FOURTH AMENDMENT

                                TO

                  AGREEMENT FOR FACILITIES LEASE

                             between

                    BRAZOS RIVER LEASING L.P.

                               and

         DIAMOND SHAMROCK REFINING AND MARKETING COMPANY

                    Dated as of April 23, 1996






















This Fourth Amendment to Agreement for Facilities Lease has been
manually executed in 8 counterparts, numbered consecutively from 1
through 8, of which this is No. ____.  To the extent, if any, that
this Fourth Amendment to Agreement for Facilities Lease constitutes
chattel paper (as such term is defined in the Uniform Commercial Code
as in effect in any jurisdiction), no security interest in this
Fourth Amendment to Agreement for Facilities Lease may be created or
perfected through the transfer or possession of any counterpart other
than the original counterpart which shall be the counterpart
identified as counterpart No. 1.



        FOURTH AMENDMENT TO AGREEMENT FOR FACILITIES LEASE

     This Fourth Amendment to Agreement for Facilities Lease is made
and entered into as of April 23, 1996, by and between BRAZOS RIVER
LEASING L.P. ("Brazos") and DIAMOND SHAMROCK REFINING AND MARKETING
COMPANY ("Diamond Shamrock R & M").

                       W I T N E S S E T H:

     WHEREAS, Brazos and Diamond Shamrock R & M have heretofore
entered into an Agreement for Facilities Lease, dated as of April 23,
1992 (as amended by the First Amendment to Agreement for Facilities
Lease, the "Agreement for Facilities Lease"); and

     WHEREAS, Brazos and Diamond Shamrock R & M desire to further
amend the Agreement for Facilities Lease to extend the acquisition
period and to otherwise set forth their mutual agreement; and

     WHEREAS, Brazos and Diamond Shamrock R & M agree that the
provisions of this amendment shall apply, to the extent provided by
law, to each Facility acquired by Brazos under the Agreement for
Facilities Lease.

     NOW, THEREFORE, in consideration of the mutual covenants herein
contained and other valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, Brazos and Diamond
Shamrock R & M agree that the Agreement for Facilities Lease is
hereby amended as follows:

     1.   Section 3.06 of the Agreement for Facilities Lease is
hereby amended by deleting in subsection (i) in Section 3.06, the
reference to "four years" and inserting in lieu thereof "five years".

     2.   Brazos and Diamond Shamrock R & M agree that this Fourth
Amendment to Agreement for Facilities Lease shall not be effective
until the approvals required by Section 9.01 of the Credit Agreement
have been obtained as evidenced by the execution of Amendment No. 5
by the necessary parties under the Credit Agreement.

     3.   Defined terms used in this Fourth Amendment to Agreement
for Facilities Lease and not otherwise defined herein have the
meanings ascribed to those terms in the Agreement for Facilities
Lease.

     IN WITNESS WHEREOF, Brazos and Diamond Shamrock R & M have
caused this Fourth Amendment to Agreement for Facilities Lease to be
executed and delivered by their duly authorized officers as of the
day and year first above written.

                              BRAZOS RIVER LEASING L.P.

                              By:  Headwater Investments L.P.,
                                   its General Partner

                                   By:  Headwater Holdings, Inc.,
                                        its General Partner

                                   By:  /s/ GREGORY C. GREENE
                                            Gregory C. Greene,
                                            President


                              DIAMOND SHAMROCK REFINING
                                   AND MARKETING COMPANY


                              By:  /s/ R. C. Becker
                              Name:    R. C. Becker
                              Title:   Vice President and
                                         Treasurer



W3997.TW