Name:

Title: Company: Sign Date: Name: Title: Company: Sign Date: Permitted Facility Representative / Date Testing Company Representative / Date 

### Midwest Generation Will County Unit 4

Final Test Report for

/ / Based on information and belief formed after reasonable inquiry, I certify that the statements and information in this test report are true, accurate, and complete. I have reviewed all testing details and results in this test report and hereby certify that the test report is authentic and accurate.

Tuesday, February 08, 2011 Page 1 of 20Midwest Generation Will County Unit 4

Facility Information: Midwest Generation - Will County Unit 4 529 E. 135th Street

Romeoville IL 60446 Contact: Scott B. Miller Phone: 630-771-7859 Fax: 312-788-5219 Email: smiller@mwgen.com Testing Company: Platt Environmental Services, Inc. 1520 Kensington Road Suite 204 Oak Brook IL 60523-2141 Contact: Eric L. Ehlers Phone: 630-699-7690 Fax: 630-521-9494 Email: eehlers@plattenv.com

Air Permit Number: 95090080 Permitted Source ID/Name: Will County 884 Permitted Maximum Process Rate: 5016 mmBtu/hr Max. Normal Operation Process Rate: 5016 mmBtu/hr Target Process Test Rate 4412 mmBtu/hr

Description of the source (including control equipment). Please see the attachments for source or process flow diagram: Unit 4 is a tangentially fired boiler rated at 551 MW and 5,016 mmBtu/hr. The steam generator is capable of delivering 3,900,000 pounds of steam per hour. The outlet header pressure is 2,490 psig at 1005 degrees F with feed water at 533 degrees F. The steam generator will reheat 2,771,100 pounds of steam per hour for 608 degrees F and 475 psia to 1005 degrees F and 447 psia. Unit 4 is a twin furnace and includes an economizer, four regenerativeair heaters, eight coal feeders and pulverizers, oil ignitors, superheat and reheat temperature control. Unit 4 burns primarily pulverized coal. Additionally, Unit 4 utilizes fuel oil ignition during startup and for flame stabilization. Heat produced in the boiler converts water to high-pressure steam in the boiler. Steam is forced through the turbine, causing the turbine blades and shaft to rotate. The turbine shaft turns the attached generator shaft, which produces electricity. The pollution controls consist of low NOx burners and overfire air for NOx, low sulfur coal for SO2, a cold ESP for PM and activated carbon injection for mercury. Industry/SCC/NAIS 221112

Sampling Location Information:

Test Parameter Information: AFS #: 17-197-0166 FRS #: 110000432933

SCC / Description 10100222 External Combustion Boilers - Electric Generation - Bituminous/Subbituminous Coal - Pulverized Coal: Dry Bottom (Subbituminous Coal)
The following state and federal regulations that apply to the proposed testing:

Location Round

Duct Diam. Distance from upstream dist. Distance from

downstream dist. Number of

Traverse Ports Equiv. Diam Min.Travers Points Rect. Duct Length /Width Stack 198 0 0 4 0 12 0 0

Target Parameter Test Method Number of

Test Runs Test Run

Duration Sample

Points Comments Location Regulation Description Compound Limit Unit 0

Tuesday, February 08, 2011 Page 2 of 20Midwest Generation Will County Unit 4

The following describes any modifications and/or deviations to the applicable test methods. If alternative methods were requested, see the attachments for documentation of request AND approval, including dates. Target Parameter Test Method Number of

Test Runs Test Run

Duration Sample

Points Comments Location Mercury 30B-Hg 3 120 0 Stack % H2O Method 1 - 4 3 120 0 Stack Flowrate Method 1 - 4 3 120 0 Stack Total PM2.5 OTM - 27/28 3 360 0 Stack Filterable Particulate OTM - 27/28 3 360 0 Stack Organic Condensible

Particulate OTM - 27/28 3 360 0 Stack
Total Particulate OTM - 27/28 3 360 0 Stack Inorganic (Aqueous)

Condensible Part. OTM - 27/28 3 360 0 Stack
Filterable PM2.5 OTM - 27/28 3 360 0 Stack Arsenic Method 29 3 240 0 Stack Selenium Method 29 3 240 0 Stack Nickel Method 29 3 240 0 Stack Manganese Method 29 3 240 0 Stack Antimony Method 29 3 240 0 Stack Cobalt Method 29 3 240 0 Stack Chromium Method 29 3 240 0 Stack Beryllium Method 29 3 240 0 Stack Cadmium Method 29 3 240 0 Stack Filterable Particulate Method 29 3 240 0 Stack Lead Method 29 3 240 0 Stack Co2 Method 3A CO2 3 360 0 Stack O2 Method 3A O2 3 360 0 Stack

Tuesday, February 08, 2011 Page 3 of 20Midwest Generation Will County Unit 4

Sampling / Stack Data Results Summary Location Stack - Method 29 Average Run Number MM5/29-1 MM5/29-2 MM5/29-3 Test Date 6/30/2010 7/1/2010 7/2/2010 Run Start Time 8:25:00 AM 8:30:00 AM 8:00:00 AM
Run Finish Time 12:40:00 PM 12:45:00 PM 12:13:00 PM
Net Run Time, minutes 240 240 240 Dry Gas Meter Volume Sampled, dscf 141.671 142.266 140.989 141.642 Moisture Content of Stack Gas, % 11.35 10.36 11.78 11.163 Moisture Saturation at Stack Gas Temperature, % 100.00 100.00 100.00 100.000 Carbon Dioxide, % 14.3 14.5 14.2 14.333 Oxygen, % 5.3 5.1 5.2 5.200 Average Stack Gas Temperature, °F 318.42 320.42 320.58 319.807 Dry Volumetric Flow Rate, dry scfm 1,138,942.4 1,161,773.3 1,138,110.9 1,146,275.53 3 Actual Wet Volumetric Flue Gas Flow Rate, acfm 1,954,189.4 1,973,690.3 1,971,124.4 1,966,334.70 0 Percent Isokinetic of Sampling Rate, % 102.2 100.6 101.8 101.533 F-Factor, dscfm/MMBtu @ %O2 8525 9802 8705 9,010.667 Fw 0 0 0 0.000 Fc 1768 1886 1775 1,809.667

Location Stack - Method 3A CO2 Average Run Number Test Date Run Start Time Run Finish Time Carbon Dioxide, % Oxygen, % Dry Volumetric Flow Rate, dry scfm F-Factor, dscfm/MMBtu @ %O2 Moisture, % Fuel Type Fw Fc

Tuesday, February 08, 2011 Page 4 of 20Midwest Generation Will County Unit 4

Location Stack - Method 3A O2 Average Run Number Test Date Run Start Time Run Finish Time Carbon Dioxide, % Oxygen, % Dry Volumetric Flow Rate, dry scfm F-Factor, dscfm/MMBtu @ %O2 Moisture, % Fuel Type Fw Fc

Location Stack - OTM - 27/28 Average Run Number Test Date Run Start Time Run Finish Time Net Run Time, minutes Dry Gas Meter Volume Sampled, dscf Moisture Content of Stack Gas, % Moisture Saturation at Stack Gas Temperature, % Carbon Dioxide, % Oxygen, % Average Stack Gas Temperature, °F Dry Volumetric Flow Rate, dry scfm Actual Wet Volumetric Flue Gas Flow Rate, acfm Percent Isokinetic of Sampling Rate, % F-Factor, dscfm/MMBtu @ %O2 Fw Fc

Tuesday, February 08, 2011 Page 5 of 20Midwest Generation Will County Unit 4

Emissions Summary Location: Stack - Method 29 Compound: Antimony Average RunNumber MM5/29-1 MM5/29-2 MM5/29-3 Mass_mg 0.004 0.004 0.004 0.004 lb/mmBtuO2 7.11E-07 8.04E-07 7.25E-07 0.000 Compound: Arsenic Average RunNumber MM5/29-1 MM5/29-2 MM5/29-3 Mass_mg 0.0065 0.0055 0.0056 0.006 lb/mmBtuO2 1.16E-06 1.11E-06 1.01E-06 0.000 Compound: Beryllium Average RunNumber MM5/29-1 MM5/29-2 MM5/29-3 Mass_mg 0.001 0.001 0.001 0.001 lb/mmBtuO2 1.78E-07 2.01E-07 1.81E-07 0.000 Compound: Cadmium Average RunNumber MM5/29-1 MM5/29-2 MM5/29-3 Mass_mg 0.0011 0.001 0.001 0.001 lb/mmBtuO2 1.96E-07 2.01E-07 1.81E-07 0.000 Compound: Chromium Average RunNumber MM5/29-1 MM5/29-2 MM5/29-3 Mass_mg 0.01401 0.01821 0.01991 0.017 lb/mmBtuO2 2.49E-06 3.66E-06 3.61E-06 0.000 Compound: Cobalt Average RunNumber MM5/29-1 MM5/29-2 MM5/29-3 Mass_mg 0.00491 0.00392 0.00347 0.004 lb/mmBtuO2 8.73E-07 7.88E-07 6.29E-07 0.000 Compound: Filterable Particulate Average RunNumber MM5/29-1 MM5/29-2 MM5/29-3 Mass_mg 138.3 131.6 102.1 124.000 lb/mmBtuO2 2.46E-02 2.64E-02 1.85E-02 0.023 Compound: Lead Average RunNumber MM5/29-1 MM5/29-2 MM5/29-3 Mass_mg 0.01401 0.01031 0.01213 0.012 lb/mmBtuO2 2.49E-06 2.07E-06 2.20E-06 0.000 Compound: Manganese Average Tuesday, February 08, 2011 Page 6 of 20Midwest Generation Will County Unit 4

Process Run Data RunNumber MM5/29-1 MM5/29-2 MM5/29-3 Mass_mg 0.03457 0.02903 0.03177 0.032 lb/mmBtuO2 6.14E-06 5.83E-06 5.76E-06 0.000 Compound: Nickel Average RunNumber MM5/29-1 MM5/29-2 MM5/29-3 Mass_mg 0.03314 0.01994 0.02784 0.027 lb/mmBtuO2 5.89E-06 4.01E-06 5.04E-06 0.000 Compound: Selenium Average RunNumber MM5/29-1 MM5/29-2 MM5/29-3 Mass_mg 0.0152 0.0146 0.0213 0.017 lb/mmBtuO2 2.70E-06 2.93E-06 3.86E-06 0.000
Location: Stack - OTM - 27/28 Compound: Filterable Particulate Average RunNumber MOTM27/OTM28-1 MOTM27/OTM28-2 MOTM27/OTM28-3 Mass_mg 231.8 142.3 106 160.033 lb/mmBtuO2 4.81E-02 3.31E-02 2.23E-02 0.035 Compound: Filterable PM2.5 Average RunNumber MOTM27/OTM28-1 MOTM27/OTM28-2 MOTM27/OTM28-3 Mass_mg 56.7 51.8 68.5 59.000 lb/mmBtuO2 1.18E-02 1.20E-02 1.44E-02 0.013 Compound: Inorganic (Aqueous) Condensible Pa Average RunNumber MOTM27/OTM28-1 MOTM27/OTM28-2 MOTM27/OTM28-3 Mass_mg 14 21.4 36.9 24.100 lb/mmBtuO2 2.91E-03 4.97E-03 7.78E-03 0.005 Compound: Organic Condensible Particulate Average RunNumber MOTM27/OTM28-1 MOTM27/OTM28-2 MOTM27/OTM28-3 Mass_mg 1 0.5 0.4 0.633 lb/mmBtuO2 2.08E-04 1.16E-04 8.43E-05 0.000 Compound: Total Particulate Average RunNumber MOTM27/OTM28-1 MOTM27/OTM28-2 MOTM27/OTM28-3 Mass_mg 246.8 164.2 143.3 184.767 lb/mmBtuO2 5.12E-02 3.81E-02 3.02E-02 0.040 Compound: Total PM2.5 Average RunNumber MOTM27/OTM28-1 MOTM27/OTM28-2 MOTM27/OTM28-3 Mass_mg 71.7 73.7 105.8 83.733 lb/mmBtuO2 1.49E-02 1.71E-02 2.23E-02 0.018

Tuesday, February 08, 2011 Page 7 of 20Midwest Generation Will County Unit 4

Process Run Data

Run Name Value UOM Comments Target Value 1 Steam Output 3751.0 1000lb steam/hr Test 1, 6/30/10, OTM27/OTM28, 8:25-14:47 0

2 Steam Output 3739.7 1000lb steam/hr Test 2, 7/1/10, OTM27/OTM28, 8:30-14:42 0

3 Steam Output 3677.5 1000lb steam/hr Test 3, 7/2/10, OTM27/OTM28, 8:00-14:11 0

4 Steam Output 3751.5 1000lb steam/hr Test 1, 6/30/10, M5/29, 8:25-12:40 0
5 Steam Output 3748.0 1000lb steam/hr Test 2, 7/1/10, M5/29, 8:30-12:45 0

6 Steam Output 3692.9 1000lb steam/hr Test 3, 7/2/10, M5/29, 8:00-12:13 0

7 Steam Output 3760.7 1000lb steam/hr Test 1, 6/30/10, M30B, 8:25-10:25 0
8 Steam Output 3762.5 1000lb steam/hr Test 2, 7/1/10, M30B, 8:30-10:30 0
9 Steam Output 3696.2 1000lb steam/hr Test 3, 7/2/10, M30B, 8:00-10:00 0
1 Unit Gross Electric Generation 539.02 MW Test 1, 6/30/10, OTM27/OTM28, 8:25-14:47 0

2 Unit Gross Electric Generation 538.92 MW Test 2, 7/1/10, OTM27/OTM28, 8:30-14:42 0

3 Unit Gross Electric Generation 527.70 MW Test 3, 7/2/10, OTM27/OTM28, 8:00-14:11 0

4 Unit Gross Electric Generation 538.93 MW Test 1, 6/30/10, M5/29, 8:25-12:40 0
5 Unit Gross Electric Generation 539.24 MW Test 2, 7/1/10, M5/29, 8:30-12:45 0

6 Unit Gross Electric Generation 527.75 MW Test 3, 7/2/10, M5/29, 8:00-12:13 0

7 Unit Gross Electric Generation 538.95 MW Test 1, 6/30/10, M30B, 8:25-10:25 0
8 Unit Gross Electric Generation 538.84 MW Test 2, 7/1/10, M30B, 8:30-10:30 0
9 Unit Gross Electric Generation 527.71 MW Test 3, 7/2/10, M30B, 8:00-10:00 0

Tuesday, February 08, 2011 Page 8 of 20Midwest Generation Will County Unit 4

1 Unit Net Electric Generation 509.56 MWh Test 1, 6/30/10, OTM27/OTM28, 8:25-14:47 0

2 Unit Net Electric Generation 509.56 MWh Test 2, 7/1/10, OTM27/OTM28, 8:30-14:42 0

3 Unit Net Electric Generation 499.5 MWh Test 3, 7/2/10, OTM27/OTM28, 8:00-14:11 0

4 Unit Net Electric Generation 509.56 MWh Test 1, 6/30/10, M5/29, 8:25-12:40 0
5 Unit Net Electric Generation 509.53 MWh Test 2, 7/1/10, M5/29, 8:30-12:45 0

6 Unit Net Electric Generation 499.56 MWh Test 3, 7/2/10, M5/29, 8:00-12:13 0

7 Unit Net Electric Generation 509.53 MWh Test 1, 6/30/10, M30B, 8:25-10:25 0
8 Unit Net Electric Generation 509.57 MWh Test 2, 7/1/10, M30B, 8:30-10:30 0
9 Unit Net Electric Generation 499.71 MWh Test 3, 7/2/10, M30B, 8:00-10:00 0
1 Sorbent Type and Sorbent Injection Rate 596.62 lbs/hr Test 1, 6/30/10, OTM27/OTM28, 8:25-14:47 0

2 Sorbent Type and Sorbent Injection Rate 587.97 lbs/hr Test 2, 7/1/10, OTM27/OTM28, 8:30-14:42 0

3 Sorbent Type and Sorbent Injection Rate 578.76 lbs/hr Test 3, 7/2/10, OTM27/OTM28, 8:00-14:11 0

4 Sorbent Type and Sorbent Injection Rate 594.11 lbs/hr Test 1, 6/30/10, M5/29, 8:25-12:40 0
5 Sorbent Type and Sorbent Injection Rate 586.40 lbs/hr Test 2, 7/1/10, M5/29, 8:30-12:45 0

6 Sorbent Type and Sorbent Injection Rate 577.57 lbs/hr Test 3, 7/2/10, M5/29, 8:00-12:13 0

7 Sorbent Type and Sorbent Injection Rate 590.5 lbs/hr Test 1, 6/30/10, M30B, 8:25-10:25 0
8 Sorbent Type and Sorbent Injection Rate 585.5 lbs/hr Test 2, 7/1/10, M30B, 8:30-10:30 0
9 Sorbent Type and Sorbent Injection Rate 575.30 lbs/hr Test 3, 7/2/10, M30B, 8:00-10:00 0
1 Flue Gas Sampling Point Temperature 312.9 Deg F Test 1, 6/30/10, OTM27/OTM28, 8:25-14:47 0

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2 Flue Gas Sampling Point Temperature 315.9 Deg F Test 2, 7/1/10, OTM27/OTM28, 8:30-14:42 0

3 Flue Gas Sampling Point Temperature 315 Deg F Test 3, 7/2/10, OTM27/OTM28, 8:00-14:11 0

4 Flue Gas Sampling Point Temperature 311.1 Deg F Test 1, 6/30/10, M5/29, 8:25-12:40 0
5 Flue Gas Sampling Point Temperature 314.1 Deg F Test 2, 7/1/10, M5/29, 8:30-12:45 0

6 Flue Gas Sampling Point Temperature 313.9 Deg F Test 3, 7/2/10, M5/29, 8:00-12:13 0

7 Flue Gas Sampling Point Temperature 308.6 Deg F Test 1, 6/30/10, M30B, 8:25-10:25 0
8 Flue Gas Sampling Point Temperature 311.8 Deg F Test 2, 7/1/10, M30B, 8:30-10:30 0
9 Flue Gas Sampling Point Temperature 311.5 Deg F Test 3, 7/2/10, M30B, 8:00-10:00 0
1 Average Heat Input 5280.5 mmBtu/hr Test 1, 6/30/10, OTM27/OTM28, 8:25-14:47 0

2 Average Heat Input 5305.3 mmBtu/hr Test 2, 7/1/10, OTM27/OTM28, 8:30-14:42 0

3 Average Heat Input 5314.1 mmBtu/hr Test 3, 7/2/10, OTM27/OTM28, 8:00-14:27 0

4 Average Heat Input 5312.6 mmBtu/hr Test 1, 6/30/10, M5/29, 8:25-12:40 0
5 Average Heat Input 5324.1 mmBtu/hr Test 2, 7/1/10, M5/29, 8:30-12:45 0

6 Average Heat Input 5142.8 mmBtu/hr Test 3, 7/2/10, M5/29, 8:00-12:13 0

7 Average Heat Input 5320.4 mmBtu/hr Test 1, 6/30/10, M30B, 8:25-10:25 0
8 Average Heat Input 5330.8 mmBtu/hr Test 2, 7/1/10, M30B, 8:30-10:30 0
9 Average Heat Input 5158.9 mmBtu/hr Test 3, 7/2/10, M30B, 8:00-10:00 0
1 Flue Gas Carbon Dioxide Content 12.77 % Test 1, 6/30/10, OTM27/OTM28, 8:25-14:47 0

2 Flue Gas Carbon Dioxide Content 13.03 % Test 2, 7/1/10, OTM27/OTM28, 8:30-14:42 0

Tuesday, February 08, 2011 Page 10 of 20Midwest Generation Will County Unit 4

3 Flue Gas Carbon Dioxide Content 12.79 % Test 3, 7/2/10, OTM27/OTM28, 8:00-14:11 0

4 Flue Gas Carbon Dioxide Content 12.84 % Test 1, 6/30/10, M5/29, 8:25-12:40 0
5 Flue Gas Carbon Dioxide Content 13.04 % Test 2, 7/1/10, M5/29, 8:30-12:45 0

6 Flue Gas Carbon Dioxide Content 12.81 % Test 3, 7/2/10, M5/29, 8:00-12:13 0

7 Flue Gas Carbon Dioxide Content 12.91 % Test 1, 6/30/10, M30B, 8:25-10:25 0
8 Flue Gas Carbon Dioxide Content 13.04 % Test 2, 7/1/10, M30B, 8:30-10:30 0
9 Flue Gas Carbon Dioxide Content 12.84 % Test 3, 7/2/10, M30B, 8:00-10:00 0
1 Flue Gas Oxygen Content 6.96 % Test 1, 6/30/10, OTM27/OTM28, 8:25-14:47 0

2 Flue Gas Oxygen Content 6.67 % Test 2, 7/1/10, OTM27/OTM28, 8:30-14:42 0

3 Flue Gas Oxygen Content 6.93 % Test 3, 7/2/10, OTM27/OTM28, 8:00-14:11 0

4 Flue Gas Oxygen Content 6.88 % Test 1, 6/30/10, M5/29, 8:25-12:40 0
5 Flue Gas Oxygen Content 6.67 % Test 2, 7/1/10, M5/29, 8:30-12:45 0

6 Flue Gas Oxygen Content 6.92 % Test 3, 7/2/10, M5/29, 8:00-12:13 0

7 Flue Gas Oxygen Content 6.8 % Test 1, 6/30/10, M30B, 8:25-10:25 0
8 Flue Gas Oxygen Content 6.67 % Test 2, 7/1/10, M30B, 8:30-10:30 0
9 Flue Gas Oxygen Content 6.88 % Test 3, 7/2/10, M30B, 8:00-10:00 0
1 Flue Gas Flowrate 1E+06 dscfm Test 1, 6/30/10,OTM27/O TM28, 8:25-14:47 0

2 Flue Gas Flowrate 1E+06 dscfm Test 2, 7/1/10, OTM27/OTM28, 8:30-14:42 0

3 Flue Gas Flowrate 1E+06 dscfm Test 3, 7/2/10, OTM27/OTM28, 8:00-14:27 0

4 Flue Gas Flowrate 1E+06 dscfm Test 1, 6/30/10, M5/29, 8:25-12:40 0

Tuesday, February 08, 2011 Page 11 of 20Midwest Generation Will County Unit 4

5 Flue Gas Flowrate 1E+06 dscfm Test 2, 7/1/10, M5/29, 8:30-12:45 0

6 Flue Gas Flowrate 1E+06 dscfm Test 3, 7/2/10, M5/29, 8:00-12:13 0

7 Flue Gas Flowrate 1E+06 dscfm Test 1, 6/30/10, M30B, 8:25-10:25 0
8 Flue Gas Flowrate 1E+06 dscfm Test 2, 7/1/10, M30B, 8:30-10:30 0
9 Flue Gas Flowrate 1E+06 dscfm Test 3, 7/2/10, M30B, 8:00-10:00 0
1 Coal Firing Rate 616.9 klbs/hr Test 1, 6/30/10, OTM27/OTM28, 8:25-14:47 0

2 Coal Firing Rate 619.8 klbs/hr Test 2, 7/1/10, OTM27/OTM28, 8:30-14:42 0

3 Coal Firing Rate 599.9 klbs/hr Test 3, 7/2/10, OTM27/OTM28, 8:00-14:11 0

4 Coal Firing Rate 616.9 klbs/hr Test 1, 6/30/10, M5/29, 8:25-12:40 0
5 Coal Firing Rate 622 klbs/hr Test 2, 7/1/10, M5/29, 8:30-12:45 0

6 Coal Firing Rate 600.8 klbs/hr Test 3, 7/2/10, M5/29, 8:00-12:13 0

7 Coal Firing Rate 621.6 klbs/hr Test 1, 6/30/10, M30B, 8:25-10:25 0
8 Coal Firing Rate 622.8 klbs/hr Test 2, 7/1/10, M30B, 8:30-10:30 0
9 Coal Firing Rate 602.7 klbs/hr Test 3, 7/2/10, M30B, 8:00-10:00 0
1 Flue Gas Moisture Content 11.2 % Test 1, 6/30/10, OTM27/OTM28, 8:25-14:47 0

2 Flue Gas Moisture Content 11.2 % Test 2, 7/1/10, OTM27/OTM28, 8:30-14:42 0

3 Flue Gas Moisture Content 11.2 % Test 3, 7/2/10, OTM27/OTM28, 8:00-14:11 0

4 Flue Gas Moisture Content 11.2 % Test 1, 6/30/10, M5/29, 8:25-12:40 0
5 Flue Gas Moisture Content 11.2 % Test 2, 7/1/10, M5/29, 8:30-12:45 0

6 Flue Gas Moisture Content 11.2 % Test 3, 7/2/10, M5/29, 8:00-12:13 0

7 Flue Gas Moisture Content 0 % 0 Tuesday, February 08, 2011 Page 12 of 20Midwest Generation Will County Unit 4

8 Flue Gas Moisture Content 11.2 % Test 2, 7/1/10, M30B, 8:30-10:30 0
9 Flue Gas Moisture Content 0 % 0 1 Synfuel Firing Rate 0 0 2 Synfuel Firing Rate 0 0 3 Synfuel Firing Rate 0 0 4 Synfuel Firing Rate 0 0 5 Synfuel Firing Rate 0 0 6 Synfuel Firing Rate 0 0 7 Synfuel Firing Rate 0 0 8 Synfuel Firing Rate 0 0 9 Synfuel Firing Rate 0 0 1 Petroleum Coke Firing Rate 0 0 2 Petroleum Coke Firing Rate 0 0 3 Petroleum Coke Firing Rate 0 0 4 Petroleum Coke Firing Rate 0 0 5 Petroleum Coke Firing Rate 0 0 6 Petroleum Coke Firing Rate 0 0 7 Petroleum Coke Firing Rate 0 0 8 Petroleum Coke Firing Rate 0 0 9 Petroleum Coke Firing Rate 0 0 1 Coal Gas Firing Rate 0 0 2 Coal Gas Firing Rate 0 0 3 Coal Gas Firing Rate 0 0 4 Coal Gas Firing Rate 0 0 5 Coal Gas Firing Rate 0 0 6 Coal Gas Firing Rate 0 0 7 Coal Gas Firing Rate 0 0 8 Coal Gas Firing Rate 0 0 9 Coal Gas Firing Rate 0 0 1 Fuel Oil Firing Rate 0 0 2 Fuel Oil Firing Rate 0 0 3 Fuel Oil Firing Rate 0 0 4 Fuel Oil Firing Rate 0 0 5 Fuel Oil Firing Rate 0 0 6 Fuel Oil Firing Rate 0 0

Tuesday, February 08, 2011 Page 13 of 20Midwest Generation Will County Unit 4

7 Fuel Oil Firing Rate 0 0 8 Fuel Oil Firing Rate 0 0 9 Fuel Oil Firing Rate 0 0 1 Pressure Drop Across FGD (if applicable) 0 in H2O 0 2 Pressure Drop Across FGD (if applicable) 0 in H2O 0 3 Pressure Drop Across FGD (if applicable) 0 in H2O 0 4 Pressure Drop Across FGD (if applicable) 0 in H2O 0 5 Pressure Drop Across FGD (if applicable) 0 in H2O 0 6 Pressure Drop Across FGD (if applicable) 0 in H2O 0 7 Pressure Drop Across FGD (if applicable) 0 in H2O 0 8 Pressure Drop Across FGD (if applicable) 0 in H2O 0 9 Pressure Drop Across FGD (if applicable) 0 in H2O 0 1 FGD Scrubber Liquor Flow Rate 0 gal/min 0 2 FGD Scrubber Liquor Flow Rate 0 gal/min 0 3 FGD Scrubber Liquor Flow Rate 0 gal/min 0 4 FGD Scrubber Liquor Flow Rate 0 gal/min 0 5 FGD Scrubber Liquor Flow Rate 0 gal/min 0 6 FGD Scrubber Liquor Flow Rate 0 gal/min 0 7 FGD Scrubber Liquor Flow Rate 0 gal/min 0 8 FGD Scrubber Liquor Flow Rate 0 gal/min 0 9 FGD Scrubber Liquor Flow Rate 0 gal/min 0 1 Flue Gas Pressure 0 atm 0 2 Flue Gas Pressure 0 atm 0 3 Flue Gas Pressure 0 atm 0 4 Flue Gas Pressure 0 atm 0 5 Flue Gas Pressure 0 atm 0 6 Flue Gas Pressure 0 atm 0 7 Flue Gas Pressure 0 atm 0 8 Flue Gas Pressure 0 atm 0 9 Flue Gas Pressure 0 atm 0 1 Standard Pressure 0 atm 0 2 Standard Pressure 0 atm 0 3 Standard Pressure 0 atm 0 4 Standard Pressure 0 atm 0 5 Standard Pressure 0 atm 0 6 Standard Pressure 0 atm 0
Tuesday, February 08, 2011 Page 14 of 20Midwest Generation Will County Unit 4

APCD Run Data 7 Standard Pressure 0 atm 0 8 Standard Pressure 0 atm 0 9 Standard Pressure 0 atm 0 1 Standard Temp 0 Deg F 0 2 Standard Temp 0 Deg F 0 3 Standard Temp 0 Deg F 0 4 Standard Temp 0 Deg F 0 5 Standard Temp 0 Deg F 0 6 Standard Temp 0 Deg F 0 7 Standard Temp 0 Deg F 0 8 Standard Temp 0 Deg F 0 9 Standard Temp 0 Deg F 0 1 FGD Scrubber Liquor pH 0 pH 0 2 FGD Scrubber Liquor pH 0 pH 0 3 FGD Scrubber Liquor pH 0 pH 0 4 FGD Scrubber Liquor pH 0 pH 0 5 FGD Scrubber Liquor pH 0 pH 0 6 FGD Scrubber Liquor pH 0 pH 0 7 FGD Scrubber Liquor pH 0 pH 0 8 FGD Scrubber Liquor pH 0 pH 0 9 FGD Scrubber Liquor pH 0 pH 0 1 Subbituminous Coal Burned 0 1000 Tons/hr 0

Run Name Value UOM Comments Target Value 1 ELECTROSTATIC PRECIPITATOR 0 0 2 ELECTROSTATIC PRECIPITATOR 0 0 3 ELECTROSTATIC PRECIPITATOR 0 0 1 LOW NOX BURNERS 0 0 2 LOW NOX BURNERS 0 0 3 LOW NOX BURNERS 0 0 1 OVERFIRE AIR 0 0 2 OVERFIRE AIR 0 0 3 OVERFIRE AIR 0 0 1 ACTIVATED CARBON ADSORPTION 5 lbs/macf 0

Tuesday, February 08, 2011 Page 15 of 20Midwest Generation Will County Unit 4

Process Lab Run Data 2 ACTIVATED CARBON ADSORPTION 5 lbs/macf 0 3 ACTIVATED CARBON ADSORPTION 5 lbs/macf 0 1 0 0

Run Name Value UOM Comments 1 Fuel Higher Heating Value 0 Btu/lb 1 Fuel Moisture 0 % 1 Fuel Mercury Content 0 ppm 1 Fuel Cadmium Content 0 ppm 1 Ultimate/Proximate Analysis 0 1 Fuel Nickel Content 0 ppm 1 Fuel Arsenic Content 0 ppm 1 Fuel Chromium Content 0 ppm 1 Fuel Beryllium Content 0 ppm 1 Fuel Lead Content 0 ppm 1 Fuel Manganese Content 0 ppm 1 Fuel Chlorine Content 0 ppm 1 Fuel Fluorine Content 0 ppm

Tuesday, February 08, 2011 Page 16 of 20Midwest Generation Will County Unit 4

Sampling / Stack Data Results Detail Location Stack - Method 29 Average Run Number MM5/29-1 MM5/29-2 MM5/29-3 Test Date 6/30/2010 7/1/2010 7/2/2010 Run Start Time 8:25:00 AM 8:30:00 AM 8:00:00 AM Run Finish Time 12:40:00 PM 12:45:00 PM 12:13:00 PM Net Traversing Points 16 16 16 Net Run Time, minutes 240 240 240 Nozzle Diameter, inches 0.141 0.141 0.141 0.141 Pitot Tube Coefficient 0.84 0.84 0.84 0.840 Dry Gas Meter Calibration Factor 1.003 1.003 1.003 1.003 Barometric Pressure, inches of Mercury 29.05 29.09 29 29.047 Average Orifice Meter Differential, inches H2O 1.13 1.12 1.11 1.120 Dry Gas Meter Volume Sampled, cubic feet 148.956 148.691 149.276 148.974 Average Dry Gas Meter Temperature, °F 82.17 79.67 85.00 82.280 Dry Gas Meter Volume Sampled, dscf 141.671 142.266 140.989 141.642 Total Moisture Liquid collected, g 385.2 349.4 399.8 378.133 Volume of Water Vapor, standard cubic feet 18.13 16.45 18.82 17.800 Moisture Content of Stack Gas, % 11.35 10.36 11.78 11.163 Moisture Saturation at Stack Gas Temperature, % 100.00 100.00 100.00 100.000 Dry Mole Fraction 0.8865 0.8964 0.8822 0.888 Carbon Dioxide, % 14.3 14.5 14.2 14.333 Oxygen, % 5.3 5.1 5.2 5.200 Carbon Monoxide & Nitrogen, % 80.4 80.4 80.6 80.467 Fuel Factor 1.09 1.09 1.11 Dry Molecular Weight, lb/lb-Mole 30.50 30.52 30.48 30.500 Wet Molecular weight, lb/lb-Mole 29.08 29.22 29.01 29.103 Flue Gas Static Pressure, inches of H2O -0.7 -0.7 -0.7 -0.700 Absolute Flue Gas Pressure, inches of Mercury 29.00 29.04 28.95 28.997 Average Stack Gas Temperature, °F 318.42 320.42 320.58 319.807 Average Velocity Head, inches of H2O 4.8742297211 0506 4.989732201

56733 4.924626936

20427 4.930 Average Stack Gas Velocity, feet/second 152.32 153.84 153.64 153.267 Stack Cross-Sectional Area, square feet 213.825 213.825 213.825 213.825 Dry Volumetric Flow Rate, dry scfm 1,138,942.4 1,161,773.3 1,138,110.9 1,146,275.5 33 Actual Wet Volumetric Flue Gas Flow Rate, acfm 1,954,189.4 1,973,690.3 1,971,124.4 1,966,334.7 00 Percent Isokinetic of Sampling Rate, % 102.2 100.6 101.8 101.533 Percent Excess Air, % 33.3 31.6 32.3 32.400 F-Factor, dscfm/MMBtu @ %O2 8525 9802 8705 9,010.667 Round Duct Diameter, inches 198 198 198 Rectangular Duct Width, inches 0 0 0 Rectangular Duct Length, inches 0 0 0 Fw 0 0 0 0.000 Fc 1768 1886 1775 1,809.667

Tuesday, February 08, 2011 Page 17 of 20Midwest Generation Will County Unit 4

Location Stack - Method 3A CO2 Average Run Number Test Date Run Start Time Run Finish Time Carbon Dioxide, % Oxygen, % Fuel Factor Dry Volumetric Flow Rate, dry scfm F-Factor, dscfm/MMBtu @ %O2 Moisture, % Analyzer Make Analyzer Model Analyzer Serial Number Operating Range Operating Units No. Readings/Avg. Calibration Set Calibration Pre Zero Cylinder ID Calibration Pre Zero Cylinder Instrument Response Calibration Pre Zero Cylinder Bias Calibration Pre Zero Cylinder Drift Calibration Pre High Cylinder ID Calibration Pre High Cylinder Instrument Response Calibration Pre High Cylinder Bias Calibration Pre High Cylinder Drift Calibration Post Zero Cylinder ID Calibration Post Zero Cylinder Instrument Response Calibration Post Zero Cylinder Bias Calibration Post Zero Cylinder Drift Calibration Post High Cylinder ID Calibration Post High Cylinder Instrument Response Calibration Post High Cylinder Bias Calibration Post High Cylinder Drift Cavg Cavg Units Cgas Cgas Units Fuel Type Fw Fc Cgasw Cgasw Units

Tuesday, February 08, 2011 Page 18 of 20Midwest Generation Will County Unit 4

Location Stack - Method 3A O2 Average Run Number Test Date Run Start Time Run Finish Time Carbon Dioxide, % Oxygen, % Fuel Factor Dry Volumetric Flow Rate, dry scfm F-Factor, dscfm/MMBtu @ %O2 Moisture, % Analyzer Make Analyzer Model Analyzer Serial Number Operating Range Operating Units No. Readings/Avg. Calibration Set Calibration Pre Zero Cylinder ID Calibration Pre Zero Cylinder Instrument Response Calibration Pre Zero Cylinder Bias Calibration Pre Zero Cylinder Drift Calibration Pre High Cylinder ID Calibration Pre High Cylinder Instrument Response Calibration Pre High Cylinder Bias Calibration Pre High Cylinder Drift Calibration Post Zero Cylinder ID Calibration Post Zero Cylinder Instrument Response Calibration Post Zero Cylinder Bias Calibration Post Zero Cylinder Drift Calibration Post High Cylinder ID Calibration Post High Cylinder Instrument Response Calibration Post High Cylinder Bias Calibration Post High Cylinder Drift Cavg Cavg Units Cgas Cgas Units Fuel Type Fw Fc Cgasw Cgasw Units

Tuesday, February 08, 2011 Page 19 of 20Midwest Generation Will County Unit 4

Location Stack - OTM - 27/28 Average Run Number Test Date Run Start Time Run Finish Time Net Traversing Points Net Run Time, minutes Nozzle Diameter, inches Pitot Tube Coefficient Dry Gas Meter Calibration Factor Barometric Pressure, inches of Mercury Average Orifice Meter Differential, inches H2O Dry Gas Meter Volume Sampled, cubic feet Average Dry Gas Meter Temperature, °F Dry Gas Meter Volume Sampled, dscf Total Moisture Liquid collected, g Volume of Water Vapor, standard cubic feet Moisture Content of Stack Gas, % Moisture Saturation at Stack Gas Temperature, % Dry Mole Fraction Carbon Dioxide, % Oxygen, % Carbon Monoxide & Nitrogen, % Fuel Factor Dry Molecular Weight, lb/lb-Mole Wet Molecular weight, lb/lb-Mole Flue Gas Static Pressure, inches of H2O Absolute Flue Gas Pressure, inches of Mercury Average Stack Gas Temperature, °F Average Velocity Head, inches of H2O Average Stack Gas Velocity, feet/second Stack Cross-Sectional Area, square feet Dry Volumetric Flow Rate, dry scfm Actual Wet Volumetric Flue Gas Flow Rate, acfm Percent Isokinetic of Sampling Rate, % Percent Excess Air, % F-Factor, dscfm/MMBtu @ %O2 Round Duct Diameter, inches Rectangular Duct Width, inches Rectangular Duct Length, inches Fw Fc

Tuesday, February 08, 2011 Page 20 of 20