the Issuer pertaining to the property pledged hereunder
            and the Bonds, and to take such memoranda from and in regard thereto
            as may be desired.




                                       43
<PAGE>   48







                  (i) The Trustee shall not be required to give any bond or
            surety with respect to the execution of the said trusts and powers
            or otherwise in respect of the premises.

                  (j) Notwithstanding anything elsewhere in this Indenture
            contained, the Trustee shall have the right, but shall not be
            required, to demand, with respect to the authentication of any
            Bonds, the withdrawal of any cash, the release of any property or
            any action whatsoever within the purview of this Indenture, any
            showings, certificates, opinions, appraisals or other information,
            or corporate action or evidence thereof, in addition to that by the
            terms hereof required, as a condition of such action by the Trustee
            deemed reasonably necessary for the purpose of establishing the
            right of the Issuer to the authentication of any Bonds, the
            withdrawal of any cash, the release of any property or the taking of
            any other action by the Trustee.

                  (k) Before taking any action under this Section 901 other than
            an acceleration when required pursuant to Section 802 hereof, the
            Trustee may require that a satisfactory indemnity bond be furnished
            for the reimbursement of all expenses to which it may be put and to
            protect it against all liability, except liability which is
            adjudicated to have resulted from its negligence or willful default
            in connection with any action so taken.

                  (l) All moneys received by the Trustee shall, until used or
            applied or invested as provided in this Indenture, be held in trust
            for the purposes for which they were received but need not be
            segregated from other funds except to the extent required by law, by
            this Indenture. The Trustee shall not be under any liability for
            interest on any moneys received hereunder except such as may be
            agreed upon.

                  (m) If any Event of Default under this Indenture shall have
            occurred and be continuing, the Trustee shall exercise such of the
            rights and powers vested in it by this Indenture and shall use the
            same degree of care as a prudent person would exercise or use in the
            circumstances in the conduct of such prudent person's own affairs.

      SECTION 902. COMPENSATION AND EXPENSES OF TRUSTEE. The Trustee shall be
entitled to payment and/or reimbursement for reasonable fees for its services
rendered hereunder (including services as Registrar, Co-Registrar, paying agent
and authenticating agent and services relating to the transfer of Bonds) and all
advances, counsel fees and other expenses reasonably and necessarily made or
incurred by each of them in connection with such services. Upon an Event of
Default hereunder, but only upon such an Event of Default, the Trustee shall
have a right of payment prior to payment on account of principal of, or premium,
if any, or interest on, any Bond for the foregoing advances, fees, costs and
expenses incurred; provided, however, that in no event shall the Trustee have
any such prior right of payment or claim therefor against moneys or obligations
deposited with or paid to the Trustee for the redemption or payment of Bonds
which are deemed to have been paid in accordance with Article VI hereof.

      SECTION 903. NOTICE TO BONDHOLDERS IF DEFAULT OCCURS. If a default occurs
of which the Trustee is by subsection (g) of Section 901 hereof required to take
notice or if notice of default be given as in said subsection (g) provided, then
the Trustee shall give or cause to be


                                       44
<PAGE>   49



given written notice thereof by first-class mail, postage prepaid, to the owners
of all then Outstanding Bonds.

      SECTION 904. GOOD FAITH RELIANCE. The Trustee shall be protected and shall
incur no liability in acting or proceeding in good faith upon any resolution,
notice, telegram, telex or facsimile transmission, request, consent, waiver,
certificate, statement, affidavit, voucher, bond, requisition or other paper or
document which it shall in good faith believe to be genuine and to have been
passed or signed by the proper board, body or person or to have been prepared
and furnished pursuant to any of the provisions of this Indenture or the Loan
Agreement, or upon the written opinion of any attorney, engineer, accountant or
other expert believed by the Trustee to be qualified in relation to the subject
matter, and the Trustee shall be under no duty to make any investigation or
inquiry as to any statements contained or matters referred to in any such
instrument, but may accept and rely upon the same as conclusive evidence of the
truth and accuracy of such statements. The Trustee shall not be bound to
recognize any person as an owner of Bonds or to take any action at such person's
request unless satisfactory evidence of the ownership of such Bond shall be
furnished to such entity.

      SECTION 905. DEALINGS IN BONDS. The Trustee, in its individual capacity,
may in good faith buy, sell, own, hold and deal in any of the Bonds issued
hereunder, and may join in any action which any owner may be entitled to take
with like effect as if it did not act in any capacity hereunder. The Trustee in
its individual capacity, either as principal or agent, may also engage in or be
interested in any financial or other transaction with the Company, any Affiliate
of the Company, the Guarantor, or the Issuer, and may act as depositary, trustee
or agent for any committee or body of owners of Bonds secured hereby or other
obligations of the Issuer, the Company, the Guarantor, or any such Affiliate as
freely as if it did not act in any capacity hereunder.

      SECTION 906. INTERVENTION BY TRUSTEE. In any judicial proceeding to which
the Issuer is a party and which in the opinion of the Trustee and its counsel
has a substantial bearing on the interests of owners of the Bonds, the Trustee
may intervene on behalf of Bondholders and, subject to the provisions of Section
901(k) hereof, shall do so if requested in writing by the owners of at least
twenty-five percent (25%) in aggregate principal amount of all Bonds then
Outstanding. The rights and obligations of the Trustee under this Section are
subject to the approval of a court of competent jurisdiction.

      SECTION 907. SUCCESSOR TRUSTEE BY MERGER OR CONSOLIDATION. Any corporation
or association into which the Trustee may be converted or merged, or with which
it may be consolidated, or to which it may sell or transfer its corporate trust
business and assets as a whole or substantially as a whole, or any corporation
or association resulting from any such conversion, sale, merger, consolidation
or transfer to which it is a party, provided such corporation or association is
otherwise eligible under Section 908 hereof, shall be and become successor
Trustee hereunder, vested with all of the title to the whole property or trust
estate and all the trusts, powers, discretions, immunities, privileges and all
other matters as was its predecessor under this Indenture, without the execution
or filing of any instrument or any further act, deed or conveyance on the part
of any of the parties hereto, anything herein to the contrary notwithstanding.

      SECTION 908. TRUSTEE REQUIRED; ELIGIBILITY. There shall at all times be a
Trustee hereunder which shall (a) be a commercial bank or trust company within
the State of Utah organized under the laws of the United States of America or
the State, authorized to exercise


                                       45
<PAGE>   50



corporate trust powers, subject to supervision or examination by federal or
state authorities and (b) have a reported combined capital and surplus of not
less than $50,000,000. If at any time the Trustee shall cease to be eligible in
accordance with the provisions of this Section, it shall resign immediately in
the manner provided in Section 909 hereof. No resignation or removal of the
Trustee and no appointment of a successor Trustee shall become effective until
the successor Trustee has accepted its appointment under Section 913 hereof.

      SECTION 909. RESIGNATION BY THE TRUSTEE. The Trustee and any successor
Trustee may at any time resign from the trusts created by this Indenture by
executing an instrument in writing resigning such trusts and specifying the date
when such resignation shall take effect, and filing the same with the Issuer and
the Company not less than 45 days before the date specified in such instrument
when such resignation shall take effect (subject to Section 908 hereof), and by
giving notice of such resignation by first class mail, postage prepaid, not less
than 20 days prior to such resignation date, to each registered owner of Bonds
then Outstanding.

      SECTION 910. REMOVAL OF THE TRUSTEE. The Trustee may be removed at any
time, by filing with the Trustee so removed, and with the Issuer and the
Company, an instrument or instruments in writing, appointing a successor, or an
instrument or instruments in writing, consenting to the appointment by the
Issuer of a successor and accompanied by an instrument of appointment by the
Issuer of such successor, and in any event executed by the owners of not less
than fifty-one percent (51%) in aggregate principal amount of Bonds then
Outstanding.

      SECTION 911. APPOINTMENT OF SUCCESSOR TRUSTEE BY THE BONDHOLDERS;
TEMPORARY TRUSTEE. In case the Trustee hereunder shall resign or be removed, or
be dissolved, or shall be in the process of dissolution or liquidation, or
otherwise becomes incapable of acting hereunder, or in case it shall be taken
under the control of any public officer or officers, or of a receiver appointed
by a court, then a vacancy shall forthwith and ipso facto exist in the office of
Trustee and a successor may be appointed by the owners of fifty-one percent
(51%) in aggregate principal amount of Bonds then Outstanding, by filing with
the Issuer and the Company, an instrument or concurrent instruments in writing
signed by such owners, or by their attorneys in fact duly authorized; provided,
nevertheless, that in case of such vacancy the Issuer, by an instrument executed
and signed by an Authorized Issuer Representative, may appoint a temporary
Trustee to fill such vacancy until a successor Trustee shall be appointed by the
Bondholders in the manner above provided; provided further, that if no permanent
successor Trustee shall have been appointed by the Bondholders within the six
(6) calendar months next succeeding the month during which the Issuer appoints
such a temporary Trustee, such temporary Trustee shall without any further
action on the part of the Issuer or the Bondholders become the permanent
successor Trustee. After any appointment by the Issuer as provided herein, the
Issuer shall cause notice of such appointment to be given to the Company and the
Rating Services and to be given by first class mail, postage prepaid, to all
Bondholders. The foregoing notwithstanding, any such temporary Trustee so
appointed by the Issuer shall immediately and without further act be superseded
by any successor Trustee so appointed by such Bondholders as provided above
within the six (6) calendar months next succeeding the month during which such
temporary Trustee is appointed.

      SECTION 912. JUDICIAL APPOINTMENT OF SUCCESSOR TRUSTEE. In case at any
time the Trustee shall resign and no appointment of a successor Trustee shall be
made pursuant to the foregoing provisions of this Article IX prior to the date
specified in the notice of resignation as the date when such resignation is to
take effect, the resigning Trustee may forthwith apply to a court of competent
jurisdiction for the appointment of a successor Trustee. If no appointment




                                       46
<PAGE>   51




of a successor Trustee shall be made pursuant to the foregoing provisions of
this Article IX within six (6) calendar months after a vacancy shall have
occurred in the office of Trustee, any Bondholder may apply to any court of
competent jurisdiction to appoint a successor Trustee. Such court may thereupon,
after such notice, if any, as it may deem proper and prescribe, appoint a
successor Trustee.

      SECTION 913. CONCERNING ANY SUCCESSOR TRUSTEES. Every successor Trustee
appointed hereunder shall execute, acknowledge and deliver to its predecessor
and also to the Issuer an instrument in writing accepting such appointment
hereunder, and thereupon such successor, without any further act, deed or
conveyance, shall become fully vested with all the estates, properties, rights,
powers, trusts, duties and obligations of its predecessor; but such predecessor
shall, nevertheless, on the written request of the Issuer, or of its successor,
execute and deliver an instrument transferring to such successor Trustee all the
estates, properties, rights, powers and trusts of such predecessor hereunder;
and every predecessor Trustee shall deliver all securities and moneys held by it
as Trustee hereunder to its successor. Should any instrument in writing from the
Issuer be required by any successor Trustee for more fully and certainly vesting
in such successor the estate, rights, powers and duties hereby vested or
intended to be vested in the predecessor, any and all such instruments in
writing shall, on request, be executed, acknowledged and delivered by the
Issuer. The resignation of any Trustee and the instrument or instruments
removing any Trustee and appointing a successor hereunder, together with all
other instruments provided for in this Article, shall be filed and/or recorded
by the successor Trustee in each recording office, if any, where this Indenture
shall have been filed and/or recorded.

      SECTION 914. SUCCESSOR TRUSTEE AS TRUSTEE OF FUNDS. In the event of a
change in Trustee, the predecessor Trustee which has resigned or been removed
shall cease to be Trustee of the funds and accounts created hereunder or
pursuant hereto and shall cease to be the Registrar, authenticating agent, and
paying agent for principal of, premium, if any, and interest on the Bonds, as
provided herein, and the successor Trustee shall become such Trustee, Registrar
and paying agent.




                                       47
<PAGE>   52




                                    ARTICLE X

                             SUPPLEMENTAL INDENTURES

      SECTION 1001. SUPPLEMENTAL INDENTURES NOT REQUIRING CONSENT OF
BONDHOLDERS. Subject to the limitation set forth in Section 1002 hereof with
respect to this Section 1001, the Issuer and the Trustee may (and, in the case
of clause (k) of this Section, shall at the written request of the Authorized
Company Representative), without the consent of, or notice to, any of the
Bondholders, enter into such indenture or indentures supplemental to this
Indenture as shall not be inconsistent with the terms and provisions hereof, for
any one or more of the following purposes:

                  (a) to cure any ambiguity or formal defect or omission in this
            Indenture;

                  (b) to grant to or confer upon the Trustee for the benefit of
            the Bondholders any additional rights, remedies, powers or authority
            that may lawfully be granted to or conferred upon the Bondholders
            and the Trustee, or either of them;

                  (c) to assign and pledge under or subject to this Indenture
            additional revenues, properties or collateral;

                  (d) to evidence the appointment of a separate trustee or the
            succession of a new trustee hereunder;

                  (e) to modify, amend or supplement this Indenture or any
            indenture supplemental hereto in such manner as to permit the
            qualification of this Indenture under the Trust Indenture Act of
            1939, as then amended, or any similar federal statute hereafter in
            effect or to permit the qualification of the Bonds for sale under
            the securities laws of any state of the United States;

                  (f) to modify, amend or supplement this Indenture or any
            indenture supplemental hereto in such manner as to permit continued
            compliance with the Proceeds Certificate or any similar certificate
            executed in connection with the issuance of any Bonds;

                  (g) to provide for the refunding of any Bonds, including the
            right to establish and administer an escrow fund and to take related
            action in connection therewith or to provide for the issuance of
            Additional Bonds as provided in Section 208 herein;

                  (h) to provide for the issuance of Bonds to the extent
            permitted by this Indenture, including but not limited to such
            provisions as are necessary for the Trustee and the Issuer to
            accept, implement and administer any additional security as herein
            authorized, including debt service reserve or similar funds, letters
            or lines of credit, bond insurance policies or other forms of credit
            enhancement and establishing terms and provisions for such Bonds
            which may differ from those established for Bonds then outstanding;



                                       48
<PAGE>   53


                  (i) to evidence or give effect to or facilitate the delivery
            and administration under this Indenture of one or more credit
            facilities, including a letter of credit, a bond insurance policy or
            any other credit facility, to provide credit enhancement relating to
            payment of principal of and interest on the Bonds, provided that
            prior to the entry into of a supplemental indenture pursuant to this
            Section 1001(i), the Trustee shall be provided with an opinion of
            Bond Counsel to the effect that the provisions outlined in such
            supplemental indenture or indentures with respect to the delivery of
            one or more credit facilities for such purposes will not have an
            adverse impact on the excludability of interest on the Bonds from
            the gross income of the owners thereof for federal income tax
            purposes;

                  (j) to effect changes in the Indenture so as to secure or
            maintain ratings on the Bonds from the Rating Services, which
            changes will not restrict, limit or reduce the obligation of the
            Issuer to pay the principal of, premium, if any, and interest on the
            Bonds as provided in this Indenture or otherwise materially
            adversely affect the owners of the Bonds under this Indenture; and

                  (k) to make any change that in the judgment of the Trustee
            does not materially adversely affect the rights of any Bondholders.

      SECTION 1002. SUPPLEMENTAL INDENTURES REQUIRING CONSENT OF BONDHOLDERS.

                  (a) In addition to supplemental indentures covered by Section
            1001 hereof and subject to the terms and provisions contained in
            this Section, and not otherwise, the holders of not less than
            fifty-one percent (51%) in aggregate principal amount of the Bonds
            which are Outstanding hereunder at the time of the execution of any
            such supplemental indenture and, in case less than all of the Bonds
            Outstanding are affected thereby, the holders of not less than
            fifty-one percent (51%) in aggregate principal amount of the Bonds
            so affected, shall have the right, from time to time, anything
            contained in this Indenture to the contrary notwithstanding, to
            consent to and approve the execution by the Issuer and the Trustee
            of such other indenture or indentures supplemental hereto as shall
            be deemed necessary and desirable by the Issuer for the purpose of
            modifying, altering, amending, adding to or rescinding, in any
            particular, any of the terms or provisions contained in this
            Indenture or in any supplemental indenture; provided, however, that
            nothing in this Section contained or in Section 1001 hereof shall
            permit, or be construed as permitting, a supplemental indenture to
            effect: (i) an extension of the stated maturity or reduction in the
            principal amount of, or reduction in the rate of or extension of the
            time of paying interest on, or reduction of any premium payable on
            the redemption of, any Bonds, without the consent of the holders of
            such Bonds; (ii) a reduction in the amount or extension of the time
            of any payment required to be made to or from the Bond Fund or any
            interest or sinking fund applicable to any Bonds, without the
            consent of the holders of all of the Bonds at the time Outstanding;
            (iii) the creation of any lien prior to or on a parity with the lien
            of this Indenture on the Trust Estate or the deprivation of any
            Bondholders of the lien created by this Indenture on such Trust
            Estate, without the consent of the holders of all the Bonds at the
            time Outstanding, provided that nothing in this subparagraph (iii)
            shall be construed to require the consent of Bondholders to the
            issuance of Bonds pursuant to this Indenture; (iv) a reduction in
            the




                                       49
<PAGE>   54

            aforesaid aggregate principal amount of Bonds the owners of which
            are required to consent to any such supplemental indenture, without
            the consent of the owners of all the Bonds at the time Outstanding
            which would be affected by the action to be taken; or (v) a
            modification of the rights, duties or immunities of the Trustee,
            without the written consent of the Trustee.

                  (b) If at any time the Issuer or the Company shall request the
            Trustee to enter into any such supplemental indenture for any of the
            purposes of this Section, the Trustee shall, upon being
            satisfactorily indemnified with respect to expenses, cause notice of
            the proposed execution of such supplemental indenture to be mailed
            by registered or certified mail to the owners of the Bonds. Such
            notice shall briefly set forth the nature of the proposed
            supplemental indenture and shall state that copies thereof are on
            file at the Principal Office of the Trustee for inspection by all
            Bondholders. The Trustee shall not, however, be subject to any
            liability to any Bondholder by reason of its failure to mail such
            notice, and any such failure shall not affect the validity of such
            supplemental indenture when consented to and approved as provided in
            this Section. If the holders of the requisite principal amount of
            Bonds which are Outstanding hereunder at the time of the execution
            of any such supplemental indenture shall have consented to and
            approved the execution thereof as herein provided, no holder of any
            Bond shall have any right to object to any of the terms and
            provisions contained therein, or the operation thereof, or in any
            manner to question the propriety of the execution thereof, or to
            enjoin or restrain the Trustee or the Issuer from executing the same
            or from taking any action pursuant to the provisions thereof. Upon
            the execution of any such supplemental indenture as in this Section
            permitted and provided, this Indenture shall be and be deemed to be
            modified and amended in accordance therewith.

                  (c) Anything herein to the contrary notwithstanding, a
            supplemental indenture under this Article X which adversely affects
            the Company shall not become effective unless and until the Company
            shall have consented in writing to the execution and delivery of
            such supplemental indenture. In this regard, the Trustee shall cause
            notice of the proposed execution and delivery of any such
            supplemental indenture to which the Company has not already
            consented, together with a copy of the proposed supplemental
            indenture and a written consent form to be signed by the Company, to
            be mailed by certified or registered mail to the Company at least
            thirty (30) days (or such shorter period of time acceptable to the
            Company) prior to the proposed date of execution and delivery of any
            such supplemental indenture.

                  (d) Subject to the terms and provisions contained in this
            Section 1002(d), the owners of all the Bonds at any time Outstanding
            shall have the right, and the Issuer and the Trustee by their
            execution and delivery of this Indenture hereby expressly confer
            upon such owners the right, to modify, alter, amend or supplement
            this Indenture in any respect, including without limitation in
            respect of the matters described in clauses (i), (ii) and (iii) of
            the proviso contained in subsection (a) of this Section 1002, by
            delivering to the Issuer, the Trustee and the Company a written
            instrument or instruments, executed by or on behalf of such owners,
            containing a form of supplemental indenture which sets forth such
            modifications, alterations,



                                       50
<PAGE>   55


            amendments and supplements, and, upon the expiration of a 30-day
            period commencing on the date of such delivery during which no
            notice of objection shall have been delivered by the Issuer or the
            Trustee to such owners at an address specified in such written
            instrument, such supplemental indenture shall be deemed to have been
            approved and confirmed by the Issuer and the Trustee, to the same
            extent as if actually executed and delivered by the Issuer and the
            Trustee, and such supplemental indenture shall thereupon become and
            be for all purposes in full force and effect without further action
            by the Issuer or the Trustee. The foregoing provisions are, however,
            subject to the following conditions:

                        (i)   no such supplemental indenture shall in any way
                  affect the limited nature of the obligations of the Issuer
                  under this Indenture as set forth in Section 205 hereof, or
                  otherwise, or adversely affect any of its rights hereunder;

                        (ii)  no such supplemental indenture shall be to the
                  prejudice of the Trustee, and no such supplemental indenture
                  which adversely affects the Company shall become effective
                  unless consented to by the Company in the manner provided in
                  Section 1002(c) hereof; and

                        (iii) there shall have been delivered to the Issuer, the
                  Trustee and the Company an opinion of Bond Counsel stating
                  that such supplemental indenture is authorized or permitted by
                  this Indenture and the Act, complies with their respective
                  terms, will, upon the expiration of the aforesaid 30-day
                  period, be valid and binding upon the Issuer in accordance
                  with its terms and will not adversely affect the exclusion
                  from gross income for federal income tax purposes of interest
                  on any of the Bonds.





                                       51
<PAGE>   56







                                   ARTICLE XI

                        AMENDMENTS TO THE LOAN AGREEMENT

      SECTION 1101. AMENDMENTS, ETC. TO LOAN AGREEMENT NOT REQUIRING CONSENT.
The Issuer, the Company and the Trustee may, without the consent of or notice to
the owners of the Bonds, consent to any supplemental loan agreement which
effects such amendment, change or modification of the Loan Agreement as may be
required (a) by the provisions of this Indenture or the Loan Agreement; (b) for
the purpose of curing any ambiguity or formal defect or omission; (c) in
connection with the issuance of Bonds as provided in Section 207 or Section 208
hereof; (d) for the purpose of complying with the provisions of the Proceeds
Certificate; (e) to evidence or give effect to or facilitate the delivery and
administration under this Indenture of one or more credit facilities including a
letter of credit, a bond insurance policy or any other credit facility to
provide credit enhancement relating to payment of principal of and interest on
the Bonds, provided that prior to the entering into of a supplemental loan
agreement pursuant to this Section 1101, the Trustee shall be provided with an
opinion of Bond Counsel to the effect that the provisions outlined in such
supplemental loan agreement or loan agreements with respect to the delivery of
one or more credit facilities for such purposes will not have an adverse impact
on the excludability of interest on the Bonds from the gross income of the
owners thereof for federal income tax purposes; (f) to secure or maintain
ratings on the Bonds from the Rating Services, which changes will not restrict,
limit or reduce the obligation of the Issuer to pay the principal of and
premium, if any, and interest on the Bonds as provided in this Indenture or
otherwise materially adversely affect the owners of the Bonds; (g) to amend or
supplement the description of the Project set forth in Exhibit A to the Loan
Agreement, provided that no such amendment or supplement shall be entered into
that would cause the Company to violate its covenants set forth in Section 3.7
of the Loan Agreement; or (h) to make any other change therein which, in the
judgment of the Trustee, does not materially adversely affect the rights of the
Trustee or the owners of the Bonds, provided, however, that nothing in this
Section 1101 shall permit, or be construed as permitting, any amendment, change
or modification of the Loan Agreement that may result in anything described in
the numbered clauses of Section 1002(a) hereof, without the consent of each
Bondholder affected. If at any time the Company shall request the Issuer and the
Trustee to consent to any amendment, change or modification of the Loan
Agreement pursuant to subparagraph (h) above, the Trustee shall cause notice of
the proposed execution of such amendment, change or modification to the Loan
Agreement to be given to the Rating Services at least thirty (30) days prior to
the execution of such amendment, change or modification to the Loan Agreement,
which notice shall include a copy of the proposed amendment, change or
modification to the Loan Agreement.

      Before the Issuer shall enter into, and the Trustee shall consent to, any
modification, alteration, amendment or supplement to the Loan Agreement pursuant
to this Section 1101, there shall have been delivered to the Issuer and the
Trustee an opinion of Bond Counsel stating that such modification, alteration,
amendment or supplement is authorized or permitted by the Loan Agreement or this
Indenture and the Act, complies with their respective terms, will, upon the
execution and delivery thereof, be valid and binding upon the Issuer in
accordance with its terms and will not adversely affect the exclusion from gross
income for federal income tax purposes of interest on any of the Bonds.

      SECTION 1102. AMENDMENTS, ETC. TO LOAN AGREEMENT REQUIRING CONSENT OF
BONDHOLDERS. Except for the amendments, changes or modifications as provided in
Section 1101 hereof, neither the Issuer nor the Trustee shall consent to any
amendment,





                                       52
<PAGE>   57






change or modification of the Loan Agreement without the prior written approval
or consent, given and procured as in this Section provided, of the owners of not
less than fifty-one percent (51%) in aggregate principal amount of the Bonds
Outstanding hereunder at the time of the execution of such amendment or
modification and, in case less than all of the Bonds Outstanding are affected
thereby, of the holders of not less than fifty-one percent (51%) in aggregate
principal amount of the Bonds so affected. If at any time the Issuer and the
Company shall request the consent of the Trustee to any such proposed amendment,
change or modification of the Loan Agreement, the Trustee shall, upon being
satisfactorily indemnified with respect to expenses, cause notice of such
proposed amendment, change or modification to be mailed in the same manner as
provided by Section 1002 hereof with respect to supplemental indentures. Such
notice shall briefly set forth the nature of such proposed amendment, change or
modification and shall state that copies of the instrument embodying the same
are on file at the Principal Office of the Trustee for inspection by all
Bondholders. The Trustee shall not, however, be subject to any liability to any
Bondholder by reason of its failure to mail such notice, and any such failure
shall not affect the validity of such amendment, change or modification when
consented to and approved as provided in this Section. If the holders of not
less than fifty-one percent (51%) in aggregate principal amount of the Bonds
Outstanding which are affected by the amendment to the Loan Agreement shall have
consented to and approved the execution thereof as herein provided, no holder of
any Bond shall have any right to object to any of the terms and provisions
contained therein, or the operation thereof, or in any manner to question the
propriety of the execution thereof, or to enjoin or restrain the Trustee or the
Issuer from executing the same or from taking any action pursuant to the
provisions thereof. The foregoing notwithstanding, no amendment or supplement
may be made which permits the assignment of the Loan Agreement by the Company
other than as permitted by Section 6.1 of the Loan Agreement or which results in
anything described in the numbered clauses of Section 1002(a) hereof unless the
holders of 100% in aggregate principal amount of the Bonds Outstanding shall
have consented to such amendment or supplement.

         Before the Issuer shall enter into, and the Trustee shall consent to,
any modification, alteration, amendment or supplement to the Loan Agreement
pursuant to this Section 1102, there shall have been delivered to the Issuer and
the Trustee an opinion of Bond Counsel stating that such modification,
alteration, amendment or supplement is authorized or permitted by the Loan
Agreement or this Indenture and the Act, complies with their respective terms,
will, upon the execution and delivery thereof, be valid and binding upon the
Issuer in accordance with its terms and will not adversely affect the exclusion
from gross income for federal income tax purposes of interest on any of the
Bonds.



                                       53
<PAGE>   58



                                   ARTICLE XII

                                  MISCELLANEOUS

      SECTION 1201. PARTIES IN INTEREST. With the exception of rights herein
expressly conferred, nothing expressed or mentioned in or to be implied from
this Indenture or the Bonds is intended or shall be construed to give to any
person other than the Issuer, the Trustee, the Company and the holders of the
Bonds any legal or equitable right, remedy or claim under or with respect to
this Indenture or any covenants, conditions and provisions herein contained;
this Indenture and all of the covenants, conditions and provisions hereof being
intended to be and being for the sole and exclusive benefit of the Issuer, the
Trustee, the Company and the holders of the Bonds as herein provided.

      SECTION 1202. SEVERABILITY. If any provision of this Indenture shall be
held or deemed to be or shall, in fact, be inoperative or unenforceable as
applied in any particular case in any jurisdiction or jurisdictions or in all
jurisdictions, or in all cases because it conflicts with any other provision or
provisions of any constitution or statute or rule of public policy, or for any
other reason, such circumstances shall not have the effect of rendering the
provision in question inoperative or unenforceable in any other case or
circumstance, or of rendering any other provision or provisions herein contained
invalid, inoperative or unenforceable to any extent whatever. The invalidity of
any one or more phrases, sentences, clauses or Sections in this Indenture
contained shall not affect the remaining portions of this Indenture or any part
thereof.

      SECTION 1203. DELIVERY OF NOTICES; DELIVERY OF BONDS. Except as otherwise
provided in this Indenture, all notices, certificates, requests, requisitions or
other communications by the Issuer, the Company, or the Trustee, pursuant to
this Indenture shall be in writing and shall be sufficiently given and shall be
deemed given when mailed by first class mail, postage prepaid, addressed as
follows:

                  If to the Issuer:      Carbon County
                                         Board of County Commissioners
                                         County Courthouse
                                         120 East Main Street
                                         Price, Utah  84501
                                         Telecopier: (801) 637-4700
                                         Attention:  Chairman

                  If to the Trustee:     West One Bank, Utah
                                         107 South Main Street, Suite 303
                                         Salt Lake City, Utah  84111
                                         Telecopier:  (801) 534-6208
                                         Attention:  Corporate Trust Department

                  If to the Company:     ECDC Environmental, L.C.
                                         127 South 500 East
                                         Suite 675
                                         Salt Lake City, Utah 84102
                                         Telecopier: (801) 355-9167
                                         Attention:  V.P. Finance



                                       54
<PAGE>   59

                  If to the Guarantor:   Laidlaw Inc.
                                         3221 North Service Road
                                         Burlington, Ontario
                                         Canada  L7R3Y8
                                         Telecopier:  (905) 336-3976
                                         Attention:  Senior Vice President and
                                           General Counsel

      SECTION 1204. COUNTERPARTS. This Indenture may be simultaneously executed
in several counterparts, each of which shall be an original and all of which
shall constitute but one and the same instrument.

      SECTION 1205. GOVERNING LAW. This Indenture shall be governed exclusively
by and construed in accordance with the laws of the State of Utah.

      SECTION 1206. IMMUNITY OF OFFICERS AND EMPLOYEES OF ISSUER. No recourse
shall be had for the payment of the principal of or premium, if any, or interest
on any of the Bonds or for any claim based thereon or upon any obligation,
covenant or agreement in this Indenture contained against any past, present or
future officer, employee or agent of the Issuer, or any officer, employee or
agent of any successor body politic, either directly or through the Issuer or
any successor body politic, under any rule of law or equity, statute or
constitution or by the enforcement of any assessment or penalty or otherwise,
and all such liability of any such officers, employees or agents, as such, is
hereby expressly waived and released as a condition of and consideration for the
execution of this Indenture and the issuance of any of the Bonds.

      SECTION 1207. BONDS OWNED BY THE ISSUER, THE GUARANTOR OR THE COMPANY. In
determining whether the owners of the requisite aggregate principal amount of
the Bonds have concurred in any direction, consent or waiver under this
Indenture, Bonds which are owned by the Issuer, the Guarantor or the Company or
by any person directly or indirectly controlling or controlled by or under
direct or indirect common control with the Company or the Guarantor (unless the
Issuer, the Company or such person owns all Bonds which are then Outstanding,
determined without regard to this Section) shall be disregarded and deemed not
to be Outstanding for the purpose of any such determination, except that, for
the purpose of determining whether the Trustee shall be protected in relying on
any such direction, consent or waiver, only Bonds which the Trustee knows are so
owned shall be so disregarded. Bonds so owned which have been pledged in good
faith may be regarded as Outstanding if the pledgee establishes to the
satisfaction of the Trustee the pledgee's right so to act with respect to such
Bonds and that the pledgee is not the Issuer, the Guarantor or the Company or
any person directly or indirectly controlling or controlled by or under direct
or indirect common control with the Company or the Guarantor. In case of a
dispute as to such right, any decision by the Trustee taken upon the advice of
counsel shall be full protection to the Trustee.

      SECTION 1208. PLEDGE AND UNDERTAKING OF THE STATE. In entering into this
Indenture and otherwise providing for the issuance of the Series 1995A Bonds,
the Issuer and the Trustee have specifically relied upon Section 11-17-13 of the
Act, which provides:

      The State of Utah does hereby pledge to and agree with the holders of any
      bonds issued under this act and with those parties who may enter into
      contracts with any county or municipality under this act, that the state
      will not alter, impair or limit the rights thereby vested until the bonds,
      together with applicable interest, are fully met and discharged and such
      contracts are fully


                                       55

<PAGE>   60



      performed. Nothing contained in this act shall preclude such alteration,
      impairment or limitation if and when adequate provision shall be made by
      law for the protection of the holders of the bonds or persons entering
      into contracts with any county or municipality. Each county and
      municipality is authorized to include this pledge and undertaking for the
      state in such bonds or contracts.

      The Issuer hereby incorporates herein the foregoing pledge and undertaking
for the State.




                                       56
<PAGE>   61



      IN WITNESS WHEREOF, CARBON COUNTY, UTAH has caused these presents to be
signed in its name and on its behalf by the Chairman of its Board of County
Commissioners and its corporate seal to be hereunto affixed and attested by its
County Clerk, and to evidence its acceptance of the trusts hereby created WEST
ONE BANK, UTAH has caused these presents to be signed in its name and on its
behalf by its Vice President and its official seal to be hereunto affixed, all
as of the day and year first above written.

                                                 CARBON COUNTY, UTAH


                                                 By /s/ William D. Krompel
                                                    ---------------------------
[Seal]                                                      Chairman,
                                                  Board of County Commissioners
Attest:
 /s/ Robert P. Pew
----------------------------------------
                  County Clerk



                                                 WEST ONE BANK, UTAH, as Trustee


                                                 By /s/
                                                    ---------------------------
[Seal]                                                   Vice President




                                       57
<PAGE>   62








                                   EXHIBIT "A"

                             [FORM OF FRONT OF BOND]

REGISTERED                                                           REGISTERED

NO. R-                                                       $
     -------------------------                                 ----------------

                            UNITED STATES OF AMERICA

                                  STATE OF UTAH

                                COUNTY OF CARBON

                   SOLID WASTE DISPOSAL REFUNDING REVENUE BOND
         (LAIDLAW INC./ECDC ENVIRONMENTAL, L.C. PROJECT), 1995 SERIES A



   Interest           Maturity                 Issue
     Rate               Date                   Date                   CUSIP
   --------           --------                 -----                  -----


                   February 1, 2010


Registered Owner:

Principal Amount:                                                       Dollars


      Carbon County, Utah (the "Issuer"), a duly organized and existing
political subdivision of the State of Utah, for value received, hereby promises
to pay (but only from the sources hereinafter mentioned) to the Registered Owner
identified above or registered assigns, on the Maturity Date set forth above,
upon presentation and surrender hereof, the Principal Amount set forth above and
to pay solely from such sources interest on said Principal Amount at the
Interest Rate set forth above, calculated on the basis of a 360-day year of
twelve (12) thirty (30) day months, from the Interest Payment Date next
preceding the date of authentication hereof unless (i) this Bond is
authenticated as of an Interest Payment Date in which event this Bond shall bear
interest from such Interest Payment Date or (ii) this Bond is authenticated
prior to the first Interest Payment Date in which event this Bond shall bear
interest from the Issue Date set forth above; provided, however, that if
interest on the Bonds shall be in default as shown by the records of the
Trustee, interest shall accrue at the Default Rate (as defined in the Indenture
hereinafter described) from the Interest Payment Date to which interest has been
paid in full, until the payment of such Principal Amount (except as the
provisions set forth in the Indenture hereinafter described with respect to
redemption prior to maturity may be applicable hereto), such interest being
payable semiannually on each February 1 and August 1, commencing August 1, 1995
(each an "Interest Payment Date"). Payments of interest shall be made to the
Registered Owner hereof, as of the fifteenth day of the month next preceding
such Interest Payment Date, by check or draft mailed on the Interest Payment
Date to the address of such Registered Owner as it appears on the registration
books of the Issuer maintained by the Trustee as Bond Registrar, or to such
other address as may be furnished to said Trustee in writing by such Registered
Owner. Payment of principal or redemption price of


                                       A-1





<PAGE>   63







and premium, if any, on this Bond shall be made by check or draft only upon
presentation and surrender of this Bond at the principal corporate trust office
of West One Bank, Utah, Salt Lake City, Utah, as Paying Agent (the "Paying
Agent"), or at the office designated for such payment of any successor thereof
or of any other paying agent as provided in said Indenture. The principal of,
premium, if any, and interest on this Bond are payable by check or draft
denominated in any coin or currency of the United States of America which, at
the respective times of payment is legal tender for the payment of public and
private debts. As used herein the term "Business Day" means any day other than a
Saturday, Sunday or a day on which banking institutions in the State of Utah or
the city in which the principal corporate trust office of the Trustee is
located, or the New York Stock Exchange are closed or required by law to close.
If any payment of principal of, premium, if any, or interest required to be made
on this Bond becomes due and payable on a day other than a Business Day, then
such payment shall be made on the next succeeding Business Day, with the same
force and effect as if made on the Interest Payment Date, the date of maturity
or the date fixed for redemption, and such payment shall not include the
interest for the period between such date and the next succeeding Business Day.

         Reference is hereby made to the further provisions of this Bond set
forth on the reverse side hereof, which further provisions shall for all
purposes have the same effect as if set forth at this place.

         This Bond is one of an issue of Bonds which is issued under the
provisions of, and in full compliance with, the Constitution and laws of the
State of Utah, particularly Title 11, Chapter 17, Utah Code Annotated 1953, as
amended. The Bonds are special, limited obligations of the Issuer, payable by
the Issuer solely from certain amounts received by the Issuer under, and secured
by a pledge of certain rights of the issuer under and pursuant to, the Loan
Agreement (as such term is defined in the Indenture), and, further, from the
funds and accounts created under the Indenture (but not including the Rebate
Fund created under the Indenture) and investment earnings thereon, all of which
shall be used for no other purpose than to pay the principal of, premium, if
any, and interest on the Bonds, except as may be otherwise expressly authorized
in the Indenture. Neither the faith and credit nor the taxing power of the State
of Utah or any political subdivision thereof is pledged to the payment of the
principal of, premium, if any, or interest on the Bonds. The Bonds and the
interest thereon do not constitute or give rise to a general obligation or
liability of the Issuer or a charge against its general credit or taxing powers,
and the Bonds do not constitute a loan of the credit of the Issuer within the
meaning of any constitutional restriction or statutory limitation of the State
of Utah.

         It Is Hereby Certified, Recited and Declared that all acts, conditions
and things required to exist, happen and be performed precedent to and in the
execution and delivery of the indenture and the issuance of this Bond do exist,
have happened and have been performed in due time, form and manner as required
by law, and that the issuance of this Bond and the series of which it forms a
part, together with all other obligations of the Issuer, does not exceed or
violate any constitutional or statutory limitation on indebtedness, and that
payment in full for this Bond has been received.

         This Bond shall not be valid or become obligatory for any purpose or be
entitled to any security or benefit under the Indenture unless and until the
Certificate of Authentication hereon shall have been duly executed by the
Trustee, as provided in the Indenture.


                                       A-2





<PAGE>   64







         In Witness Whereof, Carbon County, Utah has caused this Bond to be
executed in its name by the facsimile signature of the Chairman of its Board of
County Commissioners, and the facsimile of its official seal to be imprinted
hereon and attested by the facsimile signature of its County Clerk.

                                             CARBON COUNTY, UTAH


                                             By
                                                -------------------------------
[Seal]                                                   Chairman,
                                                 Board of County Commissioners
Attest:

-------------------------------
         County Clerk






                                       A-3





<PAGE>   65







                          CERTIFICATE OF AUTHENTICATION

         This Bond is one of the Bonds described in the within-mentioned
Indenture of Trust.

Date of registration and authentication:





                                               WEST ONE BANK, UTAH,
                                                 as Trustee


                                               By
                                                  -----------------------------
                                                    Authorized Signatory



                            (FORM OF REVERSE OF BOND)

      This Bond is one of the duly authorized Carbon County, Utah Solid Waste
Disposal Refunding Revenue Bonds (Laidlaw Inc./ECDC Environmental, L.C.
Project), 1995 Series A, to be issued in an aggregate principal amount not
exceeding $23,000,000 (the "Bonds"), pursuant to certain resolutions
(collectively, the "Resolution") duly adopted by the Issuer's Board of County
Commissioners (the "Board"), in accordance with the applicable provisions of the
Utah Industrial Facilities and Development Act, Title 11, Chapter 17, Utah Code
Annotated 1953, as amended (the "Act"), under an Indenture of Trust dated as of
February 1, 1995 (the "Indenture"), between the Issuer and West One Bank, Utah,
as Trustee (the "Trustee", which term shall include any successor Trustee), for
the purpose of providing a portion of the funds necessary to refund up to
$23,000,000 outstanding principal amount of certain solid waste disposal revenue
bonds previously issued by the Issuer to provide a portion of the funds
necessary to finance among other things a solid waste disposal facility located
within the boundaries of the Issuer (the "Project") for ECDC Environmental,
L.C., a Utah limited liability company (the "Company"). Proceeds from the sale
of the Bonds are to be loaned by the Issuer to the Company, under the terms of a
Loan Agreement dated as of February 1, 1995 (the "Loan Agreement"). The Bonds
are all issuable under and are equally and ratably secured by and are entitled
to the benefits of the Indenture, including the security of the pledge and
assignment of certain amounts payable to the Issuer pursuant to the Loan
Agreement, and all receipts of the Trustee credited under the provisions of the
Indenture against the payment of such amounts, and from any other moneys held by
the Trustee under the Indenture for such purpose. The Project is not security
for the Bonds.

      Pursuant to a Guaranty dated as of February 1, 1995 from Laidlaw Inc., a
Canadian corporation (the "Guarantor"), to the Trustee, the Guarantor has agreed
to guaranty timely payment of the Company's obligations relating to the Bonds.

      Any term used herein as a defined term but not defined herein shall have
the meaning ascribed to such term in the Indenture or the Loan Agreement.


                                       A-4





<PAGE>   66







Part I -- Redemption Provisions

         Optional Redemption of Bonds. The Series 1995A Bonds are subject to
optional redemption prior to maturity by the Trustee at the direction of the
Company, in whole at any time or in part on any Interest Payment Date, in
inverse order of maturity and by lot within each maturity at any time on or
after February 1, 2005, at a redemption price expressed as a percentage of
principal amount of Series 1995A Bonds to be redeemed set forth in the table
below, together with accrued interest to the Redemption Date:

<TABLE>
<CAPTION>
              Redemption Date                    Redemption Price
              ---------------                    ----------------
<S>                                                    <C> 
February 1, 2005 - January 31, 2006                    102%
February 1, 2006 - January 31, 2007                    101%
February 1, 2007 and thereafter                        100%
</TABLE>

         Extraordinary Optional Redemption. The Series 1995A Bonds shall be
subject to extraordinary optional redemption prior to maturity by the Trustee,
at the direction of the Company, in whole or in part, on any date at a
redemption price equal to the principal amount of the Series 1995A Bonds to be
redeemed plus accrued interest to the redemption date, within 365 days following
the occurrence of any one of the following events (or, in the case of
subparagraph (a) and (b) below, at the option of the Company, within sixty (60)
days following the receipt of any proceeds relating to such event):

                           (a) The Facility (as defined in the Indenture) or a
                  substantial portion thereof shall have been damaged or
                  destroyed by fire or other casualty (i) to such extent that,
                  in the opinion of the Company, within a period of twelve
                  consecutive months following such damage or destruction it is
                  not practicable or desirable to rebuild, repair or restore the
                  Facility, or (ii) to such extent that, in the opinion of the
                  Company, the Facility is or will be prevented thereby from
                  operating normally for a period of twelve (12) consecutive
                  months.

                           (b) Title to, or the temporary use of, all or
                  substantially all of the Facility shall have been taken under
                  the exercise of the power of eminent domain (including such a
                  taking or takings as results or is likely to result, in the
                  opinion of the Company, in normal operations at the Facility
                  being interrupted for a period of twelve (12) consecutive
                  months or results or is likely to result in rendering the
                  Facility, in the opinion of the Company, unsuitable for use).

                           (c) As a result of any changes in the Constitution of
                  the State of Utah or the Constitution of the United States of
                  America or of legislative or administrative action (whether
                  state or federal) or by final decree, judgment or order of any
                  court or administrative body (whether state or federal)
                  entered after the contest thereof by the Company in good
                  faith, the Loan Agreement shall have become void or
                  unenforceable or impossible of performance in accordance with
                  the intent and purposes of the parties as expressed in the
                  Loan Agreement, or unreasonable burdens or excessive
                  liabilities shall have been imposed on the Issuer or the
                  Company, including without limitation, federal, state or other
                  ad valorem, property, income or other taxes not being imposed
                  on the date of the Loan Agreement or changes since the date of
                  initial issuance of the Bonds in regulatory requirements,
                  technology or the economic availability of raw materials,
                  operating supplies, equipment or waste requiring treatment

                                       A-5





<PAGE>   67







                  and disposal, which condition cannot reasonably be expected to
                  improve materially within a period of twelve (12) consecutive
                  months and causes the Company to determine that the Facility
                  should not be completed or that operation of the Facility
                  should be discontinued.

         Special Mandatory Redemption. The Series 1995A Bonds are also subject
to Special Mandatory Redemption in whole by the Issuer on any date prior to
maturity at a redemption price of 100% of the principal amount thereof together
with accrued interest to the date of redemption, upon the occurrence of a
Determination of Taxability (as defined in the Indenture), as soon as
practicable, but in no event later than thirty (30) days after the occurrence of
such Determination of Taxability.

         Notice of Redemption. Notice of redemption shall be given by
first-class mail, postage prepaid, mailed not less than thirty (30) nor more
than sixty (60) days prior to the redemption date (except in the case of Special
Mandatory Redemption, in which case the Trustee will give immediate notice as
provided in the Indenture), to each owner of a Bond to be redeemed at the
address of such Bondholder appearing in the Bond Register. Failure to give such
notice to any Bondholder, or any defect therein, shall not affect the validity
of the proceedings for the redemption of any Bond or portion thereof with
respect to which no such failure has occurred. The Indenture provides for the
giving of additional notice under certain circumstances, provided that no defect
in or failure to give such additional notice shall in any manner defeat the
effectiveness of a call for redemption with respect to Bonds for which notice
was properly given as described above. Notice of redemption having been given as
aforesaid, the Bond so to be redeemed shall, on the redemption date, become due
and payable at the redemption price therein specified and from and after such
date (unless the Issuer shall default in the payment of the redemption price)
such Bond shall cease to bear interest. Upon surrender of any such Bond for
redemption in accordance with said notice, the redemption price of such Bond
shall be paid. If any Bond called for redemption shall not be so paid upon
surrender thereof for redemption, the principal (and premium, if any) shall,
until paid, bear interest from the redemption date at the rate last borne by the
Bond.

         If at the time of mailing of notice of an optional redemption there
shall not have been deposited with the Trustee moneys sufficient to redeem all
the Bonds called for redemption, which moneys are or will be available for
redemption of Bonds, such notice will state that it is conditional, that is,
subject to the deposit of the redemption moneys with the Trustee not later than
the close of business of the fifth day prior to the Redemption Date, and such
notice shall be of no effect unless such moneys are so deposited.

         Partial Redemption. The Trustee, upon surrender of any Bond to be
redeemed in part, shall authenticate and deliver to the owner of such Bond,
without service charge, a new Bond or Bonds in aggregate principal amount equal
to and in exchange for the unpurchased or unredeemed portion of the principal of
the Bond so surrendered, which new Bond or Bonds shall be in any Authorized
Denominations and shall be identical to the Bond being purchased or redeemed
with respect to stated maturity and interest rate, and bearing numbers not
contemporaneously outstanding. If less than all the Bonds are to be redeemed,
the particular Bonds or portion thereof to be redeemed shall be selected prior
to the redemption date by the Trustee, by lot by such method as the Trustee
shall deem fair and appropriate and which may provide for the selection for
redemption of portions of the principal of Bonds of a denomination larger than
the minimum Authorized Denomination. The unredeemed portion of a Bond selected
for partial redemption must be equal to an Authorized Denomination.


                                       A-6





<PAGE>   68







Part II -- General

         The owner of this Bond shall have no right to enforce the provisions of
the Indenture or to institute any suit, action or proceeding in equity or at law
for the enforcement of the Indenture or for the appointment of a receiver or for
the enforcement of any other remedy under the Indenture, except as provided in
the Indenture. The Issuer, the Trustee, and the Company may treat the registered
owner of this Bond as the absolute owner hereof for all purposes, whether or not
this Bond shall be overdue, and shall not be bound by any notice to the
contrary.

         If provision is made for the payment of the principal of, premium, if
any, and interest on this Bond in accordance with the Indenture, this Bond shall
no longer be deemed Outstanding under the Indenture, shall cease to be entitled
to any lien, benefit or security under the Indenture, except for purposes of
registration and exchange and of such payment.

         Modifications or alterations of the Indenture or of any supplements
thereto, may be made only to the extent and in the circumstances permitted by
the Indenture.

         Except as otherwise provided in the Indenture, the Bonds are issuable
only as fully registered Bonds, without coupons, in denominations of $5,000 and
any integral multiple of $5,000 in excess thereof.

         The transfer of this Bond shall be registered upon the books kept at
the Principal Office of the Trustee, upon surrender of this Bond, duly endorsed
by, or accompanied by a written instrument or instruments of transfer in form
satisfactory to the Trustee and duly executed by the Bondholder or such
Bondholder's attorney duly authorized in writing and with guarantee of
signature.

         Subject to the limitations contained in the Indenture, this Bond may be
exchanged at any time at the Principal Office of the Trustee, upon surrender
hereof together with an assignment duly executed by the registered owner hereof
or such owner's attorney or legal representative in such form and with guarantee
of signature as shall be satisfactory to the Trustee for an equal aggregate
principal amount of Bonds of any Authorized Denomination as the Bonds
surrendered for exchange, which Bonds shall be identical to the Bonds being
exchanged with respect to interest rate and stated maturity, and bearing numbers
not contemporaneously outstanding.

         Reference is hereby made to the Indenture, the Loan Agreement and the
Proceeds Certificate, copies of which are on file with the Trustee, for the
provisions, among others, with respect to the nature and extent of the rights,
duties and obligations of the Issuer, the Company, the Trustee, and the owners
of the Bonds, including provisions relating to acceleration under certain
circumstances and provisions relating to the issuance of additional bonds under
the Indenture. The owner of this Bond, by acceptance hereof, is deemed to have
agreed and consented to and to be bound by the terms and provisions of the
Indenture, the Loan Agreement and the Proceeds Certificate.

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


                                       A-7





<PAGE>   69







                                UNIF GIFT MIN ACT


TEN COM      --      as tenants in common                    Custodian
                                                     -------           --------
TEN ENT      --      as tenants by the entirety      (Cust)(Minor)

JT TEN       --      as joint tenantss with right    Under Uniform Gifts tp
                     of survivorship and not as      Minors Act
                                                                 -------------
                        tenants in common                  (State)


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

                                   ASSIGNMENT

      FOR VALUE RECEIVED, THE UNDERSIGNED HEREBY SELLS, ASSIGNS AND TRANSFERS
UNTO

PLEASE INSERT SOCIAL SECURITY OR
OTHER IDENTIFYING NUMBER OF ASSIGNEE

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


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

--------------------------------------------------------------------------------
       (Please Print or Typewrite Name and Address, including Zip Code, of
                                    Assignee)

the within Bond of CARBON COUNTY, UTAH, and all rights thereunder, and hereby
irrevocably constitutes and appoints

--------------------------------------------------------------------------------
attorney to register the transfer of said Bond on the books kept for
registration thereof, with full power of substitution in the premises.




Dated:                                Signature:
      ----------------------                    ---------------------------

Signature
Guaranteed:
           ---------------------------------------------------------------------
Notice:           The signature to this assignment must correspond with the name
                  as it appears upon the face of the within Bond in every
                  particular, without alteration or enlargement or any change
                  whatever.

Notice:           The signature(s) should 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 S.E.C.
                  Rule 17Ad-15.



                                       A-8





<PAGE>   70






                                   EXHIBIT "B"

                          DTC LETTER OF REPRESENTATIONS

                       (See Transcript Document No. 27)























                                       B-1