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April 17, 2006

Air Docket

Environmental Protection Agency

Mail code: 6102T

1200 Pennsylvania Ave., NW

# Washington, D.C. 20460

Re: Docket ID No. OAR-2003-0062

The Air Pollution Control Division of the Colorado Department of Public
Health and Environment (hereafter "APCD") respectfully submits the
following comments regarding the December 20, 2005 proposed rule on
National Ambient Air Quality Standards (NAAQS) for Particulate Matter
(PM) (Docket ID No. EPA-HQ-OAR-2001-0017). Essentially, the state does
not agree that two source categories of PM coarse should be exempted
from control or regulation, nor does Colorado agree that the PM coarse
standard should not apply in rural areas (\<100,000) since a national
ambient air quality standard should apply to all areas of the nation.

*[Comment 1:]{.underline} The EPA proposes to exempt agricultural
sources, mining sources, and other similar sources of crustal material
from being subject to control in meeting the proposed PM coarse
(PM~10-2.5~) NAAQS. Based on EPA's Review of the NAAQS for PM (December
2005), it appears that the logic for this exemption is founded on very
limited epidemiologic evidence suggesting no significant health effects
from short-term exposure to natural crustal materials that may comprise
a major fraction of coarse particles in non-urban or rural areas.*

Just because there is little evidence of adverse health effects caused
by coarse particles in rural areas, does not mean that coarse particles
are not affecting people's health in rural areas. Causation is difficult
to prove; therefore, EPA should err on the side of caution. Given the
limited amount of comprehensive epidemiological data supporting a
causative link between exposure to "natural" crustal materials and no
significant health effects, it is relevant to question the proposed
exemption of agriculture and mining from any emission controls in
meeting such a standard. The proposal attempts to ascertain which coarse
particles are harmful to public health by exempting those source
categories that EPA contends are less conclusively linked to adverse
health effects because EPA states that, rural crustal particles are
possibly less harmful than urban particles. Although numerous
epidemiological studies show a clear association between urban
particulates and negative health impacts, the association is less
supported for rural areas partly due to a lack of studies in rural areas
and not on conclusive research. The proposal cites a study (Schwartz et.
al. 1999) done in Spokane, Washington that suggests "coarse" crustal
material suspended during high wind events is not associated with
increased mortality. Although it is debatable as to whether the study
appears to support the conclusion that crustal particulates are less
harmful, it clearly fails to address the short-term health effects on
sensitive populations that didn't die during the study. Since the
national ambient air quality standards are fundamentally based on
protecting public health, it is not reasonable to exempt major
contributors to coarse particulate matter from controls.

Colorado has extensive agricultural development and mining activities
that contribute to localized PM impacts. Agricultural communities such
as Lamar and Alamosa have experienced limited duration (24-hour) PM
impacts associated with wind blown dust that have caused exceedances of
the daily PM~10~ NAAQS in the past. Several Colorado mountain
communities are located adjacent to mines with disturbed areas that
contain heavy metals and other crustal contaminants.

Coarse particulate matter from mining operations may contain heavy
metals such as lead (Pb), mercury (Hg), cadmium (Cd), and arsenic (As);
also minerals such as asbestos, and radioactive substances all have
deleterious effects. Furthermore, lead and arsenic have no known
threshold level for health effects; they can have toxic effects at all
concentrations especially in children. These hazardous air pollutants
may cause cancer and other deleterious health effects from either high
acute levels or low-level chronic exposures. Heavy metals are natural
components of the Earth\'s crustal material, which cannot be degraded or
destroyed, and can bioaccumulate in humans. These heavy metals and toxic
minerals can be released during mining operations, transportation, and
as fugitive dust off the mine's site.

Moreover, the proposed exemptions would further hamper the State's
efforts in protecting its rural citizens and citizens in cities and
towns with less than 100,000 population from PM coarse exposure and
controlling some major contributing sources of the problem. It is the
State's position that there is little difference between PM in smaller
communities and PM in urban areas with greater that 100,00 people.

*[Comment 2:]{.underline} The proposal incorrectly concludes that
short-term exposure to "natural" or crustal geologic material (in the
form of coarse particulates) originating from rural or non-urban areas
results in no significant health effects.*

The contention that exposure to "natural" particulate matter in rural or
non-urban areas results in no significant health effects clearly
contradicts previous medical research indicating that even chemically
non-reactive PM is damaging to lung tissue. The inhalation of inert
"natural" sand particles (silica) has long been associated with
Silicosis (Hardy et al. 94). Short-term exposures to [high]{.underline}
levels of "natural" particulates result in lung inflammation and
accumulations of fluids causing severe shortness of breath and low blood
oxygen levels. Further, long-term exposures to even [low]{.underline}
amounts of silica dust provoke the formation of nodules of chronic
inflammation and scarring in the lungs and lymph nodes. Clearly, rural
populations may experience both short and long-term exposures at a
variety of levels that can result in health effects, particularly for
sensitive populations.

Colorado has evidence that shows there are toxic substances in
particulate matter in rural areas of the state. Most particulate
monitoring near mining operations in Colorado has focused on PM~10~ or
TSP monitoring without analyzing the data for toxics. This is because
analyses for toxic material is expensive and if the emissions of TSP and
PM~10~ are controlled there is no need to conduct these expensive
analyses. Thus, Colorado has a very limited data set of toxic analyses
of PM~10~/TSP in rural areas of the State. However, an ambient air study
of the Eagle Mine area (a CERCLA site near Minturn, Colorado with a
population of 1,106 in 2004) was conducted with PM~10~ and TSP monitors
at two sites for a short period in 1989.

The PM~10~ and TSP emissions were monitored on a one in three day
frequency from May 4 to Dec 3, 1989. The highest concentrations found
were 94 ug/m^3^ TSP (n=69) and 48 ug/m^3^ PM~10~ (n=68) at the North
site and 42 ug/m^3^ TSP (n=70) and 35 ug/m^3^ PM~10~ (n=65) at the
Minturn Middle School site. TSP samples (n=72) were analyzed for lead,
arsenic, and cadmium by x-ray fluorescence (XRF). A total of 11 arsenic
and six cadmium samples were above the reporting trigger levels, which
are 0.5 ug/m^3^ for lead, 0.01 ug/m^3^ for cadmium and arsenic. The
maximum reported XRF concentrations were 0.483 ug/m^3^, 0.245 ug/m^3^
and 0.034 ug/m^3^ for lead, arsenic and cadmium respectively. The action
levels were exceeded even though the PM~10~ and TSP levels were well
below the NAAQS.

Similar levels of heavy metals were also found in the TSP/PM~10~
emissions in Central City, Colorado; population 515 in 2002 (Colorado
Dept. of Local Affairs). A three-month monitoring study of the tailings
piles near the towns' main parking lot was conducted from August 14 --
November 9, 1989. This is considered the cleanest season for particulate
matter in Colorado mountain areas. XRF analysis for eight heavy metals
including (Arsenic, Beryllium, Cadmium, Chromium, Copper, Lead, Nickel,
and Zinc) was performed on both the PM~10~ and TSP filters. The maximum
TSP concentration was only 31 ug/m3, but the levels of heavy metals on
both PM~10~ and TSP filters were elevated on numerous filters. Table 1
below, shows the results. Clearly, particulates in rural areas cannot be
considered safe if they contain toxic substances.

**Table 1 Central City, Colorado 1989 Tailings Pile Parking Lot Study**

### *September - November 1989*

Samplers located at Central City Fire Station, 116 Lawrence St.

  ---------- ------------- --------------- ------------- -------------- ------------- ------------- ------------- -------------
             **Arsenic**   **Beryllium**   **Cadmium**   **Chromium**   **Copper**    **Lead**      **Nickel**    **Zinc**
             \[ug/m^3^\]   \[ug/m^3^\]     \[ug/m^3^\]   \[ug/m^3^\]    \[ug/m^3^\]   \[ug/m^3^\]   \[ug/m^3^\]   \[ug/m^3^\]

  **Max.     0.0038        0.0007          0.0090        0.0208         0.2284        0.0925        0.0189        0.2743
  TSP**                                                                                                           

  **Mean     0.0014        0.0006          0.0015        0.0085         0.1520        0.0334        0.0093        0.1051
  TSP**                                                                                                           

  **Max.     0.0015        0.0008          0.0038        0.0136         0.0748        0.0469        0.0257        0.1051
  PM~10~**                                                                                                        

  **Mean     0.0008        0.0007          0.0006        0.0037         0.0469        0.0238        0.0103        0.0510
  PM~10~**                                                                                                        
  ---------- ------------- --------------- ------------- -------------- ------------- ------------- ------------- -------------

*[Comment 3:]{.underline} The proposal to exclude rural or low
population areas from ambient PM monitoring programs is not protective
of such populations since it would be impossible to identify areas
out-of-compliance with the NAAQS if such areas are not monitored.
Moreover, existing PM monitoring programs throughout Colorado have
identified otherwise unknown air quality problems in rural communities
that have been mitigated through State Implementation Plan (SIP)
requirements that were triggered by the very monitoring proposed to be
eliminated.*

Colorado has always operated from the fundamental perspective that all
citizens deserve to breathe healthy air. Further, citizens and
communities have a right to know what levels of pollution may be in the
air they are breathing. If the proposed PM standards were in place in
the 1980s and 90s a significant number of rural Colorado towns would
have unknowingly continued for years (even decades) to breath high
levels of particulate matter (aerosols, carbon and crustal materials
combined) without any compelling mandate to reduce emissions or to
monitor air quality. Removing PM~10~ monitoring and not adding
PM~10-2.5~ monitoring from areas that had PM~10~ problems in the past
may cause backsliding in the future, particularly in cities with
populations less than 100,000.

The existing PM~10~ standard is a basically a coarse particle standard
but it's value as a driver for the development of SIP control measures
that reduce both fine and coarse PM is not taken into consideration in
the proposal. The factors that contribute to high pollution levels in
small (rural) Colorado communities have little to do with wind blown
fugitive crustal material. Rather, the causes of high levels are the
result of human activity. Motor vehicles, wood burning and paved/unpaved
road particulate matter are the major causes. The PM~10~ SIPs developed
in Colorado for both small and large communities address wood burning,
diesel vehicles, road sanding and emissions from industrial facilities.
However, the SIP compliance demonstrations in the small communities have
relied almost solely, with the exception of industrial sources, on
woodburning and road dust reduction strategies.

It is also important to note that the elected leadership in these
communities fully embraced the control of these sources in their
communities. They realized that residential wood burning reduction
programs, enhanced street cleaning, improved street dust control
enhanced the community quality of life.

Colorado has many rural PM~10~ Maintenance areas (Aspen, Canon City,
Lamar, Pagosa Springs, Steamboat Springs, and Telluride) that presumably
would not have any particulate regulatory requirements if the proposed
revocation of the PM~10~ standard were implemented along with the
proposal to exclude rural populations from ambient PM monitoring. The
discontinuation of monitoring in these rural communities may erode the
motivation to continue existing PM control programs that are often
expensive and labor-intensive maintain but have resulted in significant
improvements in air quality. Further, some of these communities
periodically experience natural events such as wildfire smoke, or wind
generated dust, that result in unhealthy particulate levels sometimes
resulting in exceedances of the PM~10~ NAAQS. Although these monitors do
not provide real-time data for alerting the public to limit exposure,
they do provide valuable documentation on the magnitude and extent of
wildfire smoke or wind generated dust. This data could prove invaluable
in accessing the health impacts to rural populations that is currently
lacking in published studies on PM health effects.

Colorado is concerned looking forward as well. Energy development
(particularly oil and gas drilling) is having a major impact on the air
quality in rural towns in Colorado. This pace of activity is projected
to continue or expand over the next 10-15 years. The states need tools
such as monitoring and other means to identify and mitigate these
impacts.

*[Comment 4:]{.underline} We disagree with the proposed exemption of
mining and agriculture sources because it ignores the PM coarse impacts
these sources have on Colorado's regional haze problem.*

Currently, all Colorado mandatory Class I federal areas need
improvements in visibility by 2018 and 2064 the two planning deadlines
for regional haze. Data from monitoring sites in Colorado\'s wilderness
areas and national parks indicates from 7% to 12% of the average
visibility impairment is due to PM coarse. When considering the 20%
worst days, (the point at which success of the planning and control
effort is judged) between 10% and 26% of the visibility problem is
attributed to PM coarse, equal to the impacts of most other sources. To
exempt such sources from control in Colorado would force other types of
sources, mainly large industry, unpaved roads and prescribed fire to add
further controls to make up the difference.

*[Comment 5:]{.underline} A host of issues arise when the proposed
mining exemption is coupled with the proposed removal of the PM~10~
NAAQS.*

Issue 1: Mining activities meeting the definition of major stationary
source that previously implemented emission controls solely to
demonstrate compliance with Prevention of Significant Deterioration
(PSD) requirements and the PM~10~ NAAQS could presumably relax emission
controls since the proposed PM coarse NAAQS exempts mining activities
from control and the existing PM~10~ PSD Program and PM~10~ NAAQS would
be no longer applicable. Under this scenario, air quality near a mining
source could clearly experience significant deterioration.

Issue 2: Mining operations at major PSD sources that previously would
have been subject to PSD pre and post construction monitoring
requirements would no longer be subject to such monitoring. If sources
are not required to monitor air quality before and/or after
construction, it will be more difficult to determine the contribution
from the mining operation and if PM coarse levels are safe for the
affected public.

Issue 3: High concentration gradients of PM coarse can exist near
fugitive sources such as haul roads, open pit mines, and gravel pits. If
mining sources are exempt from emission controls, PM coarse
concentration levels may be allowed to reach levels well in excess of
"typical ambient exposure concentration" levels. These hot spots might
constitute a health risk to some populations. In the Denver metropolitan
area, there are large gravel pits and quarries with PM ~10-2.5~
concentrations that will be extremely difficult to mitigate under the
proposed exemption for mining. Further, the blanket exemption from
emission controls for a given source category could prevent state and
local air quality agencies from protecting the health and welfare of the
general public near large stationary sources that include mining
activities. A relaxation of emission controls could lead to significant
deterioration of air quality in some locations, particularly in
neighborhoods located near mining sources. EPA should conduct additional
studies to determine if there are health risks associated with exposure
to PM coarse concentrations within the high concentration gradient areas
near mining operations.

*[Comment 6:]{.underline} It appears that the proposal fails to
explicitly define* *agricultural sources, mining sources, and other
similar sources of crustal material that are proposed for exemption from
being subject to control in meeting the proposed PM coarse (PM10-2.5)
NAAQS.*

It is difficult to provide specific comment on this issue because
agriculture and mining sources comprise such a wide variety of
operations and our comments may differ depending on how these terms are
defined. It seems reasonable that more detail should be provided on what
is meant by "agricultural, mining or other sources of crustal material".
For example, does the agricultural source category include not only the
traditional farmers that may generate some dust during the plowing
season but also large confined animal feeding operations that may
generate dust throughout the dry season?

During a winter conference call[^1], Lydia Wegman stated that presumably
the Standard Industrial Classification (SIC) could be used to
distinguish mining and agricultural sources. This approach may be
problematic since mining sources typically obtain some type of
major/minor source air permit that may comprise a variety of operations
including mining but the mining SIC code may not be clearly specified in
the permit. Moreover, it is not clear under the proposal if emissions
from everything associated with the mining operation (mine, haul roads,
crushers, screens, etc.) are exempted or if only the emissions from the
actual mine operation (open pit, shaft, quarry, etc.) are exempted?

*[Comment 7:]{.underline} Colorado is concerned that the lack of PM~10~
monitoring and the decreased number of monitoring sites proposed for PM
coarse monitoring and reduction of PM~2.5~ sites will allow backsliding
of PM air pollution in the state, and western region.*

Without PM~10-2.5~ monitoring we won't be able to determine if a problem
exists. Monitoring is the first line of defense in air pollution
problems. Without adequate monitoring we cannot begin to solve or
prevent particulate matter air pollution problems. Colorado is the 8^th^
largest state in square miles and it has the 24^th^ largest population.
It also has one of the highest population growth rates in the nation.
From 1990 to 2000 Colorado population growth ranked third at 30.1%;
adding over 1,000,000 people. The state of Colorado covers 103,711
square miles and ranges in elevation from about 3500 feet (1,000 m) to
54 peaks over 14,000 feet (4,270 m). This complex terrain has many
airsheds ranging from small mountain valleys to large Front Range basins
that trap particle pollution with temperature inversions. Six PM coarse
monitors in three cities along the front range is not adequate to
address Colorado's complex terrain and air quality problems from
regional haze to high local hot spot concentrations. Attached in
Appendix A are two maps showing the Colorado particulate matter
monitoring network as it existed in 2005 (Figure 1) and how it may look
in the future (Figure 2) if the EPA proposals are adopted. The future
map also reflects the National Monitoring Strategy Plans, which may show
less reduction in particulate sites than the proposed PM NAAQS.

For the State of Colorado, the task of fully funding the existing PM
monitoring network is daunting, given the following facts: (1) the U.S.
EPA 103 Grant for PM2.5 monitoring is being reduced by 13 -- 14% in
2006; (2) the U.S. EPA 103 Grant for PM2.5 monitoring is converting from
a 103 Grant, which is fully funded by U.S. EPA to the 105 Grant, which
is only 60% funded by the U.S. EPA; the State must match the other 40%
and (3) the 103 to 105 Grant conversion is scheduled to take place in
fiscal year 2007, which begins on October 1, 2006, which doesn't give
the Division time to request funding from the State Legislature for the
current legislative session.

Thank you for your consideration,

Margie Perkins

Director, Air Pollution Control Division

cc: Mark Komp, EPA Region VIII

# Figure 1: Existing Particulate Monitoring Network

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# Figure 2: Anticipated Particulate Monitoring Network based on PM NAAQS Proposal

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[^1]: December 22, 2005 conference call between STAPPA-ALAPCO and EPA
    regarding the December 20, 2005 proposed rule on National Ambient
    Air Quality Standards (NAAQS) for Particulate Matter (PM) (Docket ID
    No. EPA-HQ-OAR-2001-0017)