MarkWest Energy Partners, LP (MWE)

We have agreed to:

·                                          unload any NGLs that MarkWest Hydrocarbon delivers to our Siloam facility by railcar;

·                                          accept and fractionate into NGL products all of the NGLs that MarkWest Hydrocarbon delivers;

·                                          furnish and be responsible for all of the fuel needed in the operation of our Siloam facility;

·                                          operate, maintain and, if necessary, replace all facilities for loading the NGL products for shipment;

·                                          lease tracking rights on our Siloam railroad siding to MarkWest Hydrocarbon for no additional charge;

·                                          at our sole risk be responsible for loading the finished NGL products for shipments as directed by MarkWest Hydrocarbon; and

·                                          at the direction of MarkWest, store the finished NGL products in underground storage caverns at our Siloam facility and, if also directed by MarkWest Hydrocarbon, withdraw the products from such storage caverns.

As compensation for providing our fractionating, loading and above ground storage services, MarkWest Hydrocarbon pays us a monthly fractionation fee based on the gallons delivered to us for fractionation. As compensation for our storage of the NGL products in underground storage caverns, MarkWest Hydrocarbon pays us an annual storage fee. As compensation for unloading any NGLs that MarkWest Hydrocarbon delivers to us by railcar, MarkWest Hydrocarbon pays us a monthly fee based on the gallons unloaded. A portion of each of the above fees is adjusted on January 1 of each year to

127

reflect changes in the Producers Price Index for Oil and Gas Field Services. Under the agreement, MarkWest Hydrocarbon incurs all incidental losses incurred at our facilities, or the losses or gains due to variations in measurement equipment.

We have agreed to:

•                                          unload any NGLs that MarkWest Hydrocarbon delivers to our Siloam facility by railcar;

•                                          accept and fractionate into NGL products all of the NGLs that MarkWest Hydrocarbon delivers;

•                                          furnish and be responsible for all of the fuel needed in the operation of our Siloam facility;

•                                          operate, maintain and, if necessary, replace all facilities for loading the NGL products for shipment;

•                                          lease tracking rights on our Siloam railroad siding to MarkWest Hydrocarbon for no additional charge;

•                                          at our sole risk be responsible for loading the finished NGL products for shipments as directed by MarkWest Hydrocarbon; and

•                                          at the direction of MarkWest, store the finished NGL products in underground storage caverns at our Siloam facility and, if also directed by MarkWest Hydrocarbon, withdraw the products from such storage caverns.

As compensation for providing our fractionating, loading and above ground storage services, MarkWest Hydrocarbon pays us a monthly fractionation fee based on the gallons delivered to us for fractionation. As compensation for our storage of the NGL products in underground storage caverns, MarkWest Hydrocarbon pays us an annual storage fee. As compensation for unloading any NGLs that MarkWest Hydrocarbon delivers to us by railcar, MarkWest Hydrocarbon pays us a monthly fee based on the gallons unloaded. A portion of each of the above fees is adjusted on January 1 of each year to reflect changes in the Producers Price Index for Oil and Gas Field Services. Under the agreement, MarkWest Hydrocarbon incurs all incidental losses incurred at our facilities, or the losses or gains due to variations in measurement equipment.

We have agreed to:

•                                          unload any NGLs that MarkWest Hydrocarbon delivers to our Siloam facility by railcar;

•                                          accept and fractionate into NGL products all of the NGLs that MarkWest Hydrocarbon delivers;

•                                          furnish and be responsible for all of the fuel needed in the operation of our Siloam facility;

•                                          operate, maintain and, if necessary, replace all facilities for loading the NGL products for shipment;

•                                          lease tracking rights on our Siloam railroad siding to MarkWest Hydrocarbon for no additional charge;

•                                          at our sole risk be responsible for loading the finished NGL products for shipments as directed by MarkWest Hydrocarbon; and

•                                          at the direction of MarkWest, store the finished NGL products in underground storage caverns at our Siloam facility and, if also directed by MarkWest Hydrocarbon, withdraw the products from such storage caverns.

As compensation for providing our fractionating, loading and above ground storage services, MarkWest Hydrocarbon pays us a monthly fractionation fee based on the gallons delivered to us for fractionation. As compensation for our storage of the NGL products in underground storage caverns, MarkWest Hydrocarbon pays us an annual storage fee. As compensation for unloading any NGLs that MarkWest Hydrocarbon delivers to us by railcar, MarkWest Hydrocarbon pays us a monthly fee based on the gallons unloaded. A portion of each of the above fees is adjusted on January 1 of each year to reflect changes in the Producers Price Index for Oil and Gas Field Services. Under the agreement, MarkWest Hydrocarbon incurs all incidental losses incurred at our facilities, or the losses or gains due to variations in measurement equipment.

We have agreed to:

•                                          unload any NGLs that MarkWest Hydrocarbon delivers to our Siloam facility by railcar;

•                                          accept and fractionate into NGL products all of the NGLs that MarkWest Hydrocarbon delivers;

•                                          furnish and be responsible for all of the fuel needed in the operation of our Siloam facility;

•                                          operate, maintain and, if necessary, replace all facilities for loading the NGL products for shipment;

•                                          lease tracking rights on our Siloam railroad siding to MarkWest Hydrocarbon for no additional charge;

•                                          at our sole risk be responsible for loading the finished NGL products for shipments as directed by MarkWest Hydrocarbon; and

•                                          at the direction of MarkWest, store the finished NGL products in underground storage caverns at our Siloam facility and, if also directed by MarkWest Hydrocarbon, withdraw the products from such storage caverns.

As compensation for providing our fractionating, loading and above ground storage services, MarkWest Hydrocarbon pays us a monthly fractionation fee based on the number of gallons delivered to us for fractionation. As compensation for our storage of the NGL products in underground storage caverns, MarkWest Hydrocarbon pays us an annual storage fee. As compensation for unloading any NGLs that MarkWest Hydrocarbon delivers to us by railcar, MarkWest Hydrocarbon pays us a monthly fee based on the number of gallons unloaded. A portion of each of the above fees is annually adjusted on January 1 of each year to reflect changes in the Producers Price Index for Oil and Gas Field Services. Under the agreement, MarkWest Hydrocarbon incurs all of the incidental losses incurred at our facilities, or the losses or gains due to variations in measurement equipment.