MarkWest Pioneer, L.L.C.

Original Volume No. 1

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

Original Sheet No. 67 Original Sheet No. 67

GENERAL TERMS AND CONDITIONS

(Continued)

11.3. Notice of an OFO will be issued via telephone and followed by a facsimile.

OFOs will also be posted on Transporter’s Website. Transporter shall also

post, as soon as available, information about operational parameters, which

affect when an OFO will begin and end (e.g., significant changes in pressure

on any pipeline segment, status of facility repairs, etc.). Transporter

shall provide as much advance warning as practicable of: (i) conditions

which may create the need to issue an OFO; and (ii) the issuance,

termination or modification of an OFO. Transporter will endeavor to post

the notice that it will issue an OFO on its Website before 4:00 pm Central

Time or otherwise will endeavor to notify Shippers via its Website by 4:00

pm Central Time that they should check Transporter’s Website again at a

specified later time to see whether an OFO will be in effect for the next

Day. Additionally, if Shipper has provided to Transporter the e-mail

address as specified in NAESB Standard 5.3.35, such posting will be provided

via e-mail in the format as defined in NAESB Standard 5.3.38 at least four

(4) hours prior to the start of the Day before an OFO will be effective as

to a Shipper; provided, however, that Transporter may issue an OFO on as

little as one (1) hour notice where operationally necessary. Such notice

shall specify the anticipated duration of the OFO. An OFO will be effective

at the start of a Day and will continue until the end of the Day and through

the end of successive Days until Transporter notifies Shippers on its

Website that the OFO has been lifted.

11.4. Shipper Compliance - A Shipper must comply with an OFO within the time

period set forth therein unless the shipper is able to demonstrate that such

compliance is prevented due to a Force Majeure event as defined in Section

27 of the GT&C, provided however, that the Shipper shall make a good faith

effort to comply with any such OFO.

11.5. Waiving of Penalty/Charges – A shipper shall not incur any charges or

penalties if such charges or penalties resulted from Shipper’s compliance

with an OFO, including any preliminary action taken by Shipper in response

to an OFO watch issued by Transporter as a precondition to an OFO.