Portland Natural Gas Transmission System

Second Revised Volume No. 1

Effective Date: 09/01/2008, Docket: RP08-306-000, Status: Suspended

First Revised Sheet No. 307 First Revised Sheet No. 307 : Suspended

Superseding: Original Sheet No. 307

GENERAL TERMS AND CONDITIONS (Continued)

2.51 Total Heating Value: shall mean, when applied to a Cubic Foot of

Gas, the number of British Thermal Units produced by the complete combustion

in a recording calorimeter at constant pressure, of the amount of Gas which

would occupy a volume of one Cubic Foot at a temperature of 60 degrees

Fahrenheit, with the Gas free of water vapor, and under a pressure equal to

that of 30 inches of mercury at 32 degrees Fahrenheit and under a standard

gravitational force (acceleration of 980.665 cm per second per second) with

air of the same temperature and pressure as the Gas, when the products of

combustion are cooled to the initial temperature of the Gas and air, and when

the water formed by combustion is condensed to the liquid state.

2.52 Transporter: shall mean Portland Natural Gas Transmission System,

its successors or assignees.

2.53 Transporter Overrun Costs: shall mean the costs incurred by

Transporter due to unauthorized Shipper overruns, which costs are not

otherwise included in Transporter's rates. Such costs shall consist of : (a)

costs incurred by Transporter to correct the effect of any tampering with or

alteration of Transporter's facilities which permitted an overall overrun to

occur at the affected Delivery Point and the costs incurred by Transporter to

repair such facilities; (b) costs incurred by Transporter to acquire

additional gas to prevent or alleviate curtailments and to reestablish

appropriate operating pressure on its system; (c) penalties paid by

Transporter to third parties; and(d) costs incurred by Transporter to collect

overrun penalties and to administer the crediting provisions set forth in

Section 8.4.

2.54 Year: shall mean any period of twelve consecutive Months.

2.55 100% Load Factor Equivalent Rate: shall mean, for any Rate

Schedule, the sum of the products of: (1) the Recourse Demand Rate times the

number of Months the service is Applicable each Year, and/or (2) the Recourse

Usage Rate times the number of days the service is applicable each Year;

divided by the number of days Transporter may schedule service under such Rate

Schedule in each Year.