Document:

<Page>

--------------------------------------------------------------------------------

                                OMNIBUS AGREEMENT

                                      among

                      ULTRAMAR DIAMOND SHAMROCK CORPORATION

                           SHAMROCK LOGISTICS GP, LLC

                            RIVERWALK LOGISTICS, L.P.

                            SHAMROCK LOGISTICS, L.P.

                                       and

                       SHAMROCK LOGISTICS OPERATIONS, L.P.

                                OMNIBUS AGREEMENT

--------------------------------------------------------------------------------

<Page>

                               OMNIBUS AGREEMENT

         THIS OMNIBUS AGREEMENT is entered into on, and effective as of, the
Closing Date by and among Ultramar Diamond Shamrock Corporation, a Delaware
corporation ("UDS"), Shamrock Logistics GP, LLC, a Delaware limited liability
company ("Shamrock GP"), Riverwalk Logistics, L.P., a Delaware limited
partnership and general partner of the MLP and the OLP ("Riverwalk"), Shamrock
Logistics, L.P., a Delaware limited partnership (the "MLP"), and Shamrock
Logistics Operations, L.P., a Delaware limited partnership (the "OLP").

                                 R E C I T A L:

         UDS, the MLP, the OLP, Shamrock GP in its capacity as the general
partner of Riverwalk, and Riverwalk in its capacity as the general partner of
each of the MLP and the OLP, desire by their execution of this Agreement to
evidence their understanding, (i) as more fully set forth in Article II of this
Agreement, with respect to (a) those business opportunities that UDS will not
pursue unless the MLP has declined to engage in such business opportunities for
its own account and (b) the procedures whereby such business opportunities are
to be offered to the MLP and accepted or declined; (ii) as more fully set forth
in Article III of this Agreement, with respect to the indemnification
obligations of UDS relating to certain environmental and income tax liabilities,
and (iii) as more fully set forth in Article IV of this Agreement, with respect
to the options by the MLP to purchase certain assets currently under
construction which were retained by UDS at the time of the Formation
Transactions.

         In consideration of the premises and the covenants, conditions, and
agreements contained herein, and for other good and valuable consideration, the
receipt and sufficiency of which are hereby acknowledged, the parties hereto
hereby agree as follows:

                                   ARTICLE I.

                                  DEFINITIONS

         1.1 DEFINITIONS. (a) Capitalized terms used herein but not defined
herein shall have the meanings given them in the MLP Agreement.

               (b) As used in this Agreement, the following terms shall have the
respective meanings set forth below:

               "AFFILIATE" shall have the meaning attributed to such term in the
         MLP Agreement.

               "AGREEMENT" means this Omnibus Agreement, as amended, modified,
         or supplemented from time to time in accordance with the terms hereof.

               "CHANGE OF CONTROL" shall have the meaning attributed to such
         term in Section 2.4.

               "CLAIM" means any claim, lawsuit, demand, suit, inquiry made,
         hearing, investigation, notice of a violation, litigation, proceeding,
         arbitration, or other dispute, whether civil, criminal, administrative
         or otherwise.

                                        1
<Page>

               "CLOSING DATE" means the date of the closing of the initial
         public offering of common units representing limited partner interests
         in the MLP.

               "CONFLICTS COMMITTEE" shall have the meaning attributed to such
         term in the MLP Agreement.

               "CONTAMINANT" means any substance regulated under any
         Environmental Law, or any substance defined by Environmental Law as
         being hazardous or toxic or as being a pollutant.

               "CONTRACT" means any agreement, contract, commitment, or other
         binding arrangement or understanding, whether written or oral.

               "ENVIRONMENTAL LAWS" means any and all laws, statutes, judgments,
         ordinances, rules, regulations, orders, determinations,
         interpretations, or guidance of any Governmental Authority pertaining
         to health or the environment in effect in any and all jurisdictions in
         which any UDS Entity or Partnership Entity or any of their respective
         Affiliates is conducting or at any time has conducted business, or
         where any property of any UDS Entity or Partnership Entity or any of
         their respective Affiliates, whether leased or owned, is located, or
         where any hazardous substances generated or disposed of by any UDS
         Entity or Partnership Entity or any of their respective Affiliates are
         located. The term "ENVIRONMENTAL LAW" includes, without limitation, the
         Comprehensive Environmental Response, Compensation and Liability Act of
         1980, as amended by the Superfund Amendments and Reauthorization Act of
         1986 and as subsequently amended, 42 U.S.C. Section 9601 et seq.; the
         Resource Conversation and Recovery Act, as amended, 42 U.S.C. Section
         6901 et seq.; the Clean Air Act, as amended, 42 U.S.C. Section 7401 et
         seq.; and the Oil Pollution Act, as amended, 33 U.S.C. Section 2701 et
         seq.

               "ENVIRONMENTAL LIABILITIES AND COSTS" means all Losses from any
         Claim by any Person whether based on Contract, tort, implied or express
         warranty, strict liability, criminal or civil statute, including under
         any Remedial Action, Environmental Law, Environmental Permit,
         Environmental Lien, Order or agreement with any Governmental Authority,
         arising from environmental, health or safety conditions, or the release
         of a Contaminant into the environment.

               "ENVIRONMENTAL LIEN" means any Lien in favor of any Governmental
         Authority for Environmental Liabilities and Costs.

               "ENVIRONMENTAL PERMIT" shall mean any Permit, license, approval,
         consent or other authorization required by or pursuant to any
         applicable Environmental Law.

               "EXCHANGE ACT" means the Securities Exchange Act of 1934, as
         amended.

               "FORMATION TRANSACTIONS" means (i) the contributions to the OLP
         of certain crude oil pipeline and storage assets and refined product
         pipeline and terminalling assets pursuant to those certain Conveyance,
         Assignment and Bill of Sale Agreements dated effective as of July 1,
         2000, by and among the OLP and certain subsidiaries of UDS and (ii) the
         transfers of certain crude oil pipeline and storage assets and refined
         product

                                        2
<Page>

         pipeline and terminalling assets and certain ownership interests in
         Skelly-Belview Pipeline Company, L.L.C. to the OLP by virtue of the
         mergers of certain subsidiaries of UDS with and into the OLP effective
         as of July 1, 2000.

               "GOVERNMENTAL AUTHORITy" shall mean (a) the United States of
         America, (b) any state, county, municipality, or other governmental
         subdivision within the United States of America, and (c) any court or
         any governmental department, commission, board, bureau, agency, or
         other instrumentality of the United States of America or of any state,
         county, municipality, water rights, taxing, or zoning authority, or
         other governmental subdivision within the United States of America.

               "INDEMNIFIED PARTY" shall have the meaning assigned to such term
         in Section 3.2(a).

               "INDEMNIFYING PARTY" shall have the meaning assigned to such term
         in Section 3.2(a).

               "LOSSES" means all liabilities, losses, costs, damages (including
         punitive, consequential and treble damages), penalties or expenses
         (including, without limitation, reasonable attorneys' fees and expenses
         and costs of investigation and litigation), and also including any
         expenditures or expenses incurred to cover, remedy or rectify any such
         Losses.

               "MLP" means Shamrock Logistics, L.P., a Delaware limited
         partnership, and any successors thereto.

               "MLP AGREEMENT" means the Second Amended and Restated Agreement
         of Limited Partnership of the MLP, dated as of the Closing Date, as
         such agreement is in effect on the Closing Date, to which reference is
         hereby made for all purposes of this Agreement. No amendment or
         modification to the MLP Agreement subsequent to the Closing Date shall
         be given effect for the purposes of this Agreement unless consented to
         by each of the parties to this Agreement.

               "OLP" means Shamrock Logistics Operations, L.P., a Delaware
         limited partnership, and any successors thereto.

               "OPTION PURCHASE AMOUNT" means (i) $64,000,000 for the Wichita
         Falls Pipeline, (ii) $6,500,000 for the Ringgold Storage Facility or
         (iii) $5,600,000 for the Southlake Terminal, respectively.

               "ORDER" means any decree, order, injunction, rule, judgment,
         consent of or by a Governmental Authority.

               "PARTNERSHIP ENTITIES" means Shamrock GP, Riverwalk, the MLP and
         the OLP.

               "PERSON" means an individual, partnership, corporation, limited
         liability company, trust, incorporated or unincorporated association,
         joint venture, joint stock company, Governmental Authority or other
         legal entity of any kind.

                                        3
<Page>

               "PERMITS" means any licenses, permits, registrations, variances,
         interim permits, permit applications, certificates, approvals or other
         authorizations under any Regulation applicable to any UDS Entity or
         Partnership Entity.

               "REGULATION" means any law, statute, regulation, ruling, rule,
         Order or Permit, of, administered or enforced by or on behalf of any
         Governmental Authority, as may be amended from time to time.

               "REMEDIAL ACTION" means all actions required to (a) clean up,
         remove, treat or in any other way address Contaminants in the indoor or
         outdoor environment; (b) prevent the release or threat of release or
         minimize the further release of Contaminants so they do not migrate or
         endanger or threaten to endanger public health or welfare or the indoor
         or outdoor environment; or (c) perform pre-remedial studies and
         investigations and post-remedial monitoring and care.

               "RESTRICTED BUSINESS" has the meaning attributed to such term in
         Section 2.1.

               "RINGGOLD STORAGE FACILITY" means a new crude oil storage
         facility at Ringgold, Texas that is currently being constructed by UDS
         and which will have a storage capacity of approximately 600,000
         barrels.

               "RIVERWALK" means Riverwalk Logistics, L.P., a Delaware limited
         partnership and general partner of the MLP and OLP.

               "SHAMROCK GP" means Shamrock Logistics GP, LLC, a Delaware
         limited liability company and general partner of Riverwalk.

               "SOUTHLAKE TERMINAL" means a refined product terminal in
         Southlake, Texas that is currently undergoing construction conducted by
         UDS.

               "TRANSFERRED ASSETS" means the assets contributed or transferred
         to the Partnership Entities in the Formation Transactions.

               "UDS" means Ultramar Diamond Shamrock Corporation.

               "UDS ENTITIES" means UDS and any of its Affiliates, other than
         the Partnership Entities.

               "VOTING STOCK" means securities or membership interests of any
         class or series of either UDS, Shamrock GP or Riverwalk entitling the
         holders thereof to vote on a regular basis in the election of members
         of the board of directors, board of managers or other governing body of
         such entity.

               "WICHITA FALLS PIPELINE" means the crude oil pipeline from
         Wichita Falls, Texas to UDS' McKee Refinery with a current capacity of
         approximately 85,000 barrels a day, which is being expanded by UDS to a
         capacity of approximately 110,000 barrels per day, along with related
         crude oil storage facilities with a storage capacity of approximately
         360,000 barrels.

                                        4
<Page>

                                  ARTICLE II.
                             BUSINESS OPPORTUNITIES

         2.1 RESTRICTED BUSINESSES. Subject to the terms of the MLP Agreement,
for as long as (i) Shamrock GP (or any Affiliate of UDS) is the general partner
of Riverwalk and (ii) Riverwalk (or any Affiliate of UDS) is the general partner
of the MLP or the OLP, each of the UDS Entities are prohibited from engaging in,
whether by acquisition or otherwise, the business of transporting crude oil or
refined petroleum products (including petrochemicals) or operating crude oil
storage or refined petroleum products terminalling assets in the United States
(a "Restricted Business").

         2.2 PERMITTED EXCEPTIONS. Notwithstanding any provision of Section 2.1,
a UDS Entity may pursue an opportunity to purchase or invest in, and may
ultimately purchase, own and/or operate, a Restricted Business under any of the
following circumstances:

               (a) Any business retained by a UDS Entity at the Closing;

               (b) Any further development of the Diamond-Koch Joint Venture
                      petrochemicals business;

               (c) Any business with a fair market value (as determined by the
                      board of directors of UDS in good faith) of less than $10
                      million;

               (d) Any business acquired by a UDS Entity that constitutes less
                      than 50% of the fair market value (as determined by a
                      nationally recognized independent financial advisor) of a
                      larger acquisition by such UDS Entity; provided the MLP
                      has been offered and declined (with the concurrence of a
                      majority of the members of the Conflicts Committee) the
                      opportunity to purchase such business in accordance with
                      the procedures set forth in Section 2.3;

               (e) Each of the Wichita Falls Pipeline, the Southlake Terminal
                      and the Ringold Storage Facility should the MLP decline to
                      exercise its option to purchase them pursuant to the
                      Purchase Option described in more detail in Article IV
                      hereof; or

               (f) Any logistics assets newly constructed by a UDS Entity that
                      the MLP has not elected to purchase pursuant to
                      Section 4.3.

         2.3 PROCEDURES.

               (a) If a UDS Entity becomes aware of an opportunity to purchase a
Restricted Business, then, as soon as practicable, such UDS Entity shall notify
Shamrock GP of such opportunity and deliver to Shamrock GP all information
prepared by or on behalf of such UDS Entity relating to such potential purchase.
As soon as practicable but in any event within 30 days after receipt of such
notification and information, Shamrock GP, on behalf of the MLP, shall notify
the UDS Entity that either (i) Shamrock GP, on behalf of the MLP, has elected,
with the approval of a majority of the members of the Conflicts Committee, not
to cause the MLP to pursue the opportunity to acquire such Restricted Business,
or (ii) Shamrock GP, on behalf of the

                                        5
<Page>

MLP, has elected to cause the MLP to pursue the opportunity to acquire such
Restricted Business. If, at any time, Shamrock GP or its Affiliates abandons
such opportunity (as evidenced in writing by Shamrock GP or such Affiliates
following the request of the UDS Entity), the UDS Entity may pursue such
opportunity. Any Restricted Business which is permitted to be purchased by an
UDS Entity must be so purchased (i) within 12 months of the time the UDS Entity
becomes able to pursue such acquisition in accordance with the provisions of
this Section 2.3 and (ii) on terms not materially more favorable to the UDS
Entity than were offered to the MLP. If either of these conditions are not
satisfied, the opportunity must be reoffered to the MLP.

               (b) If a UDS Entity acquires a Restricted Business as part of a
larger transaction in accordance with the provisions of Section 2.2(d), then,
within 30 days after the consummation of such purchase, such UDS Entity shall
notify Shamrock GP of such purchase and such UDS Entity shall offer the MLP the
opportunity to purchase the Restricted Business constituting a portion of such
purchase and deliver to Shamrock GP all information prepared by or on behalf of
or in the possession of such UDS Entity relating to the Restricted Business. As
soon as practicable but in any event within 30 days after receipt of such
notification, Shamrock GP shall notify the UDS Entity that either (i) Shamrock
GP, on behalf of the MLP, has elected, with the approval of a majority of the
members of the Conflicts Committee, not to cause the MLP to purchase such
Restricted Business, in which event the UDS Entity shall be free to continue to
engage in such Restricted Business and shall be free to improve and expand such
Restricted Business if necessary to maintain existing market share, or (ii)
Shamrock GP, on behalf of the MLP, has elected to cause the MLP to purchase such
Restricted Business, in which event the following procedures shall be followed:

                    (i)   The UDS Entity shall submit a good faith offer to
          Shamrock GP to sell the Restricted Business (the "Offer") to any
          member of the Partnership Group designated by Shamrock GP on the terms
          and for the consideration stated in the Offer.

                    (ii)  The UDS Entity and Shamrock GP shall negotiate in good
          faith, for 120 days after receipt of such Offer by Shamrock GP, the
          terms on which the Restricted Business will be sold to the MLP. The
          UDS Entity shall provide all information concerning the business,
          operations and finances of such Restricted Business as may be
          reasonably requested by Shamrock GP.

                         (A) If the UDS Entity and Shamrock GP agree on such
               terms within 120 days after receipt by Shamrock GP of the Offer,
               the MLP shall purchase the Restricted Business on such terms as
               soon as commercially practicable after such agreement has been
               reached.

                         (B) If the UDS Entity and Shamrock GP are unable to
               agree on the terms of a sale during such 120-day period, the UDS
               Entity shall attempt to sell the Restricted Business to a Person
               that is not an Affiliate of the UDS Entity (a "NonAffiliate
               Purchaser") within nine months of the termination of such 120-day
               period. Any such sale to a NonAffiliate Purchaser must be for a
               purchase price, as determined by the board of directors of UDS,
               not less than 95% of the purchase price last offered by the MLP.

                                        6
<Page>

                         (C) During such 120-day period the UDS Entity shall be
               free to make capital expenditures to maintain the Restricted
               Business and to improve or expand the Restricted Business if
               necessary to maintain the Restricted Business' existing market
               share.

                    (iii) If, after the expiration of the nine-month period
          referred to in clause (ii)(B) above, the UDS Entity has not sold the
          Restricted Business to a NonAffiliate Purchaser, it shall submit
          another Offer (the "Second Offer") to Shamrock GP within seven days
          after the expiration of such nine-month period. The UDS Entity shall
          provide all information concerning the business, operations and
          finances of such Restricted Business as may be reasonably requested by
          Shamrock GP.

                         (A) If Shamrock GP, with the concurrence of a majority
               of the members of the Conflicts Committee, elects not to cause
               the MLP to pursue the Second Offer, the UDS Entity shall be free
               to continue to engage in such Restricted Business.

                         (B) If Shamrock GP shall elect to cause the MLP to
               purchase such Restricted Business, then Shamrock GP and the UDS
               Entity shall negotiate the terms of such purchase for 60 days. If
               the UDS Entity and Shamrock GP agree on such terms within 60 days
               after receipt by Shamrock GP of the Second Offer, the MLP shall
               purchase the Restricted Business on such terms as soon as
               commercially practicable after such agreement has been reached.

                         (C) If during such 60-day period, no agreement has been
               reached between the UDS Entity and Shamrock GP or a member of the
               Partnership Group, the UDS Entity and Shamrock GP will engage an
               independent investment banking firm with a national reputation to
               determine the value of the Restricted Business. Such investment
               banking firm will determine the value of the Restricted Business
               within 30 days and furnish the UDS Entity and Shamrock GP its
               opinion of such value. The UDS Entity and Shamrock GP shall share
               equally the fees and expenses of such investment banking firm.
               Upon receipt of such opinion, Shamrock GP will have the option,
               subject to the approval of a majority of the members of the
               Conflicts Committee, to (A) cause the MLP to purchase the
               Restricted Business for an amount equal to the value determined
               by such investment banking firm or (B) decline to purchase such
               Restricted Business, in which event the UDS Entity will be free
               to continue to engage in such Restricted Business.

         2.4 CHANGE OF CONTROL. If a Change of Control of UDS or each of
Shamrock GP or Riverwalk occurs, the provisions of this Article II shall not
apply to the existing logistics activities of any acquiring entity. A Change of
Control of UDS or each of Shamrock GP or Riverwalk shall be deemed to have
occurred upon the occurrence of one or more of the following events: (i) any
sale, lease, exchange or other transfer (in one transaction or a series of
related transactions) of all or substantially all of the assets of the UDS or
Shamrock GP to any Person or its Affiliates, unless immediately following such
sale, lease, exchange or other transfer such assets are owned, directly or
indirectly, by the UDS Entities or Shamrock GP; (ii) the

                                        7
<Page>

consolidation or merger of UDS or Shamrock GP with or into another Person
pursuant to a transaction in which the outstanding Voting Stock of UDS or
Shamrock GP is changed into or exchanged for cash, securities or other property,
other than any such transaction where (a) the outstanding Voting Stock of UDS or
Shamrock GP is changed into or exchanged for Voting Stock of the surviving
corporation or its parent and (b) the holders of the Voting Stock of UDS or
Shamrock GP immediately prior to such transaction own, directly or indirectly,
not less than a majority of the Voting Stock of the surviving corporation or its
parent immediately after such transaction; or (iii) a "person" or "group"
(within the meaning of Sections 13(d) or 14(d)(2) of the Exchange Act) being or
becoming the "beneficial owner" (as defined in Rules 13d-3 and 13d-5 under the
Exchange Act) of more than 50% of all Voting Stock of UDS or Shamrock GP then
outstanding, other than in a merger or consolidation which would not constitute
a Change of Control under clause (ii) above.

         2.5 SCOPE OF RESTRICTED BUSINESS PROHIBITION. Except as provided in
this Article II and the Partnership Agreement, each UDS Entity shall be free to
engage in any business activity whatsoever, including those that may be in
direct competition with any Partnership Entity.

         2.6 ENFORCEMENT. The UDS Entities agree and acknowledge that the
Partnership Group does not have an adequate remedy at law for the breach by the
UDS Entities of the covenants and agreements set forth in this Article II, and
that any breach by the UDS Entities of the covenants and agreements set forth in
Article II would result in irreparable injury to the Partnership Group. The UDS
Entities further agree and acknowledge that any member of the Partnership Group
may, in addition to the other remedies which may be available to the Partnership
Group hereunder or under applicable law, file a suit in equity to enjoin the UDS
Entities from such breach, and consent to the issuance of injunctive relief
hereunder.

                                  ARTICLE III.
                                INDEMNIFICATION

         3.1 INDEMNIFICATION OF PARTNERSHIP ENTITIES BY UDS.  In addition to
its indemnification obligations under certain (i) Indemnity Agreements entered
into in connection with the mergers of certain subsidiaries of UDS with and into
the OLP effective as of July 1, 2000, and (ii) Conveyance, Assignment and Bill
of Sale Agreements dated effective as of July 1, 2000, by and among the OLP and
certain subsidiaries of UDS, UDS, on behalf of each of the respective UDS
Entities, shall indemnify, defend and hold harmless the Partnership Entities
from and against (A) any and all Losses that are caused by, arise out of or are
attributable to Environmental Liabilities and Costs related to the Transferred
Assets that arose or relate to conditions existing prior to Closing and which
are discovered by the MLP within 10 years of the Closing (excluding
Environmental Liabilities and Costs to the extent such Environmental Liabilities
and Costs result from a change in law after closing) and (B) all federal, state
and local income tax liabilities attributable to the operation of the
Transferred Assets prior to the Closing Date, including any such income tax
liabilities of UDS and its Affiliates that may result from the consummation of
the Formation Transactions.

         3.2 INDEMNIFICATION PROCEDURES.

                                        8
<Page>

         (a) As used in this Section 3.2, the term "Indemnifying Party" refers
to UDS in the case of any indemnification obligation arising under Section 3.1,
and the term "Indemnified Party" refers to the Partnership Entities, as
applicable, in the case of any indemnification obligation arising under
Section 3.1.

         (b) If any action, suit or proceeding shall be brought against an
Indemnified Party, or if the Indemnified Party should otherwise become aware of
facts giving rise to a claim for indemnification pursuant to Section 3.1, the
Indemnified Party shall promptly notify the Indemnifying Party in writing
specifying the nature of and specific basis for such claim.

         (c) The Indemnifying Party shall have the right to control all aspects
of the defense of (and any counterclaims with respect to) any claims brought
against the Indemnified Party that are covered by the indemnification set forth
in Section 3.1, including, without limitation, the selection of counsel,
determination of whether to appeal any decision of any court and the settling of
any such matter or any issues relating thereto; PROVIDED, HOWEVER, that no such
settlement shall be entered into without the consent of the Indemnified Party
unless it includes a full release of the Indemnified Party from such matter or
issues, as the case may be.

         (d) The Indemnified Party agrees, at its own cost and expense, to
cooperate fully with the Indemnifying Party with respect to all aspects of the
defense of any claims covered by the indemnification set forth in Section 3.1,
including, without limitation, the prompt furnishing to the Indemnifying Party
of any correspondence or other notice relating thereto that the Indemnified
Party may receive, permitting the name(s) of the Indemnified Party to be
utilized in connection with such defense, the making available to the
Indemnifying Party of any files, records or other information of the Indemnified
Party that the Indemnifying Party considers relevant to such defense and the
making available to the Indemnifying Party of any employees of the Indemnified
Party; PROVIDED, HOWEVER, that in connection therewith the Indemnifying Party
agrees to use reasonable efforts to minimize the impact thereof on the
operations of such Indemnified Party. In no event shall the obligation of the
Indemnified Party to cooperate with the Indemnifying Party as set forth in the
immediately preceding sentence be construed as imposing upon the Indemnified
Party an obligation to hire and pay for counsel in connection with the defense
of any claims covered by the indemnification set forth in this Article III;
PROVIDED, HOWEVER, that an Indemnified Party may, at its own option, cost and
expense, hire and pay for counsel in connection with any such defense. The
Indemnifying Party agrees to keep any such counsel hired by the Indemnified
Party reasonably informed as to the status of any such defense, but the
Indemnifying Party shall have the right to retain sole control over such
defense.

         (e) In determining the amount of any Loss for which any Indemnified
Party is entitled to indemnification under this Article III, the gross amount
thereof will be reduced by any insurance proceeds realized or to be realized by
such Indemnified Party, and such correlative insurance benefit shall be net of
any insurance premium that becomes due as a result of such claim.

                                  ARTICLE IV.

         4.1. PURCHASE OPTION FOR ASSETS CURRENTLY UNDER CONSTRUCTION. UDS, on
behalf of the UDS Entities, hereby grants the MLP, on behalf of the OLP, the
unconditional right

                                        9
<Page>

and option to purchase and acquire from the applicable UDS Entity all of the
respective UDS Entity's right, title and interest in, to and under any or all of
(i) the Wichita Falls Pipeline, (ii) the Ringgold Storage Facility and (iii) the
Southlake Terminal, at any time, from time to time and no later than one year
from the date of notice from UDS of completion of construction of such asset,
such notice to be given as soon as practicable, for a purchase price that is
equal to the respective Option Purchase Amount, by delivery to UDS, on behalf of
the respective UDS Entity, of a written notice of the exercise of such purchase
option. The MLP may exercise this purchase option with respect to all, part or
none of the enumerated assets.

         4.2. CLOSING OF PURCHASE OPTION. Closing of purchase and sale pursuant
to this Article IV shall be conducted at such location mutually agreed upon by
UDS and the MLP. At closing, UDS will sell and assign to the OLP by deed, bill
of sale, assignment of contract rights or other appropriate documentation all of
UDS's (or the applicable UDS Entity's) right, title and interest in, to and
under the Wichita Falls Pipeline, the Ringgold Storage Facility or the Southlake
Terminal, as applicable, and the OLP shall make payment of the applicable Option
Purchase Amount to UDS or the applicable UDS Entity in cash or by electronic
wire transfer of immediately available funds to an account designated by UDS in
writing.

         4.3. PURCHASE OPTION FOR LOGISTICS ASSETS CONSTRUCTED BY UDS IN THE
FUTURE. If a UDS Entity constructs any new logistics assets then, as soon as
practicable, such UDS Entity shall notify Shamrock GP of the completion of such
construction and such UDS Entity shall offer the MLP the opportunity to elect to
purchase, or have a subsidiary elect to purchase, the newly constructed assets
by written notice delivered to the UDS Entity no later than one year from the
date of notice. If Shamrock GP, with the concurrence of a majority of the
members of the Conflicts Committee, elects to purchase such assets, then
Shamrock GP and the UDS Entity shall negotiate the terms of such purchase for 60
days. If the UDS Entity and Shamrock GP agree on such terms within 60 days after
receipt by the UDS Entity of the notice of election to purchase, the MLP shall
purchase the newly constructed assets on such terms as soon as commercially
practicable after such agreement has been reached.

         If during such 60-day period, no agreement has been reached between the
UDS Entity and Shamrock GP, the UDS Entity and Shamrock GP will engage an
independent investment banking firm with a national reputation to determine the
value of the newly constructed assets. Such investment banking firm will
determine the value of the newly constructed assets within 30 days and furnish
the UDS Entity and Shamrock GP its opinion of such value. The UDS Entity and
Shamrock GP shall share equally the fees and expenses of such investment banking
firm. Upon receipt of such opinion, Shamrock GP will have the option, subject to
the approval of a majority of the members of the Conflicts Committee, to (A)
purchase the newly constructed assets for an amount equal to the value
determined by such investment banking firm or (B) decline to purchase such newly
constructed assets, in which event, the UDS Entity will be free to continue to
own and operate such newly constructed assets.

                                   ARTICLE V
                                 MISCELLANEOUS

                                       10
<Page>

         5.1 CHOICE OF LAW; SUBMISSION TO JURISDICTION. This Agreement shall be
subject to and governed by the laws of the State of Delaware, excluding any
conflicts-of-law rule or principle that might refer the construction or
interpretation of this Agreement to the laws of another state.

         5.2 NOTICE. All notices or requests or consents provided for or
permitted to be given pursuant to this Agreement must be in writing and must be
given by depositing same in the United States mail, addressed to the Person to
be notified, postpaid, and registered or certified with return receipt requested
or by delivering such notice in person or by telecopier or telegram to such
party. Notice given by personal delivery or mail shall be effective upon actual
receipt. Notice given by telegram or telecopier shall be effective upon actual
receipt if received during the recipient's normal business hours, or at the
beginning of the recipient's next business day after receipt if not received
during the recipient's normal business hours. All notices to be sent to a party
pursuant to this Agreement shall be sent to or made at the address set forth
below such party's signature to this Agreement, or at such other address as such
party may stipulate to the other parties in the manner provided in this
Section 5.2.

         5.3 ENTIRE AGREEMENT; SUPERSEDURE. This Agreement constitutes the
entire agreement of the parties relating to the matters contained herein,
superseding all prior contracts or agreements, whether oral or written, relating
to the matters contained herein.

         5.4 EFFECT OF WAIVER OR CONSENT. No waiver or consent, express or
implied, by any party to or of any breach or default by any Person in the
performance by such Person of its obligations hereunder shall be deemed or
construed to be a consent or waiver to or of any other breach or default in the
performance by such Person of the same or any other obligations of such Person
hereunder. Failure on the part of a party to complain of any act of any Person
or to declare any Person in default, irrespective of how long such failure
continues, shall not constitute a waiver by such party of its rights hereunder
until the applicable statute of limitations period has run.

         5.5 AMENDMENT OR MODIFICATION. This Agreement may be amended or
modified from time to time only by the written agreement of all the parties
hereto; provided, however, that the MLP may not, without the prior approval of a
majority of the members of the Conflicts Committee, agree to any amendment or
modification of this Agreement that, in the reasonable discretion of Shamrock
GP, will adversely affect the holders of Common Units. Each such instrument
shall be reduced to writing and shall be designated on its face an "Amendment"
or an "Addendum" to this Agreement.

         5.6 ASSIGNMENT. No party shall have the right to assign its rights or
obligations under this Agreement without the consent of the other parties
hereto.

         5.7 COUNTERPARTS. This Agreement may be executed in any number of
counterparts with the same effect as if all signatory parties had signed the
same document. All counterparts shall be construed together and shall constitute
one and the same instrument.

         5.8 SEVERABILITY. If any provision of this Agreement or the application
thereof to any Person or circumstance shall be held invalid or unenforceable to
any extent, the remainder of this

                                       11
<Page>

Agreement and the application of such provision to other Persons or
circumstances shall not be affected thereby and shall be enforced to the
greatest extent permitted by law.

         5.9 GENDER, PARTS, ARTICLES AND SECTIONS. Whenever the context
requires, the gender of all words used in this Agreement shall include the
masculine, feminine and neuter, and the number of all words shall include the
singular and plural. All references to Article numbers and Section numbers refer
to Parts, Articles and Sections of this Agreement, unless the context otherwise
requires.

         5.10 FURTHER ASSURANCES. In connection with this Agreement and all
transactions contemplated by this Agreement, each signatory party hereto agrees
to execute and deliver such additional documents and instruments and to perform
such additional acts as may be necessary or appropriate to effectuate, carry out
and perform all of the terms, provisions and conditions of this Agreement and
all such transactions.

         5.11 WITHHOLDING OR GRANTING OF CONSENT. Each party may, with respect
to any consent or approval that it is entitled to grant pursuant to this
Agreement, grant or withhold such consent or approval in its sole and
uncontrolled discretion, with or without cause, and subject to such conditions
as it shall deem appropriate.

         5.12 LAWS AND REGULATIONS. Notwithstanding any provision of this
Agreement to the contrary, no party hereto shall be required to take any act, or
fail to take any act, under this Agreement if the effect thereof would be to
cause such party to be in violation of any applicable law, statute, rule or
regulation.

         5.13 NEGOTIATION OF RIGHTS OF LIMITED PARTNERS, ASSIGNEES, AND THIRD
PARTIES. The provisions of this Agreement are enforceable solely by the parties
to this Agreement, and no Limited Partner, Assignee or other Person shall have
the right, separate and apart from the MLP, to enforce any provision of this
Agreement or to compel any party to this Agreement to comply with the terms of
this Agreement.

                                       12
<Page>

         IN WITNESS WHEREOF, the parties have executed this Agreement on, and
effective as of, the Closing Date.

                                  ULTRAMAR DIAMOND SHAMROCK CORPORATION

                                  By:/s/ Robert S. Shapard
                                     -------------------------------------------
                                  Name:  Robert S. Shapard
                                         ---------------------------------------
                                  Title: Executive Vice President and Chief
                                         ---------------------------------------
                                         Financial Officer
                                         ---------------------------------------

                                  Address for Notice: 6000 North Loop 1604 West
                                                      --------------------------
                                                      San Antonio, TX  68249
                                                      --------------------------

                                  Telecopy Number:
                                                      --------------------------

                                  SHAMROCK LOGISTICS GP, LLC

                                  By:/s/ Curtis V. Anastasio
                                     -------------------------------------------
                                  Name:  Curtis V. Anastasio
                                         ---------------------------------------
                                  Title: President and Chief Executive Officer
                                         ---------------------------------------
                                  Address for Notice: 6000 North Loop 1604 West
                                                      --------------------------
                                                      San Antonio, TX  78249
                                                      --------------------------

                                  Telecopy Number:
                                                      --------------------------

<Page>

                                  RIVERWALK LOGISTICS, L.P.

                                  By:     Shamrock Logistics GP, LLC
                                          its general partner

                                  By:/s/ Curtis V. Anastasio
                                     -------------------------------------------
                                  Name:  Curtis V. Anastasio
                                         ---------------------------------------
                                  Title: President and Chief Executive Officer
                                         ---------------------------------------

                                  Address for Notice: 6000 North Loop 1604 West
                                                      --------------------------
                                                      San Antonio, TX  78249
                                                      --------------------------

                                  Telecopy Number:
                                                      --------------------------

                                  SHAMROCK LOGISTICS, L.P.

                                  By:     Riverwalk Logistics, L.P.
                                          its general partner

                                  By:     Shamrock Logistics GP, LLC
                                          Its general partner

                                  By:/s/ Curtis V. Anastasio
                                     -------------------------------------------
                                  Name:  Curtis V. Anastasio
                                         ---------------------------------------
                                  Title: President and Chief Executive Officer
                                         ---------------------------------------

                                  Address for Notice: 6000 North Loop 1604 West
                                                      --------------------------
                                                      San Antonio, TX  78249
                                                      --------------------------

                                  Telecopy Number:
                                                      --------------------------

<Page>

                                  SHAMROCK LOGISTICS OPERATIONS, L.P.

                                  By:     Riverwalk Logistics, L.P.
                                          its general partner

                                  By:     Shamrock Logistics GP, LLC
                                          Its general partner

                                  By:/s/ Curtis V. Anastasio
                                     -------------------------------------------
                                  Name:  Curtis V. Anastasio
                                         ---------------------------------------
                                  Title: President and Chief Executive Officer
                                         ---------------------------------------

                                  Address for Notice: 6000 North Loop 1604 West
                                                      --------------------------
                                                      San Antonio, TX  78249
                                                      --------------------------

                                  Telecopy Number:
                                                      --------------------------<Page>

                               SERVICES AGREEMENT

               THIS SERVICES AGREEMENT is entered into on, and effective as of,
July 1, 2000 (the "Effective Date") by and among DIAMOND SHAMROCK REFINING AND
MARKETING COMPANY, a Delaware corporation ("DSRMC"), SHAMROCK LOGISTICS, L.P.
(the "Partnership"), SHAMROCK LOGISTICS OPERATIONS, L.P. (the "Operating
Partnership"), and their general partner RIVERWALK LOGISTICS, L.P. (the "General
Partner"), all Delaware limited partnerships (collectively, the "Partnership
Entities"), and Riverwalk Logistics, L.P.'s general partner, SHAMROCK LOGISTICS
GP, LLC ("Shamrock GP"). The Partnership Entities and the General Partner will
sometimes be referred to herein as the "Entities".

                                R E C I T A L S:

               WHEREAS, Shamrock GP, as the general partner of the General
Partner, manages all activities of the Partnership Entities;

               WHEREAS, DSRMC will provide, and will cause certain of DSRMC's
Affiliates (including, but not limited to, the Affiliates listed on Exhibit A
hereto) to provide, on behalf of Shamrock GP, certain services to the Entities,
for which they will be compensated as provided herein; and

               WHEREAS, DSRMC and the Entities desire by their execution of this
Agreement to evidence their understanding concerning the provision of those
services by DSRMC to the Entities;

               NOW, THEREFORE, in consideration of the premises and the
covenants, conditions, and agreements contained herein, and for other good and
valuable consideration, the receipt and sufficiency of which are hereby
acknowledged, the parties hereto hereby agree as follows:

               1.     SERVICES.

               (i)    CORPORATE, GENERAL, AND ADMINISTRATIVE SERVICES. During
the term of this Agreement, in consideration for the fee set forth in Section
4(i) herein, DSRMC agrees to provide, or cause certain of its Affiliates
(including, but not limited to, those listed on Exhibit A hereto) to provide to
the Entities the services set forth on EXHIBIT B hereto (the "Corporate,
General, and Administrative Services").

               (ii)   OTHER SERVICES. During the term of this Agreement, in
consideration for reimbursement as set forth in Section 4(ii) herein, DSRMC
agrees to provide, or cause certain of its Affiliates (including, but not
limited to, those listed on Exhibit A hereto) to provide to the Entities the
services and personnel necessary to operate and maintain the Entities and their
assets, relating to the items set forth on EXHIBIT C hereto (the "Other
Services" and, together with the Corporate, General, and Administrative
Services, the "Services").

<Page>

               (iii)  USE OF THIRD-PARTY SERVICE PROVIDERS. DSRMC may cause one
or more third party contractors to provide any of the Other Services (with any
such Other Services so provided by a third party contractor being referred to
herein as an "Outsourced Service"); PROVIDED, HOWEVER, that (a) any Outsourced
Service provided solely for the benefit of the Entities shall require approval
by the General Partner, and (b) except as expressly provided in this Agreement,
any Outsourced Services shall be subject to the provisions of this Agreement the
same way an Other Service that is not an Outsourced Service is subject to the
provisions of this Agreement. If, from time to time, DSRMC determines to publish
a request for proposal for a third party to provide as Outsourced Services any
one or more of the Other Services then being provided under this Agreement,
DSRMC shall give the Entities at least ten days prior written notice of such
decision and shall promptly advise the Entities of the terms of any winning bid.
The Entities shall hold confidential the terms of any proposal disclosed to them
pursuant to the foregoing sentence. The Entities shall advise DSRMC in writing
within seven business days after receipt of notice of the terms whether or not
the Entities desire to participate in the Outsourced Services at the level of
service set out in the winning bid (the "Agreed Level of Service") and, in the
case of an Outsourced Service provided solely for the benefit of the Entities
(a "Direct Outsourced Service"), that the General Partner, on behalf of the
Entities, has approved the contractor and the terms and conditions of such
Outsourced Service. In the case of a Direct Outsourced Service, the General
Partner has the option to contract directly with the provider of such Direct
Outsourced Service. In the event the Entities decide to terminate the Other
Service contemplated to become an Outsourced Service, such Other Service shall
be terminated effective as of the effective date of the new contract between
DSRMC (or any of its Affiliates, as applicable) and the third party providing
the Other Service. If the Entities desire to continue to be provided with such
Other Service, they shall be obligated to reimburse DSRMC (or any of its
Affiliates, as applicable) for their proportionate share of the costs incurred
by DSRMC (or any of its Affiliates, as applicable) under the agreement between
DSRMC (or any of its Affiliates, as applicable) and the third party provider of
the Outsourced Service (up to the Agreed Level of Service). No agreement entered
into by DSRMC (or any of its Affiliates, as applicable) after the Effective Date
shall give to any third party a preferential right to provide the Entities with
services following the expiration of this Agreement.

               2.     CANCELLATION OR REDUCTION OF SERVICES.

               Except as provided below in this Section 2, the Entities may
terminate or reduce the level of any Other Service on 30 days' prior written
notice to DSRMC; provided that if the provisions of any third party agreement
for an Outsourced Service require more than 30 days' prior written notice for
the termination of such agreement, the Entities shall be required to provide the
same notice as required in such agreement. Should the Entities terminate any
Other Service being provided hereunder, DSRMC shall have no liability to the
Entities for the Entities' failure or inability to replace such terminated Other
Services except that no Direct Charges (as defined in Section 4(ii)) shall be
incurred (or the amount of the Direct Charges in respect of the Services shall
be reduced in the case of a reduction in the level of Service) pursuant to
Section 4(ii). Further, if the Entities terminate any Other Service, the
Entities agree that DSRMC shall not be required to provide the terminated Other
Service to the Entities in the future.

                                       -2-
<Page>

               3.     NATURE/QUALITY OF SERVICES. The nature and quality of the
Services shall be substantially identical to those provided to other
subsidiaries and Affiliates of DSRMC. Outsourced Services will be of the nature
and quality provided in the agreement with the third party provider.

               4.     PAYMENT.

               (i) CORPORATE, GENERAL, AND ADMINISTRATIVE SERVICES. In
consideration of the Corporate, General, and Administrative Services, the
General Partner shall pay DSRMC $5,200,000 annually (the "Administrative Fee"),
which amount shall be paid in twelve equal monthly installments in arrears, the
first such payment being made with respect to the month ended July 31, 2000;
provided, however, that the Administrative Fee may be increased at the request
of DSRMC and subject to the approval and consent of the Conflicts Committee of
Shamrock GP, as follows:

               (a) for each year during the term of this agreement, beginning
with the year that starts on the first anniversary of the Effective Date, an
increase not to exceed 1.5% per year plus an additional percentage not to exceed
the percentage increase in the Consumer Price Index for Urban Wage Earners and
Clerical published by the United States Department of Labor Bureau of Labor
Statistics for the preceding calendar year; and

               (b) in connection with expansions of the Partnership's operations
through acquisition or construction of new assets that require additional
Corporate, General, and Administrative Services.

               The Administrative Fee shall be decreased (a) on a pro rata basis
if one or more of the Corporate, General, and Administrative Services are for
any reason no longer provided under this Agreement, whether on a temporary or
permanent basis, for such time as such Services are not provided or (b) if the
level of any Corporate, General and Administrative Service is reduced for any
reason.

               (ii) OTHER SERVICES. In consideration of the Other Services, the
General Partner Partnership shall reimburse DSRMC for (i) all out-of-pocket
expenses incurred by DSRMC exclusively to provide the Other Services to the
Entities, (ii) the actual cost of any item purchased by DSRMC exclusively for
the use of the Entities, and (iii) all expenses actually incurred by DSRMC for
Outsourced Services and allocable to the Entities consistent with Section 1(iii)
of this Agreement (the amounts referred to in (i), (ii), and (iii) being
collectively referred to as the "Direct Charges"); provided, however, that in no
event shall Direct Charges include expenses or costs incurred for the provision
of Corporate, General, and Administrative Services, and provided further that
the General Partner shall not be invoiced for or required to pay Direct Charges
in connection with an Other Service that is not being provided under this
Agreement for any reason, whether on a temporary or permanent basis, for such
time as such Other Services are not provided.

        (iii) TAXES. If the compensation for the Services does not include
sales, use, excise, value added or similar taxes, if any such taxes are imposed
on the Services, and if under

                                       -3-
<Page>

applicable laws any such taxes are to be collected and remitted to the
appropriate authorities by DSRMC, the General Partner shall pay or reimburse
DSRMC for any such taxes.

               5.     INVOICING FOR DIRECT CHARGES.

               (i)    DSRMC shall invoice, or cause its Affiliates to invoice,
the General Partner on the last business day of each month for all Direct
Charges with respect to the preceding month and any adjustments that may be
necessary to correct prior invoices. All invoices shall reflect in reasonable
detail a description of the Other Services performed during the preceding month,
and shall be due and payable within 30 days of the date of the invoice. In the
event of default in payment by the General Partner, upon 30 days' written notice
to the General Partner, delivered as provided below, DSRMC may terminate this
Agreement as to those Other Services which relate to the unpaid portion of the
invoice if it has not received payment within such 30 days. In the event of a
dispute as to the propriety of invoiced amounts (a "Dispute"), the General
Partner shall pay all undisputed amounts on each invoice, but shall be entitled
to withhold payment of any amount in dispute and shall notify DSRMC within 10
business days from receipt of the disputed invoice of the disputed amount and
the reasons each such charge is disputed. DSRMC shall provide the General
Partner with records relating to the disputed amount so as to enable the parties
to resolve the Dispute. If the Dispute cannot be resolved by mutual agreement of
the Chief Financial Officer of DSRMC and the Chief Financial Officer of Shamrock
GP within 15 days of DSRMC's receiving such notification, any party may initiate
arbitration proceedings in the manner provided for by Section 5(iii). So long as
the parties are attempting in good faith to resolve the Dispute, DSRMC shall not
be entitled to terminate the Other Services related to and by reason of the
disputed charge.

               (ii)   Any statement or payment not disputed in writing by either
party within one year of the date of such statement or payment shall be
considered final and no longer subject to adjustment. The General Partner shall
not be obligated to pay for any Direct Charges for which statements for payment
are submitted more than one year after the termination of this Agreement.

               (iii)  Resolution of Disputes shall be exclusively governed by
and settled in accordance with the provisions of this Section 5(iii); PROVIDED
HOWEVER, that nothing contained herein shall preclude any party from seeking or
obtaining (i) injunctive relief or (ii) equitable or other judicial relief, in
each case to preserve the status quo, pending resolution of Disputes hereunder.
DSRMC or any of the Entities may commence proceedings hereunder by delivering
written notice to the other party expressly requesting arbitration hereunder
after a Dispute has remained unresolved for the period of time specified under
Section 5(i) hereof. The parties hereby agree to submit all Disputes to
arbitration hereunder, which arbitration shall be final, conclusive, and binding
upon the parties, their successors and assigns. The arbitration shall be
conducted in San Antonio, Texas by a sole arbitrator selected by mutual
agreement of the parties not later than ten (10) days after delivery of such
notice, or, failing such agreement, appointed pursuant to the commercial
arbitration rules of the American Arbitration Association, as amended from time
to time ("AAA Rules"). The arbitrators shall be generally knowledgeable about
the pipeline and terminal operating industry and the nature of the issues to be
arbitrated and shall be qualified by education, experience, and training to
render a decision upon the issues

                                       -4-
<Page>

to be arbitrated. If the arbitrator selected becomes unable to serve, his or her
successor shall be similarly selected or appointed. The arbitration shall be
conducted in accordance with the AAA Rules to the extent such rules do not
conflict with the terms of this agreement. Notwithstanding the foregoing: (i)
each party shall have the right to audit the books and records of any other
party that are reasonably related to a Dispute; (ii) each party shall provide to
the other parties involved in a Dispute, reasonably in advance of any hearing,
copies of all documents which such party intends to present at such hearing; and
(iii) each party shall be allowed to conduct reasonable discovery through
written requests for information, document requests, requests for stipulation of
fact, and depositions, the nature and extent of which discovery shall be
determined by the arbitrator, taking into account the needs of the parties and
the desirability of making discovery expeditious and cost effective. All
hearings shall be conducted on an expedited schedule, and all proceedings shall
be confidential. Any party may, at its expense, make a stenographic record
thereof. The arbitrator shall complete all hearings not later than sixty days
after his or her selection or appointment and shall make a final award not later
than thirty days thereafter. All claims presented for arbitration shall be
particularly identified, and the parties to the arbitration shall each prepare a
written statement of their position and their proposed course of action. These
written statements of positions and proposed courses of action shall be
submitted to the arbitrator. In making his or her decision, the arbitrator must
accept in its entirety the position of one party or the other and make an
arbitration award based on that party's proposed course of action. The
arbitrator shall not be empowered in reaching his or her decision to equitably
adjust the scope of the written statements. All costs and expenses of
arbitration, including the fees and expenses of the arbitrator or of any
experts, shall be borne equally between the prevailing and non-prevailing party,
except that each party shall pay all of its respective attorney's fees,
consultant's fees, and other costs of participating in the Arbitration
proceeding. Notwithstanding the foregoing, in no event may the arbitrator award
multiple, punitive, or exemplary damages. Any arbitration award shall be binding
and enforceable against each party involved in the Dispute and judgment may be
entered thereon in any court of competent jurisdiction. Payment of any such
award shall be made within five (5) business days of the arbitrator's decision.

               6.     INPUT FROM ENTITIES. Any input necessary for DSRMC or any
third party provider to perform any Services shall be submitted by the Entities
in a manner consistent with the practices utilized during the one year period
prior to the Effective Date, which manner shall not be altered except by mutual
written agreement of the parties. Should the Entities' failure to supply such
input render performance of any Services by or on behalf of DSRMC unreasonably
difficult, DSRMC, upon reasonable notice, may provide a lesser quality of
Services or refuse to perform such Services.

               7.     ENTITIES ARE SOLE BENEFICIARIES. The Entities acknowledge
that the Services shall be provided only with respect to their business as
currently operated or as mutually agreed by the parties hereto. The Entities
shall not request performance of any Services for the benefit of any entity
other than themselves. The Entities represent and agree that they will use the
Services only in accordance with all applicable federal, state, and local laws
and regulations and communications and common carrier tariffs, and in accordance
with the reasonable conditions, rules, regulations, and specifications which may
be set forth in any manuals, materials, documents, or instructions furnished
from time to time by DSRMC to the

                                       -5-
<Page>

Entities. DSRMC reserves the right to take all actions, including termination of
any Services, that DSRMC reasonably believes to be necessary to assure
compliance with applicable laws, regulations, and tariffs. DSRMC will notify the
Entities of the reasons for any such termination of Services.

               8.     LIMITED WARRANTY, LIMITATION OF LIABILITY.

               DSRMC represents that it will provide or cause the Services to be
provided to the Entities with reasonable care and in accordance with all
applicable laws, rules, and regulations, including without limitation those of
the Federal Energy Regulatory Commission. EXCEPT AS SET FORTH IN THE IMMEDIATELY
PRECEDING SENTENCE AND IN SECTION 3, ALL PRODUCTS OBTAINED FOR THE ENTITIES ARE
AS IS, WHERE IS, WITH ALL FAULTS. DSRMC MAKES NO (AND HEREBY DISCLAIMS AND
NEGATES ANY AND ALL) REPRESENTATIONS AND WARRANTIES, EXPRESS OR IMPLIED,
INCLUDING THE WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE
WITH RESPECT TO THE SERVICES RENDERED OR PRODUCTS OBTAINED FOR THE ENTITIES.
FURTHERMORE, THE ENTITIES MAY NOT RELY UPON ANY REPRESENTATION OR WARRANTY,
EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A
PARTICULAR PURPOSE MADE TO DSRMC BY ANY PARTY (INCLUDING, AN AFFILIATE OF DSRMC)
PERFORMING SERVICES ON BEHALF ON DSRMC HEREUNDER, UNLESS SUCH PARTY MAKES AN
EXPRESS WARRANTY TO SHAMROCK GP OR THE PARTNERSHIP ENTITIES. HOWEVER, IN THE
CASE OF OUTSOURCED SERVICES PROVIDED SOLELY FOR THE ENTITIES, IF THE THIRD PARTY
PROVIDER OF SUCH SERVICES MAKES AN EXPRESS WARRANTY TO ANY OF THE ENTITIES, THE
ENTITIES ARE ENTITLED TO CAUSE DSRMC TO RELY ON AND TO ENFORCE SUCH WARRANTY.

               IT IS EXPRESSLY UNDERSTOOD BY THE ENTITIES THAT DSRMC AND ITS
AFFILIATES SHALL HAVE NO LIABILITY FOR THE FAILURE OF THIRD PARTY PROVIDERS TO
PERFORM ANY SERVICES HEREUNDER AND FURTHER THAT DSRMC AND ITS AFFILIATES SHALL
HAVE NO LIABILITY WHATSOEVER FOR THE SERVICES PROVIDED BY ANY SUCH THIRD PARTY
UNLESS IN EITHER EVENT SUCH SERVICES ARE PROVIDED IN A MANNER WHICH WOULD
EVIDENCE GROSS NEGLIGENCE OR INTENTIONAL MISCONDUCT ON THE PART OF DSRMC OR ITS
AFFILIATES BUT DSRMC SHALL, ON BEHALF OF THE PARTNERSHIP, PURSUE ALL RIGHTS AND
REMEDIES UNDER ANY SUCH THIRD PARTY CONTRACT. THE ENTITIES AGREE THAT THE
REMUNERATION PAID TO DSRMC HEREUNDER FOR THE SERVICES TO BE PERFORMED REFLECT
THIS LIMITATION OF LIABILITY AND DISCLAIMER OF WARRANTIES. IN NO EVENT SHALL
DSRMC BE LIABLE TO THE ENTITIES OR ANY OTHER PERSON FOR ANY INDIRECT, SPECIAL,
OR CONSEQUENTIAL DAMAGES RESULTING FROM ANY ERROR IN THE PERFORMANCE OF SERVICES
OR FROM THE BREACH OF THIS AGREEMENT, REGARDLESS OF THE FAULT OF DSRMC, ANY
DSRMC AFFILIATE, OR ANY THIRD PARTY PROVIDER OR WHETHER DSRMC, ANY DSRMC
AFFILIATE, OR THE THIRD PARTY PROVIDER ARE WHOLLY, CONCURRENTLY, PARTIALLY, OR
SOLELY

                                       -6-
<Page>

NEGLIGENT. TO THE EXTENT ANY THIRD PARTY PROVIDER HAS LIMITED ITS LIABILITY TO
DSRMC OR ITS AFFILIATE FOR SERVICES UNDER AN OUTSOURCING OR OTHER AGREEMENT, THE
ENTITIES AGREE TO BE BOUND BY SUCH LIMITATION OF LIABILITY FOR ANY PRODUCT OR
SERVICE PROVIDED TO THE ENTITIES BY SUCH THIRD PARTY PROVIDER UNDER DSRMC'S OR
SUCH AFFILIATE'S AGREEMENT.

               9.     FORCE MAJEURE.

               DSRMC SHALL HAVE NO OBLIGATION TO PERFORM OR CAUSE THE SERVICES
TO BE PERFORMED IF ITS FAILURE TO DO SO IS CAUSED BY OR RESULTS FROM ANY ACT OF
GOD, GOVERNMENTAL ACTION, NATURAL DISASTER, STRIKE, FAILURE OF ESSENTIAL
EQUIPMENT OR ANY OTHER CAUSE OR CIRCUMSTANCE BEYOND THE REASONABLE CONTROL OF
DSRMC, OR, IF APPLICABLE, ITS AFFILIATES OR THIRD PARTY PROVIDERS OF SERVICES TO
DSRMC ("EVENT OF FORCE MAJEURE"). DSRMC WILL NOTIFY THE ENTITIES OF ANY EVENT OF
FORCE MAJEURE. DSRMC AGREES THAT UPON RESTORING THE SERVICE FOLLOWING ANY EVENT
OF FORCE MAJEURE, DSRMC WILL ALLOW THE ENTITIES TO HAVE EQUAL PRIORITY WITH
DSRMC AND ITS AFFILIATES, IN ACCORDANCE WITH PRIOR PRACTICE, WITH RESPECT TO
ACCESS TO THE RESTORED SERVICE.

               10.    SEVERABILITY.

               In the event any portion of this Agreement shall be found by a
court of competent jurisdiction to be unenforceable, that portion of the
Agreement will be null and void and the remainder of the Agreement will be
binding on the parties as if the unenforceable provisions had never been
contained herein.

               11.    ASSIGNMENT.

               Except for the ability of DSRMC to cause one or more of the
Services to be performed by a third party provider (subject to the terms of this
Agreement), no party shall have the right to assign its rights or obligations
under this Agreement without the consent of the other party.

               12.    ENTIRE AGREEMENT, SUPERSEDURE.

               This Agreement constitutes the entire agreement of the parties
relating to the performance of the Services; all prior or contemporaneous
written or oral agreements are merged herein; this Agreement may not be changed
except by a writing signed by both parties.

                                       -7-
<Page>

               13.    CHOICE OF LAW.

               This Agreement shall be subject to and governed by the laws of
the State of Texas, excluding any conflicts-of-law rule or principle that might
refer the construction or interpretation of this Agreement to the laws of
another state.

               14.    AMENDMENT OR MODIFICATION.

               This Agreement may be amended or modified from time to time only
by a written amendment signed by the Entities and DSRMC; provided however that
the Partnership and the Operating Partnership may not, without the prior
approval of the Conflicts Committee of Shamrock GP, agree to any amendment or
modification of this Agreement that, in the reasonable discretion of the General
Partner, will adversely affect the Holders of the Common Units.

               15.    NOTICES.

               Any notice, request, instruction, correspondence or other
document to be given hereunder by either party to the other (herein collectively
called "Notice") shall be in writing and delivered personally or mailed, postage
prepaid, or by telegram or telecopier, as follows:

                      If to DSRMC:

                      Diamond Shamrock Refining and Marketing Company
                      P.O. Box 696000
                      San Antonio, TX  78269-6000
                      Attention:  Legal Department
                      Telecopy: (210)592-2202

                      If to the Entities:

                      Shamrock Logistics GP, LLC
                      P.O. Box 696000
                      San Antonio, TX  78269-6000
                      Attention:  President
                      Telecopy: (210)592-2202

               Notice given by personal delivery or mail shall be effective upon
actual receipt. Notice given by telecopier shall be effective upon actual
receipt if received during the recipient's normal business hours, or at the
beginning of the recipient's next business day after receipt if not received
during the recipient's normal business hours. Any party may change any address
to which Notice is to be given to it by giving Notice as provided above of such
change of address.

               16.    FURTHER ASSURANCES.

In connection with this Agreement and all transactions contemplated by this
Agreement each signatory party hereto agrees to execute and deliver such
additional documents and instruments

                                       -8-
<Page>

as may be required for DSRMC to provide the Services hereunder and to perform
such other additional acts as may be necessary or appropriate to effectuate,
carry out, and perform all of the terms, provisions, and conditions of this
Agreement.

               17.    DESIGNATED CONTACT PERSON.

               Without limiting the obligations of the parties hereto with
respect to the delivery of notices, requests or consents pursuant to sections 14
and 15, DSRMC hereby designates the Corporate Secretary of Ultramar Diamond
Shamrock Corporation (phone no. (210) 592-4516) as a person with whom
representatives of the Entities may communicate regarding any Services to be
performed hereunder. The Entities hereby designate the Vice President-Operations
of Shamrock GP (phone no. (210) 592-2000) as its designated person with whom
DSRMC may communicate regarding any problems or other matters that DSRMC may
have in providing any Service hereunder by itself or any third party provider.

               18.    ACKNOWLEDGMENT REGARDING CERTAIN PROVISIONS.

               EACH OF THE PARTIES HERETO SPECIFICALLY ACKNOWLEDGES AND AGREES
(a) THAT IT HAS A DUTY TO READ THIS AGREEMENT AND THAT IT IS CHARGED WITH NOTICE
AND KNOWLEDGE OF THE TERMS HEREOF, (b) THAT IT HAS IN FACT READ THIS AGREEMENT
AND IS FULLY INFORMED AND HAS FULL NOTICE AND KNOWLEDGE OF THE TERMS, CONDITIONS
AND EFFECTS OF THIS AGREEMENT, (c) THAT IT HAS BEEN REPRESENTED BY LEGAL COUNSEL
OF ITS CHOICE THROUGHOUT THE NEGOTIATIONS PRECEDING THE EXECUTION OF THIS
AGREEMENT AND HAS RECEIVED THE COUNSEL IN CONNECTION WITH ENTERING INTO THIS
AGREEMENT, AND (d) THAT IT RECOGNIZES THAT CERTAIN OF THE TERMS OF THIS
AGREEMENT PROVIDE FOR THE ASSUMPTION BY ONE PARTY OF, AND/OR RELEASE OF THE
OTHER PARTY FROM, CERTAIN LIABILITIES ATTRIBUTABLE TO THE MATTERS COVERED BY
THIS AGREEMENT THAT SUCH PARTY WOULD OTHERWISE BE RESPONSIBLE FOR UNDER THE LAW.
EACH PARTY HERETO FURTHER AGREES AND COVENANTS THAT IT WILL NOT CONTEST THE
VALIDITY OR ENFORCEABILITY OF ANY SUCH PROVISIONS OF THIS AGREEMENT ON THE BASIS
THAT THE PARTY HAD NO NOTICE OR KNOWLEDGE OF SUCH PROVISION OR THAT SUCH
PROVISIONS ARE NOT "CONSPICUOUS".

               19.    DEFINITIONS. The following terms shall have the indicated
meanings for the purposes of this Agreement:

               "Affiliate" shall have the meaning attributed to such term in the
Master Partnership Agreement; provided, however, that for the purposes of this
Agreement neither Shamrock GP, the General Partner, the Partnership, the
Operating Partnership, nor any Person controlled by the Partnership or the
Operating Partnership (as the term "control" is used in the definition of
"Affiliate" in the Partnership Agreement) shall be deemed to be an Affiliate of
DSRMC.

                                       -9-
<Page>

               "Common Units" shall mean limited partnership interests that have
been so designated under the terms of the Master Partnership Agreement.

               "Master Partnership Agreement" shall mean the Second Amended and
Restated Agreement of Limited Partnership of the Partnership, as it may be
hereafter amended or restated.

               20.    NO THIRD PARTY BENEFICIARY. The provisions of this
Agreement are enforceable solely by the parties to this Agreement, and no
limited partner, assignee or other person shall have the right, separate and
apart from Shamrock GP and the General Partner, to enforce any provision of this
Agreement or to compel any party to this Agreement to comply with the terms of
this Agreement.

               21.    DURATION; TERMINATION. This Agreement shall terminate upon
the eighth anniversary of the Effective Date (the "Initial Term"); provided that
this Agreement shall automatically continue for successive two year terms after
the Initial Term unless or until one year's advance notice is given to terminate
this Agreement is given by DSRMC or the General Partner, in which case this
agreement shall terminate one year after such notice is delivered.
Notwithstanding the foregoing, the General Partner (a) may terminate the
provision of one or more Other Services or reduce the level of one or more Other
Services in accordance with the provisions of Section 2 hereof and (b) shall
have the right at any time to terminate this Agreement by giving written notice
to DSRMC, and in such event this Agreement shall terminate one hundred and
eighty (180) days from the date on which such notice is given.

                                      -10-
<Page>

               IN WITNESS WHEREOF, the parties hereto have caused this Agreement
to be signed on their behalf by their duly authorized officers on the date first
above written.

                                       DIAMOND SHAMROCK REFINING AND MARKETING
                                       COMPANY, ON BEHALF OF ITSELF AND ITS
                                       AFFILIATES LISTED ON SCHEDULE A

                                       By:  /s/ Robert S. Shapard
                                          --------------------------------------
                                       Name:  Robert S. Shapard
                                       Title: Executive Vice President and CFO

                                       SHAMROCK LOGISTICS, L.P.

                                            BY: RIVERWALK LOGISTICS, L.P.,
                                                its General Partner

                                               BY: SHAMROCK LOGISTICS GP, LLC,
                                                   its General Partner

                                                  By: /s/ Curtis V. Anastasio
                                                     ---------------------------
                                                  Name: Curtis V. Anastasio
                                                  Title: President and CEO

                                       SHAMROCK LOGISTICS OPERATIONS, L.P.

                                            BY: RIVERWALK LOGISTICS, L.P.,
                                                its General Partner

                                               BY: SHAMROCK LOGISTICS GP, LLC,
                                                   its General Partner

                                                  By:  /s/ Curtis V. Anastasio
                                                     ---------------------------
                                                  Name: Curtis V. Anastasio
                                                  Title: President and CEO

<Page>

                                       RIVERWALK LOGISTICS, LP

                                            BY: SHAMROCK LOGISTICS GP, LLC,
                                                  its General Partner

                                               By: /s/ Curtis V. Anastasio
                                                  ------------------------------
                                               Name: Curtis V. Anastasio
                                               Title: President and CEO

                                       SHAMROCK LOGISTICS GP, LLC,

                                       By:  /s/ Curtis V. Anastasio
                                          --------------------------------------
                                       Name: Curtis V. Anastasio
                                       Title: President and CEO

<Page>

                                    EXHIBIT A

Diamond Shamrock Refining Company, L.P.
Sigmor Corporation
TPI Pipeline Corporation
The Shamrock Pipe Line Corporation

<Page>

                                    EXHIBIT B

CORPORATE, GENERAL AND ADMINISTRATIVE SERVICES

Aviation and Travel Services
Corporate Development
Data Processing and Information Technology Services
Financial Accounting and Reporting
Foreign Trade Zone Reporting and Accounting
Group Accounting
Health and Safety Services
Human Resources Services
   Benefits
   Benefit Accounting
   Benefit Plans
   Retirement Plans
   401(k) Savings Plans
   Payroll Services
   Training Services
Internal Audit
Legal
   General Litigation Support
   General Corporate
   Corporate Secretary
   Tariff Maintenance
Office Services
   Mail Center
   Health Club
   Building and Office Maintenance
Purchasing/Fleet Management
Records Management
Real Estate Management
Risk and Claims Management Services
Security Services
Shareholder, Investor, Public, and Government Relations
Tax Accounting
Treasury & Banking
   Finance Services
   Cash Management
   Credit Services

<Page>

                                    EXHIBIT C

Other Services

Costs incurred in the Pipeline and Terminal Operating and Maintenance
Departments include the following:

      -  Construction
      -  Safety
      -  Engineering
      -  Right of Way
      -  Corrosion Control
      -  SCADA and Automation
      -  Control Centers
      -  Product and Crude Administration
      -  In addition to the above departments, there are direct operating
         personnel that operating the individual pipelines and terminals.

Costs incurred in the Operations and Maintenance of the Pipelines and Terminals
include the following:

-  Salary, Wages and Benefits Costs for Employees devoted to the operation and
   maintenance of the MLP assets. Including the following:
   -Gross payroll, including bonuses
   -FICA
   -Vacation pay
   -Sick pay
   -Life insurance
   -Disability insurance
   -401(k) matching contribution costs (qualified and non-qualified plans)
   -Defined benefit pension costs
   -Post retirement health and medical costs

-  Insurance Costs for the following insurance coverages:
   -General liability
   -Automobile liability
   -Comprehensive liability
   -Excess liability
   -Property
   -Directors & Officers

-  Incidental Costs incurred by the MLP or Employees devoted to the operation
   and maintenance of the MLP assets.

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00035-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00035-of-00352.parquet"}]]