Updated FLAG Document

Click on title to go to a National Park Service page with a link to the October 2010 updated FLAG document.

MDEQ Modeling Guidance

1998 Policy Memo -- When Modeling is Required

Draft 2007 Modeling Guideline Document
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Wind Erosion Calculation

Notes on wind erosion calculations, AP-42 13.2.5 method:

AP-42 13.2.5 with notes

Calculation Notes

Fastest mile vs. 3-sec gusts 1

Fastest mile vs. 3-sec gusts 2

Fastest mile vs. 3-sec gusts 3

ASOS User's Guide
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Wyoming 3-Year Emissions Inventory

Wyoming DEQ website for emission inventory information:
http://deq.state.wy.us/aqd/ei.asp

Here's the introduction with my assumed updates inserted:

In accordance with 40 CFR part 51, Subpart A, states are required to report total state-wide emissions to the United States Environmental Protection Agency (EPA) every three years. Calendar year 2008 [2011] marks the third [fourth] year for the reporting period for which emission inventories are required to be collected by each state and submitted to EPA for the National Emissions Inventory. As such, the Wyoming Department of Environmental Quality (DEQ), Air Quality Division (AQD) is requiring each minor source located in the state of Wyoming to complete an air emissions inventory for calendar year 2008 [2011]. The completed 2008 [2011] Annual Minor Source inventory should be returned to the AQD no later than September 15, 2009 [presumably 2012]. This emission inventory information is required to be submitted to the Division, pursuant to W.S. 35-11-110(a)(vii).

WDEQ recently conducted a series of workshops around the state to share information about completing inventories for O&G sources. I e-mailed Scott Faber asking for presentation materials from these sessions. Here's his reply:

Kevin,

At the workshops, we had an introductory powerpoint presentation that gave some general background information on emission inventories, and then we went through the minor source inventory forms (spreadsheets). We will be posting the powerpoint presentation on our website in the coming weeks, and the tri-annual minor source inventory forms for 2008 are still posted on our website at http://deq.state.wy.us/aqd/ei.asp. You can look over those forms to see what kind of emissions information we will be requesting for 2011, and we will post the forms for 2011 later next year when we have made some updates to them. The main change being that we will be asking for PM2.5 emissions along with PM10.

Tailoring Rule Guidance, November 2010

GHG PSD and Title V Guidance

Regarding biogenic emissions sources, EPA indicates that it's still unsure of how to account for them and plans to issue further guidance next year. It's interesting how they think May of 2011 is "well before the start of the second phase of PSD implementation pursuant to the Tailoring Rule"; heck, that could give someone one or two whole months to respond! Here's a relevant section from the document:

“…numerous stakeholders requested that EPA exclude, either partially or wholly, emissions of GHG from bioenergy and other biogenic sources for the purposes of the BACT analysis and the PSD program based on the view that the biomass used to produce bioenergy feedstocks can also be a carbon sink and therefore management of that biomass can play a role in reducing GHGs. EPA plans to provide further guidance on the [sic] how to consider the unique GHG attributes of biomass as fuel.

“Even before EPA takes further action, however, permitting authorities may consider, when carrying out their BACT analyses for GHG, the environmental, energy and economic benefits that may accrue from the use of certain types of biomass and other biogenic sources (e.g., biogas from landfills) for energy generation, consistent with existing air quality standards. In particular, a variety of federal and state policies have recognized that some types of biomass can be part of a national strategy to reduce dependence on fossil fuels and to reduce emissions of GHGs. Federal and state policies, along with a number of state and regional efforts, are currently under way to foster the expansion of renewable resources and promote biomass as a way of addressing climate change and enhancing forest-management. EPA believes that it is appropriate for permitting authorities to account for both existing federal and state policies and their underlying objectives in evaluating the environmental, energy and economic benefits of biomass fuel. Based on these considerations, permitting authorities might determine that, with respect to the biomass component of a facility’s fuel stream, certain types of biomass by themselves are BACT for GHGs. To assist permitting authorities further in considering these factors, as well as to provide a measure of national consistency and certainty, EPA intends to issue guidance in January 2011 that will provide a suggested framework for undertaking an analysis of the environmental, energy and economic benefits of biomass in Step 4 of the top-down BACT process, that, as a result, may enable permitting authorities to simplify and streamline BACT determinations with respect to certain types of biomass.

“… Finally, EPA also plans to determine by May 2011, well before the start of the second phase of PSD implementation pursuant to the Tailoring Rule, whether the issuance of a supplemental rule is appropriate to address whether the Clean Air Act would allow the Agency and permitting authorities or permitted sources, when determining the applicability of PSD permitting requirements to sources of biogenic emissions, to quantify carbon emissions from bioenergy or biogenic sources by applying separate accounting rules for different types of feedstocks that reflect the net impact of their carbon emissions.” pages 9 & 10

Regarding BACT:
Refers to technical “white papers” that provide industry-sector-specific GHG BACT guidance, but it doesn’t say where to find these documents. (page 21)

The guidance explicitly requires consideration of alternate processes that may have better energy efficiency. They offer an example of comparing a supercritical and subcritical coal fired boiler (page 22). The guidance presents a detailed analysis of this issue starting on page 27.
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GHG Reporting, Subpart W, Petroleum and Natural Gas Systems

Final rule published 11/8/10; published in Federal Register 11/30.
Final Rule

Here's an overview article published March 2011 in the Air Pollution Consultant on-line magazine (available through Cyber Regs). (Added 6/14/11, KMM)


All the Part 98 subparts are collected here:
GHG Reporting Rule Web Site

Here's the text relating monitoring and QA/QC requirements (§98.234):

The GHG emissions data for petroleum and natural gas emissions sources must be quality assured as applicable as specified in this section. Offshore petroleum and natural gas production facilities shall adhere to the monitoring and QA/QC requirements as set forth in 30 CFR 250.

(a) You must use any of the methods described as follows in this paragraph to conduct leak detection(s) of equipment leaks and through-valve leakage from all source types listed in §98.233(k), (o), (p) and (q) that occur during a calendar year, except as provided in paragraph (a)(4) of this section [which requires optical imaging for inaccessible areas as defined].

(1) Optical gas imaging instrument. Use an optical gas imaging instrument for equipment leak detection in accordance with 40 CFR part 60, subpart A, §60.18(i)(1) and (2) of the Alternative work practice for monitoring equipment leaks [This is italicised in the original. It would seem to refer to some document, but word searching this rule yielded no other occurrence.]. Any emissions detected by the optical gas imaging instrument is a leak unless screened with Method 21 (40 CFR part 60, appendix A-7) monitoring, in which case 10,000 ppm or greater is designated a leak. In addition, you must operate the optical gas imaging instrument to image the source types required by this subpart in accordance with the instrument manufacturer’s operating parameters.

(2) Method 21. Use the equipment leak detection methods in 40 CFR part 60, appendix A-7, Method 21. If using Method 21 monitoring, if an instrument reading of 10,000 ppm or greater is measured, a leak is detected. Inaccessible emissions sources, as defined in 40 CFR part 60, are not exempt from this subpart. Owners or operators must use alternative leak detection devices as described in paragraph(a)(1) of this section to monitor inaccessible equipment leaks or vented emissions.

(3) Infrared laser beam illuminated instrument. Use an infrared laser beam illuminated instrument for equipment leak detection. Any emissions detected by the infrared laser beam illuminated instrument is a leak unless screened with Method 21 monitoring, in which case 10,000 ppm or greater is designated a leak. In addition, you must operate the infrared laser beam illuminated instrument to detect the source types required by this subpart in accordance with the instrument manufacturer’s operating parameters.

(4) Optical gas imaging instrument. An optical gas imaging instrument must be used for all source types that are inaccessible and cannot be monitored without elevating the monitoring personnel more than 2 meters above a support surface.

(5) Acoustic leak detection device. Use the acoustic leak detection device to detect through-valve leakage. When using the acoustic leak detection device to quantify the through-valve leakage, you must use the instrument manufacturer’s calculation methods to quantify the through-valve leak. When using the acoustic leak detection device, if a leak of 3.1 scf per hour or greater is calculated, a leak is detected. In addition, you must operate the acoustic leak detection device to monitor the source valves required by this subpart in accordance with the instrument manufacturer’s operating parameters.

Comments:

• Is acoustic leak detection (5) limited to only a subset of required monitoring? Appears that way.
• It looks like (4) is an extension of (1) and indicates that, in some cases, using a camera is the only option.

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SO2 Modeling Guidance

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Although this guidance offers a "first tier" approach of using the "overall highest hourly background SO2 concentration from a representative monitor" (emphasis added), it goes on to seemingly stress the appropriateness of applying professional judgment when characterizing background by modeling nearby sources and by using monitoring data. It even goes so far as to suggest that you don't necessarily have to follow the modeling guidance in the 1980 Draft NSR Workshop Manual.

EPA SO2 Modeling Policy Memo, August 2010

I noticed, too, that Appendix W seems to encourage efforts to avoid double counting through use of modeling and monitored data. This link accesses a copy of the current version of Appendix W:

EPA SCRAM site with link to Appendix W

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