October 27, 2010 RECEIVED

NOV 2 2010

Mr. Omer Shalev

PerrntS Otlice Air- Environmental Engineer U S. EPA, RegiOn 9 Air Permits Office (Air-3)

Environmental Protection Agency Region IX

75 Hawthorne Street

San Francisco, CA 94105Subject: PSD Permit ModUlcations Applicationsfor Rio Bravo Poso

and Rio Bravo Jasmin

Dear Omer: -

Below are the responses to your additional requests for information:

The previous correspondence submitted included a comparison of the concentration levels of criteria pollutants from Rio Bravo Poso (Poso) and Rio Bravo Jasmin (Jasmin) current operations (for coal and / or petroleum coke) versus the concentration levels of the same criteria pollutants from biomass firing (at Rio Bravo Rocklin (Rocklin) and Rio Bravo Fresno (Fresno)). The concentration levels from biomass firing at Poso and Jasmin were assumed to be similar to

existing data from two circulating fluidized bed (CFB) boilers at Rocklin and Fresno that are

currently firing 100% biomass. That existing data is from source tests and CEMS units. Since

the boilers on which these emission levels were measured were manufactured by the same CFI3 boiler company (Combustion Engineering — Lurgi) and the basic operating parameters are similar (temperature, residence time), it is reasonable to compare emission levels on a

concentration (ppm) basis.

The criteria pollutant emission concentrations from the biomass boilers were less than or equal to the criteria pollutant emission concentrations from a boiler fired on coal! petroleum coke (based

on source test and CEMS data). For the sake of comparison, even though the plants (Poso and Jasmin) could take credit for some emission reductions, the assumption is that the emission concentrations from biomass and coal/coke are equal. Thus the future actual emissions would be

equal to actual emissions.

The Poso and Jasmin plants are, by utility contract, baseloaded. This type ol l)hrnl runs at full load (not ramping up and down to meet daily load demand) 24 hours per day, 7 days per week, and 50 weeks per year. The boilers are identical and both will continue to operate base loaded
As you requested and to determine modification significance, the emissions need to be compared

on a mass basis, per the Code of Federal Regulations (CFR) of representative actual emissions

vs. projected actual emissions in tons per year in the tables below. The following is a

comparison of the emissions on a mass basis (tons per year)

The actual 2005 & 2006 emissions are used as representative actual emissions. The

representative actual emissions are based on source test data at Jasmin and Poso. These years

were chosen as representative actual emissions because the criteria pollutant emissions are

similar to the average emissions during the years 2000 — 2008. The VOC emissions during these

years represent one very high year and one just below the average emission rate during that same

time period. Because the concentrations of the criteria pollutants are expected to be the same ifthe boiler fires biomass, the mass emissions are expected to be the same for actual and future

actual emissions. The emission estimates are presented in the following table.

Rio Bravo Poso

Future Net Actual Actual Pollutant Avg (tpy) Actual Delta (tpy) Increase 2005 (tpy) 2006 (tpy) (tpy) (ipy)

NOx 142.38 140.82 141.60 141.60 0 0

CO 74.77 85.08 79,93 79.93 0 0

ROG 18.89 0.77 9.83 9.83 0 0 (VOC)

PM1O 9.02 8.51 8.77 8.77 0 0

S02 50.96 50.43 50.70 50.70 0 0

Rio Bravo Jasmin

F Future I Net Actual Actual Pollutant Avg (tpy) Actual Delta (tpy) Increase 2005 (tpy) 2006 (tpy) (tpy) (tpy)

NOx 145.56 134.98 140.27 140.27 0 0

CO 83.78 80.74 82.26 82.26 0 0

ROG 19.73 0.77 10.25 10.25 0 0 (VOC)PMIO 7.54 8.76 8.15 8.15 0 0

S02 52.04 46.99 49.51 49.51 0 0
measured at the Rocklin biornass

fired facility. This result is not unexpected due to the extended

residence time of the fuel in the combustion zone of the circulating fluidized bed boiler. This

data was confirmed at an identical biornass-fired (Fresno) plant. CO concentrations from therecent source test were less than 1 ppm, consistent with the Rocklin data. Thus, it is reasonable

to expect that Rio Bravo Poso and Rio Bravo Jasmin have used justifiable emissions

concentrations in projecting future actual emissions.I believe this satisfies your request for additional information. Please let us know if anything

was not clear or if additional information is desired.

Sincerely,

l3ill Rossiter

Responsible Official

Vice-President, CD Jasmin I and CD Poso I

cc: Maggie Estrada, Constellation Energy

Dr. Ted GuthFacility files