Northern Natural Gas Company                                              Sixth Revised Sheet No. 290
FERC Gas Tariff                                                                           Superseding
Fifth Revised Volume No. 1                                                Fifth Revised Sheet No. 290

                  48.   Daily Delivery Variance Charges (DDVC)
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                    A.  General

                        Shippers are required to take actual daily volumes at their delivery
                        point(s) as close to daily scheduled volumes as possible.  In the event
                        that actual daily volumes vary from daily scheduled volumes, Shippers
                        are subject to Daily Delivery Variance Charges (DDVC), after a
                        tolerance has been considered (except as provided below in System
                        Overrun Limitation).

                        There are five (5) types of DDVC's:  a Positive DDVC, a
                        Positive/Critical Day DDVC, a Negative DDVC, a Punitive DDVC and a
                        Punitive/Critical Day DDVC.  The rate for each is set forth on Sheet
                        No. 53.

                        Also, see Rate Schedule SMS of this tariff, "System Management
                        Service".

                    B.  Positive DDVC.  In the absence of an SOL or Critical Day being called
                        (as described below), the Positive DDVC shall apply under the following
                        conditions:

                          For TF, TFX, and LFT
                          --------------------
                          1)  If daily volumes scheduled at the delivery point are less than
                              the MDQ, the Positive DDVC applies to daily volumes in excess of
                              all daily volumes scheduled at the point plus a tolerance of five
                              percent (5%) of scheduled volumes at the point, up to a level
                              equal to the MDQ plus five percent (5%) of the MDQ.

                          2)  If daily volumes scheduled at the delivery point are equal to or
                              greater than the MDQ, the Positive DDVC applies to the first five
                              percent (5%) of the daily scheduled volumes in excess of all
                              daily volumes scheduled at the point plus a tolerance of five
                              percent (5%) of scheduled volumes at the point.

                          3)  If the Shipper has subscribed to service under Rate Schedule SMS,
                              the Positive DDVC, as determined in 1) and 2) above, will apply
                              to volumes in excess of the scheduled volume plus the five
                              percent (5%) tolerance plus the SMS Contract Quantity (SMSQ).

                          4)  The tolerance level for Small Customers who have not bypassed
                              Northern's system in 1) and 2) above shall be the greater of five
                              percent (5%) of all scheduled volumes at the point or 650 MMBtu.
                              The tolerance level for Bypassing Small Customers shall be equal
                              to the Bypassing Small Customer's MDQ.

                              The Positive DDVC level for Small Customers who have not bypassed
                              Northern's system is as follows: if daily volumes scheduled at
                              the delivery point are less than the MDQ, the positive DDVC
                              applies to daily volumes in excess of all daily volumes scheduled
                              at the point plus a tolerance level of the greater of five
                              percent (5%) of scheduled volumes at the point or 650 MMBtu, up
                              to a level equal to the MDQ plus the greater of five percent (5%)
                              of the MDQ or 650 MMBtu.  If daily volumes scheduled at the
                              delivery point are equal to or greater than the MDQ, the Positive
                              DDVC applies to the greater of the first five percent (5%) of the
                              daily scheduled volumes or 650 MMBtu in excess of all daily
                              volumes scheduled at the point plus a tolerance of the greater of
                              five percent (5%) or scheduled volumes or 650 MMBtu at the point.
Issued by: Mary Kay Miller, V.P. Regulatory & Government Affairs
Issued on: August 24, 2006                                             Effective: September 24, 2006