December 28, 1999

The Honorable David P. Boergers
Secretary
Federal Energy Regulatory Commission
888 First Street, N.E.
Washington, D.C.  20426

Re:	California Independent System Operator Corporation
	Docket Nos. ER98-496-006 and ER98-2160-004 

Dear Secretary Boergers:

	On December 22, 1999, the ISO filed the Prepared Initial Testimony and Exhibits of Eric Hildebrandt and Brian Theaker in the above-referenced dockets.   Enclosed for filing are the original affidavits of Eric Hildebrandt and Brian Theaker to replace the facsimile copies of their affidavits which were previously filed with the Commission.

	Also enclosed are two extra copies of the filing to be time/date stamped and returned to us by the messenger.  Thank you for your assistance.  

					Respectfully submitted,

					Edward Berlin
					J. Phillip Jordan
					Swidler Berlin Shereff Friedman, LLP
					3000 K Street, N.W.
					Washington D.C.  20007

					Counsel for the California
					Independent System Operator

Enclosures
cc:	The Honorable Herbert Grossman
	Restricted Service List

CERTIFICATE OF SERVICE

	I hereby certify that I have this day served the foregoing documents upon each person designated on the Restricted Service List compiled by the Presiding Judge in this proceeding.  

	Dated at Washington, D.C. on this 28th day of December, 1999.

						_______________________
						J. Phillip Jordan
						Swidler Berlin Shereff Friedman, LLP
						3000 K Street, N.W.
						Washington, D.C.  20007

						Counsel for the California
						Independent System Operator