Research Triangle Park

August 31, 2005

Lydia Wegman, USEPA RTP Mail Code C504-01 Research Triangle Park, North Carolina 27711

RE: Comments on Draft Staff Work Paper on the Use of Air Quality Data Related to Exceptional and Natural Events for the Particulate Matter Standards

Dear Ms. Wegman:

Thank you for the opportunity to review the above referenced draft staff work paper on the use of air quality data related to exceptional and natural events for particulate matter. The State of Wyoming, as a member of WESTAR, has been working for more than a year to provide recommendations on how the Natural Events Policy could be modified to function better. The workgroup recommendations that came from that effort are to be considered Wyoming’s recommendations too. While certain issues contained in WESTAR’s recommendations were partially covered, I would like to see an effort made to fully address all of them.

I am attaching a copy of our specific comments of the draft staff work paper for your further consideration. We are available to discuss any questions you may have regarding them.

Sincerely,

Dan Olson, Administrator Air Quality Division

Enclosure cc: Larry Wallace Joseph W. Paisie USEPA Mailroom USEPA Mailroom Mail Code: C504-02 Mail Code: C504-02 Research Triangle Park, NC 27711 Research Triangle Park, NC 27711 GENERAL COMMENTS:

As a participating State in the WESTAR recommendations for revising the EPA’s Natural Events Policy (NEP), Wyoming has placed considerable time and effort into making suggestions for improving the process. We find it a little disheartening that EPA has glossed over, or ignored much of the information contained in the recommendations and supporting documents.

The Joseph W. Paisie memorandum that accompanied the draft staff work paper identifies four items where the EPA is especially seeking comments. All four of the listed items are addressed to some degree in the WESTAR recommendations and they should be taken as our comments on the subjects.

An exceptional event is not supposed to recur routinely. A high wind natural event as listed in the staff paper is supposed to be unusual. It would be helpful to understand what EPA considers to be unusual because it is not defined. Further, high wind is not an ambient air problem, wind blown/generated dust is. High wind does not always generate a wind blown dust problem. There are too many other contributing factors to link this natural event to only high winds and it is not always easy to document what the other contributing factors are without some guidelines as to what will be acceptable documentation.

There are a number of PM10 NEAPs that have been developed. When the PM10 standard is revoked, do these NEAPs disappear also?

COMMENTS ON THE STAFF WORK PAPER

This staff paper appears to be only directed at particulate matter (excluding PM10, according to the last sentence in the first paragraph), but there are scattered references to Appendix I which doesn’t seem appropriate since it deals with ozone.

, last sentence in Section 1: Who is this directed at? Earlier in the paragraph it sounds like the Regional Administrator is the person who can “discount, weight or make adjustments to the data”. Are we to conclude that the Regional Administrators are the “affected air quality agencies” encouraged to follow the guidance?

The definition of natural event at #2 does not contain the EPA’s premise that the natural event has to “unusual”. The word unusual is scattered throughout this document and is not quantified for any circumstance. When discussing the use of elevated measured particulate values that do not exceed the 24 hour standard but are thought to affect the annual standard, we would think that occurrences might be more frequent than just “unusual”.

, Section 3: The purpose of flagging AQS data is to avoid misusing or misinterpreting data measurements influenced by natural or exceptional events. The staff paper states that it is not sufficient to prove that a natural event occurred; the State must provide a compelling demonstration that it caused or significantly contributed to the exceedance or violation. Has EPA reasonably considered whether it is possible to meet this demonstration criteria for all exceptional and natural events in all cases? We can appreciate EPA’s desire to assure that flagging efforts are not abused, but if the reporting agency is able to demonstrate that a natural event was occurring when an exceedance or violation occurred and BACM was in employed by all anthropomorphic sources at the time, what other purposed is served by the “compelling demonstration”? (We are presuming that a NEAP is required in order to flag data following the initial exceedance or violation of a NAAQS, as described in Section 6.)

Pages 5 and 6, Section 4: The second paragraph suggests that four steps should be used to determine whether data should be flagged, and to assist potential users in determining how the data should be used.  Step one asks whether the measured value is affected by the “event” in question.  Step two asks for a determination of what portion of the measurement is attributable to the “event” in question as well as cumulative effect of “several” similar exceptional or natural events that create significant impacts at the particular monitoring sites. We are not certain that it is always possible to apportion the measurement caused by an event. Is this always necessary if a NEAP is in place?  Step three is to identify the area influenced by the event. Isn’t this information available in reporting agency’s NEAP?  Step four is to demonstrate how the flagged data relates to the previously collected data at the monitoring site in question. It seems like this is basically the same as step one.

, Section 5: The requirement to submit adequate and compelling documentation is contained in 5.1. In the first paragraph, the staff paper offers a number of types of documentation that might be used to establish a clear causal relationship between the measured exceedance and the event in question. EPA should more clearly state that not all or even most of the examples are required in the demonstration. It would be much more useful to have a “bright line” on the degree of detail required in a demonstration. The first two paragraphs dance around the “how much is enough” question and leave the reader (and reporting agencies and regional offices) with no clear cut answers. The “I’ll know it when I see it” remaining after shifting through the words is not very useful when a reporting agency is trying to comply with this type of vagary.

, Section 5: The entire paragraph describing the time frames for submitting documentation is somewhat confusing when you start talking about 60 days, plus a possible 30 day extension, plus 60 days for EPA approval or denial, plus 30 days if you need more information, plus 30 days for the reporting agency to respond to that, plus an additional 30 days to come up with EPA approval or denial. (We think we read that correctly?) WESTAR’s comments on the timely submittal of documentation reflects our (Wyoming’s) concerns on this topic. We don’t think that the paragraph as written supports circumstances where annual standard might be exceeded. If the reporting agency would like to flag data that exceeds the nominal value of the annual standard, but that falls below the 24 hour standard are the same procedures followed?

(Use of the word “concurrence” and “nonconcurrence” implies some mutual cooperation. From our understanding of how this works EPA should just say “approval” and “disapproval”. EPA has the last word on a proposal to flag data as the staff paper is written. If the reporting agency and the EPA were operating on even footing, dispute resolutions would go to either an independent panel, or a panel containing reporting agency and EPA representatives.)

, Section 6.2, Second Paragraph: “Emissions attributed to anthropogenic activities that re- entrain volcanic ash during the first year (12 months) following an event will be treated as due to the natural event. One year is considered an adequate amount of time for cleaning…….” We believe that it is poor policy to place an absolute time limit on volcanic and seismic activity cleanups. On one hand, 12 months may be too long a period for a minor cleanup, on the other, 12 months may be insufficient. The selection of 12 months appears to be arbitrary.

Pages 10-12, Section 6.4, High Wind Events: Throughout this section, EPA identifies the problem as high wind and seems to focus on the idea that the only variable of note in the generation of fugitive dust is “high wind”. One brief sentence acknowledges that soil type and precipitation also affect fugitive dust emissions. We believe that EPA should rethink this position. We are glad to see that a “presumptive high wind speed” was not established in this policy. High winds that occur when the ground is rain saturated or covered by snow generally will not create elevated monitored particulate values. On the other hand, these circumstances make the measured wind speed more “normal”. We have noticed a marked increase in monitored particulate from wind generated dust coming from anthropomorphic sources resulting from an extended period of drought in this State.

When EPA demands that the reporting authority must provide compelling documentation that wind speeds were “unusual and untypical” for the area during the period under consideration, it is ignoring all of the other contributing factors that lead to a wind blown dust event. It’s not just the wind.

, Section 6.7: We appreciate not having to include a NEAP in our SIP. We note that we must have a NEAP to be able to flag data to be discounted from regulatory consideration, and that any approved NEAP is subject to the unilateral approval of EPA.

, Section 6.11: The process described by the proposed policy is

1. The reporting agency must flag data in the AQS database, 2. The reporting agency must submit adequate and compelling documentation which shows that the event occurred and that there was a clear and causal relationship between the event in question and the exceedance or violation that was monitored at the affected monitoring site, and 3. EPA must agree that the materials submitted are adequate, and the data can be flagged.

The last sentence in this section reads: “EPA will be disinclined to grant concurrence on flagged data unless it is determined that sufficient documentation has been submitted related to the event in question, within the time periods provided in this policy.” While we understand the intent of the statement, use of this type of phraseology is not conducive to fostering good partnership relations between EPA and the various reporting agencies.

, Section 7.1: We recommend revising item (2) to read “(2) they are determined to be unpreventable, or not to be reasonably controllable.”

, Section 7.1, first paragraph: The list of examples begins with #2.