EXHIBIT 10.15

                                                           Execution Counterpart

                  HAZARDOUS MATERIALS UNDERTAKING AND INDEMNITY


     This Hazardous  Materials  Undertaking and Indemnity (this  "Indemnity") is
executed by CALPINE  CORPORATION,  a Delaware  corporation (the "Indemnitor") in
favor of THE BANK OF NOVA SCOTIA, a Canadian chartered bank ("Scotiabank"),  for
itself  and as agent  for the  commercial  lending  institutions  to each of the
Credit Agreements (as defined below) (herein collectively, with their successors
and  assigns,  the  "Lenders";  the  Agent,  all  Issuers  and the  Lenders  are
collectively  referred to as the "Indemnified  Parties"),  with reference to the
following facts:

     A.  Indemnitor  is party to that  certain  (i) Credit  Agreement  (the "New
Credit  Agreement"),  dated as of March 8, 2002, among  Indemnitor,  the various
financial institutions as are or may become parties thereto  (collectively,  the
"New Lenders"), The Bank of Nova Scotia, and Bayerische Landesbank Girozentrale,
as lead arrangers and  bookrunners,  Salomon Smith Barney Inc. and Deutsche Banc
Alex. Brown Inc., as lead arrangers and bookrunners,  Bank of America,  National
Association,  and Credit Suisse First Boston, New York Branch, as lead arrangers
and  syndication  agents and TD  Securities  (USA) Inc.,  as lead  arranger  and
Scotiabank as joint  administrative  agent and funding agent,  and Citicorp USA,
Inc., as Joint  Administrative Agent and (ii) Second Amended and Restated Credit
Agreement (the  "Existing  Credit  Agreement",  and together with the New Credit
Agreement, the "Credit Agreements"), dated as of May 23, 2000, among Indemnitor,
the various  financial  institutions  as are or may become parties  thereto (the
"Existing  Lenders"),  Bayerische  Landesbank  Girozentrale,  as co-arranger and
syndication agent for the Existing Lenders and the Agent.

     B. The Loans, the Letters of Credit, the Guaranty and all other Obligations
owing  to any of the  Lenders  under  each of the  Credit  Agreements  are to be
secured  by,  among  other  things,  all of the  right,  title and  interest  of
Indemnitor  in the real  property  and  interests  comprising  the  Domestic Gas
Reserves and all fixtures, personal property and other improvements now existing
or to be constructed on any of such properties (such properties, descriptions of
which  are  attached  hereto as  Exhibit  A,  herein  collectively  called,  the
"Properties"), with respect to which Indemnitor has executed counterparts of the
Deed of Trust.

     C. Lenders are willing to make the Credit Extensions to Indemnitor upon the
terms and conditions set forth in the Credit  Agreements,  the Deed of Trust and
the  other  Loan  Documents  (collectively,  the "Loan  Documents")  only if the
Indemnified  Parties are  indemnified and held harmless with respect to any risk
that the Properties may now or in the future be in any way contaminated,  or its
use or value impacted by any Hazardous Materials, as defined below.

     D. It is a  condition  precedent  to the  making  of the  Term B Loans  and
issuance  of the  Letters of Credit that  Indemnitor  execute  and deliver  this
Indemnity.

     E. In order to induce  the Agent and the  Lenders  to make the Loans and to
issue or cause to be issued the Letters of Credit,  and with the full  intention
and




understanding  that  the  Indemnified  Parties  will  rely  hereon,   Indemnitor
represents, warrants, covenants and agrees as follows:

     1. Certain  Definitions.  As used in this  Indemnity,  the following  terms
shall have the following respective meanings:

     "Hazardous  Materials"  means  crude or refined  oil or  fraction  thereof,
petroleum  substances,   petrochemical   products,   PCBs,  asbestos,   asbestos
containing   materials,   urea  formaldehyde,   salts,   flammable   explosives,
radioactive   materials,   hazardous  wastes,  toxic,  mutagenic  or  pathogenic
substances or related materials,  including,  without limitation, any substances
defined as or included in the definition of "hazardous  substances,"  "hazardous
wastes,"  "hazardous  materials,"  or "toxic  substances"  under any  applicable
federal or state laws or regulations.

     "Hazardous  Materials  Laws"  means  all  federal,  state  or  local  laws,
ordinances,   regulations,   orders  and  directives   pertaining  to  Hazardous
Materials.

     Capitalized  terms used and not  otherwise  defined  herein  shall have the
respective  meanings specified in either or both of the New Credit Agreement and
the Existing Credit Agreement, as context requires.

     2.  Representations and Warranties.  Without limiting the generality of any
of the  representations  or  warranties  contained in the other Loan  Documents,
Indemnitor hereby represents and warrants to the Agent and the other Indemnified
Parties  that,  except as disclosed on Exhibit B hereto,  as of the date of this
Indemnity and continuing thereafter,

          (a) the Properties and each portion thereof  (including the underlying
     groundwater)  are not and have  not  been a site  for the use,  generation,
     manufacture, discharge, assembly, processing, storage, release, disposal or
     transportation to or from of any Hazardous Materials,  except in connection
     with the production,  storage and transportation of crude oil, natural gas,
     other  hydrocarbons  and  petroleum,  and other  petroleum  products in the
     ordinary course of Indemnitor's business;

          (b) the Properties and each portion thereof  (including the underlying
     groundwater) are presently in compliance in all material  respects with all
     Hazardous Materials Laws, including,  without limitation, those relating to
     exposure to Hazardous Materials,  the labeling,  storage and containment of
     Hazardous Materials, and air, soil and surface and ground water conditions;

          (c)  there  have  been no  past,  and  there  are no  pending  or,  to
     Indemnitor's knowledge, threatened

               (i)  claims,  complaints,  notices or  requests  for  information
          received by  Indemnitor  with respect to any alleged  violation of any
          Environmental Law, including Hazardous Materials Laws, that, singly or
          in


                                      -2-


          the  aggregate,  may reasonably be expected to result in a Material
          Adverse Effect, or

               (ii)  complaints,  notices or inquiries to  Indemnitor  regarding
          potential  liability under any Environmental Law, including  Hazardous
          Materials Laws,  that,  singly or in the aggregate,  may reasonably be
          expected to result in a Material Adverse Effect;

          (d) there have been no  unremediated  Releases of Hazardous  Materials
     at, on or under any property  (including the  Properties) now or previously
     owned or leased by Indemnitor that, singly or in the aggregate,  result in,
     or may reasonably be expected to result in, a Material Adverse Effect;

          (e) Indemnitor has been issued and is in material  compliance with all
     permits,   certificates,   approvals,   licenses  and  other   governmental
     authorizations  relating to  environmental  matters and  necessary  for its
     businesses;

          (f) no property  (including the Properties) now or previously owned or
     leased by  Indemnitor  is listed or proposed for listing  (with  respect to
     owned property only) on the National Priorities List pursuant to CERCLA, on
     the CERCLIS or on any similar state list of sites  requiring  investigation
     or clean-up;

          (g) Indemnitor has not directly  transported or directly  arranged for
     the  transportation  of any  Hazardous  Material to any  location  which is
     listed or proposed for listing on the National  Priorities List pursuant to
     CERCLA, on the CERCLIS or on any similar state list or which is the subject
     of  federal,  state or local  enforcement  actions or other  investigations
     which may lead to material claims against Indemnitor for any remedial work,
     damage to natural  resources  or personal  injury,  including  claims under
     CERCLA;

          (h) there are no polychlorinated biphenyls or friable asbestos present
     at any property  (including  the  Properties)  now or  previously  owned or
     leased by Indemnitor  that,  singly or in the aggregate,  result in, or may
     reasonably be expected to result in, a Material Adverse Effect; and

          (i) no conditions  exist at, on or under any property  (including  the
     Properties) now or previously owned or leased by Indemnitor which, with the
     passage  of time,  or the  giving  of notice  or both,  would  give rise to
     liability under any Environmental  Law, which liability would reasonably be
     expected to result in a Material Adverse Effect.

     3. Covenants.  Indemnitor  hereby covenants and agrees that, so long as any
obligation  under any of the Loan Documents or otherwise in connection  with the
Loans is outstanding:

          (a)  Indemnitor  shall not permit the Properties or any portion of any
     parcel  thereof  to  be  a  site  for  the  use,  generation,  manufacture,
     discharge,   assembly,   processing,    storage,   Release,   disposal   or
     transportation to or from of


                                      -3-


     Hazardous  Materials  except (i) as disclosed on Exhibit B hereto,  (ii) in
     such  quantities  and as may be necessary for the  production,  storage and
     transportation of crude oil, natural gas and other Hydrocarbons (as defined
     in the Deed of Trust) in the ordinary  course of  Indemnitor's  business as
     conducted on the Effective Date,  (iii) as necessary or required to develop
     the Properties in the ordinary course of Indemnitor's  business and (iv) as
     may be  necessary  to  respond  to any  emergency,  each of which  excepted
     activities will be conducted in a manner designed to minimize environmental
     risk;

          (b) Indemnitor shall keep and maintain the Properties and each portion
     of any parcel  thereof in  compliance  in all  material  respects  with all
     Environmental  Laws,  including Hazardous Materials Laws (and to the extent
     there are  violations of such laws existing as of the date hereof which are
     disclosed on Exhibit B, with the remediation plans and work plans listed on
     Exhibit B), and otherwise  shall not cause or permit the  Properties or any
     portion of any parcel thereof to be in violation,  in any material respect,
     of such laws;

          (c) As to any claim or matter not  disclosed on Exhibit B,  Indemnitor
     shall immediately advise the Agent in writing of:

               (i)  any  and  all   enforcement,   cleanup,   removal  or  other
          governmental or regulatory actions instituted, completed or threatened
          against  Indemnitor  or the  Properties  pursuant  to  any  applicable
          Environmental Laws, including Hazardous Materials Laws that, singly or
          in the  aggregate,  have,  or may  reasonably  be expected to have,  a
          Material Adverse Effect;

               (ii) any and all material  claims made or threatened by any third
          party  against  Indemnitor  or the  Properties  relating to any claim,
          liability,   cause  of  action,   nuisance,   fine,  penalty,  charge,
          administrative  or judicial  order or proceeding,  judgment,  remedial
          action or cleanup requirement, enforcement, damage, contribution, cost
          recovery,  compensation,  loss or injury  resulting from any Hazardous
          Materials that, singly or in the aggregate, have, or may reasonably be
          expected to have, a Material  Adverse Effect (the matters set forth in
          Sections  3(c)(i)  and (ii)  hereof  are  hereinafter  referred  to as
          "Hazardous Materials Claims");

               (iii) any  change in any claim or matter  disclosed  in Exhibit B
          that, singly or in the aggregate,  have, or may reasonably be expected
          to have, a Material Adverse Effect; and

               (iv) For the purpose of protecting the collateral given to secure
          the  Obligations,   the  Agent  shall  have  the  right  to  join  and
          participate in, as a party if it so elects,  any legal  proceedings or
          actions  initiated in connection with any Hazardous  Materials  Claims
          and to have its reasonable  attorneys' fees and expenses in connection
          therewith paid by Indemnitor;


                                      -4-


          (d) Indemnitor  shall not,  without the Agent's prior written  consent
     (which  consent shall not be  unreasonably  withheld or delayed),  take any
     remedial action in response to the presence of any Hazardous  Materials on,
     under,  or about the  Properties  (except (i) with  respect to oil, gas and
     other  Hydrocarbons,  in the ordinary course of Indemnitor's  business,  or
     (ii) as may be necessary to respond to any  emergency),  nor enter into any
     settlement agreement, consent decree, or other compromise in respect of any
     Hazardous Material Claim in excess of $250,000;

          (e) Annually,  at the time Indemnitor's  audited financial  statements
     are  required  to  be  delivered  to  the  Agent  pursuant  to  the  Credit
     Agreements,  Indemnitor  shall  deliver  to the  Agent a report  discussing
     significant  issues or  concerns  arising,  or measures  taken,  during the
     preceding  year and those  contemplated  for the following year relating to
     compliance with Hazardous Materials Laws and Environmental Laws, including,
     without  limitation,  compliance  with  any  then  effective  order  of the
     Regional Water Quality  Control Board (or other lead agency)  pertaining to
     the  characterization,  abatement and  remediation of soil and  groundwater
     contamination of the Properties;

          (f) To the extent that  Indemnitor has the right to do so,  Indemnitor
     shall  permit  the  Agent  or  its  agents,  at the  cost  and  expense  of
     Indemnitor,  to enter upon the Properties  and all parts  thereof,  for the
     purpose  of  investigating  and  inspecting  the  condition  and  operation
     thereof,  and shall permit reasonable access to the field offices and other
     offices,  including  the  principal  place of business,  of  Indemnitor  to
     inspect and examine the Properties and to inspect,  review and reproduce as
     necessary any books,  records,  accounts,  contracts or other  documents of
     Indemnitor;

          (g) Without  limiting the generality of the foregoing  clause (f), the
     Agent  shall  have  the  right,   subject  to  any   existing   contractual
     restrictions  binding on  Indemnitor  and on  twenty-four  (24) hours prior
     notice to  Indemnitor,  to cause such persons and entities as the Agent may
     designate  to enter the  Properties  to conduct (at the cost and expense of
     Indemnitor),  or to cause Indemnitor to conduct (at the cost and expense of
     Indemnitor),  such tests and investigations as the Agent deems necessary to
     determine  whether  any  hazardous   substance  or  solid  waste  is  being
     generated,   transported,   stored,  or  disposed  of  in  accordance  with
     applicable  Environmental  Laws. Such tests and investigations may include,
     without limitation,  underground borings, ground water analyses and borings
     from the  floors,  ceilings  and walls of any  improvements  located on the
     Properties. This Section 3(g) shall not be construed to affect or limit the
     obligations of Indemnitor pursuant to Section 4 hereof;

          (h) The Agent shall have no duty to visit or observe the Properties or
     to conduct  tests,  and no site visit,  observation or testing by the Agent
     shall impose any liability on the Agent,  nor shall Indemnitor or any other
     Obligor be  entitled  to rely on any visit,  observation  or testing by the
     Agent in any  respect.  The  Agent  may,  in its  discretion,  disclose  to
     Indemnitor or any other Person, including any


                                      -5-


     governmental  agency,  any  report or  finding  made as a result  of, or in
     connection  with,  any site  visit,  observation  or  testing by the Agent.
     Indemnitor  agrees that the Agent makes no  warranty or  representation  to
     Indemnitor  or  any  other  Obligor   regarding  the  truth,   accuracy  or
     completeness  of any such  report  or  findings  that may be so  disclosed.
     Indemnitor also acknowledges  that,  depending upon the results of any site
     visit,  observation  or testing by the Agent and  disclosed to  Indemnitor,
     Indemnitor may have a legal  obligation to notify one or more  governmental
     agencies  of  such   results,   that  such   reporting   requirements   are
     site-specific,  and are to be evaluated  by  Indemnitor  without  advice or
     assistance from the Agent; and

          (i) Cooperate fully with any environmental  consultant retained by the
     Agent to prepare reports on the Properties.

     4.  Continuing  Indemnity.  Indemnitor  hereby  agrees to  indemnify,  hold
harmless and defend (by one law firm reasonably satisfactory to the Agent unless
an Event of Default  shall have  occurred and be  continuing)  the Agent and the
other  Indemnified  Parties and its and their  directors,  officers,  employees,
agents,  successors and assigns  (collectively,  "Indemnitees") from and against
any and all claims (including without limitation third party claims for personal
injury or real or  personal  property  damage),  losses,  damages,  liabilities,
fines,  penalties,  charges,  administrative and judicial proceedings (including
informal  proceedings)  and orders,  judgments,  remedial  action  requirements,
enforcement  actions  of any  kind,  and all  costs  and  expenses  incurred  in
connection therewith (including but not limited to reasonable  attorneys' and/or
paralegals'  fees and  expenses),  including,  but not  limited  to,  all  costs
incurred in connection with any  investigation  or monitoring of site conditions
or any clean-up,  remedial, removal or restoration work by any federal, state or
local government  agency,  arising directly or indirectly,  in whole or in part,
out of (i) the presence on or under the  Properties of any Hazardous  Materials,
or any escape, seepage, leakage, spillage, discharge, emission or Release of any
Hazardous  Materials  on,  under or from the  Properties,  or (ii) any  activity
carried on or  undertaken on or off the  Properties,  whether prior to or during
the term of the Loans,  and whether by Indemnitor or any predecessor in title or
any  employees,  agents,  contractors  or  subcontractors  of  Indemnitor or any
predecessor  in title,  or any third persons at any time occupying or present on
the Properties,  in connection with the handling,  treatment,  removal, storage,
decontamination, clean-up, transport or disposal of any Hazardous Materials that
at any time are  located  or  present  on or under or that at any time  migrate,
flow,  percolate,  diffuse  or in any way  move  onto or under  the  Properties;
provided  however,  that nothing  herein shall  require  Indemnitor to indemnify
Indemnitees  for any matter arising  solely from the gross  negligence or wilful
misconduct  of the Agent.  The  foregoing  indemnity  shall further apply to any
residual  contamination  on or under the  Properties,  or affecting  any natural
resources, and to any contamination of any property or natural resources arising
in connection with the generation, use, handling, storage, transport or disposal
of any  such  Hazardous  Materials,  and  irrespective  of  whether  any of such
activities  were or will be  undertaken  in  accordance  with  applicable  laws,
regulations,  codes and ordinances.  It is expressly  understood and agreed that
the indemnity provided for herein shall survive:  (i) the repayment of the Loans
and the release of or reconveyance


                                      -6-


(whether full or partial) of the Deed of Trust; or (ii) the acquisition of title
to all or any  portion of the  Properties  by the  Agent,  or any  successor  in
interest to the Agent, or any nominee or designee of any of them, by foreclosure
under or transfer in lieu of  foreclosure  of the Deed of Trust,  whether or not
the same is otherwise in satisfaction of Indemnitor's  obligations in connection
with the Loan.

     5. Time of the Essence. Time is of the essence of this Indemnity.

     6.  Governing  Law.  This  Indemnity  shall be governed by and construed in
accordance  with  the  laws of the  State  of New  York,  except  to the  extent
preempted by Federal Law. Indemnitor irrevocably agrees that any legal action or
proceeding with respect to this Indemnity may be brought in a court of competent
jurisdiction of the State of New York or of the United States of America, as the
Agent may elect,  and by execution and delivery of this Indemnity the Indemnitor
hereby  irrevocably  submits to each such  jurisdiction;  and agrees  that final
judgment  against  the  Indemnitor  in any such  action or  proceeding  shall be
conclusive  and may be enforced  in any  jurisdiction  within the United  States
including, without limitation, the State of New York, by suit on the judgment, a
certified  copy of which  shall be  conclusive  evidence  of the fact and of the
amount of the indebtedness owed.

     7. Indemnitor  Waivers.  Indemnitor  waives: (a) any defense based upon any
legal  disability  to enter  into the  Credit  Agreements  or other  defense  of
Indemnitor  under the Credit  Agreements;  (b) any defense  based on any lack of
authority of the officers, directors, partners or agents acting or purporting to
act on behalf of Indemnitor or any principal of Indemnitor, or any defect in the
formation of Indemnitor or any  principal of  Indemnitor;  (c) any defense based
upon the  application  of the proceeds of the Loans by  Indemnitor  for purposes
other than the purposes  represented  by  Indemnitor to the Agent or intended or
understood by Agent or Indemnitor;  (d) any defense based upon Agent's election,
in  any  proceeding  instituted  under  the  Federal  Bankruptcy  Code,  of  the
application of Section 111(b)(2) of the Federal Bankruptcy Code or any successor
statute;  (e) any  defense  based upon any  borrowing  or any grant of  security
interest  under Section 364 of the Federal  Bankruptcy  Code;  (f)  presentment,
demand,  protest  and notice of any kind;  and (g) the benefit of any statute of
limitations  affecting the liability of Indemnitor  hereunder or the enforcement
hereof.

     8. Other Provisions.

          (a) This  Indemnity is a Loan  Document  executed  pursuant to the New
     Credit  Agreement  and shall be  construed,  administered  and  applied  in
     accordance with the terms and provisions  thereof  (including  [Article XI]
     thereof).

          (b) All notices  pursuant to this Indemnity  shall be delivered at the
     times,  in the manner and to the addressees as set forth in Section 11.2 of
     each of the Credit Agreements.


                                      -7-


          (c) No amendment to or waiver of any  provision of this  Indemnity nor
     consent to any departure by Indemnitor  herefrom shall be effective  unless
     the same shall be in writing and signed by the Agent and Indemnitor.

          (d) This  Indemnity  shall be binding on and for the  benefit  of, the
     parties hereto, together with their respective successors and assigns.

          (e)  The  obligations  of  Indemnitor   hereunder  shall  survive  any
     termination of this Indemnity and the  termination of all the  Commitments.
     The  representations  and  warranties  made by Indemnitor in this Agreement
     shall survive the execution and delivery of this Indemnity.

          (f)  Any   provision  of  this   Indemnity   which  is  prohibited  or
     unenforceable  in any  jurisdiction  shall,  as to such  provision and such
     jurisdiction,   be  ineffective  to  the  extent  of  such  prohibition  or
     unenforceability  without  invalidating  the  remaining  provisions of this
     Indemnity or affecting the validity or  enforceability of such provision in
     any other jurisdiction.

          (g)  The  various   headings  of  this   Indemnity  are  inserted  for
     convenience only and shall not affect the meaning or interpretation of this
     Indemnity or any provisions hereof.

          (h) This  Indemnity  may be executed by the parties  hereto in several
     counterparts,  each of which shall be deemed to be an  original  and all of
     which  shall  constitute  together  but one and the  same  agreement.  This
     Indemnity  shall become  effective  when  counterparts  hereof  executed on
     behalf of Indemnitor and the Agent shall have been received by the Agent.


                                      -8-




Dated:  as of May 9, 2002

                                       "Indemnitor"

                                       CALPINE CORPORATION, a Delaware
                                       corporation

                                        By:_____________________________________
                                           Name:
                                           Title:


                                        "Agent"

                                        THE BANK OF NOVA SCOTIA, as Agent


                                        By______________________________________
                                           Name:
                                           Title:_______________________________





                                    EXHIBIT A
                                       to
                  HAZARDOUS MATERIAL UNDERTAKING AND INDEMNITY
                  --------------------------------------------

                         Legal Description of Properties






                                    EXHIBIT B
                                       to
                  HAZARDOUS MATERIAL UNDERTAKING AND INDEMNITY
                  --------------------------------------------

                            Description of Hazardous
                          Materials On Properties, etc.

                                      None