MODIFICATION NO. 10

                                       TO

                              CO-TENANCY AGREEMENT

                                     BETWEEN

                      PUBLIC SERVICE COMPANY OF NEW MEXICO

                                       AND

                          TUCSON ELECTRIC POWER COMPANY


         This  Modification  No. 10 to the Co-Tenancy  Agreement  between PUBLIC
SERVICE  COMPANY OF NEW MEXICO ("New Mexico") and TUCSON  ELECTRIC POWER COMPANY
("Tucson"),  hereinafter  sometimes referred to collectively as the "Parties" or
"Participants",  is  hereby  entered  into  and  executed  as of the 30th day of
November, 1995.

         WITNESSETH:

         WHEREAS,  the  Parties  entered  into  an  agreement  described  as the
Co-Tenancy  Agreement  between New Mexico and Tucson  effective July 1, 1969, 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,
Modification  No. 7 on April 1, 1993,  Modification No. 8 on September 15, 1993,
and  Modification  No. 9 on January 12,  1994  ("Co-Tenancy  Agreement"),  which
establishes  certain  terms  and  conditions  relating  to their  ownership  and
operation of the San Juan Project and Project Agreements; and

         WHEREAS,  on June 1, 1994,  Century Power  Corporation  ("Century") and
Tri-State  Generation and Transmission  Association,  Inc., a Colorado nonprofit
cooperative corporation ("Tri-State"), entered into the San Juan Unit 3 Purchase
Agreement ("Tri-State Purchase Agreement"), whereby Tri-State agreed to purchase
from Century an undivided 8.2 percent interest in Unit 3; and


<PAGE>

         WHEREAS, the Tri-State Purchase Agreement provides, among other things,
that Tri-State,  upon closing of the  transaction  provided for in the Tri-State
Purchase  Agreement,  will have the  voting  rights  and  obligations  of a Unit
Participant on San Juan Project  Committees as said rights and  obligations  are
set forth in the Project Agreements; and

         WHEREAS,  New  Mexico  and  Tucson  desire to  clarify  the  rights and
responsibilities  of Participants and Unit  Participants in the San Juan Project
as a result of Tri-State's purchase of an 8.2 percent undivided interest in Unit
3 pursuant to the Tri-State Purchase Agreement.

         NOW,  THEREFORE,  the Parties  agree that the  Co-Tenancy  Agreement is
hereby amended as follows:

         1.0 Effective Date.  This  Modification  No. 10 shall become  effective
immediately  upon  the  closing  of  Tri-State's  purchase  of the  8.2  percent
undivided interest in Unit 3 pursuant to the Tri-State Purchase Agreement.

         2.0  Compliance  With  Section  6.7.  Section  6.7  of  the  Co-Tenancy
Agreement  requires  that in the event either  Participant  transfers any of its
rights,  title or  interest  in the San Juan  Project,  the  Participants  shall
jointly execute a Supplement to the Co-Tenancy  Agreement,  in recordable  form,
which describes the rights,  titles and interests of each Participant  following
such transfer or assignment. On May 16, 1979, Tucson and New Mexico entered into
a Purchase Option whereby on that date (the "Transfer  Date") Tucson conveyed to
New Mexico Tucson's 50 percent undivided interest in Unit 4. On November 17,

                                      -1-
<PAGE>


1981,  New Mexico sold and  transferred  an 8.475  percent  undivided  ownership
interest in Unit 4 to the City of Farmington, New Mexico ("City of Farmington").
On December 31, 1981, Tucson and the M-S-R Public Power Agency ("M-S-R") entered
into the Tucson/M S-R Agreement-Option to Acquire Ownership Interest in San Juan
Unit 4, wherein Tucson agreed to sell to M-S-R and M-S-R agreed to purchase from
Tucson,  pursuant to the terms and  conditions of such  agreement,  on or before
November  30,  1982,  the Tucson  Option  (also  referred  to as the  "Option to
Repurchase" in the May 16, 1979, San Juan Unit 4 Purchase  Agreement between New
Mexico and Tucson).  On November 29, 1982, New Mexico and M-S-R executed the San
Juan Unit 4 Purchase and Participation Agreement, and on September 26, 1983, New
Mexico and M-S-R executed the San Juan Unit 4 Early  Purchase and  Participation
Agreement under which New Mexico sold and  transferred a 28.8 percent  undivided
ownership  interest in Unit 4 to M-S-R  effective  December 31, 1983. On October
31, 1984, Tucson transferred its 50 percent undivided ownership interest in Unit
3 to Century (formerly  Alamito  Company).  On December 28, 1984, New Mexico and
the Incorporated  County of Los Alamos, New Mexico ("Los Alamos County") entered
into the  Amended  and  Restated  San Juan  Unit 4  Purchase  and  Participation
Agreement  ("County PPA") which provided that New Mexico would sell and transfer
to Los Alamos County a 7.2 percent undivided  ownership interest in Unit 4 which
transfer  occurred as of July 1, 1985.  On March 25, 1993,  Century and Southern
California  Public Power  Authority  ("SCPPA")  entered into the San Juan Unit 3
Purchase  Agreement  ("SCPPA PA") which  provided  that  Century  would sell and
transfer to SCPPA a 41.8  percent  undivided  interest in Unit 3 which  transfer
occurred  as of July 1,  1993.  On April 26,  1991,  New  Mexico and the City of
Anaheim, California ("City of Anaheim") entered into the San Juan Unit 4 

                                      -2-
<PAGE>

Purchase and  Participation  Agreement  ("Anaheim  PPA") which provided that New
Mexico  would sell and  transfer  to City of Anaheim a 10.04  percent  undivided
interest in Unit 4 which transfer  occurred as of August 12, 1993. As of May 27,
1993, New Mexico and Utah Associated  Municipal Power Systems  ("UAMPS") entered
into the UAMPS Purchase and Participation Agreement ("UAMPS PPA") which provided
that New  Mexico  would sell and  transfer  to UAMPS a 7.028  percent  undivided
ownership  interest  in Unit 4, which  transfer  occurred  on June 2,  1994.  In
accordance with the  requirements of Section 6.7, the following  sections of the
Co-Tenancy Agreement are hereby amended to read as follows:

         Amended Section 6.3.1:

         6.3.1 For Units 1 and 2 and for all equipment and  facilities  directly
related to Units 1 and 2, in accordance with the following percentages:

         A.       Participants

                  1.  New Mexico - 50 percent

                  2.  Tucson - 50 percent

         B.       Unit Participants

                  1.  M-S-R - 0 percent

                  2.  City of Farmington - 0 percent

                  3.  Tri-State - 0 percent

                  4.  Los Alamos County - 0 percent

                  5.  SCPPA - 0 percent

                  6.  City of Anaheim - 0 percent

                  7.  UAMPS - 0 percent


                                      -3-

<PAGE>

         6.3.1.1  For  Unit 3 and  for all  equipment  and  facilities  directly
related to Unit 3 only, in accordance with the following percentages:

         A.       Participants

                  1.  New Mexico - 50 percent

                  2.  Tucson - 0 percent

         B.       Unit Participants

                  1.  M-S-R - 0 percent

                  2.  City of Farmington - 0 percent

                  3.  Tri-State - 8.2 percent

                  4.  Los Alamos County - 0 percent

                  5.  SCPPA - 41.8 percent

                  6.  City of Anaheim - 0 percent

                  7.  UAMPS - 0 percent

         Amended Section 6.3.2:

         6.3.2 For Unit 4 and for all equipment and facilities  directly related
to Unit 4 only, in accordance with the following percentages:

         A.       Participants

                  1.  New Mexico - 38.457 percent

                  2.  Tucson - 0 percent

         B.       Unit Participants

                  1.  M-S-R - 28.8 percent

                  2.  City of Farmington - 8.475 percent

                  3.  Tri-State - 0 percent

                                      -4-
<PAGE>



                  4.   Los Alamos County - 7.20 percent

                  5.  SCPPA - 0 percent

                  6.  City of Anaheim - 10.04 percent

                  7.  UAMPS - 7.028 percent

         Amended Section 6.3.3:
         6.3.3 For  equipment  and  facilities  common only to Units 1 and 2, in
accordance with the following percentages:

         A.       Participants
                  1.  New Mexico -- 50 percent
                  2.  Tucson -- 50 percent

         B.       Unit Participants
                  1.  M-S-R - 0 percent
                  2.  City of Farmington - 0 percent
                  3.  Tri-State - 0 percent
                  4.  Los Alamos County - 0 percent
                  5.  SCPPA - 0 percent
                  6.  City of Anaheim - 0 percent
                  7.  UAMPS - 0 percent

         Amended Section 6.3.4:

         6.3.4 For  equipment  and  facilities  common only to Units 3 and 4, in
accordance with the following percentages:

         A.       Participants
                  1.  New Mexico - 44.119 percent
                  2.  Tucson - 0 percent

                                      -5-

<PAGE>

         B.       Unit Participants
                  1.  M-S-R -14.4 percent
                  2.  City of Farmington - 4.249 percent (ownership  interest is
                      with  respect  to  common  facilities  not in  service  on
                      November 17, 1981;  the City of Farmington  was granted an
                      Easement  and License for use of common  facilities  which
                      were in service on November 17, 1981).
                  3.  Tri-State-4.1 percent
                  4.  Los Alamos County - 3.612 percent
                  5.  SCPPA - 20.9 percent
                  6.  City of Anaheim - 5.07 percent
                  7.  UAMPS - 3.55 percent

         Amended Section 6.3.5:

         6.3.5  For  equipment  and  facilities  common  to all of the  units in
accordance with the following percentages:

         A.       Participants
                  1.  New Mexico - 46.297 percent
                  2.  Tucson -19.8 percent

         B.       Unit Participants
                  1.  M-S-R - 8.7 percent
                  2.  City of Farmington - 2.559 percent (ownership  interest is
                      with  respect  to  common  facilities  not in  service  on
                      November 17, 1981;  the City of Farmington  was granted an
                      Easement and License for use of common facilities which 
                      were in service on November 17, 1981).

                                      -6-

<PAGE>

                  3.  Tri-State - 2.49 percent
                  4.  Los Alamos County - 2.175 percent
                  5.  SCPPA - 12.71 percent
                  6.  City of Anaheim - 3.10 percent
                  7.  UAMPS - 2.169 percent

         Amended Section 6.3.6:

         6.3.6 For the  Switchyard  Facilities  except as otherwise  provided in
Section 15 hereof, in accordance with the following percentages:

         A.       Participants
                  1.  New Mexico - 50 percent
                  2.  Tucson - 50 percent

         B.       Unit Participants
                  1.  M-S-R - 0 percent
                  2.  City of Farmington - 0 percent
                  3.  Tri-State - 0 percent
                  4.  Los Alamos County - 0 percent
                  5.  SCPPA - 0 percent
                  6.  City of Anaheim - 0 percent
                  7.  UAMPS - 0 percent

         3.0 Amended  Section  8.1.  Section 8.1 shall be amended to read in its
entirety as follows:

                                      -7-
<PAGE>

         8.1 Subject to the provisions of paragraphs 10.1 and 10.2 hereof, the
Participants shall be entitled to share the Net Effective Generating Capacity of
Units 1 and 2 in equal,  undivided one-half (1/2) interests.  New Mexico,  SCPPA
and Tri-State shall be entitled to share the Net Effective  Generating  Capacity
of Unit 3 in undivided interests in proportion to their percentage  ownership of
Unit 3 as set forth in Section 6 hereof.  New Mexico  and Unit  Participants  to
which New Mexico  conveys or has conveyed  ownership  interests  and  generation
entitlements  in Unit 4 shall  have a 100  percent  (100%)  interest  in the Net
Effective Generating Capacity of Unit 4.

         4.0 Amended  Exhibit V. Exhibit V (a-h) shall be amended to read in its
entirety as shown on the attached Exhibit V(a-h).

         5.0 Amended  Section  9.5.2.  Section 9.5.2 shall be amended to read in
its entirety as follows:

         9.5.2 With respect to matters  involving and not solely  related to San
Juan Unit 3, Tucson,  as a  Participant  holding  voting  rights on all San Juan
Project Committees,  including,  without limitation, the Coordination Committee,
the Engineering and Operating Committee and the Auditing Committee, shall retain
such voting rights for SCPPA and Tri-State in accordance  with their  respective
interests,  with the  obligation  to  consult  with SCPPA and  Tri-State  on all
matters involving the San Juan Project which affect San Juan Unit 3 as set forth
in the San Juan Unit No. 3  Purchase  Agreement,  the SCPPA PA  (Century  having
transferred to SCPPA an undivided 41.8 percent  interest in San Juan Unit 3) and
the Tri-State  Purchase  Agreement  (Century having  transferred to Tri-State an
undivided 8.2 percent interest in San Juan Unit 3).


                                      -8-

<PAGE>

         6.0 Amended Section 25.8.  Section 25.8 shall be amended to read in its
entirety as follows:

         25.8  Except  as  modified  by  the   provisions   set  forth  in  this
Modification  No.  10,  all of  the  terms  and  conditions  of  the  Co-Tenancy
Agreement,  effective as of July 1, 1969, 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,  Modification No. 7 on April
1, 1993,  Modification  No. 8 on September 15, 1993, and  Modification  No. 9 on
January 12, 1994 shall remain in full force and effect.

         7.0  Amended  Section  26.  Section  26 shall be amended to read in its
entirety as follows:

         26.0  RECOGNITION  OF M-S-R,  THE CITY OF  FARMINGTON,  TRI-STATE,  LOS
ALAMOS COUNTY, SCPPA, THE CITY OF ANAHEIM AND UAMPS ACKNOWLEDGEMENT.

         26.1  The  Parties  recognize  that  M-S-R,  the  City  of  Farmington,
Tri-State,  Los Alamos  County,  SCPPA,  the City of Anaheim  and UAMPS each has
acknowledged that it is familiar with the Project  Agreements as amended between
New Mexico and Tucson and such agreements  govern the activities of the San Juan
Project. Where a specific provision of the EPPA, the Farmington PAPA, the County
PPA, the Anaheim PPA or the UAMPS PPA is in conflict  with a provision in one or
more of the Project  Agreements,  then (a) as between New Mexico and M-S-R,  the
provisions  of the EPPA shall  govern,  all as  provided  in Section 5.2 of such
EPPA, and (b) as between New Mexico and the City of  Farmington,  the provisions
of the  Farmington  PAPA shall  govern,  all as  provided  in Section 8.2 of the
Farmington PAPA, and (c) as between New Mexico and Los Alamos County, the

                                      -9-
<PAGE>

provisions of the County PPA shall govern, all as provided in Section 5.2 of the
County PPA, (d) as between New Mexico and the City of Anaheim, the provisions of
the Anaheim PPA shall govern, all as provided in Section 7.2 of the Anaheim PPA,
and (e) as between New Mexico and UAMPS,  the  provisions of the UAMPS PPA shall
govern,  all as provided in Section 7.2 of the UAMPS PPA.  "EPPA" shall mean the
San Juan Unit 4 Early Purchase and  Participation  Agreement entered into by New
Mexico and M-S-R on  September  26, 1983.  "Farmington  PAPA" shall mean the San
Juan Unit 4 Purchase  Agreement and Participation  Agreement entered into by New
Mexico and the City of Farmington on November 17, 1981.  "County PPA" shall mean
the Amended and Restated San Juan Unit 4 Purchase  and  Participation  Agreement
entered into by New Mexico and Los Alamos County on December 28, 1984.  "Anaheim
PPA"  shall  mean the San  Juan  Unit 4  Purchase  Agreement  and  Participation
Agreement  entered into by New Mexico and the City of Anaheim on April 26, 1991.
"UAMPS PPA" shall mean the  Restated  and  Amended San Juan Unit 4 Purchase  and
Participation Agreement entered into by New Mexico and UAMPS as of May 27, 1993.

         IN WITNESS  WHEREOF,  the Parties hereto have caused this  Modification
No.  10 to  the  Co-Tenancy  Agreement  to be  executed  as of the  30th  day of
November, 1995.

                                     PUBLIC SERVICE COMPANY OF NEW MEXICO
               
                                     By  /s/ Jeffry E. Sterba
                                         --------------------------------
                                         Its' Senior Vice President

   
                                     TUCSON ELECTRIC POWER COMPANY
                                     By  /s/ Steven Glaser
                                         --------------------------------
                                         Its' Vice President


                                      -10-
<PAGE>

                                  EXHIBIT V(a)

                        FACILITIES AND EQUIPMENT SPECIFIC
                             TO SAN JUAN UNIT No. 1


                                    Ownership



                          New Mexico - 50% Tucson - 50%
                       M-S-R - 0% City of Farmington - 0%
                      Tri-State - 0% Los Alamos County - 0%
                         SCPPA - 0% City of Anaheim - 0%
                                    UAMPS- 0%

1.     Turbine Generator

2.     Condenser

3.     Condensate and Feedwater System

       a.     Condensate Pumps
       b.     Feedwater Heaters
       c.     Boiler Feed Pumps
       d.     Storage Tanks

4.     Boiler including: Air Heaters, Pulverizers, Bunkers, Feeders and Blow-
       down Tanks

5.     Forced Draft Fans and Primary Air Fans

6.     Precipitator

7.     Stack and Stack Monitoring System

8.     Cooling Tower

9.     Circulating Water Pumps

10.    Main, Start-Up, Unit Auxiliary, and SO2 Scrubber Transformers

11.    Bottom Ash System (Up to but not including Dewatering Tank or Ash Water 
       Pump building and equipment)

                                      -11-

<PAGE>

                                  EXHIBIT V(a)
                                   (continued)



12.    Fly Ash System

13.    Building HVAC System

14.    SO2  Absorbers,  Scrubbers,  Transfer  Pumps,  Booster Fans, and Flue Gas
       Reheat System including the 650-pound Reheat Steam Line and Desuperheater
       from the Plant Main Steam Line but not including  the 1 65-pound  Control
       Valve and Branch Line to the Chemical Plant

15.    Emergency Diesel Generator

16.    Electrical and Control Systems

17.    SSR Protection System

18.    Unit Specific  Piping for all Air Systems,  Chemical  Feed  Systems,  and
       Hydrogen

                                      -12-

<PAGE>

                                  EXHIBIT V(b)

                        FACILITIES AND EQUIPMENT SPECIFIC
                             TO SAN JUAN UNIT NO. 2


                                    Ownership


                          New Mexico - 50% Tucson - 50%
                       M-S-R - 0% City of Farmington - 0%
                      Tri-State - 0% Los Alamos County - 0%
                         SCPPA - 0% City of Anaheim - 0%
                                    UAMPS- 0%


1.     Turbine Generator

2.     Condenser

3.     Condensate and Feedwater System

       a.     Condensate Pumps
       b.     Feedwater Heaters
       c.     Boiler Feed Pumps
       d.     Storage Tanks

4.     Boiler including: Air Heaters, Pulverizers, Bunkers, Feeders and Blowdown
       Tanks

5.     Forced Draft Fans and Primary Air Fans

6.     Precipitator

7.     Stack and Stack Monitoring System

8.     Cooling Tower

9.     Circulating Water Pumps

10.    Main, Start-Up, Unit Auxiliary, and SO2 Scrubber Transformers

11.    Bottom Ash System (Up to but not including  Dewatering  Tank or Ash Water
       Pump building and equipment.)

                                      -13-

<PAGE>

                                  EXHIBIT V(b)
                                   (continued)

12.    Fly Ash System

13.    Building HVAC System

14.    SO2  Absorbers,  Scrubbers,  Transfer  Pumps,  Booster Fans, and Flue Gas
       Reheat System including the 650-pound Reheat Steam Line and Desuperheater
       from the Plant Main Steam Line but not including  the 1 65-pound  Control
       Valve and Branch Line to the Chemical Plant

15.    Emergency Diesel Generator

16.    Electrical and Control Systems

17.    Unit Specific  Piping for all Air Systems,  Chemical  Feed  Systems,  and
       Hydrogen

                                      -14-

<PAGE>

                                  EXHIBIT V(C)

                        FACILITIES AND EQUIPMENT SPECIFIC
                             TO SAN JUAN UNIT NO. 3


                                    Ownership


                           New Mexico- 50% Tucson- 0%
                       M-S-R - 0% City of Farmington - 0%
                     Tri-State - 8.2% Los Alamos County - 0%
                       SCPPA - 41.8% City of Anaheim - 0%
                                    UAMPS- 0%


1.     Turbine Generator

2.     Condenser

3.     Condensate and Feedwater System

       a.    Condensate Pumps
       b.    Feedwater Heaters
       c.    Boiler Feed Pumps
       d.    Storage Tanks

4.     Boiler including: Air Heaters, Pulverizers, Bunkers, Feeders and Blowdown
       Tanks

5.     Forced Draft Fans and Primary Air Fans

6.     Precipitator

7.     Stack and Stack Monitoring System

8.     Cooling Tower

9.     Circulating Water Pumps

10.    Main, Unit Auxiliary 3A and 3B Transformers*

11.    Bottom Ash System  including:  Hopper,  Dewatering  Tank,  Settling Tank,
       Surge Tank, Storage Tank, and Pump House

                                      -15-

<PAGE>

                                  EXHIBIT v(c)
                                   (continued)


12.    Fly Ash System

13.    Building HVAC System

14.    SO2  Absorbers,  Scrubbers,  Transfer  Pumps,  Booster Fans, and Flue Gas
       Reheat System

15.    Emergency Diesel Generator

16.    Electrical and Control Systems

17.    Fuel Oil Ignitor Heaters and Unit Specific Piping

18.    Unit Specific  Piping for all Air Systems,  Chemical  Feed  Systems,  and
       Hydrogen

19.    Coal Reclaim Hoppers, Feeders, Feeder Belts, Belt Scales, Fire Protection
       System, and 3C Conveyor to the Secondary Crusher Building

20.    SSR Protection System

21.    Auxiliary Steam Header Piping System:

       a.    Including the Unit Specific Branch Line to the Reheat System 
       b.    Not included is the Branch Line to the Chemical Plant















* New Mexico and Tucson each owns a 50% interest in the main unit transformer


                                      -16-
<PAGE>

                                  EXHIBIT V(d)

                        FACILITIES AND EQUIPMENT SPECIFIC
                             To SAN JUAN UNIT No. 4


                                    Ownership


                         New Mexico - 38.457% Tucson- 0%
                    M-S-R - 28.8% City of Farmington - 8.475%
                     Tri-State - 0% Los Alamos County - 7.2%
                        SCPPA - 0% City of Anaheim -10.4%
                                  UAMPS- 7.028%


1.     Turbine Generator

2.     Condenser

3.     Condensate and Feedwater System

       a.    Condensate Pumps
       b.    Feedwater Heaters
       c.    Boiler Feed Pumps
       d.    Storage Tanks

4.     Boiler including: Air Heaters, Pulverizers, Bunkers, Feeders and Blowdown
       Tanks

5.     Forced Draft Fans and Primary Air Fans

6.     Precipitator

7.     Stack and Stack Monitoring System

8.     Cooling Tower

9.     Circulating Water Pumps

10.    Main, Unit Auxiliary 4A and 4B Transformers

11.    Bottom Ash System  including:  Hopper,  Dewatering  Tank,  Settling Tank,
       Surge Tank, Storage Tank, and Pump House

12.    Fly Ash System

                                      -17-

<PAGE>

                                  EXHIBIT V(d)
                                   (continued)


13.    Building HVAC System

14.    SO2  Absorbers,  Scrubbers,  Transfer  Pumps,  Booster Fans, and Flue Gas
       Reheat System

15.    Emergency Diesel Generator

16.    Electrical and Control Systems

17.    Fuel Oil Ignitor Heaters and Unit Specific Piping

18.    Unit Specific  Piping for all Air Systems,  Chemical  Feed  Systems,  and
       Hydrogen

19.    Coal Reclaim Hoppers, Feeders, Feeder Belts, Belt Scales, Fire Protection
       System, and 3D Conveyor to the Secondary Crusher Building

20.    Auxiliary Steam Header Piping System:

       a.     Including the Unit Specific Branch Line to the Reheat System
       b.     Not included is the Branch Line to the Chemical Plant


                                      -18-

<PAGE>

                                  EXHIBIT V(e)

                         FACILITIES AND EQUIPMENT COMMON
                            TO SAN JUAN UNITS 1 AND 2


                                    Ownership

                         New Mexico - 50% Tucson - 50%
                       M-S-R - 0% City of Farmington - 0%
                     Tri-State - 0% Los Alamos County - 0%
                        SCPPA - 0% City of Anaheim - 0%
                                    UAMPS- 0%


1.     Bearing Cooling Water System

2.     Bottom Ash Dewatering Facility including: Dewatering Tank, Settling Tank,
       Surge Tank, Storage Tank, and Pump House

3.     Demineralizer System including: Clarifier, Storage Tanks, and Sump Pump

4.     Fuel Oil System (Fuel Oil for Ignition and Flame Stabilization)

5.     Premix Tank Facility (This was the wastewater neutralizer facility and is
       now operated as part of the Water Management System.)

6.     Instrument Air system, except Unit Piping

7.     Chemical Feed System, except Unit Piping

       a.     Condensate and Feedwater System
       b.     Boiler
       c.     Bearing Cooling Water System
       d.     Cooling Tower Systems
       e.     Chlorination System

8.     Plant Air System, except Unit Piping

9.     Sootblowing Air System, except Unit Piping

10.    Hydrogen Storage System, except Unit Piping

11.    Coal  Handling  Reclaim  Systems  A and B  including:  Hoppers,  Feeders,
       Reclaim Conveyors, Belt Scales, and Sprinkler System


                                      -19-
<PAGE>

                                  EXHIBIT V(e)
                                   (continued)


12.    Coal Tripper System south of column,  Line 12 including  Dust  Collection
       System

13.    Turbine Lube Oil Storage and Transfer System

14.    Control Room, Equipment Rooms, and Associated HVAC System

15.    Turbine Crane south of column, Line 12

16.    Fuel Oil, Ash, and Water Pipe Racks

17.    Boiler Fill System for Units 1 and 2

18.    All spare parts common to either unit

19.    SO2 Backup Scrubber-Absorber Transformer

20.    SAR Multiplexer Control System


                                      -20-

<PAGE>

                                  EXHIBIT V(f)

                         FACILITIES AND EQUIPMENT COMMON
                            TO SAN JUAN UNITS 3 AND 4


                                    Ownership

  New Mexico - 44.119% Tucson - 0% M-S-R - 14.4% City of Farmington - 4.249%*
    Tri-State - 4.1% Los Alamos County - 3.612% SCPPA - 20.9% City of Anaheim
                              - 5.07% UAMPS- 3.55%

1.     Bearing Cooling Water System

2.     Demineralizer  System:  including  Sump Pumps,  Filter Beds,  and Storage
       Tanks

3.     Fuel Oil System  (Fuel Oil for Ignition  and Flame  Stabilization  except
       Ignitor Heaters and Unit Specific Piping)

4.     Wastewater  Neutralizer  Facility  (This  facility is operated as part of
       Water Management System.)

5.     Instrument Air System except Unit Piping

6.     Chemical Feed System except Unit Piping

       a.  Condensate and Feedwater System
       b.  Boiler
       c.  Bearing Cooling Water System
       d.  Cooling Tower Systems
       e.  Chlorination System

7.     Plant Air System except Unit Piping

8.     Sootblowing Air System except Unit Piping

9.     Start-Up Transformers and Nonseg Bus to Units 3 and 4 Switchgear

10.    Hydrogen Storage System except Unit Piping

11.    Coal  Tripper  System  Serving  Units 3 and 4 including  Dust  Collection
       Systems


                                      -21-

<PAGE>

                                  EXHlBlT V(f)
                                   (continued)


12.    Turbine Lube Oil Storage and Transfer System

13.    Control Room, Equipment Rooms, and Associated HVAC System

14.    Boiler Fill System for Units 3 and 4

15.    Auxiliary  Cooling Systems  including  Auxiliary  Cooling Tower No. 1 and
       Pumps, but excepting No. 4 Tower Pumps and Piping which is Unit Specific

16.    CO2 Storage System

17.    Start-Up Boiler Feed Pump

18.    Turbine Bay Crane north of column, Line 12

19.    Fuel Oil, Ash, and Water Pipe Racks

20.    Fire Water Booster and Jockey Pumps

21.    Halon Fire Protection System

22.    Cooling Tower Multiplex Control System

23.    All spare parts common to either unit.











* City of Farmington's  ownership  interest is with respeci to Common Facilities
not in service on  November  17,  1981;  the City of  Farmington  was granted an
Easement  and  License  for use of Common  Facilities  which  were in service on
November 17, 1981


                                      -22-

<PAGE>

                                  EXHIBIT V(g)

                         FACILITIES AND EQUIPMENT COMMON
                           TO ALL FOUR SAN JUAN UNITS


                                    Ownership

             New Mexico -     46.297%      Tucson -                 19.8%
             M-S-R -          8.7%         City of Farmington -     2.559%*
             Tri-State -      2.49%        Los Alamos County -      2.175%
             SCPPA -          12.71%       City of Anaheim -        3.1%
                                           UAMPS-                   2.169%

1.     River and Raw Water System including:

       a.  Diversion  and intake  structures  including  all  equipment and pump
           building 
       b.  Raw water line to reservoir
       c.  Reservoir and pump buildings and all equipment
       d.  Raw water lines to plant yard
       e.  All  underground  and above  ground  fire  protection  system to each
           vendor supplied or unit specific fire distribution system

2.     Auxiliary Boiler

3.     SO2 System Chemical Plant except Absorbers

       a.  Double effect evaporator train systems
       b.  Fly ash filter system
       c.  Absorber product and feed tanks
       d.  Condensate collection, storage, and transfer systems
       e.  Soda ash storage, mixing, and distribution systems
       f.  Sulfate   purge   system   including   crystallizers,    centrifuges,
           evaporators, and salt cake system
       g.  Sulfuric  acid  plant  system  including  storage  tanks and load out
           system
       h.  Auxiliary No. 2 cooling tower, pumps, and systems

4.     Spare Main Transformer 345/24 kV for all units

5.     Maintenance, Office, and Warehousing Facilities

6.     Chemical Laboratory

7.     Coal and Ash Handling Control Facilities

                                      -23-

<PAGE>

                                  EXHIBIT V(g)
                                   (continued)

8.     Roads and grounds such as fencing,  yard lighting,  guard facilities,
       drainage and dikes

9.     Potable Water System

10.    Environmental  Monitoring  Systems  including  Air,  Water,  and  Ground.
       Excludes Stack Monitoring Systems which are unit specific.

11.    Transportation such as trucks, cars, and dozers

12.    Water Management System

       a.  Wastewater Recovery System - Northside

           1)     Reverse osmosis system including lime/soda softening clarifier
                  system
           2)     Brine concentrator Nos. 4 and 5
           3)     Process pond No. 3 and pumping system
           4)     North evaporation ponds 1, 2, and 3

       b.  SO2 Waste Treatment System - Southside

           1)     Process ponds 1 A, 1 B, 2, and pumping system
           2)     Clarifier system
           3)     Oxidation towers
           4)     Brine concentrator Nos. 2 and 3
           5)     South evaporation pond Nos. 1, 2, 3, 4, and 5

       c.  Data Acquisition System

       d.  Solid Waste Disposal Pit

       e.  Coal Pile Runoff Ponds

13.    Coal Transfer  Facilities  from the Reclaim  Conveyors to the Head-End of
       Plant Belts 4A and 4B and Dust Suppression Systems

14.    Maintenance Bay Facilities including:  Bay Bridge Crane, all Offices, and
       Support Facilities

15.    Sewage Treatment Facilities

16.    On each of Units 1 and 2, the Chemical Plant 165-pound Control Valve, and
       Branch Line from the Unit Specific 650-pound Reheat Steam Line

                                      -24-

<PAGE>

17.    On each of Units 3 and 4, the  Chemical  Plant Branch Steam Line from the
       Unit Specific Auxiliary Steam Header System

* City of Farmington's  ownership  interest is with respect to Common Facilities
not in service on  November  17,  1981;  the City of  Farmington  was granted an
Easement  and  License  for use of Common  Facilities  which  were in service on
November 17, 1981.



                                      -25-


<PAGE>
                                  EXHIBIT V(h)
                                SAN JUAN PROJECT
                             SVVITCHYARD FACILITIES
                               Cost Allocation (%)

                                                     Replacements/lmprovements
                                Installed Cost               Betterments
                                --------------               -----------

                             New Mexico    Tucson        New Mexico    Tucson
                             ----------    ------        ----------    ------

345 kV Bus 1 & 3 (East Bus)      50           50             50           50
         Bus 2 (West Bus)        50           50             50           50

Circuit Breakers
----------------

      06582 (345/230)            50           50             50           50
      05482                      50           50             50           50
      04382 (OJO)                50           50             50           50

      12982 (McKinley)           50           50             50           50
      11882                      50           50             50           50
      10782 (Unit 4)             50           50             50           50

      09882 (McKinley)          58.33         41.67          62.5         37.5
      08782                      54.16        45.84          56.25        43.75
      07682 (Unit 3)             50           50             50           50

      15282 (Four Corners)       50           50             50           50
      14182                      50           50             50           50
      13082 (Unit 2)             50           50             50           50

      18582 (West Mesa)          50           50             50           50
      17482                      50           50             50           50
      16382 (Unit 1)             50           50             50           50
      20782                      50           50             50           50

Shunt Reactors
--------------

    Ojo                         100            0            100            0
    McKinley 1                    5.36        94.64           5.36        94.64
    McKinley 2                   16.67        83.33          25           75
    WW (BA)                     100            0            100            0


                                      -26-

<PAGE>


                                  EXHIBIT V(h)
                                   (continued)

                                                     Replacements/lmprovements
                                Installed Cost               Betterments
                                --------------               -----------

                             New Mexico    Tucson        New Mexico    Tucson
                             ----------    ------        ----------    ------

Transformers
------------

  Station Aux. No. 2            100            0           100            0
     400 MVA, 345/230- 12.5
  Station Aux. No. 1            50            50            50           50
     345/4.16-12.5
  Station Aux. No. 3            50            50            50           50
     90 MVA, 345 /69- 12.5

Future Facilities
-----------------

  345169/12 kV                  66.67         33.33         66.67        33.33
  2-345 kV Bkrs (Durango)       50            50            50           50

Lower Voltage
-------------

  230 kV Control Hse            83.33         16.67         83.33        16.67
  230/69 kV Trf                 66.67         33.33         66.67        33.33
  Shiprock 230 kV line          100            0           100            0




                                      -27-
<PAGE>