MarkWest Pioneer, L.L.C.

Original Volume No. 1

Effective Date: 04/01/2009, Docket: RP09-321-000, Status: Effective

Original Sheet No. 47 Original Sheet No. 47

GENERAL TERMS AND CONDITIONS

(Continued)

4.3. Reading, calibration and adjustment of each party’s meters and related

equipment shall be performed solely by that party. Each party, however,

shall provide the other with seven (7) days prior written notice of all

reading, calibration and adjustment, and representatives of the other party

may be present for such events.

4.4. Either Transporter or Shipper may install, maintain and operate at its own

expense, such check measuring equipment as desired, provided that such

equipment shall be so installed as not to interfere with the operation of

the other’s measuring equipment. Any pressure or volume control regulators

installed by one party shall be operated so as not to interfere with the

other party’s measuring equipment.

4.5. The measuring equipment so installed by either party, together with any

building erected by it for such equipment, shall remain the property of the

party that performed the installation. However, either party shall have the

right to have representatives present at the time of any installing,

reading, cleaning, changing, repairing, inspecting, testing, calibrating or

adjusting done in connection with the other’s measuring equipment used in

measuring or checking the measurement of the delivery of Gas. The records

from such measuring equipment shall remain the property of their owner, but

upon request each will submit to the other its records and charts, together

with calculations therefrom, for inspection and verification, subject to

return within 30 days after receipt thereof.

4.6. Transporter and Shipper shall each preserve for a period of at least 5 years

all test data, charts and other similar records or such longer period as may

be required by the Commission. Microfilms of the original documents shall

be considered true records.