May 9, 1994
                       MODIFICATION NO. 8
                               TO
              SAN JUAN PROJECT OPERATING AGREEMENT
                             BETWEEN
              PUBLIC SERVICE COMPANY OF NEW MEXICO
                               AND
                  TUCSON ELECTRIC POWER COMPANY


     THIS MODIFICATION No. 8 to the San Juan Project Operating
Agreement between PUBLIC SERVICE COMPANY OF NEW MEXICO ("New
Mexico") and TUCSON ELECTRIC POWER COMPANY ("Tucson"), hereinafter
referred to collectively as the "Parties", is hereby entered into
and executed as of this ____ day of _________________, 1993.

WITNESSETH:

     WHEREAS, the Parties entered into an agreement described as
the San Juan Project Operating Agreement effective January 1, 1973,
as modified by Modification No. 1 on May 16, 1979, Modification
No. 2 on December 31, 1983, Modification No. 3 on July 17, 1984,
Modification No. 4 on October 25, 1984, Modification No. 5 on
July 1, 1985, Modification No. 6 on April 1, 1993, and Modification
No. 7 on April 1, 1993 (as so modified, the "Operating Agreement"),
which establishes certain terms and conditions relating to their
participation in and responsibility for the operation of the San
Juan Project; and

     WHEREAS, on August 18, 1980, the Parties entered into a Coal
Sales Agreement with San Juan Coal Company ("SJCC") for the supply
of coal for the San Juan Project (as from time to time amended,
supplemented or modified, the "Coal Sales Agreement"); and


     WHEREAS, in order to operate the San Juan Project more
efficiently, the Parties desire to amend the terms and conditions
under which fuel expenses are allocated among the Participants and
Unit Participants; and 

     WHEREAS, the Parties desire to amend the Operating Agreement
in other particulars as described herein,

     NOW, THEREFORE, the Parties agree that the Operating Agreement
is hereby amended as follows:

     1.0  Effective Date:  This Modification No. 8 shall, subject
to the receipt of any required regulatory action, be deemed
effective as of January 1, 1993.

     2.0  DEFINITIONS:   Section 5 is amended by adding the
following defined terms:

          5.17.1  ANNUAL MINIMUM COAL DELIVERY:  The quantities of
     coal set forth on Exhibit H to the Coal Sales Agreement, which
     amounts are shown on Attachment A to this Modification No. 8.

          5.17.2  FIXED FUEL EXPENSE:  Those expenses itemized on
     Attachment B, Summary of Fixed Fuel Expense, to this
     Modification No. 8.  To the extent further modifications to
     the Coal Sales Agreement result in changes to such expenses,
     the Operating Agent shall promptly modify Attachment B to
     reflect those changes.

          5.17.3  MINIMUM FIXED FUEL EXPENSE:  Fixed Fuel Expense
     associated with the Annual Minimum Coal Delivery.

          5.17.4  PARTICIPANT MINIMUM FIXED FUEL EXPENSE:  For each
     Participant or Unit Participant, the Minimum Fixed Fuel
     Expense multiplied by that Participant's or Unit Participant's
     Participation Share as provided in Section 6.3.5 of the
     Co-Tenancy Agreement.

          5.17.5  EXCESS FIXED FUEL EXPENSE:  Annual Fixed Fuel
     Expenses in excess of Minimum Fixed Fuel Expense.

          5.17.6  CARRY-OVER TONS:  Coal deliveries made annually
     to the San Juan Project by SJCC in excess of the Annual
     Minimum Coal Delivery, as more fully described in Section
     9.2(b)(3) of the Coal Sales Agreement.

          5.17.7  VARIABLE FUEL EXPENSES:  All fuel expenses not
     specifically identified as Fixed Fuel Expense.

          5.17.8  CARRY-OVER TONS ACCOUNT:  A record system
     established and maintained by the Operating Agent to allocate
     to the Participant or Unit Participant Carry-over Tons earned
     by the San Juan Project.

     3.0  Section 5.21, Fixed Fuel, shall be deleted in its
entirety.

     4.0  Sections 18.1 through 18.5 are amended in their entirety
to read as follows:

          18.1  The quantity of coal delivered to the San Juan
     Project shall be determined by the belt scales, in accordance
     with the Coal Sales Agreement.

          18.2  The Participants shall maintain a coal inventory
     including an Emergency Coal Storage Pile for Units 1, 2, 3 and
     4, wherein the Participants and Unit Participants shall have
     Participation Shares as provided in Section 6.3.5 of the
     Co-Tenancy Agreement.  The Engineering and Operating Committee
     shall establish an optimum coal inventory tonnage for Units 1,
     2, 3 and 4 in total.  Coal inventory shall be accounted for in
     FERC Account 151.

          18.3  Costs of the coal inventory and fuel expense shall
     be apportioned among and paid for by the Participants and Unit
     Participants on the following basis:

               18.3.1  Costs that are classified as Fixed Fuel
          Expenses shall be charged to FERC Account 151.  Such
          Fixed Fuel Expenses shall then be charged monthly to FERC
          Account 501 and shall be apportioned among and paid for
          by the Participants and Unit Participants on the basis of
          the percentage that each Participant's or Unit
          Participant's monthly Net Energy Generation and auxiliary
          generation bears to the total monthly Net Energy
          Generation and auxiliary generation.  The Fixed Fuel
          Expense balance in FERC Account 151 shall be reduced to
          zero monthly by charging Fixed Fuel Expense to FERC
          Account 501.  Such Fixed Fuel Expense shall be reconciled
          annually among the Participants and Unit Participants
          based on the Participation Shares as provided in Section
          6.3.5 of the Co-Tenancy Agreement.

               18.3.2  Costs that are classified as Variable Fuel
          Expenses shall be charged to the fuel inventory or
          credited (as withdrawn) to FERC Account 151 and such
          costs shall be apportioned among and paid for by the
          Participants and Unit Participants on the basis of the
          Participation Shares as provided in Section 6.3.5 of the
          Co-Tenancy Agreement.  Variable Fuel Expenses related to
          coal requirements shall be charged to FERC Account 501 as
          determined by dividing the total number of tons of coal
          at the beginning of the month, plus the coal delivered
          during the month, into the total recorded variable cost
          and multiplying the cost per ton so derived by the number
          of tons withdrawn.  The Variable Fuel Expenses shall be
          apportioned among and paid for by the Participants and
          Unit Participants on the basis of the percentage that
          each Participant's or Unit Participant's monthly Net
          Energy Generation bears to the total monthly Net Energy
          Generation of the Unit(s). 

               18.3.3  All other Variable Fuel Expenses (including,
          but not limited to fuel oil, fuel handling, ash disposal)
          incurred which are chargeable to FERC Account 501 shall
          be apportioned among the Participants in accordance with
          Section 18.3.2.
 
               18.3.4  The Participants acknowledge and recognize
          that the Unit Participants have acknowledged the terms
          and conditions of the Coal Sales Agreement, wherein,
          among other terms and conditions, an annual Fixed Fuel
          Expense must be paid by the San Juan Project each year to
          SJCC.  Each Participant and Unit Participant shall pay
          its Participant's Minimum Fixed Fuel Expense plus a
          proportional share of Excess Fixed Fuel Expense.  Such
          Excess Fixed Fuel Expense shall be allocated to the
          Participants and Unit Participants based on each
          Participant's and Unit Participant's percentage share of
          Carry-over Tons created during that calendar year.  

               18.3.5  The Participants acknowledge and recognize
          that the Unit Participants have acknowledged the monthly
          allocation of Fixed Fuel Expenses based on the monthly
          Net Energy Generation, as described in Section 18.3.1,
          may result in an individual Participant or Unit
          Participant having been allocated Minimum Fixed Fuel
          Expense and Excess Fixed Fuel Expense equal to, less
          than, or greater than its proportional share of such
          expenses.  Any overpayment or underpayment of a
          Participant's or Unit Participant's Minimum Fixed Fuel
          Expenses and Excess Fixed Fuel Expense shall be included
          as an adjustment to the final Participant and Unit
          Participant fuel invoices in a given year.  Payments
          received from Participants or Unit Participants which
          have underpaid during the year shall be used by the
          Operating Agent to pay SJCC for any Minimum Fixed Fuel
          Expense not paid and to compensate other Participants or
          Unit Participants which have overpaid. 

               18.3.6  The Participants acknowledge and recognize
          that the Unit Participants have acknowledged the
          provisions of the Coal Sales Agreement that create Carry-
          over Tons.  To the extent that Carry-over Tons are
          created and paid for by individual Participants or Unit
          Participants, the Carry-over Tons will be allocated to
          each Participant's or Unit Participant's Carry-over Tons
          Account in proportion to each Participant's or Unit
          Participant's allocation of Excess Fixed Fuel Expense for
          the calendar year.  At the direction of a Participant or
          Unit Participant, the Operating Agent shall transfer
          Carry-over Tons from an individual Participant's or Unit
          Participant's Carry-over Tons Account to another
          Participant's or Unit Participant's Carry-over Tons
          Account.  Carry-over Tons shall be accounted for on the
          basis of tonnage only, with no financial value attached
          thereto.  Participants and Unit Participants shall apply
          any existing Carry-over Tons from their account to the
          payment of a minimum tonnage deficiency invoice.  When
          Carry-over Tons are used by the San Juan Project,
          Participants and Unit Participants whose Carry-over Tons
          Accounts are reduced shall be compensated by Participants
          and Unit Participants whose Carry-over Tons Accounts have
          no balance or an inadequate balance to meet their
          obligation for the Annual Minimum Coal Delivery.  The
          value of this compensation shall be based on the actual
          cost billed by SJCC.

          18.3.7  The Participants acknowledge and recognize that
     the Unit Participants have acknowledged the provisions of
     Attachment C to this Modification No. 8 as representative of
     the allocation and billing methodology agreed to as a result
     of this Modification No. 8.  Attachment C reflects the
     allocation of expenses among the Participants and Unit
     Participants based on Modification No. 8 and actual expenses
     incurred for fuel expense for the month of January 1993.  

          18.4  The Operating Agent shall provide the Participants
     and Unit Participants a monthly written report on the
     following items related to coal deliveries at the San Juan
     Project:

               18.4.1  Annual Minimum Coal Delivery for the year.

               18.4.2  Annual Minimum Coal Delivery allocated among
          the Participants and Unit Participants.

               18.4.3  Total actual coal deliveries by SJCC to the
          San Juan Project for each month and for the year to date.

               18.4.4  Total actual coal deliveries to the San Juan
          Project for each month and for the year to date,
          allocated to the Participants and Unit Participants.

               18.4.5  Total cost and tonnage of inventory
          allocated to the Participants and Unit Participants.  

               18.4.6  Fixed Fuel Expense and Variable Fuel Expense
          allocated to the Participants and Unit Participants for
          each month and for the year to date.  

               18.4.7  Status of Carry-over Tons for the San Juan
          Project, allocated to the Participants and Unit
          Participants.

          18.5  The Operating Agent shall replace the tons of coal
     withdrawn from inventory on a ton for ton basis according to
     the coal withdrawn from inventory for the month, such
     replacement to reflect anticipated generation usage in the
     following month.  The cost of this replacement shall be
     apportioned among the Participants in accordance with Sections
     18.2 and 18.3.  

     5.0  Section 15.2 shall be amended in its entirety to read as
follows:

     The Engineering and Operating Committee may authorize Capital
     Additions, Capital Betterments and Capital Replacements not
     included in the annual capital expenditures budget; provided,
     that such Capital Additions, Capital Betterments, and Capital
     Replacements shall not exceed in any one year the sum of two
     hundred and fifty thousand dollars ($250,000) for each such
     addition, betterment or replacement, unless also authorized by
     the Coordination Committee.

     6.0  Section 15.4 shall be amended in its entirety to read as
follows:  

     The Operating Agent shall submit to the Participants a
     forecast of cash requirements by months for Capital Additions,
     Capital Betterments and Capital Replacements.  Said forecast
     will be submitted on a yearly basis after final budget
     approvals have been made.  A revised forecast shall be
     submitted when the capital expenditures budget is revised, or
     when significant changes in monthly expenditures from those
     previously forecast are anticipated.  The Operating Agent
     shall be authorized to make expenditures related to Capital
     Additions, Capital Betterments and Capital Replacements not
     included in the annual capital expenditures budget; provided,
     however, that such expenditures for Capital Additions, Capital
     Betterments and Capital Replacements shall not exceed in any
     one year the greater of the sum of fifty thousand dollars
     ($50,000) or a twenty percent (20%) increase in the total
     amount originally authorized for each such Capital Addition,
     Capital Betterment or Capital Replacement, unless also
     authorized by the Engineering and Operating Committee.  

     IN WITNESS WHEREOF, the Parties hereto have caused this
Modification No. 8 to the Operating Agreement to be executed as of
the _____ day of _____________, 1993.


                              PUBLIC SERVICE COMPANY OF NEW MEXICO


                              By:  ________________________________

                              Its: ________________________________



                              TUCSON ELECTRIC POWER COMPANY


                              By:  ________________________________


                              Its: ________________________________




STATE OF NEW MEXICO      )
                         )  ss.
COUNTY OF BERNALILLO     )

     This instrument was acknowledged before me on_______________,
1993, by ______________________________, as Senior Vice President
of Public Service Company of New Mexico, a New Mexico corporation,
on behalf of the corporation.  


                                   _______________________________
                                   Notary Public


My Commission Expires:  

_________________________

STATE OF ARIZONA    )
                    )  ss.
COUNTY OF PIMA      )

     This instrument was acknowledged before me
on_________________, 1993, by ________________________________, as
Vice President of Tucson Electric Power Company, an Arizona
corporation, on behalf of the corporation.  


                                   ________________________________
                                   Notary Public

My Commission Expires:

________________________