ISO Market Participants:
		This Market Notice provides additional guidance pursuant to
the Federal Energy Regulatory Commission's (FERC) April 26, Order
Establishing Prospective Mitigation and Monitoring Plan for the California
Wholesale Electric Markets and Establishing an Investigation Of Public
Utility Rates in Wholesale Western Energy Markets, and the Market Notice
issued by the ISO on April 27.
		FERC directed each gas-fired generator in California (both
those who have signed Participating Generator Agreements (PGAs) and those
non-public utility gas-fired generators who sell into the ISO's markets or
utilize the ISO Controlled Grid) to file, by May 1, 2001 with the Commission
and the ISO (on a confidential basis) the heat rate (not including start-up
and minimum load fuel costs) and emission rate for each generating unit.
The ISO's understanding at this time is that this order applies to all
gas-fired generators for which the use of their output utilizes the ISO
Controlled Grid, even if they are not covered by a PGA or sold into the
ISO's markets.  If a generation owner believes there is ambiguity in
determining whether there is use of the ISO Controlled Grid, case-specific
details may need to be considered before a final interpretation can be
provided.
		The ISO recognizes that some generators' maximum and minimum
output levels, heat rate, and emissions may vary with ambient conditions.
In such cases, the ambient conditions that apply to the provided information
(e.g., specifically-described average summer conditions) should be stated as
part of the response, and the response may further state how the provided
information would vary under different ambient conditions.  The ISO will
continue to consider this issue during implementation of FERC's decision.
Owners of new generation, for which final test results are not yet
available, should provide those final test results no later than 7 days
prior to commercial operation.
		In order to facilitate the provision and use of the heat
rate and emission data to be provided by the above-described generating
units, the ISO provided a template for submitting the required data, as part
of its April 27 Market Notice.  In completing the template, the same MW
points should be used for both heat rates and emissions data.  The heat rate
(BTU/kWh) should be stated as the average heat rate at each operating point,
rather than as the incremental heat rate.  We request that you complete the
template with heat and emission rates for as many output levels as possible,
up to preferably all 11 output levels.  A minimum of two output levels
should be provided.
		Please submit the required data, in the format specified, no
later than 5:00 PM, May 1, 2001.  Please submit such information
electronically to Jim Price at the ISO (jprice@caiso.com <jprice@caiso.com>
).  The ISO will treat all submitted data on a confidential basis.

		Byron B. Woertz, Jr.
		Director, Client Relations
		(916) 608-7066
		(800) 481-7037 - Pager