Exhibit 99.310

Mountain West Independent Scheduling Administrator
FERC Electric Tariff
Original Volume 1                                        Original Sheet No. 537



                          APPENDIX L: MARKET MONITORING


TABLE OF CONTENTS

L.1   SCOPE OF MARKET MONITORING ACTIVITIES.....................538
L.2   ISA ROLES AND AUTHORITIES.................................538
L.3   ISA MARKET MONITORING PROCESSES...........................540
L.4   MARKET PARTICIPANTS' RIGHTS AND OBLIGATIONS...............543
L.5   CAO RIGHTS AND OBLIGATIONS................................545




Mountain West Independent Scheduling Administrator
FERC Electric Tariff
Original Volume 1                                        Original Sheet No. 538


L.1   SCOPE OF MARKET MONITORING ACTIVITIES

      The ISA shall monitor for anti-competitive behavior and inefficiencies in
      the ISA's rules and protocols in relation to the markets for the services
      which are provided under the Tariff. The ISA's market monitoring
      activities shall therefore focus on the following areas ("Monitored
      Markets"):

      a)  The purchase and sale of Ancillary Services

      b)  The auction and scheduling of transmission rights (FTRs, RTRs and
          NTRs)

      c)  The operation of the Real-time energy market. (The ISA is not involved
          in the operation of the energy market in general. Monitoring of energy
          markets shall be the responsibility of the Scheduling Coordinators
          and/or regulatory agencies.)

      The ISA shall also oversee the activities of the CAOs to ensure compliance
      with the Tariff, protocols and operating procedures.

L.2   ISA ROLES AND AUTHORITIES



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FERC Electric Tariff
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      In order to carry out the obligations identified in this Appendix, the ISA
      shall be authorized to:

      a)  Monitor, investigate and report on the Monitored Markets to ensure
          that they are open, fair, competitive, efficient, do not create
          perverse incentives, and comply with the Tariff;

      b)  Monitor, investigate and report on CAOs' operation of the Grid to
          ensure that the CAOs activities are non-discriminatory, fair,
          efficient, conform to the CAO Code of Conduct, and comply with the
          Tariff;

      c)  Develop and implement processes to ensure that the ISA
          responsibilities described in this Appendix are fulfilled;

      d)  To the extent possible, ensure that the ISA's market monitoring
          activities do not interfere with competitive market signals;

      e)  Develop and maintain a manual which identifies the ISA's procedures
          documentation and reporting requirements for market monitoring;

      f)  Investigate possible anti-competitive behavior and infractions of
          rules and protocols, and recommend remedial action steps to the ISA
          Board; and





Mountain West Independent Scheduling Administrator
FERC Electric Tariff
Original Volume 1                                        Original Sheet No. 540


      g)  Make recommendations to the ISA Board regarding changes to the Tariff
          and protocols to correct problems which are identified through market
          monitoring.


L.3   ISA MARKET MONITORING PROCESSES

      The ISA shall:

      a)  On a day-to-day basis, monitor activities of the Monitored Markets,
          monitor the CAOs' dispatch and operational activities, and carry out
          any other market administration responsibilities which are assigned by
          the ISA Board;

      b)  Develop and publish information which indicates historic prices and
          behaviors, which the ISA shall use to evaluate the behavior of Market
          Participants on an ongoing basis;

      c)  Develop, with advice from the Advisory Committee, standard market
          monitoring reports. Such reports shall not contain proprietary or
          confidential information, nor shall they make accusations regarding
          the behavior of individual Market Participants until such accusations
          have been fully adjudicated;






Mountain West Independent Scheduling Administrator
FERC Electric Tariff
Original Volume 1                                        Original Sheet No. 541

      d)  Upon request, make these standard reports available to Market
          Participants, to the Commission, and to those state and federal
          regulatory bodies which have jurisdiction over the Market
          Participants;

      e)  File the proposed contents and timing of the standard reports with the
          Commission by December 1, 1999;

      f)  Design and file with the Commission by December 1, 1999, upon
          recommendation of the Advisory Committee and approval of the ISA
          Board,, proposed penalties and sanctions for anti-competitive behavior
          and for violations of the ISA Tariff or protocols;

      g)  Investigate and, if necessary, promptly request an explanation or
          justification from any Market Participant whose behavior deviates from
          normal practices in such a way that the behavior may be construed to
          be manipulation of a Monitored Market;

      h)  Conduct further investigations of such incidents if the explanation or
          justification provided under Section L.3(g) is inadequate;



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FERC Electric Tariff
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      i)  Make voluntary data requests of Market Participants and CAOs to
          augment publicly available data, if necessary, as part of an inquiry;

      j)  Develop findings, proposed remedies, or proposed assessments of
          penalties for review by the entity under investigation, the Advisory
          Committee and the ISA Board, with due consideration for commercial
          sensitivity and confidentiality of Market Participants' information;

      k)  Invite the entity under investigation to present its views to the ISA;

      l)  Recommend to the ISA Board, the Commission and/or other regulatory
          bodies such actions that it believes to be necessary and appropriate
          following the reviews under Section L.3(j);

      m)  Complete the above process in a timely manner with due consideration
          for the need for fairness and confidentiality through out the process;

      n)  Provide the results of monitoring activities to the Advisory
          Committee;



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FERC Electric Tariff
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      o)  Participate, as deemed appropriate by the ISA Board, in any regulatory
          or judicial proceedings related to the ISA's investigations; and

      p)  Recommend the initiation of regulatory or judicial proceedings before
          bodies or agencies having appropriate jurisdiction over the Market
          Participant(s) under investigation and the matter(s) under
          investigation.

      In conducting its market monitoring activities, the ISA shall comply with
      the commonly-accepted practices, standards, rules and administrative
      procedures related to confidentiality, rules of evidence, and due process.

L.4  MARKET PARTICIPANTS' RIGHTS AND OBLIGATIONS Each Market

      Participant shall have the right to:

      a)  Be promptly notified by the ISA of any perceived infraction;

      b)  Justify or explain an incident before the ISA undertakes a full
          investigation;

      c)  Comment on any reports by the ISA in which the Market Participant is
          the subject of an


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FERC Electric Tariff
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          investigation and any consequent recommendations for remedial action;

      d)  Explain its position to the ISA prior to assessment of penalties or
          implementation of remedial action;

      e)  Initiate the ADR process as a result of the ISA's market monitoring
          activities; and

      f)  Request a hearing or initiate proceedings before a regulatory or
          judicial body which has appropriate jurisdictional authority over the
          Market Participant and the matter(s) under investigation, as an
          alternative to further participation in the ISA's inquiries or
          proceedings.

      Each Market Participant shall:

      a)  Maintain records of its activities in the Monitored Markets, including
          secondary market transactions, for a period of three years from the
          trading date; and

      b)  Cooperate with the ISA by providing to the ISA, upon notification of
          an investigation, (i) non-proprietary or non-confidential data related
          to its activities in the Monitored Markets; and, at the sole
          discretion of the Market Participant,


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FERC Electric Tariff
Original Volume 1                                        Original Sheet No. 545

          proprietary and/or confidential data under terms of a formal, binding
          confidentiality agreement with the ISA.

L.5   CAO RIGHTS AND OBLIGATIONS Each CAO shall have the right to:

      a)  Be promptly notified by the ISA of any perceived infraction;

      b)  Justify or explain the incident before the ISA undertakes a full
          investigation;

      c)  Comment on any reports by the ISA and recommendations for remedial
          action;

      d)  Explain its position to the ISA prior to assessment of penalties or
          implementation of remedial action;

      e)  Initiate the ADR process as a result of the ISA's monitoring
          activities;

      f)  Request a hearing or initiate proceedings before a regulatory or
          judicial body which has appropriate jurisdictional authority over the
          CAO and the matter(s) under consideration, as an alternative to
          further participation in the ISA's inquiries or proceedings; and



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FERC Electric Tariff
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      g)  Operate and control the Grid in real time in accordance with the CAO's
          obligations to ensure reliability and to comply with applicable
          reliability criteria.

      Each CAO shall:

      a)  Immediately report to the ISA any deviations from the ISA Tariff,
          protocols or operating procedures;

      b)  Maintain records of its scheduling, dispatch, Ancillary Services and
          transmission congestion management activities for a period of three
          years from the trading date; and

      c)  Provide data to the ISA regarding the Monitored Markets, as requested
          by the ISA in connection with the ISA's market monitoring activities.