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                    [LETTERHEAD OF EASTMAN CHEMICAL COMPANY]



         March 27, 2000




         Mr. Terry Piesker
         Tengasco, Inc.
         Medical Arts Bldg.
         603 Main Ave., Suite 500
         Knoxville, TN 37902

         Dear Mr. Piesker:

         As we have discussed, Eastman's evaluations indicate that the Polymers
         area of our Plant can be operated with natural gas containing nitrogen
         up to 5% by volume. However, there are additional costs to Eastman to
         utilize gas with this higher nitrogen content. To offset these
         additional costs, Eastman proposes to amend the subject Agreement as
         follows:

         Revise the last sentence of Article 1, Quantity, Section 1.1, to read:

         "If Seller and Buyer agree upon option 4.2(b) or 4.2(c) of the General
         Terms and Conditions, then "Minimum Volume" means with respect to any
         Day, the lesser of i) 10,000 MMBtu's or ii) eighty percent (80%) of the
         Natural Gas requirements of Buyer's plant on such Day."

          Revise the Appendix, Article A-IV, Quality, Section 4.2, to read:

               "4.2 A portion of Buyer's Plant may require natural gas with
         Total Nonhydrocarbons (including Nitrogen) below 2% by volume. To
         accommodate this separate specification, Seller agrees to provide, at
         its expense, one of the following alternatives to Buyer, as determined
         by mutual agreement of Buyer and Seller, prior to the beginning of gas
         supply:

          (a.) Provide and construct separate supply piping from Buyer's
               alternate natural gas source to the portion of Buyer's Plant
               requiring the lower Total Nonhydrocarbons.

          (b.) Installation of a Nitrogen Removal Unit to reduce the Total
               Nonhydrocarbons in the Natural Gas to below 2%. The Nitrogen
               Removal Unit could be located at Seller's facilities, adjacent to
               Buyer's Plant, or in Buyer's Plant.

          (c.) Reduce the price as defined in Article 2.3 for all Natural Gas
               quantities above 5,000 MMBtu per day up to 10,000 MMBtu per day
               to Index Price plus $0.05 per MMBtu."

     Our intent is for the price reduction in 4.2(c.) to offset a portion of
     Eastman's costs while allowing additional sales volume for Tengasco at less
     cost than either alternate 4.2(a.) or 4.2(b.).



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Mr. Terry Piasker
Page 2


Add the following to the Appendix, Article A-IV, Quality,

     "4.5 If the portion of Buyers Plant that requires natural gas with Total
Nonhydrocarbons (including Nitrogen) below 2% by volume falls to operate
satisfactorily after selection of 4.2(a.), Buyer may, upon six (6) month's
written notice, request Seller to select option 4.2(a.) or 4.2(b.) and complete
construction and start up of the selected option within eighteen (18) months of
the written notice."

     If you are in agreement with these terms please have this letter signed
below on duplicate copies and return one to me for our files.

 Very truly yours,


 EASTMAN  CHEMICAL COMPANY

 /s/ S.J. Murff
 ------------------------------------
 S. J.  Murff
 Director, Olefins Energy Procurement

 Accepted  BY TENGASCO, INC.


 By: /s/ M.E. Ratliff
     ---------------------------
 Name:  M.E. Ratliff
       ---------------------------
 Title: C.E.O.
       ---------------------------