MarkWest Pioneer, L.L.C.

Original Volume No. 1

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

Original Sheet No. 78 Original Sheet No. 78

GENERAL TERMS AND CONDITIONS

(Continued)

19.3 (Continued)

guaranteeing payment to Transporter of the amount ultimately found due upon

such invoices after a final determination, which may be reached either by

agreement or judgment of the courts, as may be the case, then Transporter

shall not be entitled to terminate the FT or IT Agreement until default be

made in the conditions of such bond.

19.4. Payments received shall be applied first to accrued interest, then to the

previously outstanding principal due, and lastly, to the most current

principal due.

19.5. If Shipper disputes the amount of any invoice for any reason, Shipper shall

notify Transporter of the dispute within ten (10) Business Days after

receipt of the invoice. If Shipper fails to notify Transporter of the

dispute within ten (10) Business Days, the disputed invoice shall be paid in

full according to the terms of the FT or IT Agreement, but the payment shall

be subject to the interest rate determined in accordance with Section

154.501(d) of the Commission’s regulations. Any refund due to Shipper under

this section shall be due and payable fifteen (15) Days after the final

resolution of the dispute.

19.6. If an invoice is in dispute, Shipper shall pay the portion not in dispute

and provide documentation identifying the basis for the dispute. If Shipper

in good faith:

19.6.1. Disputes the amount of any such bill or part thereof;

19.6.2. Pays to Transporter such amounts as it concedes to be correct;

19.6.3. Provides Transporter with a written notice including a full

description of the reasons for the dispute, together with copies of

supporting documents; and