<PAGE>
                                                  Exhibit 10.20.5


        AMENDMENT NUMBER FOUR TO STEAM PURCHASE CONTRACT
            BETWEEN O'BRIEN ENERGY SYSTEMS, INC. AND
                E. I. DUPONT DE NEMOURS & COMPANY
                 (Parlin Cogeneration Facility)


      WHEREAS, O'Brien Energy Systems, Inc. (O'Brien") and E.  E.
DuPont  de  Nemours  & Company ("DuPont") entered  into  a  Steam
Purchase  Contract dated December 8, 1986, which was subsequently
modified  by  Amendment Number One, dated January 12,  1988,  but
Amendment Number Two in the form of a Letter Agreement dated July
25, 1988, and by Amendment Number Three, dated December 12, 1988;
and

     WHEREAS, the Steam Purchase Contract was assigned by O'Brien
Energy  systems to O'Brien (Parlin) Cogeneration Inc. on December
12, 1988, which assignment was consented to by DuPont on the same
date; and

      WHEREAS,  the  Parties desire to ratify said Agreement,  as
amended, and make certain further modifications thereto;

      NOW  THEREFORE,  in consideration of the  mutual  covenants
contained  herein,  the sufficiency of which is  acknowledged  by
both Parties, the Parties do hereby agree as follows:

      1.    Agreement Regarding Disposal of Process Waste  Water,
Storm  Water, and Domestic Water from the Cogeneration  Facility:
Paragraphs  3  (B) and (C) of the Third Amendment  to  the  Steam
Purchase  Agreement,  are  hereby  replaced  with  the  following
language:

     "(B)  DuPont  agrees to permit O'Brien to  provide  a  storm
     water  detention basin and connect into the  existing  plant
     industrial/storm piping system, so that rain  water  may  be
     discharged  from the site.  Additionally, DuPont  agrees  to
     permit  O'Brien to discharge non-contact process water  from
     the  Facility into the industrial/storm sewer piping  system
     subject to the following terms and conditions:

     (1)  O'Brien  shall  conduct  a  detailed  analysis  of  the
          existing  piping  system  to certify  that  the  piping
          system  has the capacity to handle all of the  existing
          flow,  including  storm water and  non-contact  process
          water  from  the  Fabricated Products  portion  of  the
          DuPont Plant, in addition to projected storm water  and
          non-contact  process water flows from the  Cogeneration
          Facility.  In the event that the existing piping system
          is  inadequate  to  handle  all  the  foregoing  flows,
          O'Brien shall have the right, at its cost, to implement
          remedial  measures such as a storage  tank,  to  ensure
          adequate capacity.

                                1

<PAGE>

     (2)  The  maximum  non-contact process water,  i.e.  cooling
          tower   and   boiler  blowdown,  and  water   treatment
          regeneration, flow from O'Brien shall be 193 gpm.

     (3)  The  water discharged into the DuPont system  from  the
          Facility  shall meet all current, proposed, and  future
          government regulations.

     (4)  O'Brien shall provide a continuous monitoring system to
          measure  flow  and  collect a sample  for  analysis  of
          constituents,  in order to audit O'Brien's  discharges.
          DuPont  shall be responsible at its costs for obtaining
          operating permits, sampling and testing.

     (5)  O'Brien and DuPont shall share costs, prorated based on
          projected    respective   volumes,   for    permitting,
          maintenance,  sampling and testing.  This will  include
          an  initial  TV  camera survey  of  the  line  and  any
          necessary repairs to the line.

     (6)  DuPont  shall  obtain written assurances from  the  New
          Jersey  Department  of  Environmental  Protection  that
          O'Brien's flow may be discharged under DuPont's permit.
          Specifically, DuPont shall obtain authorization for the
          discharge of up to 193 gpm of non-contact process waste
          water  from O'Brien's Facility.  Dupont agrees,  during
          the  term  of the Steam Purchase Agreement, to allocate
          to O'Brien, 193 gpm of capacity under its permit.

     The Parties further agree that, as long as the process waste
     water  discharged by O'Brien does not exceed the contaminant
     parameters  set out in Exhibit A, O'Brien's discharge  falls
     within the requirements of DuPont's existing permit.  Should
     DuPont's  permit  conditions change, the  Parties  agree  to
     amend  Exhibit  A  to  assure continued compliance.   DuPont
     shall  use  its  best efforts to keep its discharges  within
     permit  requirements, and will use its best efforts to  make
     certain  that O'Brien's ability to discharge is not impaired
     due  to the failure of DuPont's discharge to meet applicable
     standards.

     (C)   DuPont  hereby  agrees that it has adequate  available
     capacity to  handle the discharge of the Facility's domestic
     wastes into the DuPont sanitary sewer system.  O'Brien shall
     bear  the  cost  of  connecting to that  system,  and  shall
     provide  sampling and monitoring facilities to  continuously
     test effluent flows.  DuPont has represented to O'Brien that

                                2

<PAGE>

     the  Middlesex  County Utility Authority (MCUA)  has  stated
     that the estimated 2 GPM of additional flow will not require
     any  changes  to  DuPont's MCUA permit.   DuPont  agrees  to
     obtain  a letter from MCUA to this effect.  DuPont  will  be
     responsible  for any operation, maintenance  and  permitting
     costs  associated  with  the sanitary  sewer  line  for  the
     discharge of domestic wastes."

      2.    Agreement  Concerning Fire  Protection  System:   The
parties  agree  to  replace Paragraph 3 (E) of  Amendment  Number
Three with the following new sections 3 (E) and (F):

     "(E)  Dupont hereby confirms that it has available  adequate
     capacity  to supply 2500 gpm at 90 psig of water and  agrees
     to  permit  O'Brien  to  connect the  Facility  to  DuPont's
     existing  fire protection water supply system, in  order  to
     provide fire protection for the Facility, subject to O'Brien
     undertaking  the  following  improvements.   First,  O'Brien
     shall  replace  the existing eight inch line  from  DuPont's
     feed  point with a new line which is adequate to carry  2500
     gallons  per  minute.   Second,  O'Brien  will  provide   an
     automatic flow control valve.  Third, O'Brien agrees to  pay
     DuPont for the cost of repairing the fire water lake bottom.
     This  cost  shall  not exceed $25,000,  and  DuPont  assumes
     responsibility for an any liability associated with disposal
     of  dredged  soil.   Design and construction  of  the  above
     additions  and  modifications to the fire protection  system
     and  the  certification that the system has the capacity  to
     meet  O'Brien's  needs will be O'Brien's responsibility  and
     expense.   O'Brien  agrees to an annual test  by  DuPont  in
     accordance  with DuPont standards, of the piping  system  on
     the Facility site.

     (F)    DuPont  agrees  not  to  repair  or  alter  its  fire
     protection  water  supply system in  a  manner  which  would
     deprive  O'Brien of a sufficient water supply for  its  fire
     protection  system without the consent of O'Brien.   O'Brien
     further  agrees  to  indemnify  DuPont  in  accordance  with
     Article  16  of  this  Agreement should  such  indemnity  be
     required  in  connection  with a failure  of  DuPont's  fire
     protection  water supply system to put out  a  fire  at  the
     Facility.   If  O'Brien  connects the Facility  to  DuPont's
     fireprotection  water supply system, it agrees  to  pay  its
     proportionate share of any repair costs due to a failure  of
     the  fire protection water supply system on that portion  of
     the  fire  protection water supply system being utilized  by
     O'Brien, such costs to be computed on a pro-rata basis  with
     reference  to  the  percentage of square footage  comprising
     buildings  at  O'Brien's  Facility  as  compared  to  square
     footage  comprising buildings owned by DuPont at the  Parlin
     site.   O'Brien  further agrees to design the Facility  fire
     protection system via a fire "loop" which will tie into the

                                3

<PAGE>

     DuPont   fire  protection  water  supply  system   at   both
     connection  points  at the outer boundaries  of  the  leased
     premises  and which will eliminate the existing DuPont  fire
     protection   water  supply  system  piping  on  the   leased
     premises."

      3.    Complete Agreement:  This Fourth Amendment,  combined
with  the original contract, as amended, constitutes the complete
agreement between the Parties.  Any further amendment shall be in
writing, and signed by both Parties.


AGREED AND ACCEPTED:

E. I. DUPONT DE NEMOURS & COMPANY       O'BRIEN (PARLIN)
                                        COGENERATION INC.



By: /s/ George R. Carson                By: /s/ Joel D. Cooperman

Date: 7/26/89                           Date: 7/14/89

                                4