Operation

Overview of Emissions Sources and Control Measures

The main potential sources of emissions from the plant would consist of two combustion units (i.e., spreader-stoker boilers), ash management systems, an activated carbon storage silo, a lime storage silo, an emergency generator, a firefighting pump, a four-chamber cooling tower, and an ammonia storage tank.

The municipal combustion units would use processed refuse fuel as their primary fuel and would be capable of using supplemental fuel, when available, consisting of automotive shredder

residue, tire-derived fuel, and processed urban wood waste. These supplemental fuels would replace a portion of the processed refuse fuel; however, they would be subject to the same emissions standards as set for processed refuse fuel combustion.

MSW would be received at the tipping floor of the storage area and separated into acceptable, unacceptable, non-processable, and readily recyclable materials. Acceptable materials would be shredded and then processed to magnetically remove approximately 70 percent of the ferrous metal, which would be recycled. The remaining processed material, which is known as processed refuse fuel, would be stored or loaded on conveyors to stoke the boilers. Supplemental fuels would be distributed separately from the MSW, and unloaded and stored in a designated space in the enclosed MSW storage area. Tire-derived fuel and processed urban wood waste would be received already shredded or would be shredded at the facility. Automotive shredder residue would be delivered only in shredded form. Supplemental fuels could be mixed with MSW before being shredded or could be mixed directly in the processed refuse fuel stream before burning. Supplemental fuels would only be mixed and burned with processed refuse fuel, and there would only be one supplemental fuel present in the processed refuse fuel mixture at any given time. Mixing supplemental fuel with processed refuse fuel is subject to completion of a combustion demonstration program and EPA approval, as discussed in Section 2.2.2.9.

Each municipal waste combustion unit would have a nominal production capacity of 359,779 pounds of steam per hour. The steam originating from municipal waste would operate a steam turbine, which would have the capacity to produce about 79 MW of electricity, for a net Project output of about 67 MW after in-plant needs are considered. Ultra-low sulfur diesel would be

used with a maximum sulfur concentration of 0.0015 percent (15 parts per million by weight) for: the auxiliary municipal waste combustion unit burners during warm-up and shut-down, and for maintaining the temperature of the combustion chamber during short-term interruptions in the supply of waste; the emergency generator; the firefighting pump; and the RSCR system burners to provide the necessary temperature range for nitrogen control.

Each municipal waste combustion unit would use the following air pollution control equipment: a Turbosorp dry circulating gas scrubber, an activated carbon injection system, fabric filters, and a RSCR system with a catalytic oxidizer module and a selective catalytic reduction module. The fabric filters would control the particulate emissions resulting from the emission units of the ash management systems and the silos. Additionally, the cooling tower would be equipped with drift eliminators for controlling particulate emissions.

Emissions Inventory

Table 3-20 provides an overview of the annual emissions of criteria and non-criteria pollutants

associated with the operation of the Project. Table 3-20 also indicates the thresholds for PSD

applicability and whether or not PSD review applies to the Project for each pollutant. Table 3-20. Potential to Emit Criteria and Hazardous Air Pollutants

Pollutant PSD Significant Emission Rate (tons/year) Proposed Emission Rate (tons/year) PSD Review Required

Carbon monoxide 100 357 Yes

Nitrogen oxides (as NO2) 40 352 Yes

Sulfur dioxide 40 260 Yes

Particulate matter (PM)– filterable 25 51.7 Yes

Particulate matter < 10 microns (PM10)– filterable and

condensable

15 104 Yes

Particulate matter < 2.5 microns (PM2.5)– filterable and condensable

10 90 Yes

Volatile organic (as ozone precursor) 40 52.4 Yes

Lead 0.6 0.31 No Beryllium 0.0004 0.0032 Yes Nickel NA 0.024 NA Cadmium NA 0.041 NA Chromium NA 0.016 NA Zinc NA 0.93 NA

Pollutant PSD Significant Emission Rate (tons/year) Proposed Emission Rate (tons/year) PSD Review Required Ammonia NA 28.8 NA

Fluorides (as HF) 3 10.8 Yes

Mercury 0.1 0.0692 No

Sulfuric acid 7 16.6 Yes

Hydrogen Chloride NA 124 NA

Municipal waste combustor organics- measured as 2,3,7,8- Tetrachlorodibenzodioxin (TCDD- 2378)

3.5E-6 4.07E-05 Yes

Municipal waste combustor metals

(measured as particulate matter) 15 42.8 Yes

Municipal waste combustor acid gases (measured as sulfur dioxide and hydrogen chloride)

40 415 Yes

Arsenic Any Emission Rate 0.0020 Yes

Source: Energy Answers (2011b)

Note: NA – Not Applicable, no PSD significant emission rate established Air Quality Modeling

A detailed air quality modeling analysis was completed in support of the PSD permit application (February 2011, revised July 2011 and October 2011). The latest available version of the

AERMOD (11103) dispersion model was used at the time of the final modeling analysis was performed.9

The air quality modeling examined the impacts of normal operations under a variety of boiler load scenarios, as well as the impact from boiler startup and shutdown emissions. A screening analysis was completed that first compared the maximum potential impact to the “Significant Impact Level” under PSD regulations. If an individual facility projects an increase in air quality impacts less than the corresponding Significant Impact Level, its impact is said to be de minimis,