Document:

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                                                                    Exhibit 10.8

                  PIPELINE LIQUIDS TRANSPORTATION AGREEMENT

     This Pipeline Liquids Transportation Agreement ("Agreement") is made and
entered into this ____ day of ______, 2002, by and between MARKWEST ENERGY
APPALACHIA, L.L.C., a Delaware limited partnership ("MEA"), and MARKWEST
HYDROCARBON, INC.,  a Delaware corporation ("MarkWest"). MEA and MarkWest may
be referred to individually as "Party", or collectively as "Parties".

     Section 1.     SCOPE OF AGREEMENT AND GENERAL TERMS AND CONDITIONS.
MarkWest agrees to deliver, or cause to be delivered, Raw Make, as defined
below, to MEA, and MEA agrees to receive and transport that Raw Make to MEA's
Siloam Fractionation facility, all in accordance with this Agreement.  This
Agreement does not apply to Raw Make and Plant Products covered by that
certain Natural Gas Liquids Transportation And Fractionation Agreement
(Maytown), between MarkWest and MEA, of even date herewith.  This Agreement
incorporates and is subject to all of the General Terms and Conditions
attached hereto, together with any other Exhibits attached hereto.

     Section 2.     EFFECTIVE DATE. The date on which the obligations and
duties of the Parties shall commence, being the "Effective Date", shall be
_______________, 2002.

     Section 3.     TERM. This Agreement shall remain in full force and
effect from the Effective Date through December 31, 2015 (the "Primary
Term"), and shall continue thereafter on a year-to-year basis until
terminated by either Party by providing at least 60 days written notice to
the other Party in advance of the termination of the Primary Term or of any
one-year extension thereof.

     Section 4.     FEES AND CONSIDERATION.

     A.  As full consideration for the services provided by MEA, MarkWest
     shall pay the following fees and MEA shall make the following deliveries:

          i.     For the transportation of Raw Make by MEA, MarkWest shall
          pay MEA a Transportation Fee equal to the gallons of Raw Make
          delivered to MEA at the Receipt Point(s) multiplied by $*.

          ii.    A portion of each of the Transportation Fee shall be subject
          to annual adjustments. *% of the Transportation Fee, shall be
          adjusted on an annual basis in proportion to the percentage change,
          from the preceding year, in the Producer Price Index for oil and Gas
          field services (SIC 138) as published by the Department of Labor
          ("PPI").  The adjustment of the Fees shall be made effective
          January 1 of each year, and shall reflect the percentage change in
          the PPI as it existed for the immediately preceding January from the
          PPI for the second immediately preceding January.

          iii.   MEA shall deliver the Raw Make transported for MarkWest to
          the Redelivery Point.

     B.  During the Primary Term of this Agreement or any extension thereof,
     MarkWest (i) shall not seek to challenge the level of the Transportation
     Fee before any regulatory

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                  *Denotes Confidential Portion Omitted and
                     Filed Separately with the Commission

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     authorities of the federal government or of any state in which the
     facilities of the Pipeline are located; (ii) shall not seek to invoke
     the jurisdiction of any such regulatory authorities with regard to the
     Transportation Fee; and (iii) shall not encourage, assist, or support
     any other person in invoking the jurisdiction of any such regulatory
     authorities with regard to the Transportation Fee.

     Section 5.     NOTICES. All notices, statements, invoices or other
communications required or permitted between the Parties shall be in writing
and shall be considered as having been given if delivered by mail, courier,
hand delivery, or facsimile to the other Party at the designated address or
facsimile numbers.  Normal operating instructions can be delivered by
telephone or other agreed means.  Notice of events of Force Majeure may be
made by telephone and confirmed in writing within a reasonable time after the
telephonic notice.  Monthly statements, invoices, payments and other
communications shall be deemed delivered when actually received.  Either
Party may change its address or facsimile and telephone numbers upon written
notice to the other Party:

     MarkWest:

          Address:       155 Inverness Drive West, Suite 200
                         Englewood, Colorado 80112
                         Attn: Contract Administration
                         Fax: (303)

     MEA:

          Address:       155 Inverness Drive West, Suite 200
                         Englewood, Colorado 80112
                         Attn: Contract Administration
                         Fax: (303)

     Section 6.     EXECUTION. This Agreement may be executed in any number
of counterparts, each of which shall be considered and original, and all of
which shall be considered one instrument.

IN WITNESS WHEREOF, the Parties have executed this Agreement on the date
first set forth above.

                                        MARKWEST HYDROCARBON, INC.

                                        By:
                                            ---------------------------
                                        Name:
                                        Title:

                                        MARKWEST ENERGY APPALACHIA, L.L.C.

                                        By:
                                            ---------------------------
                                        Name:
                                        Title:

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                         GENERAL TERMS AND CONDITIONS
                 ATTACHED TO AND MADE A PART OF THAT CERTAIN
                  PIPELINE LIQUIDS TRANSPORTATION AGREEMENT
                                   BETWEEN
                  MARKWEST HYDROCARBON, INC., AS "MARKWEST"
                                     AND
                 MARKWEST ENERGY APPALACHIA, L.L.C., AS "MEA"
                                    DATED:

ARTICLE 1:  DEFINITIONS

ACCOUNTING PERIOD.  The period commencing at 8:00 a.m., Eastern Time, on
the first day of a calendar month and ending at 8:00 a.m., Eastern Time, on
the first day of the next succeeding month.

FORCE MAJEURE.  Any cause or condition not within the reasonable control
of the Party claiming suspension and which by the exercise of reasonable
diligence, such Party is unable to prevent or overcome.

FRACTIONATION AGREEMENT.  That certain Fractionation, Storage and Loading
Agreement between MarkWest and MEA, of even date herewith.

INCIDENTAL LOSSES OR GAINS.  The incidental losses incurred in MEA's
facilities, or the losses or gains incurred due to variations in measurement
equipment.

INDEMNIFYING PARTY AND INDEMNIFIED PARTY.  As defined in Article 8, below.

LOSSES.  Any actual loss, cost, expense, liability, damage, demand, suit,
sanction, claim,  judgment, lien, fine or penalty which are incurred by the
applicable Indemnified Party on account of injuries (including death) to any
person or damage to or destruction of any property, sustained or alleged to
have been sustained in connection with or arising out of the matters for
which the Indemnifying Party has indemnified the applicable Indemnified Party.

MEA PLANTS.  Gas processing and extraction plants, owned and/or operated
by MEA.

PIPELINE.  The liquids transportation pipelines owned or leased by MEA for
transporting liquefied hydrocarbons from their respective extraction plants
to Siloam.

RAW MAKE.  A combined stream of propane and heavier liquefied
hydrocarbons, including incidental ethane.

RECEIPT POINT.  The inlet flanges of  the Pipeline at or near the tailgate
of the applicable MEA Plants, where MarkWest delivers, or causes to be
delivered, Raw Make for transportation hereunder.

REDELIVERY POINT.  The inlet flange of the Raw Make metering facilities of
MEA at or near Siloam.

SILOAM.  MEA's Siloam fractionation facility located near South Shore,
Kentucky, including any treating equipment, Products separation and
fractionation vessels, all above ground Products storage vessels and all
below ground Products storage caverns and facilities, and associated
condensing, heating, pumping, conveying, and other equipment and
instrumentation; including all structures associated with those facilities;
and, all Products loading facilities, including railcar loading, truck
loading and barge loading facilities and including all easements,
rights-of-way, and other property rights pertaining to the construction and
operation of those facilities; wherever those facilities, structures,
easements, rights-of-way, and other property rights are located.

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ARTICLE 2:  MARKWEST COMMITMENTS

2.1.  MarkWest hereby commits and agrees to deliver at the applicable
Receipt Points all of MarkWest's Raw Make acquired from the MEA Kenova Gas
Extraction facility, and such of MarkWest's Raw Make as it desires to deliver
from MEA's Boldman Gas Extraction facility, or from other extraction plants
or sources in the Appalachian region as agreed upon by the Parties.

ARTICLE 3:  OPERATION OF MEA'S FACILITIES

3.1.  MEA shall, at its sole cost, risk, and expense, maintain and operate
the Pipeline to transport MarkWest's Raw Make from the Receipt Points to the
Redelivery Point.

3.2  All Incidental Losses and Gains incurred in the Pipeline shall be
for the benefit or detriment, as applicable, of MarkWest.

ARTICLE 4: QUALITY

4.1.  RAW MAKE QUALITY.

A.  The Raw Make transported under this Agreement shall be of a quality
that, when fractionated, will result in products meeting the specifications
set forth in Exhibit A, attached to the Fractionation Agreement.

B.  Should any of the Raw Make fail to meet the above specifications,
then:

          i.     MEA may take receipt of the non-conforming Raw Make, and
          that receipt shall not be construed as a waiver or change of
          standards for future Raw Make deliveries; or

          ii.    MEA may, at its sole discretion, cease receiving the
          non-conforming Raw Make, and shall notify MarkWest that it has, or
          will, cease receiving the non-conforming Raw Make.

ARTICLE 5:     MEASUREMENT EQUIPMENT AND PROCEDURES AND ANALYSES

     5.1.  RAW MAKE. Raw Make shall be measured at the Receipt Point(s) as
follows:

     A.  MEA shall measure the weight of the Raw Make delivered hereunder
using either turbine or coriolis mass flow meters installed, operated and
maintained in accordance with GPA Standard 8182-latest edition and/or API
Manual of Petroleum Measurement Standards Draft Standard, Measurement of
Single-Phase, Intermediate and Finished Hydrocarbon Fluids by Coriolis
Meters-latest edition.

     B.  MEA shall measure the composition of the Raw Make delivered
hereunder using a chromatograph installed, operated and maintained in
accordance with GPA Standard 2165-latest edition, GPA Standard 2145-latest
edition, GPA Standard 2261-latest edition, GPA Standard 2177-latest edition
and the manufacturer's specifications and standards. Factors for hexanes and
heavier shall be in accordance with Table IV of GPA Standard 2261-latest
edition or determined by periodic samples taken by the MEA. Samples shall be
taken at intervals not to exceed 20 minutes. The arithmetic average of the
samples during a day shall be deemed to be the Raw Make Composition for such
day.

     C.  The weight of each Raw Make component shall be converted to
gallons at 60DEG.F in accordance with GPA Standard 8173-latest edition and
GPA Standard 2145-latest edition.

ARTICLE 6:  PAYMENTS

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6.1.  MEA shall provide MarkWest with a statement explaining fully how all
consideration due under the terms of this Agreement was determined not later
than the 15th day of the Accounting Period following the Accounting Period
for which the consideration is due.

6.2.  Any sums due MEA under this Agreement shall be paid no later than
the last day of the Accounting Period in which the statement under Section
6.1 was received.

6.3.  Either Party, on 10 days prior written notice, shall have the right
at its expense, at reasonable times during business hours, to audit the books
and records of the other Party to the extent necessary to verify the accuracy
of any statement, measurement, computation, charge, or payment made under or
pursuant to this Agreement. A Party electing to audit ("Auditing Party")
shall complete its audit within 3 months following the date on which the
books and records of the other Party ("Audited Party") are first made
available for inspection following the Auditing Party's notice of audit.
Within that 3-month period, the Auditing Party shall submit, in writing, all
exceptions disclosed by the audit to the Audited Party.  The Audited Party
shall have 30 days following receipt of the exceptions in which to respond in
writing to the exceptions.  If the Audited Party fails to respond within that
30-day period, the exceptions shall be deemed accepted and appropriate
adjustments and settlements shall be made and, as applicable, paid.  If the
Parties are unable to reach agreement as to any exceptions to which the
Audited Party timely responded within 30 days of the Audited Party's
response, then either Party may submit the matter to arbitration in
accordance with the provisions in Article 9.

ARTICLE 7:  FORCE MAJEURE

7.1.  In the event a Party is rendered unable, wholly or in part, by Force
Majeure, to carry out its obligations under this Agreement, other than the
obligation to make any payments due hereunder, the obligations of that Party,
so far as they are affected by Force Majeure, shall be suspended from the
inception and during the continuance of the inability, and the cause of the
Force Majeure, as far as possible, shall be remedied with commercially
reasonable diligence.  The Party affected by Force Majeure shall provide the
other Party with written notice of the Force Majeure event, with reasonably
full detail of the Force Majeure within a reasonable time after the affected
Party learns of the occurrence of the Force Majeure event.  The settlement of
strikes, lockouts, and other labor difficulty shall be entirely within the
discretion of the Party having the difficulty and nothing herein shall
require the settlement of strikes, lockouts, or other labor difficulty.

ARTICLE 8:  LIABILITY AND INDEMNIFICATION

8.1.  As among the Parties hereto, MarkWest and any of its designees shall
be in custody, control and possession of the Raw Make hereunder, until the
Raw Make is delivered to MEA at the Receipt Point.

8.2.  As among the Parties hereto, MEA and any of its designees shall be
in custody, control and possession of the Raw Make hereunder after Raw Make
is delivered at the Receipt Point.

8.3.  Each Party ("Indemnifying Party") hereby covenants and agrees with
the other Party, and its affiliates (except for the Indemnifying Party
itself), and each of their directors, officers and employees ("Indemnified
Parties"), that except to the extent caused by the Indemnified Parties' gross
negligence or willful conduct, the Indemnifying Party shall protect, defend,
indemnify and hold harmless the Indemnified Parties from, against and in
respect of any and all Losses incurred by the Indemnified Parties to the
extent those Losses arise from or are related to: (a) the

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Indemnifying Party's facilities; or (b) the Indemnifying Party's possession
and control of the Raw Make or Products, as applicable.

ARTICLE 9:  MISCELLANEOUS

9.1.  The failure of any Party hereto to exercise any right granted
hereunder shall not impair nor be deemed a waiver of that Party's privilege
of exercising that right at any subsequent time or times.

9.2.  This Agreement shall be governed by, construed, and enforced in
accordance with the laws of the State of Colorado without regard to choice of
law principles.

9.3.  This Agreement shall extend to and inure to the benefit of and be
binding upon the Parties, and their respective successors and assigns,
including any assigns of MarkWest's Interests covered by this Agreement.  No
assignment of this Agreement shall be binding on either of the Parties until
the first day of the Accounting Period following the date a certified copy of
the instrument evidencing that sale, transfer, assignment or conveyance has
been delivered to the other Party.  Further, each assigning Party shall
notify its assignee of the existence of this Agreement and obtain a
ratification of this Agreement prior to such assignment.  No assignment by
either Party shall relieve that Party of its continuing obligations and
duties hereunder without the express consent of the other Party.

9.4.  Any change, modification or alteration of this Agreement shall be in
writing, signed by the Parties; and, no course of dealing between the Parties
shall be construed to alter the terms of this Agreement.

9.5   This Agreement, including all exhibits and appendices, contains the
entire agreement between the Parties with respect to the subject matter
hereof, and there are no oral or other promises, agreements, warranties,
obligations, assurances, or conditions precedent, affecting it.

9.6   NO BREACH OF THIS AGREEMENT OR CLAIM FOR LOSSES UNDER ANY INDEMNITY
OBLIGATION CONTAINED IN THIS AGREEMENT SHALL CAUSE ANY PARTY TO BE LIABLE
FOR, NOR SHALL LOSSES INCLUDE, ANY DAMAGES OTHER THAN ACTUAL AND DIRECT
DAMAGES, AND EACH PARTY EXPRESSLY WAIVES ANY RIGHT TO CLAIM ANY OTHER
DAMAGES, INCLUDING, WITHOUT LIMITATION, CONSEQUENTIAL, SPECIAL, INDIRECT,
PUNITIVE OR EXEMPLARY DAMAGES.

9.7   DISPUTE RESOLUTION. Any dispute arising under this Agreement
("Arbitrable Dispute") shall be referred to and resolved by binding
arbitration in Denver, Colorado, by three (3) arbitrators, in accordance with
the rules and procedures of the Judicial Arbiter Group ("JAG"); and, to the
maximum extent applicable, the Federal Arbitration Act (Title 9 of the United
States Code).  If there is any inconsistency between this Section and any
statute or rules, this Section shall control.  Arbitration shall be initiated
within the applicable time limits set forth in this Agreement and not
thereafter or if no time limit is given, within the time period allowed by
the applicable statute of limitations, by one party ("Claimant") giving
written notice to the other party ("Respondent") and to JAG, that the
Claimant elects to refer the Arbitrable Dispute to arbitration, and that the
Claimant has appointed an arbitrator, who shall be identified in such notice.
 The Respondent shall notify the Claimant and JAG within thirty (30) Days
after receipt of Claimant's notice, identifying the arbitrator the Respondent
has appointed.  The two (2) arbitrators so chosen shall select a third
arbitrator within thirty (30) Days after the second arbitrator has been
appointed (upon failure of a party to act within the time specified for
naming an arbitrator, such arbitrator shall be appointed by the
administrator's designee).  MarkWest shall pay the compensation and expenses
of the

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arbitrator named by or for it, MEA shall pay the compensation and expenses of
the arbitrator named by or for it, and MarkWest and MEA shall each pay
one-half of the compensation and expenses of the third arbitrator.  All
arbitrators must be neutral parties who have never been officers, directors,
employees, contractors or agents of the parties or any of their Affiliates,
must have not less than ten (10) years experience in the oil and gas
industry, and must have a formal financial/accounting, engineering or legal
education.  The parties shall have all rights of discovery in accordance with
the Federal Rules of Civil Procedure.  The hearing shall be commenced within
thirty (30) Days after the selection of the third arbitrator.  The parties
and the arbitrators shall proceed diligently and in good faith in order that
the arbitral award shall be made as promptly as possible.  The
interpretation, construction and effect of this Agreement shall be governed
by the laws of Colorado, and to the maximum extent allowed by law, in all
arbitration proceedings the laws of Colorado shall be applied, without regard
to any conflicts of laws principles.  All statutes of limitation and of
repose that would otherwise be applicable shall apply to any arbitration
proceeding.  The tribunal shall not have the authority to grant or award
indirect or consequential damages, punitive damages or exemplary damages.

7<Page>

                                                                    Exhibit 10.9

          NATURAL GAS LIQUIDS TRANSPORTATION AND FRACTIONATION AGREEMENT
                                    (MAYTOWN)

         This Natural Gas Liquids Transportation and Fractionation Agreement
("Agreement") is made and entered into this ____ day of ______, 2002, by and
between MARKWEST ENERGY APPALACHIA, L.L.C., a Delaware limited partnership
("MEA"), and MARKWEST HYDROCARBON, INC., a Delaware corporation ("MarkWest").
MEA and MarkWest may be referred to individually as "Party", or collectively as
"Parties".

         Section 1. SCOPE OF AGREEMENT AND GENERAL TERMS AND CONDITIONS.
MarkWest will acquire certain Raw Make under the Maytown Agreement (as defined
below), and MarkWest agrees to deliver, or cause to be delivered, the Raw Make
to MEA and MEA agrees to receive, transport and fractionate the Raw Make into
Plant Products and to deliver those Plant Products to MarkWest, all in
accordance with this Agreement. This Agreement incorporates and is subject to
all of the General Terms and Conditions attached hereto, together with any other
Exhibits attached hereto.

         Section 2. EFFECTIVE DATE AND RELATION TO OTHER AGREEMENTS.

         A. The date on which the obligations and duties of the Parties shall
         commence, being the "Effective Date", shall be _______________, 2002.

         B. With respect to the Raw Make and Plant Products covered by this
         Agreement, this Agreement shall be the exclusive agreement with respect
         to the transportation, fractionation, storage and loading thereof and
         shall prevail over that certain Fractionation, Storage and Loading
         Agreement (Siloam), and that certain Pipeline Liquids Transportation
         Agreement, both between MarkWest and MEA and both of even date
         herewith.

         Section 3. TERM. This Agreement shall remain in full force and effect
from the Effective Date through the termination of the Maytown Agreement.

         Section 4. CONSIDERATION.

         A. As full consideration for the transportation and fractionation of
         the Raw Make and the delivery of the Plant Products attributable from
         the Raw Make acquired by MarkWest under the Maytown Agreement, MarkWest
         shall pay MEA the amounts under i., and ii., below, less the amounts
         under iii., below, determined as follows:

                  i. For each Accounting Period, MarkWest shall pay to MEA *% of
                  the Net Sales Price per gallon, times the gallons of
                  individual Plant Product contained in the Raw Make acquired by
                  MarkWest under the Maytown Agreement, as determined at the
                  Measurement Point and delivered to MEA at the Receipt Points
                  during that Accounting Period.

                  ii. MarkWest pay MEA a fee of [$*] multiplied by * and
                  multiplied by the number of gallons of Raw Make measured at
                  the Measurement Point and delivered to MEA at the Receipt
                  Points during the applicable Accounting Period. *% of this
                  fee, shall be adjusted on an annual basis in proportion to the
                  percentage change, from the preceding year, in the Producer
                  Price Index for oil

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                    *Denotes Confidential Portion Omitted and
                      Filed Separately with the Commission

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                  and gas field services (SIC 138) as published by the
                  Department of Labor ("PPI"). The adjustment of the Fees shall
                  be made effective January 1 of each year, and shall reflect
                  the percentage change in the PPI as it existed for the
                  immediately preceding January from the PPI for the second
                  immediately preceding January.

                  iii. The amounts payable by MarkWest to MEA shall be reduced
                  by $* per Accounting Period. This reduction shall be
                  adjusted on an annual basis in proportion to the percentage
                  change, from the preceding year, in the Producer Price Index
                  for oil and gas field services (SIC 138) as published by the
                  Department of Labor ("PPI"). The adjustment of the Fees shall
                  be made effective January 1 of each year, and shall reflect
                  the percentage change in the PPI as it existed for the
                  immediately preceding January from the PPI for the second
                  immediately preceding January.

                  iv. All Plant Products shall be delivered to MarkWest at the
                  Plant Products Delivery Point and shall be marketed by
                  MarkWest.

                  v. Under that certain Fractionation, Storage and Loading
                  Agreement, between MarkWest and MEA, of even date herewith,
                  MarkWest has the exclusive rights to utilize the Cavern of MEA
                  for storage of MarkWest's Plant Products. The Plant Products
                  produced under this Agreement shall also be subject to those
                  storage rights, with no additional compensation beyond that
                  contained in the Fractionation, Storage and Loading Agreement.

         B. From and after the Effective Date and until the termination of
         this Agreement, MarkWest (i) shall not seek to challenge the level of
         the consideration payable by MarkWest pursuant to this Agreement
         before any regulatory authorities of the federal government or of any
         state in which the facilities of the Pipeline are located; (ii) shall
         not seek to invoke the jurisdiction of any such regulatory authorities
         with regard to the consideration payable pursuant to this Agreement;
         and (iii) shall not encourage, assist, or support any other person in
         invoking the jurisdiction of any such regulatory authorities with
         regard to the consideration payable pursuant to this Agreement.

         Section 5. NOTICES. All notices, statements, invoices or other
communications required or permitted between the Parties shall be in writing and
shall be considered as having been given if delivered by mail, courier, hand
delivery, or facsimile to the other Party at the designated address or facsimile
numbers. Normal operating instructions can be delivered by telephone or other
agreed means. Notice of events of Force Majeure may be made by telephone and
confirmed in writing within a reasonable time after the telephonic notice.
Monthly statements, invoices, payments and other communications shall be deemed
delivered when actually received. Either Party may change its address or
facsimile and telephone numbers upon written notice to the other Party:

         MarkWest:

                  Address:          155 Inverness Drive West, Suite 200
                                    Englewood, Colorado 80112
                                    Attn: Contract Administration
                                    Fax: (303)

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                    *Denotes Confidential Portion Omitted and
                      Filed Separately with the Commission

<Page>

         MEA:

                  Address:          155 Inverness Drive West, Suite 200
                                    Englewood, Colorado 80112
                                    Attn: Contract Administration
                                    Fax: (303)

         Section 6. EXECUTION. This Agreement may be executed in any number of
counterparts, each of which shall be considered and original, and all of which
shall be considered one instrument.

IN WITNESS WHEREOF, the Parties have executed this Agreement on the date first
set forth above.

                                              MARKWEST HYDROCARBON, INC.

                                              By: ___________________________
                                              Name:
                                              Title:

                                              MARKWEST ENERGY APPALACHIA, L.L.C.

                                              By: ___________________________
                                              Name:
                                              Title:

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                          GENERAL TERMS AND CONDITIONS
                   ATTACHED TO AND MADE A PART OF THAT CERTAIN
         NATURAL GAS LIQUIDS TRANSPORTATION AND FRACTIONATION AGREEMENT
                                     BETWEEN
                    MARKWEST HYDROCARBON, INC., AS "MARKWEST"
                                       AND
                  MARKWEST ENERGY APPALACHIA, L.L.C., AS "MEA"
                                     DATED:

ARTICLE 1: DEFINITIONS

ACCOUNTING PERIOD. The period commencing at 8:00 a.m., Eastern Time, on the
first day of a calendar month and ending at 8:00 a.m., Eastern Time, on the
first day of the next succeeding month.

CAVERN. The two underground Plant Products storage cavern owned and operated by
MEA at Siloam with a capacity of approximately 11,000,000 gallons.

FORCE MAJEURE. Any cause or condition not within the reasonable control of the
Party claiming suspension and which by the exercise of reasonable diligence,
such Party is unable to prevent or overcome.

FRACTIONATION FUEL. All Gas, Plant Products, vapors or other forms of energy
utilized as fuel in Siloam.

GAS. All hydrocarbon and non-hydrocarbon substances in a gaseous state.

INCIDENTAL LOSSES OR GAINS. The incidental losses incurred in MEA's facilities,
or the losses or gains incurred due to variations in measurement equipment.

INDEMNIFYING PARTY and INDEMNIFIED PARTY. As defined in Article 8, below.

LOSSES. Any actual loss, cost, expense, liability, damage, demand, suit,
sanction, claim, judgment, lien, fine or penalty which are incurred by the
applicable Indemnified Party on account of injuries (including death) to any
person or damage to or destruction of any property, sustained or alleged to have
been sustained in connection with or arising out of the matters for which the
Indemnifying Party has indemnified the applicable Indemnified Party.

MAYTOWN AGREEMENT. That certain Gas Processing Agreement (Maytown), between
Equitable Production Company and MarkWest Hydrocarbon, Inc., dated May 16, 1999,
as amended.

MAYTOWN PLANT. The gas processing and extraction facility as described in the
Maytown Agreement.

MEASUREMENT POINT. The inlet flanges of the Pipeline at or near the tailgate of
the Maytown Plant, as defined in the Maytown Agreement, where MarkWest acquires
Raw Make from the Maytown Plant; provided, when the Receipt Point is at the
unloading facilities of MEA, at or near Siloam, then the Measurement Point shall
be at that Receipt Point.

NET SALES PRICE. The Net Sales Price as defined in and determined in accordance
with the Maytown Agreement, as it, from time to time, exists.

PIPELINE. That certain Pipeline leased to MarkWest by Equitable under the
Pipeline Lease Agreement attached to the Maytown Agreement.

PLANT PRODUCTS. The finished liquid products fractionated from the Raw Make
delivered

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hereunder, including propane, isobutane, normal butane and natural gasoline.

PLANT PRODUCTS DELIVERY POINT. The point at which the Plant Products are
delivered to, or for the account of, MarkWest into transportation facilities
furnished by MarkWest.

RAW MAKE. A combined stream of propane and heavier liquefied hydrocarbons,
including incidental ethane.

RECEIPT POINT. The interconnection of the Pipeline and the facilities of MEA,
located in the vicinity of Ranger, West Virginia; provided, when the Raw Make is
not transported by the Pipeline, the Receipt Point shall be the inlet flange of
the Raw Make unloading facilities of MEA at or near Siloam.

SILOAM. MEA's Siloam fractionation facility located near South Shore, Kentucky,
including any treating equipment, Plant Products separation and fractionation
vessels, all above ground Plant Products storage vessels and all below ground
Plant Products and Raw Make storage caverns and facilities, and associated
condensing, heating, pumping, conveying, and other equipment and
instrumentation; including all structures associated with those facilities; and,
all Plant Products loading facilities, including railcar loading, truck loading
and barge loading facilities and including all easements, rights-of-way, and
other property rights pertaining to the construction and operation of those
facilities; wherever those facilities, structures, easements, rights-of-way, and
other property rights are located.

ARTICLE 2: MARKWEST COMMITMENTS

2.1. MarkWest hereby commits and agrees to deliver at the Receipt Points all of
MarkWest's Raw Make acquired under the Maytown Agreement.

ARTICLE 3: OPERATION OF MEA'S FACILITIES

3.1. Subject to the other provisions of this Agreement, MEA agrees to accept all
of MarkWest's Raw Make delivered from the Maytown Plant, fractionate the Raw
Make into Plant Products in accordance with this Agreement and to store and load
Plant Products for MarkWest as provided herein.

3.3 MEA agrees that it shall, at its sole cost, risk, and expense, furnish all
Fractionation Fuel for operating Siloam, and in no event shall any of MarkWest's
Raw Make delivered hereunder or Plant Products or any vapors therefrom be
consumed or utilized by MEA as Fractionation Fuel or in any other manner prior
to delivery of Plant Products to MarkWest as herein provided.

3.4 MEA agrees that it shall, at its sole cost, risk, and expense, operate,
maintain, and replace (if necessary) docks, loading racks, pipelines, and all
other facilities for loading each Product for shipment by highway, rail, and
marine transportation from the vicinity of Siloam. MEA agrees that all
facilities operated by MEA which are required in the performance of the services
herein agreed upon shall, at its sole cost, risk, and expense, be maintained and
operated at all times as a prudent operator would maintain and operate similar
facilities. MEA hereby agrees to lease and let MarkWest, at no additional
consideration, trackage rights on MEA's Siloam railroad siding to move Product
hereunder.

3.5. MEA agrees that it shall, at its sole cost, risk, and expense, be
responsible for all loading of each Product for shipments in accordance with
reasonable authorizations and instructions given from time to time by MarkWest,
including, but not limited to, preparation and distribution of all shipping
papers pertaining to movement of Plant Products from Siloam, rail, truck and
barge bills of lading, loading tickets, and reports and odorization
certifications. MEA shall

5

<Page>

furnish all trained employees required to perform these services and shall
maintain complete records of all Product dispositions.

3.6. MEA agrees that it shall, at its sole risk, be responsible for placing
Plant Products into storage in the Cavern and withdrawing Plant Products from
the Cavern in accordance with reasonable authorizations and instructions given
from time to time by MarkWest.

3.7 All Incidental Losses and Gains incurred at Siloam shall be for the benefit
or detriment, as applicable, of MarkWest.

ARTICLE 4: QUALITY

4.1. RAW MAKE QUALITY.

A. As long as the Raw Make delivered hereunder for fractionation is of a quality
which, when fractionated, meets the applicable specifications set forth on
Exhibit A, attached hereto, then MEA agrees to receive and fractionate that Raw
Make into Plant Products meeting the specifications set forth herein.

B. Should any of the Raw Make fail to meet the above specifications, then:

         i. MEA may take receipt of the non-conforming Raw Make, and that
         receipt shall not be construed as a waiver or change of standards for
         future Raw Make deliveries; or

         ii. MEA may, at its sole discretion, cease receiving the non-conforming
         Raw Make, and shall notify MarkWest that it has, or will, cease
         receiving the non-conforming Raw Make.

4.2 PLANT PRODUCTS QUALITY. MEA shall fractionate all Raw Make meeting the
requirements under Section 4.1, to produce Plant Products meeting the
specifications set forth on Exhibit A, attached hereto.

ARTICLE 5: MEASUREMENT EQUIPMENT AND PROCEDURES AND ANALYSES

5.1. RAW MAKE. Raw Make shall be measured at the Measurement Point; provided, if
the Raw Make is not delivered by the Pipeline, then Raw Make will be measured at
the other respective Receipt Point(s), in which case the fees under Section 4.,
A., ii., of this Agreement shall not apply. All measurement procedures shall
conform to applicable API and GPA standards for pipeline, truck, and rail car
measurement as follows:

         (1) For Raw Make delivered by the Pipeline to the Receipt Point, the
Raw Make and composition of Plant Products contained therein shall be measured
and determined at the Measurement Point in accordance with the practices and
procedures set forth in the Maytown Agreement.

         (2) The trucks shall be weighed empty and full. GPA Standard 8186, as
revised, is the standard to be used on all truck deliveries.

         (3) Rail cars shall be measured using strapping tables and liquid spew
gauges. Vapor correction calculations will be made as required by applicable
industry standards.

5.2  PLANT PRODUCTS MEASUREMENT.

Measurement of all Plant Products and deliveries shall be converted to 60
DEG. F and shall conform to applicable API and GPA standards for barge,
truck, and rail car measurement:

         (1) Barge loading will be by strapping tables. Vapor correction will be
included on delivery tickets on all Plant Products except gasoline.

6

<Page>

         (2) The trucks shall be weighed empty and full. GPA Standard 8186, as
revised, is the standard to be used on all truck deliveries.

         (3) Rail cars shall be measured using strapping tables and liquid spew
gauges. Vapor correction calculations will be made as required by applicable
industry standards.

5.3 INVENTORY.

A. MEA will maintain and provide MarkWest with daily reports setting forth the
volumes of MarkWest's Raw Make and Plant Products held in inventory at Siloam.

B. MEA shall measure the inventory of each above ground storage tank using tank
gauges and shall measure the inventory in the Cavern using inlet and outlet
meters and gauges. Such meters and gauges shall be installed, operated and
maintained in accordance with applicable industry standards.

5.4 ANALYSES.

A. Except for analyses to be conducted at the Measurement Point in accordance
with the Maytown Agreement, MEA shall, at its sole cost, risk, and expense,
install, operate, and maintain equipment to analyze the composition of the Raw
Make and of the Plant Products in accordance with applicable GPA standards.

B. With respect to Raw Make delivered by tank and truck cars, and with respect
to Plant Products, samples shall be analyzed in accordance with applicable GPA
standards. The analysis shall also include the determination of the molecular
weight, density, and heating value of the hexane and heavier fraction be
extended analysis, quarterly in accordance with industry recognized standards.
MarkWest or MEA or their representatives may take samples for verification of
composition and may be present during any of the other party's sampling
operations.

ARTICLE 6: PAYMENTS

6.1. MEA shall provide MarkWest with a statement explaining fully how all
consideration due under the terms of this Agreement was determined not later
than the 15th day of the Accounting Period following the Accounting Period for
which the consideration is due.

6.2. Any sums due MEA under this Agreement shall be paid no later than the last
day of the Accounting Period in which the statement provided under Section 6.1
was received.

6.3. Either Party, on 10 days prior written notice, shall have the right at its
expense, at reasonable times during business hours, to audit the books and
records of the other Party to the extent necessary to verify the accuracy of any
statement, measurement, computation, charge, or payment made under or pursuant
to this Agreement. A Party electing to audit ("Auditing Party") shall complete
its audit within 3 months following the date on which the books and records of
the other Party ("Audited Party") are first made available for inspection
following the Auditing Party's notice of audit. Within that 3-month period, the
Auditing Party shall submit, in writing, all exceptions disclosed by the audit
to the Audited Party. The Audited Party shall have 30 days following receipt of
the exceptions in which to respond in writing to the exceptions. If the Audited
Party fails to respond within that 30-day period, the exceptions shall be deemed
accepted and appropriate adjustments and settlements shall be made and, as
applicable, paid. If the Parties are unable to reach agreement as to any
exceptions to which the Audited Party timely responded within 30 days of the
Audited Party's response, then either Party may submit the matter to arbitration
in accordance with the provisions in Article 9.

7

<Page>

ARTICLE 7: FORCE MAJEURE

7.1. In the event a Party is rendered unable, wholly or in part, by Force
Majeure, to carry out its obligations under this Agreement, other than the
obligation to make any payments due hereunder, the obligations of that Party, so
far as they are affected by Force Majeure, shall be suspended from the inception
and during the continuance of the inability, and the cause of the Force Majeure,
as far as possible, shall be remedied with commercially reasonable diligence.
The Party affected by Force Majeure shall provide the other Party with written
notice of the Force Majeure event, with reasonably full detail of the Force
Majeure within a reasonable time after the affected Party learns of the
occurrence of the Force Majeure event. The settlement of strikes, lockouts, and
other labor difficulty shall be entirely within the discretion of the Party
having the difficulty and nothing herein shall require the settlement of
strikes, lockouts, or other labor difficulty.

ARTICLE 8: LIABILITY AND INDEMNIFICATION

8.1. As among the Parties hereto, MarkWest and any of its designees shall be in
custody, control and possession of the Raw Make hereunder, until the Raw Make is
delivered to MEA at the applicable Receipt Point, and shall be in custody
control and possession of the Plant Products after the Plant Products are loaded
by MEA into transportation facilities provided by MarkWest.

8.2. As among the Parties hereto, MEA and any of its designees shall be in
custody, control and possession of the Raw Make hereunder after Raw Make is
delivered at the Receipt Point and shall be in custody, control and possession
of the Plant Products until the Plant Products are loaded by MEA into
transportation facilities provided by MarkWest.

8.3. Each Party ("Indemnifying Party") hereby covenants and agrees with the
other Party, and its affiliates (except for the Indemnifying Party itself), and
each of their directors, officers and employees ("Indemnified Parties"), that
except to the extent caused by the Indemnified Parties' gross negligence or
willful conduct, the Indemnifying Party shall protect, defend, indemnify and
hold harmless the Indemnified Parties from, against and in respect of any and
all Losses incurred by the Indemnified Parties to the extent those Losses arise
from or are related to: (a) the Indemnifying Party's facilities; or (b) the
Indemnifying Party's possession and control of the Raw Make or Plant Products,
as applicable.

ARTICLE 9: MISCELLANEOUS

9.1. The failure of any Party hereto to exercise any right granted hereunder
shall not impair nor be deemed a waiver of that Party's privilege of exercising
that right at any subsequent time or times.

9.2. This Agreement shall be governed by, construed, and enforced in accordance
with the laws of the State of Colorado without regard to choice of law
principles.

9.3. This Agreement shall extend to and inure to the benefit of and be binding
upon the Parties, and their respective successors and assigns, including any
assigns of MarkWest's Interests covered by this Agreement. No assignment of this
Agreement shall be binding on either of the Parties until the first day of the
Accounting Period following the date a certified copy of the instrument
evidencing that sale, transfer, assignment or conveyance has been delivered to
the other Party. Further, each assigning Party shall notify its assignee of the
existence of this Agreement and obtain a ratification of this Agreement prior to
such assignment. No assignment by either Party shall relieve that Party of its
continuing obligations and duties hereunder without the express consent of the
other Party.

8

<Page>

9.4. Any change, modification or alteration of this Agreement shall be in
writing, signed by the Parties; and, no course of dealing between the Parties
shall be construed to alter the terms of this Agreement.

9.5 This Agreement, including all exhibits and appendices, contains the entire
agreement between the Parties with respect to the subject matter hereof, and
there are no oral or other promises, agreements, warranties, obligations,
assurances, or conditions precedent, affecting it.

9.6 NO BREACH OF THIS AGREEMENT OR CLAIM FOR LOSSES UNDER ANY INDEMNITY
OBLIGATION CONTAINED IN THIS AGREEMENT SHALL CAUSE ANY PARTY TO BE LIABLE FOR,
NOR SHALL LOSSES INCLUDE, ANY DAMAGES OTHER THAN ACTUAL AND DIRECT DAMAGES, AND
EACH PARTY EXPRESSLY WAIVES ANY RIGHT TO CLAIM ANY OTHER DAMAGES, INCLUDING,
WITHOUT LIMITATION, CONSEQUENTIAL, SPECIAL, INDIRECT, PUNITIVE OR EXEMPLARY
DAMAGES.

9.7 DISPUTE RESOLUTION. Any dispute arising under this Agreement ("Arbitrable
Dispute") shall be referred to and resolved by binding arbitration in Denver,
Colorado, by three (3) arbitrators, in accordance with the rules and procedures
of the Judicial Arbiter Group ("JAG"); and, to the maximum extent applicable,
the Federal Arbitration Act (Title 9 of the United States Code). If there is any
inconsistency between this Section and any statute or rules, this Section shall
control. Arbitration shall be initiated within the applicable time limits set
forth in this Agreement and not thereafter or if no time limit is given, within
the time period allowed by the applicable statute of limitations, by one party
("Claimant") giving written notice to the other party ("Respondent") and to JAG,
that the Claimant elects to refer the Arbitrable Dispute to arbitration, and
that the Claimant has appointed an arbitrator, who shall be identified in such
notice. The Respondent shall notify the Claimant and JAG within thirty (30) Days
after receipt of Claimant's notice, identifying the arbitrator the Respondent
has appointed. The two (2) arbitrators so chosen shall select a third arbitrator
within thirty (30) Days after the second arbitrator has been appointed (upon
failure of a party to act within the time specified for naming an arbitrator,
such arbitrator shall be appointed by the administrator's designee). MarkWest
shall pay the compensation and expenses of the arbitrator named by or for it,
MEA shall pay the compensation and expenses of the arbitrator named by or for
it, and MarkWest and MEA shall each pay one-half of the compensation and
expenses of the third arbitrator. All arbitrators must be neutral parties who
have never been officers, directors, employees, contractors or agents of the
parties or any of their Affiliates, must have not less than ten (10) years
experience in the oil and gas industry, and must have a formal
financial/accounting, engineering or legal education. The parties shall have all
rights of discovery in accordance with the Federal Rules of Civil Procedure. The
hearing shall be commenced within thirty (30) Days after the selection of the
third arbitrator. The parties and the arbitrators shall proceed diligently and
in good faith in order that the arbitral award shall be made as promptly as
possible. The interpretation, construction and effect of this Agreement shall be
governed by the laws of Colorado, and to the maximum extent allowed by law, in
all arbitration proceedings the laws of Colorado shall be applied, without
regard to any conflicts of laws principles. All statutes of limitation and of
repose that would otherwise be applicable shall apply to any arbitration
proceeding. The tribunal shall not have the authority to grant or award indirect
or consequential damages, punitive damages or exemplary damages.

9

<Page>

                                    EXHIBIT A

                         PRODUCTS QUALITY SPECIFICATIONS

PROPANE

<Table>
<Caption>

      PRODUCT CHARACTERISTICS           MINIMUM            MAXIMUM         TEST METHODS
      -----------------------           -------            -------        LATEST REVISION
                                                                          ---------------
<S>                                     <C>          <C>                  <C>
1.  COMPOSITION                                                              ASTM E-260
PERCENT BY LIQUID VOLUME:

Ethane                                               As limited by other
                                                       components and
                                                       vapor pressure

HD-5 Propane                              90                 100

Propylene                                                     5

Butanes & Heavier                                            2.5             ASTM D-2163

2.  VAPOR PRESSURE (psig @ 100                               208             ASTM D-1267
degrees F.)

3.  CORROSION
Copper Strip @ 100 deg. F.                                   1-b             ASTM D-1838

4.  TOTAL SULFUR (PPM by                                     123             ASTM D-2784
weight in liquid)

5.  NON-VOLATILE RESIDUE
     a) Milliliters @ 100 deg. F.                           0.05             ASTM D-2158
                      b) Oil Stain                          Pass

</Table>

10

<Page>

NORMAL BUTANE

<Table>
<Caption>

      PRODUCT CHARACTERISTICS           MINIMUM            MAXIMUM         TEST METHODS
      -----------------------           -------            -------        LATEST REVISION
                                                                          ---------------
<S>                                     <C>                <C>            <C>
1.  COMPOSITION                                                              ASTM E-260
PERCENT BY LIQUID VOLUME:

Isobutane and Lighter                                         5              ASTM D-2163

Butylene (Percent of N. Butane)                               1

Normal Butane & Butylene                  95                 100              GPA 2165

Pentanes & Heavier                                            2

2.  VAPOR PRESSURE  (psig @ 100                               50             ASTM D-1267
degrees F.)

3.  CORROSION
Copper Strip @ 100 deg. F.                                   1-b             ASTM D-1838

4.  TOTAL SULFUR (PPM by weight                              140             ASTM D-3246
in liquid)

5.  VOLATILE RESIDUE
95% Evaporated-Temperature,                                plus 36           ASTM D-1837
degrees F.

</Table>

11

<Page>

ISOBUTANE

<Table>
<Caption>

      PRODUCT CHARACTERISTICS           MINIMUM            MAXIMUM         TEST METHODS
      -----------------------           -------            -------        LATEST REVISION
                                                                          ---------------
<S>                                     <C>             <C>                <C>
1.  COMPOSITION                                                              ASTM E-260
PERCENT BY LIQUID VOLUME:

Propane, Propylene and Lighter                                3             ASTM D-2163

Isobutane                                 96                 100

Butylene, Normal Butane & Heavier                             4

2.  VAPOR PRESSURE  (psig @ 100                               62             ASTM D-1267
degrees F.)

3.  CORROSION
Copper Strip @ 100 deg. F.                                   1-b             ASTM D-1838

4.  TOTAL SULFUR (PPM by weight                              140             ASTM D-3246
in liquid)

5.  VOLATILE RESIDUE
95% Evaporated-Temperature,                                plus 16           ASTM D-1837
degrees F.

6.  DRYNESS                                             No free water           Visual

</Table>

12

<Page>

NATURAL GASOLINE

<Table>
<Caption>

      PRODUCT CHARACTERISTICS           MINIMUM            MAXIMUM         TEST METHODS
      -----------------------           -------            -------        LATEST REVISION
                                                                          ---------------
<S>                                     <C>             <C>            <C>
1.  COMPOSITION                                                              ASTM E-260
PERCENT BY LIQUID VOLUME:

Butanes and Lighter                                           3               GPA 2165

Pentanes & Heavier                        97                 100

2.  VAPOR PRESSURE  (psig @ 100                               14             ASTM D-323
degrees F.)

3.  CORROSION
Copper Strip @ 104 deg. F.                                   1-b             ASTM D-130

4.  DOCTOR TEST                                            Negative           GPA 1138

5.  DRYNESS                                             No free water          Visual

6.  COLOR                                                  No Color       Field White Cup Method
            Saybolt No.                 plus 25                               Lab-ASTM D-156

7.  DISTILLATION
        End Point, deg. F.                                   375             ASTM D-216

</Table>

13

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