7.0 AIR QUALITY AND METEOROLOGY

7.1 Applicability

This section addresses the Project's effect on local and regional air quality. Regulatory programs related to air emissions control are outlined. A description of the proposed air quality impact assessment is presented.

In its air quality study, TGE will demonstrate that it will comply with all applicable air quality requirements, with minimal air emissions relative to the amount of power it produces. During the course of its licensing, coordinated with the Article X process, the Project will apply for a Prevention of Significant Deterioration (PSD) Permit and a State Facility Permit pursuant to 6 NYCRR 201 from NYSDEC, to which EPA has delegated its authority under the Clean Air Act. New York City also has a long-standing air quality control ordinance that the Project will address in the Application. The studies proposed to be performed are detailed in Stipulation 1.

7.2 Background Ambient Air Quality, Meteorology and Climatology

7.2.1 Background Ambient Air Quality

Ambient air quality data (ambient pollutant concentrations) collected from NYSDEC monitoring stations closest to the Project site will be used to characterize existing local air quality conditions. There are several types of air quality monitoring stations in or near Greenpoint. The monitoring stations used for each pollutant are summarized in Table 7-1. The latest 3 years of data available for each of these sites from NYSDEC's Air Quality Reports (1998 through 2000) are presented in Table 7?2.

7.2.2 Precipitation and Temperature

TGE will propose to use LaGuardia Airport weather data for meteorological modeling. Annual precipitation recorded at LaGuardia over a 59-year period of record averages 42.1 inches. Rainfall is generally distributed equally through the year, with each month receiving approximately 3.5 inches of precipitation (snowfall is melted to obtain the liquid equivalent). February is normally the driest month of the year, with an overall of average 2.86 inches of precipitation. January and October are also normally dry months with each month typically receiving 3 inches of precipitation.

Establishing representative ambient temperature extremes is important to defining turbine performance and assessing resultant impacts. NYSDEC recognized this and has developed unpublished guidance for establishing turbine performance ambient temperature set points. The guidance instructs all applicants with projects located in New York City to establish the following turbine performance set points:

· Minimum Temperature = minus (-) 5 degrees Fahrenheit (°F); · Maximum Temperature = 100°F; and · Average Temperature = Value presented in the local climatological summary sheet of the National Weather Service station that is to represent the source of meteorological data for the impact modeling.

The mean dry bulb temperature measured over a 52-year period of record at LaGuardia Airport is 54.6°F. Therefore, the three turbine performance set points (minimum, maximum and average annual), following guidance established by the NYSDEC, are -5°F, 100°F and 54.6°F.

7.2.3 Wind Speed and Direction

Air quality dispersion models use wind speed and direction data. According to NYSDEC Air Guide 26, modeling analyses should utilize 5 years of the closest, most recent National Weather Service observations. LaGuardia Airport (in Queens) satisfies this criterion. It is situated approximately 5 miles northeast of the Project site and records meteorological observations 24 hours daily. Figure 7-1 (Annual Windrose Diagram for LaGuardia Airport, 1991-1995) shows the frequency distribution of wind speed and direction for the period 1991 through 1995. The data show a persistence of winds from the northeast and northwest, with a third significant component from the south.

Figure 7-1: Annual Windrose Diagram for LaGuardia Airport (1991-1995)

7.3 Programs of Study

NYSDEC and EPA have promulgated air quality regulations that establish ambient air quality standards and emission limits. These regulations include: (1) National Ambient Air Quality Standards (NAAQS) and New York Air Quality Standards (NYAQS); (2) New Source Review (NSR) requirements for major sources and modifications, including Prevention of Significant Deterioration (PSD) review and Nonattainment NSR (NNSR); and (3) New Source Performance Standards (NSPS). In addition, the New York City Air Pollution Control Code contains limits on NOx and opacity emissions. These standards and limits provide the basis for an evaluation of the potential impacts of proposed projects on ambient air quality.

7.3.1 National and New York Ambient Air Quality Standards

EPA has established NAAQS for six air contaminants, known as criteria pollutants, for the protection of public health and welfare. These criteria pollutants are sulfur dioxide (SO2), particulate matter having a diameter of 10 microns or less (PM10), nitrogen dioxide (NO2), carbon monoxide (CO), ozone (O3), and lead (Pb). A standard has also been set for particulate matter having a diameter of 2.5 microns or less (PM2.5). EPA has set both primary and secondary NAAQS. Primary standards protect human health, while secondary standards protect public welfare from known or anticipated adverse effects associated with the presence of air pollutants, such as damage to property or vegetation. EPA has established both short-term and long-term standards. NYSDEC has adopted these limits as the NYAQS. See Table 7-3. Through air quality modelling, TGE will demonstrate the Project's compliance with applicable standards. Furthermore, TGE will conduct cumulative modelling with all other proposed in-City power plants that have Article X applications deemed compliant and non-Article X plants that have recently been issued NYSDEC air permits and demonstrate that the addition of all these generating sources does not cause a contravention of ambient air quality standards.

TGE notes the following concern in the previously cited GWAPP report: "Of particular concern is the level of PM-2.5 emissions that will result from plant operation." The Project, states the Report, "is likely to produce considerable amounts of PM-2.5 as a result of the direct combustion of fuel and as a consequence of chemical reactions in the atmosphere that involve sulfur dioxide, NOX, and VOCs." It should be noted that a primary purpose behind the fine particulate rule promulgated by EPA is the secondary formation of fine particulate. Coarse particulate (less than 10 but greater than 2.5 micrometers) is directly emitted with the exhaust flow, with a portion that is condensable particulates forming soon after the exhaust clears the stack. PM-2.5, on the other hand, can be formed after a long atmospheric residence time by precursor pollutants. Ambient data on PM-2.5 are still being collected as part of the required three year monitoring program. Therefore, EPA and NYSDEC are required to implement the classification process in order to determine emission requirements for new sources. In the interim, EPA has issued, and TGE will follow, the guidance for evaluating the PM-2.5 potential emissions from the Project. In addition, in the Application, TGE will demonstrate that it will meet applicable regulatory requirements for all three of the air precursors of PM-2.5.

7.3.2 Non-Attainment Area New Source Review (NNSR)

One of the basic goals of federal and state air regulations is to ensure that ambient air quality, including the impact of existing sources and new sources, complies with ambient standards (i.e., NAAQS and NYAQS). Toward this end, EPA has classified all areas of the country as either "attainment," "nonattainment," or "unclassified" with respect to the ambient standards.

If an area is designated "nonattainment" for a given pollutant, then major new sources or major modifications of existing sources of the nonattainment pollutant are subject to NNSR. The NNSR regulations have more stringent requirements for source emission rates, including application of controls to achieve Lowest Achievable Emission Rate (LAER). The proposed new or modified source must also offset potential emissions of the subject pollutant(s).

If an area is "attainment" or "unclassified" for a particular pollutant, then new major sources or major modifications of existing sources require permitting under the PSD program. PSD permitting requires application of Best Available Control Technology (BACT) and a NAAQS compliance demonstration for subject pollutants.

The Project site is in an area designated as either attainment or unclassified for SO2, NO2, Pb, and PM10. It is in an area of "severe nonattainment" for ozone and "moderate nonattainment" for CO. Both the severe ozone nonattainment area and the CO nonattainment area cover all of New York City. Manhattan (New York County) is a PM10 nonattainment area, but Brooklyn (Kings County) is in attainment for PM10. It is anticipated that the Project will have potential NOx emissions and VOC emissions each greater than 25 tons per year (tpy). Therefore, it will be subject to NNSR for both NOx and VOC. It will also have CO emissions greater than 100 tpy, and will therefore be subject to NNSR for CO. However, it is anticipated that Brooklyn will be redesignated as an attainment area for CO. In that case, NNSR for CO will not apply. The Application will address all the required analyses under New York's NNSR program (6 NYCRR 231) implementing the Lowest Achievable Emission Rate (LAER) for non-attainment pollutants.

7.3.3 Prevention of Significant Deterioration (PSD) Review

PSD review is a federally mandated program for major new sources or major modifications to existing major sources of regulated pollutants. A new source that exceeds the major source threshold for one pollutant must also meet the PSD requirements for the other pollutants that exceed their respective significant emission rate. Federal regulations stipulate that major sources must apply Best Available Control Technology (BACT) controls for all PSD-applicable pollutants. EPA has delegated PSD review authority to NYSDEC. A summary of the PSD major source thresholds and significant emission rates for a new combined-cycle generating facility is provided in Table 7-4.

It is anticipated that the Project will have potential emissions of NOx, SO2, TSP and PM10 each greater than 100 tpy. Therefore, BACT analysis will be required for these pollutants. Emissions of all other pollutants are expected to be below their respective PSD significant emission rates, and therefore, those pollutants will not be subject to the requirements of PSD.

The PSD regulations require: 1) application of Best Available Control Technology for each regulated pollutant that will be emitted in significant amounts; 2) analysis of impacts to ambient air quality (described in Section 7.3.4 below); 3) analysis of impacts on soils, vegetation, and visibility as well as from any emissions tied to economic growth arising out of the source; and 4) assessment of "Class I area" impacts.

Class I areas are designated pristine wilderness areas, which are protected by federal land management against manmade haze, for which reason new air emission sources within 100 km (62 miles) of a Class I area are analyzed. Even though the Project is not within 100 km of a Class I area, a screening assessment of visibility impairment will be conducted for the nearest Class I area (Edwin Forsythe National Wildlife Refuge in New Jersey).

For those pollutants for which the Project is subject to PSD review, the federal PSD Program specifies that pre-construction monitoring may be required. EPA has established PSD monitoring threshold concentrations known as monitoring exemption levels. If the predicted Project impacts are below these monitoring exemption levels, then the Project is eligible for exemption from pre?construction ambient monitoring. It is anticipated that the predicted impacts of NOx, VOC, SO2, CO, TSP, and PM10 will be below the monitoring exemption levels.

7.3.4 Air Quality Modeling

An air dispersion modeling protocol proposing the specific procedures that will be used for the analysis will be submitted for approval to NYSDEC, DPS, NYSDOH, NYCDEP and the EPA. Other stakeholders may participate in this review process. This refined modeling analysis will be conducted using 5 years of meteorological data and receptor points placed along terrain elevations and at tall buildings. The receptors will be arranged in a radial pattern around the Project site. For terrain below stack height, the Industrial Source Complex (ISCST3) model will be used. For terrain above stack height, a complex terrain model will be used. This exercise also includes the modeling of downwash and the determination of an appropriate "Good Engineering Practices" stack height for the Project.

Impacts concentrations will initially be compared to the Significant Impact Levels (SILs) for criteria pollutants. If model predicted maximum concentrations are less than corresponding SILs, then compliance will be demonstrated and no additional modeling with other regional sources is required. If predicted impacts exceed the SILs, interactive source modeling will be conducted, as necessary, to demonstrate compliance with the applicable ambient air quality standards and PSD increments.

7.3.5 Environmental Justice

In 1994, the President of the United States issued Executive Order 12898, requiring federal agencies to identify and address as appropriate, those policies and procedures that could result disproportionately high and adverse human health or environmental effects unfair to minorities and/or low-income populations. The EPA is subject to this requirement as part of its oversight authority under the Clean Air Act. Hence, TGE will conduct an Environmental Justice analysis as part of the air quality studies.

7.3.6 New Source Performance Standards

Federal New Source Performance Standards regulate the amount of air contaminants that may be emitted from specific processes. Emission limitations generated by the PSD and NNSR programs are generally far more stringent than NSPS, so the Project will easily comply with NSPS.

7.3.7 Title IV Sulfur Dioxide Allowances

According to 40 CFR 72, the Project will be designated as a Phase II Acid Rain "New Affected Unit" 90 days after commencement of commercial activities. An application for the Project's acid rain permit will be submitted as required. The Acid Rain Program aims to reduce SO2 emissions from power plants by allocating a limited number of marketable allowances to existing power plants and by requiring all plants, including new plants that were not allocated allowances, to obtain allowances to offset their actual annual SO2 emissions. Because the Project is fueled primarily with natural gas and because the proposed backup fuel oil will have a very low sulfur content, the Project's expected SO2 emissions will be much lower than existing conventional power plants.

7.3.8 New York State Air Regulations

TGE expects the Project to easily comply with NYSDEC limits for sulfur in oil and solid fuels (6 NYCRR 225-1.2) and the limits on PM from stationary sources (6 NYCRR 227-1.2). Opacity of emissions will be limited to 20 percent. State regulations also require that NOx emissions must be continuously monitored with an approved Continuous Emissions Monitoring System (CEMS).

The Project will be subject to the NYSDEC NOx Budget Rule (6 NYCRR 204), a NOx allowance program designed to limit statewide NOx emissions during the ozone season (May-September). The Project will receive each year a quantity of NOx allowances from New York State's New Budget Source Holding Account. In the event that there are not sufficient allowances in the New Budget Source Holding Account to cover the source's actual emissions, then the Project will secure additional allowances in the marketplace.

The Project will be subject to NYSDEC's Title V Operating Permit Program (6 NYCRR 201-6). This program ensures that a project's air emissions comply with its permitted limits. As a new stationary source, the Project will be required to submit a Title V permit application within 1 year after commencement of operation. As noted above, under New York's permit to construct regulations, a new major source must obtain a permit to construct and operate prior to construction pursuant to 6 NYCRR Part 201. This permit may serve as the operating permit until the Title V permit is issued.

7.3.9 New York City Programs

New York City's Air Pollution Control Code sets NOx and opacity limits. The Code also contains a fugitive dust regulation, which will be described in the Application, together with the Project's proposed practices to prevent and limit fugitive dust emissions. The Code also lists air toxics emission limits, although the state program (see below) is more comprehensive in that it requires modeling and a demonstration of compliance with concentrations at individual receptor points.

NYCDEP administers a permit program pursuant to the Air Pollution Control Code. Pursuant to Article X, as with all applicable local laws, TGE will evaluate its compliance with NYCDEP's applicable air quality requirements. At this time, TGE expects that findings of compliance will be incorporated into the Certificate that will be issued by the Siting Board. According to NYCDEP, requirements will include a comprehensive cumulative assessment of major and minor sources, per the City Environmental Quality Review (CEQR) methodology, which measures impacts compared to background concentrations.

7.3.10 New York State Air Toxics Program

NYSDEC Air Guide 1 provides guidelines for the control of toxic ambient air contaminants. Air Guide 1 requires each project to provide an assessment of the ambient air quality impacts of air toxics emissions. The predicted impacts are then compared to the applicable short-term and annual guideline concentrations (SGC and AGC) identified in NYSDEC's "Complete & HAP Listing of AGCs, SGCs, and Air Quality Standards" (from Toxics Assessment Section, Bureau of Stationary Sources). In addition, NYSDOH requires a health-based assessment of predicted impacts for emissions of air toxics. Specifically, NYSDOH requires an assessment of Project impacts with respect to health-based threshold limits published in available scientific literature.

As described in Stipulation 1, the air toxics impact assessment will be based on an estimate of short-term and annual concentrations of each pollutant, based on the same modeling effort that will have been used for criteria pollutants. If Project impacts exceed certain minimal thresholds, the need for a cumulative assessment with other air toxics sources will be evaluated. In addition, the toxics analysis will assess cumulative impacts from all new in-City generation units proposed under Article X, for which applications have been filed and determined compliant, as well as new peaking units that have been issued air permits.

7.3.11 New York Acid Deposition Control Act

The Project will be subject to the state's Acid Deposition Control Act. The Act requires that TGE quantify the proposed Project's contribution to the New York State total deposition of sulfates and nitrates. An assessment of Project impacts on acid deposition will be performed according to the guidelines specified in a March 4, 1993, memorandum from Leon Sedefian to Impact Assessment Meteorology Staff. In general, the assessment approach is based upon previous model results performed by NYSDEC. The approach uses source-receptor matrices (emission rate - deposition rate) to scale the proposed source's potential impacts. Modeled sources that are spatially appropriate are first identified. The ratio of Project emissions to model source emissions will be multiplied by the depositions predicted for the modeled source at each receptor location to assess the impacts.

7.3.12 Stack Plume Visibility

On very cold and humid days, depending on the generating technology used, water vapor emissions can condense and become visible prior to dispersing. Opacity regulations exempt the visibility due to water vapor, but TGE will conduct this analysis for aesthetics and visibility purposes. The stack plume visibility analysis will consist of an assessment of the predicted length and frequency of any visible water vapor plumes that may be created by the Project. This information will also be used in the visual resources study to generate a photosimulation or rendering of the plant during possible visible-plume conditions.

7.3.13 Global Warming

An assessment of the Project's emissions of CO2 and other suspected greenhouse gases from the Project will be conducted. TGE anticipates that the assessment will include a summary of emission reduction goals of the Kyoto Protocols; an estimate of the Project's emissions of CO2 and other significant greenhouse gases, on the basis of EPA-specified factors; and a comparison of the projected emissions with New York State, national and/or global emissions, and with emissions from existing generation units that would be operated if the Project were not generating. In addition, the Application will include an update on New York City carbon dioxide reduction efforts and the Project's compliance with them.

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