<PAGE>
 
                                                                 EXHIBIT 10.24

                               SERVICE AGREEMENT
                    APPLICABLE TO THE STORAGE OF NATURAL GAS
                            UNDER RATE SCHEDULE GSS
                                 (SECTION 7(C))
                                        

          AGREEMENT made as of this  ________  day of November, 1993, by and
between CNG TRANSMISSION CORPORATION, a Delaware corporation, hereinafter called
"Pipeline," and BOSTON GAS COMPANY, a Massachusetts corporation, hereinafter
called "Customer."

          WITNESSETH: That in consideration of the mutual covenants herein
contained, the parties hereto agree that Pipeline will store natural gas for
Customer during the term, at the rates and on the terms and conditions
hereinafter provided and, with respect to gas delivered by each of the parties
to the other, under and subject to Pipeline's Rate Schedule GSS and all of the
General Terms and Conditions contained in Pipeline's FERC Gas Tariff and any
revisions thereof that may be made effective hereafter:

                                   ARTICLE I
                                   QUANTITIES
                                   ----------
                                        
          Beginning as of October 1, 1993 and thereafter for the remaining term
of this agreement, Customer agrees to deliver to Pipeline and Pipeline agrees to
receive for storage in Pipeline's underground storage properties, and Pipeline
agrees to inject or cause to be injected into storage for Customer's account,
store, withdraw from storage, and deliver to Customer and Customer agrees to
receive, quantities of natural gas as set forth on Exhibit A, attached hereto.

                                   ARTICLE II
                                      RATE
                                      ----

          A.  For storage service rendered by Pipeline to Customer hereunder,
Customer shall pay Pipeline in accordance with Rate Schedule GSS contained in
Pipeline's effective FERC Gas Tariff or any effective superseding rate schedule.
Said rate schedule or superseding rate schedule and any revisions thereof which
shall be filed and made effective shall apply to and be a part of this
Agreement. Pipeline shall have the right to propose to and file with the Federal
Energy Regulatory Commission or other body having jurisdiction, changes and
revisions of any effective rate schedule, or to propose and file superseding
rate schedules, for the purpose of changing the rate, charges, and other
provisions thereof effective as to Customer; provided, however, that any request
by Pipeline to amend the terms and conditions of Rate Schedule GSS must be
consistent with the terms and conditions of Article VII, Part 2,
<PAGE>
 
Paragraph (F) of the Stipulation filed on March 31, 1993 by Pipeline in Docket
No. RS92-14 and conform to the requirements of Section 7(b) of the Natural Gas
Act, if applicable, and provided further that Pipeline and Customer agree that
they will not seek to place in effect a change in any aspect of the terms and
conditions under Section 8 of Rate Schedule GSS for a period of two years from
the date of such request. The filing of requests, changes and revisions of Rate
Schedule GSS shall be without prejudice to the right of Customer to contest or
oppose such requests, filings or revisions and their effectiveness.

          B.  The Storage Demand Charge and the Storage Capacity Charge provided
in the aforesaid rate schedule shall commence on October 1, 1993.

                                  ARTICLE III
                               TERM OF AGREEMENT
                               -----------------

          Subject to all the terms and conditions herein, this Agreement shall
be effective as of October 1, 1993, and shall continue in effect for a primary
term through and including March 31, 2006, and for subsequent annual terms of
April 1 through March 31 thereafter, until either party terminates this
Agreement by giving written notice to the other at least twenty-four months
prior to the start of an annual term.

                                   ARTICLE IV
                         POINTS OF RECEIPT AND DELIVERY
                         ------------------------------

          The Points of Receipt for Customer's tender of storage injection
quantities, and the Point(s) of Delivery for withdrawals from storage shall be
specified on Exhibit A, attached hereto.

                                   ARTICLE V
                          SPECIAL OPERATING CONDITIONS
                          ----------------------------
                                        
          For the sole purpose of calculating Customer's Storage Gas Balance to
determine the initial decline in Customer's Daily Entitlement, Pipeline shall
multiply Customer's actual Storage Gas Balance by a factor of 1.176. For
purposes other than calculating the initial decline in Customer's Daily
Entitlement, Customer's Storage Gas Balance shall remain equal to Customer's
actual inventory in storage.

                                   ARTICLE VI
                                 MISCELLANEOUS
                                 -------------

          A.  No change, modification or alteration of this Agreement shall be
or become effective until executed in

                                     -2-
                                        
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writing by the parties hereto; provided, however, that the parties do not intend
that this Article VI.A. requires a further written agreement either prior to
the making of any request or filing permitted under Article II hereof or prior
to the effectiveness of such request or filing after Commission approval,
provided further, however, that nothing in this Agreement shall be deemed to
prejudice any position the parties may take as to whether the request, filing or
revision permitted under Article II must be made under Section 7 or Section 4 of
the Natural Gas Act.

          B.  Any notice, request or demand provided for in this Agreement, or
any notice which either party may desire to give the other, shall be in writing
and sent to the following addresses:

     Pipeline:      CNG Transmission Corporation 
                    445 West Main Street
                    Clarksburg, West Virginia   26301
                    Attention:  Vice President, Marketing and Customer Services

     Customer:      Boston Gas Company
                    One Beacon Street
                    Boston, MA    02108
                    Attention:  Manager, Gas Supply


or at such other address as either party shall designate by formal written
notice.

          C.  No presumption shall operate in favor of or against either party
hereto as a result of any responsibility either party may have had for drafting
this Agreement.

          D.  The subject headings of the provisions of this Agreement are
inserted for the purpose of convenient reference, and are not intended to become
a part of or to be considered in any interpretations of such provisions.

                                  ARTICLE VII
                                PRIOR CONTRACTS
                                ---------------
                                        
          This Service Agreement shall supersede and cancel, as of the effective
date, the Service Agreements for storage service between Customer and Pipeline
dated June 1, 1993.

                                     -3-
<PAGE>
 
          IN WITNESS WHEREOF, the parties hereto have caused this Agreement to
be signed by their duly authorized officials as of the day and year first above
written.

                              CNG TRANSMISSION CORPORATION (PIPELINE)

                              BY:  /s/ Joseph A. Curin
                                   --------------------------------  
                              ITS:     VICE PRESIDENT 



                              BOSTON GAS COMPANY (CUSTOMER)

                              BY:  /s/ William R. Luthern
                                   --------------------------------   
                              ITS:     VICE PRESIDENT 
                                   --------------------------------   
                                              (TITLE)

                                      -4-
<PAGE>
 
                                   EXHIBIT A
                           TO THE GSS (SECTION 7(C))
                           STORAGE SERVICE AGREEMENT
                           DATED NOVEMBER ____, 1993
                    BETWEEN CNG TRANSMISSION CORPORATION AND
                               BOSTON GAS COMPANY
                                        
A.   QUANTITIES
     ----------

     The quantities of natural gas storage service which Customer may utilize
under this Service Agreement, as well as Customer's applicable Billing
Determinants, are as follows:

     1.   Storage Capacity of 4,698,132 Dekatherms (Dt), and

     2.   Storage Demand of 42,457 Dt per day.

B.   POINTS OF RECEIPT AND DELIVERY
     ------------------------------

  1. The Points of Receipt for Customer's tender of storage injection
     quantities, and the maximum quantities and character of service for each
     point shall be as set forth below. Pipeline will use due care and diligence
     to assure, and Customer will use due care and diligence to cause its
     transporter to assure, that uniform pressures will be maintained at the
     Receipt Points as reasonably may be required to render service hereunder,
     but Pipeline will not be required to accept gas at less than the minimum
     pressures specified herein.

     a.   Up to 26,101 Dt per Day at the interconnection of the facilities of
          Pipeline and Texas Eastern Transmission Corporation ("Texas Eastern")
          or Transcontinental Gas Pipe Line Corporation ("Transco") or other
          pipeline(s) in Clinton County, Pennsylvania, known as the Leidy
          Interconnection, at a pressure of not less than one thousand (1,000)
          pounds per square inch gauge ("psig").

     b.   Up to 26,101 Dt per Day at the "Texas Eastern Market Zone 2 Point"
          which shall consist of any combination of the following points:

          1.   The interconnection of the facilities of Pipeline and Texas
               Eastern or other pipeline(s) in Westmoreland County,
               Pennsylvania, known as the Oakford Interconnection, at a pressure
               of not less than five hundred seventy-five (575) psig.

          2.   An existing point of interconnection between Pipeline and Texas
               Eastern Transmission Corporation ("Texas Eastern") located in
               Noble County, Ohio, at Texas Eastern Measuring Station 450, at
               the operating pressure existing at the point of delivery.
<PAGE>
 
                                                                      EXHIBIT A
                                NOVEMBER ___, 1993 GSS (SECTION 7(C)) AGREEMENT 
                                       BETWEEN CNG TRANSMISSION CORPORATION AND 
                                                             BOSTON GAS COMPANY 
                                                                    PAGE 2 OF 3
 
          3.   An existing point of interconnection between Pipeline and Texas
               Eastern located in Monroe County , Ohio, at Texas Eastern
               Measuring Station 471, at a pressure of not less than two hundred
               (200) psig.

          4.   An existing point of interconnection between Pipeline and Texas
               Eastern located in Monroe County, Ohio, at Texas Eastern
               Measuring Station 983, at a pressure of not less than three
               hundred (300) psig.
               
          5.   An existing point of interconnection between Pipeline and Texas
               Eastern located in Monroe County, Ohio, at Texas Eastern
               Measuring Station 004, at the pressure provided for in the
               General Terms and Conditions of Texas Eastern's FERC Gas Tariff.

          6.   An existing point of interconnection between Pipeline and Texas
               Eastern located in Marshall County, West Virginia at Texas
               Eastern Measuring Station 372, at the operating pressure existing
               at the point of delivery.

          7.   An existing point of interconnection between Pipeline and Texas
               Eastern located in Green County, Pennsylvania at Texas Eastern
               Measuring Station 037, at the pressure provided for in the
               General Terms and Conditions of Texas Eastern's FERC Gas Tariff.

          8.   An existing point of interconnection between Pipeline and Texas
               Eastern located in Somerset County, Pennsylvania at Texas Eastern
               Measuring Station 051, at the pressure provided for in the
               General Terms and Conditions of Texas Eastern's FERC Gas Tariff.

2.   The quantity of gas which Customer shall be entitled to tender to Pipeline
     for injection into storage at the Leidy Interconnection on a firm basis on
     any Day during the Storage Year shall be one-one hundred eightieth
     (1/180th) of Customer's Storage Capacity whenever Customer's Storage Gas
     Balance is less than or equal to one half of Customer's Storage Capacity,
     and one-two hundred fourteenth (1/214th) of Customer's Storage Capacity
     whenever Customer's Storage Gas Balance is greater than one half of
     Customer's Storage Capacity.
<PAGE>
 
                                                                      EXHIBIT A
                                NOVEMBER ___, 1993 GSS (SECTION 7(C)) AGREEMENT 
                                       BETWEEN CNG TRANSMISSION CORPORATION AND
                                                BOSTON GAS COMPANY PAGE 3 OF 3

3. The Points of Delivery for withdrawals from storage, and the maximum
   quantities and character of service for each point, shall be as set forth
   below.  Pipeline will use due care and diligence to assure, and Customer will
   use due care and diligence to cause its transporter to assure, that uniform
   pressures will be maintained at the Delivery Points as reasonably may be
   required to render service hereunder, and Pipeline will use due care and
   diligence to deliver gas (or cause gas to be delivered) within the pressure
   limitations specified herein.

   a.   Up to 42,457 Dt per Day at the interconnection of the facilities of
        Pipeline and Texas Eastern or other pipeline(s) in Westmoreland County,
        Pennsylvania, known as the Oakford Interconnection, at a pressure of not
        less than eight hundred fifty (850) psig.

   b.   Up to 42,457 Dt per Day at an existing point of interconnection between
        the facilities of Pipeline and Texas Eastern, in Franklin County,
        Pennsylvania, known as the Chambersburg Interconnection, on an
        interruptible basis if operating conditions permit, at a pressure of not
        more than seven hundred (700) psig.

   c.   Up to 42,457 Dt per Day at an existing point of interconnection between
        the facilities of Pipeline and Texas Eastern, in Greene County,
        Pennsylvania, known as the Crayne Interconnection, on an interruptible
        basis if operating conditions permit, at a pressure of not more than
        eight hundred sixty-five (865) psig.

   d.   Up to 42,457 Dt per Day at an existing point of interconnection between
        the facilities of Pipeline and Texas Eastern, in Cambria County,
        Pennsylvania, known as the Rager Mountain Interconnection, on an
        interruptible basis if mutually agreed between Pipeline and Customer, at
        the operating pressure existing at the point of delivery.

   e.   Up to 42,457 Dt per Day at the interconnection of the facilities of
        Pipeline and Texas Eastern or Transcontinental Gas Pipe Line Corporation
        ("Transco") or other pipeline(s) in Clinton County, Pennsylvania, known
        as the Leidy Interconnection, at a pressure of not less than one-
        thousand, two-hundred (1,200) psig, if, in Pipeline's sole opinion, its
        operating or other circumstances permit.