October 12, 2010 Mr. Omer Shalev Lrivironmental Engineer Air Permits Office (Air3) bnvronmental Protection Agency Region 1X 75 Hawthorne Street San Francisco, CA 94105 Subject:
Rio Bravo Poso and Jasmin PSD Permit Modifications Dear Mr. Shalev: Below arethe answers
to the three (3) questions youasked regarding the submittal

of the above referenced PSD Permit Modilica ions: I. Provide future and actual emissions data. Thereis110‘WOrstcase”fuel orcombination

of fuels from anair emissions standpoint.

in the caseof oxides of nitrogen (N0c) when

a“set point” slightly below the permitted concentration limit is reached, additional ammonia injection (for the Thermal De NOx reaction)

is automatically triggered. Thus, the NOx concentrations resulting from fur each fuel/blend
are equaL Likewise with S02, the set point automatically injects more limestone,

sothat equal S02 pollutant levels areachieved for each fuel/blend. 1 he baghouse controls the Particulate Matter (PM) emissions which are comprised primarily
of ash from the fuel and gypsum (calcium sulfate), the product of the reaction of limestone wiil 502. Biomass typically has anash concentration between that of petroleum coke and coal, and
a sulfur content well bekw that of petroleum coke orcoal (which meansless limestone

is needed and hence less solid CaSO 4

is brrned-than with petroleum coke or coal) which will result in equal orlower PM emissions. The extended combustion zoneresidence time in a circulating fluidized bed combustor results
in minimization

of carbon monoxide (CX)) and hydrocarbons, independent

of fuel/blend. Thereibre. the levels will be equivalent. in summary,the addition
of bio.mass fuel will result in equal orlower amounts
of all criteria pollutant emissions.

In a]] cases,criteria pollutant fttture emissions minus actual emissions equals zeroorless than zero.Use zerofor all criteria pollutant “future actuals minus actual” values. (See attached tahM.EMISSIONS CONCENTRATIONS

Mr. Omer Shalev October
12. 2010 Page

2 POLLUTANT FUTURE ACTUAL ACTUAL..-OibflIMBTU O 2-_...—______
0003* 1bLMF4B__..... _PL___ :.0241b/ML 0 0.000*lbjMMBtu 0.046*1b/MMBtu •0.046__ LYQc__.._

o.ooo*iitwati *1MM 1b/MMBtu_* From source test at Rio Bravo Rocklln /a 25MW biomass-fired

CE Lurgi circulating fluidized bed boiler **From source test at Rio Bravo Paso

/ a 33MW coal/petroleum coke-fired
CE Lurgi circulating fluidized bed boiler Note For PM 0 , the Rio Bravo Rocldin plant has an Electrostatic Precipitator, which does not control partic.ulates

as well as a baghouse, like Rio Bravo Poso and Jasmin have. Since biomass has substantially less ash than either coal or petroleum coke, and also less sulfur which means less solid CaSO 4 formed-that must be controlled) than either coal or cake, the resulting future PMw emissions from adding biomass
to the Rio Bravo Poso and Jasmin plants minus actual emissions will be zero or less than zero 2. Specify what type of hiornass

is intended

to be burned
at each thcility. Rio Bravo Paso and Jasmin will burn

a combination

of urban, agricultural, contniction
and forest wood material, typical of that currently comnbusted

at the Rio Bravo Fresno and Rio Bravo Rocklin biomass-fired power plants. The fuel will consist of wood residue from the h,rest products industry (saw mills), aithard prunings, almond, walnut and pistachio shells. frj pits, vineyard pmunings, grape stems and pumice, alfalfa, beanstraw, corn, oats and wheat (vegetable crop hiomnass residues). No painted, oiled or stained ficis will he burned. Rio Bravo Poso and Rio Bravo Jasmin will ensure that only clean biomass will be combusted

at the facility.

In accordance with the draft Authority

to Construct Permit from the APC D, the plant will be limited
to the following materials

in the hiomass: Biomuss introduced into the coinhuTtor shalt not contain more than 2% by weight non-biornass muiericil pIastics, metal, painted and preservative-treated wood, roofing mtueriai, fIber glass, etc.).

I DLtrici Rule 4)02/4;

Mr. Omer Shale’ October
12, 2010 Page

3 To comply with this limit the facility has included the following requirement

as partof all of its hiornass procurement agreements Excluded Materials The hioinoss shall not contain anyfree ash, soil, or cinder, and shall he free of foreign material, including, hut not limited to, sand, stone, metal, glass, rubber, plastics, pre.suretreated orlead based painted wood, chemicals and anyhazardous

ortoxic substances

asdefined under (J’cdifbrnia orfèderal law. 3. How do the sourcesintend
to comply with the 836,520 pounds per day on 30—day rolling averagelimits? How do the facilities currently ShoW compliance with the 34,855 pounds perhour limits? (‘urrently Rio Bravo Poso and Rio Bravo Jasmin demonstrate compliance with their daily and monthly the! limits by useof a weigh belt built into their fuel conveying systems. These weigh belts will continue

to be used with bionwss fuel oncethe permit modifications

are approved. Flie weigh belts arecalibrated
onasemiannua1 basis. To accommodate

the biomass fuel Rio Bravo Poso and Rio Bravo Jasm.in seek

acondition with language similar
to the language EPA approved earlier this yearfor the Mt Poso Cogeneration. Company (attached);
seeCondition IXG, page

9 of PSD Permit Number
Si 86-09. Following the format of the Mt Poso permit language, Rio Bravo Poso and Rio Bravo Jasmin wish to have the following language modification

to their Condition IX-H, page

7 of the PSI) permits: The sumof the combined cocil and coke throughput and 1⁄4 times the throughput

of hiomassfd into the coin hustor shall no:exceed 34,855 pounds perhour onadi basis, The jiAel shall he compthed
of ablend ofpetralewn coke and hiornas-,
upto 100% by weight. If the boiler
is fired on100% hiomass, the fidel throughput shall not exceed 34.855 tons perhour ona thy basis. Lastly, Rio Bravo Poso arid Rio Bravo Jasmin formally requestRPA approval

to conduct

asix month (‘l80-day experimental ‘trial burn” using biomass

asfue’ while EPA
is reviewing our request for PSI) permit modification.
Rio Bravo Poso and Rio Bravo Jasmin intend
to commence
the hiomass tiial buni onoraround November

1, 2010. Records of all fuels burned Will be kept. Emissions data will also be compiled and tbrwarded

to yourollice ona monthly basis for yourreview unless otherwise directed.

It is understood
the maxinuxn length of this test is 180 days, with the intent to utilize this period
totestburn the biomass fuel onacontinuous basis. Testing will be performed

by blending biornass fuel in various combinations With currenty permitted ftels. including coal and/or petroleum coke, utilizing fly,.existing

# Mr. Omer Sbaiev October
12, 2010 Page

4 equipment.
No physical modification

of any kind is required

to perform the experimental trial burn. Note: Laura Yannayon
of your office successflully obtained Deborah Jordan’s signature for an experimental biomass trial burn for the Mt Poso Cogeneration Company facility while PSD permit modification application was being reviews. EPA determined that the blomass trial burn was justified since the rest program would be temporary and would have no significant impact on air quality. As such EPA considered the allowance
of the test burn to be administrative

in nature and not subject
to public review requirements. EPA therefore amended the permit
as requested and stated “this amendment

to the permit shall take effect immediately.

if you have any questions, please ask Laura (972-3534) about this experimental trial burn approval process. Rio Bravo Poso and Rio Bravo Jasmin believe this information satisfies your questions. Please refer any firnher questions you have regarding this request during your review
to Dr. Ted Guth at (619) 987-1111. Thank you in advance for your expedited response

to the Bravo Pos&s and Jasmin’s requests for approval

to conduct the 180-day biomass trial burns. Bill Rossiter Vice President Title V Responsible Official cc: Maggie lstrada, Constellation Energy Ted Guth, Rio Bravo Facility tiles