MarkWest Pioneer, L.L.C.

Original Volume No. 1

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

Original Sheet No. 43 Original Sheet No. 43

GENERAL TERMS AND CONDITIONS

(Continued)

2.4.3. No waiver by Transporter of any default by Shipper in any of the

specifications set forth above or in any other provision of this

Tariff shall operate as a continuing waiver of such specification or

as a waiver of any subsequent default whether of a like or different

character.

3. MEASUREMENT

3.1. The volume and the total heating value of Gas received and delivered by

Transporter shall be determined as follows:

3.1.1. The unit of Gas received and delivered by Transporter shall be an

MMBtu.

3.1.2. The unit of volume, for the purpose of measurement, shall be one

cubic foot of Gas. The readings and registrations of the measuring

equipment provided for herein and determinations of Gross Heating

Value shall be computed in terms of such volumes.

3.2. The factors required to determine the volume of Gas received, such as

pressure, temperature, specific gravity and deviations from Boyle’s Law,

shall be calculated in accordance with the American Gas Association Bulletin

Number 3 and any modifications and amendments thereof, and applied in a

practical manner.

3.3. Measurement at the Delivery Points – Each item of equipment shall be

calibrated to provide an accuracy of plus or minus five-tenths of one

percent of full scale.

3.4. Resolving Differences at the Delivery Point(s) – If the testing and

calibration performed at the Delivery Point(s) pursuant to Section 4 show

that any item of equipment installed by Transporter does not conform to the

accuracy requirements of Section 4, all previous readings of that item of

equipment shall be corrected to zero error for any period which the

equipment was known to be in error. If this period is not known, the

correction shall be made for a period extending back one-half of the time

elapsed since the last testing and calibration