# Addendum to the

“ Technical Support Document

For the April 3 , 2009 Pagosa Springs Exceptional Event ”

Prepared by the Technical Services Program

Air Pollution Control Division Colorado Department of Public Health and

Environment

September 30 , 2013

## 1.0 Introduction

This addendum serves to incorporate additional requested information regarding Section 5 “Local Dust

Control Measures ” of the “ Technical Support Document f or the April 3 , 2009 Pagosa Springs Exceptional

Event” submitted to the EPA on June 30, 2012. This addendum addresses additional support regarding

local sources and controls outlined in the letter sent by EPA Region 8 on April 2, 2013 . This letter states
that the Exceptional Event documentation submitted by APCD did not “ sufficiently in vestigate whether local sources of windblown dust may have contributed to the exceedances

. ” Since receiving the EPA letter, the Colorado Air Pollution Control Division (Division) conducted a thorough invest igation, including EPA’s suggestions, of local so urces of windblown dust and relevant reasonable controls in place at the time of the April 3 , 2009 Exceptional Event. These sources include the nine acre park along

South 5 th Street, the lots on the southeast corners of U.S. Highway 160 and Main Street/Lew is Street, and the expansion of the Springs Resort and Spa

. This addendum documents the results of this investigation.

In addition, this addendum also provides additional information for Section 1 “Introduction” of the “Technical Support Document for the April 3, 2009 Pagosa Springs Exceptional Event” submitted to the

EPA on June 30 , 2012 . Specifically, this addendum provides information regarding prompt public notification of the event, as required in 40 CFR 50.14 (c)(1)(i).

This addendum, the original report, and the analysis and data contained within it, clearly shows that this exceptional event passed the required tests under 40 CFR 50.14 (3)(iv).



## 2.0 Public Notification

The Federal EER requirements include public notification when an event occurs or is reasonably anticipated to occur which may result in the exceedance of an applicable air quality standard

, per 40 CFR 50.14(c)(1) (i).

In 2009, the Division was not providing detailed advisories for the entire state on a website. At that time, the focus of the Division website was AQI reporting and advisories fo r areas with populations over 350,000, as required in 40 CFR 58.50, as well as advisories for areas under a Natural Events Action Plan. For other areas, p hone calls or emails were provided to local officials as forecasting predicted that natural

events had a likelihood of occurring. For the high wind/dust event on April 3 , 2009, it is unknown if an advisory phone call or email was provided to local officials in Arc huleta County or Pagosa Springs as, p er State of Colorado archive requirements, phone and email records are not kept for extended periods

.

It s h ould be noted that the high values from this exceptional event were not from real

- time samplers, but

were from filt er

- based samplers where the values are not known for a few weeks after sampling.

## 3.0 Not Reasonably Controllable or Preventable: Local

Particulate Matter Control Measures

While it is likely that some dust was generated within the local communities as gusts from the regional dust storm passed thro ugh the area, the amount of dust generated locally was easily overwhelmed by, and largely unnoticeable as compared to the dust transported in from the source regions of the dust storm. The following sections will describe in detail the regulations and pro grams in place designed to control

PM 10 in the affected community. These sections will demonstrate that the event was not reasonably controllable, as laid out in Section 50.1(j) of Title 40 CFR 50, within the context of reasonable local particulate matter control measures.

The Colorado Air Pollution Control Division (Division) conducted thorough analyses and outreach with local governments to confirm that no unusual anthropogenic PM 10 - producing activities occurred in Pagosa Springs and that despite reas onable control measures in place, high wind conditions overwhelmed all reasonably available controls. The following subsections describe in detail Best Available Control Measures (BACM), other reasonable control measures, applicable federal, state, and loc al regulations, appropriate land use management, and an in

- depth analysis of potential areas of local soil disturbance for

the affected community during the March 30, 2012 event, as well as subsequent outreach designed to

administer these activities. This information shall confirm that no unusual anthropogenic actions

occurred in Pagosa Springs during this time.

Regulatory Measures

- State The Division’s regulations on PM 10 emissions are summarized in Table 1

.

Table 1 : State Regulations Regulating Particulate Matter Emissions

Rule/Ordinance Description Colorado Department of Public Health and

Environment Regulation 1

- Emission Control For Particulate Matter, Smoke, Carbon Monoxide, And Sulfur

Oxides Applicable sections include but are not limited to:

Everyone who manages a source or activity that is subject to controlling fugitive particulate emissions must employ such control measures and operating procedures through the use of all available practical methods which are technologically feasible and economically reasonable and which reduce, prevent

and control emissions so as to facilitate the

achievement of the maximum practical degree of air purity in every portion of the State. Section III.D.1

. a )

Anyone clearing or leveling of land greater than five

acres in attainment areas or one acre in non

- attainment areas from which fugitive particulate emissions will be

emitted are required to use all available and practical methods which are technologically feasible and economically reasonable in order to minimize fugitive particulate emissions.(Section III.D.2.b)

Control measures or operational procedures for fugitive particul ate emissions to be employed may include planting vegetation cover, providing syntheticcover, watering, chemical stabilization, furrows, compacting, minimizing disturbed area in the winter, wind breaks and other methods or techniques approved by the Divis ion. (Section III.D.2

. b )

Any owner or operator responsible for the construction or maintenance of any existing or new unpaved roadway which has vehicle traffic exceeding 200 vehicles per day in the attainment/maintenance area and surrounding areas must st abilize the roadway in order to minimize fugitive dust emissions (Section III.D.2.a.(i )) Colorado Department of Public Health and

Environment Regulation 3

- Stationary Source Permitting and Air Pollutant Emission Notice Requirements Construction Permit required if a land development project exceeds 25 acres and spans longer than 6

months in duration (Section II.D.1.j )

Colorado Department of Public Health and

Environment Regulation 6

- Standards of Performance for New Stationary Sources Implements federa l standards of performance for new stationary sources including ones that have particulate

matter emissions. (Section I )

Colorado Department of Public Health and

Environment Regulation 9

- Open Burning, Prescribed Fire, and Permitting Prohibits open burnin g throughout the state unless a permit has been obtained from the appropriate air pollution control authority. In granting or denying any such permit, the authority will base its action on the potential contribution to air pollution in the area,

climatic c onditions on the day or days of such burning, and the authority’s satisfaction that there is no practical alternate method for the disposal of the material to be burned. Among other permit conditions, the authority granting the permit may impose

conditions on wind speed at the time of the burn to minimize smoke impacts on smoke

- sensitive areas. (Section III )

Federal Motor Vehicle Emission Control Program The federal motor vehicle emission control program

has reduced PM 10 emissions through a continuing

proc ess of requiring diesel engine manufacturers to produce new vehicles that meet tighter and tighter emission standards. As older, higher emitting diesel vehicles are replaced with newer vehicles; the

PM 10 emissions in areas will be reduced.

3.1 Pagosa Springs

Regulatory Measures

- City and County

The Division and Archuleta County are responsible for implementing regulatory measures to control emissions from agricultural sources, stationary sources, fugitive dust sources, and open burning within the city limits of Pagosa Springs and Archuleta County

. Archuleta County regulations pertaining to PM 10 emissions are summarized in Table 2

.Table 2 : Rules and Ordinances Regulating Particulate Matter Emissions in Archuleta County

Rule/Ordinance Description Pagosa Springs Land Use and Development Code 6.6.3(h) Requires that all new developments have paved

streets. Pagosa Springs Land Use and Development Code 6.6.3(m)(i) All new roads having a projected trip generation of 200 or greater ADT (average daily traffic) shall be paved.

The following control measures resulted in the area ’ s attainment of the PM 10 NAAQS, and these

measures should ensure continued maintenance of the PM 10 NAAQS through the year 2021, which is the

dur ation of the maintenance period:

Control of Emissions through Road Paving The Town of Pagosa Springs paved 6.5 miles of unpaved roads during 1992, 1993, and 1994 in

order to reduce PM 10 emissions. This strategy was adopted locally in 1991 and included in State regulation in 1992 (Section I.B. of the State Implementation Plan

- Specific Regulations for

Nonattainm ent

- Attainment/Maintenance Areas (Local Elements)). The rule was approved by EPA in 1994 and was removed from the Colorado regulation in 2000 as the paving requirements had been completed.

Street Sanding Controls There is a requirement that any user tha t applies street sanding material on Highway 160 and Highway 84 in the Pagosa Springs attainment/maintenance area must use materials containing less than one percent fines. Users of street sand on these highways must also use 15 percent less

sand than an established base sanding amount. These strategies were adopted in 1992 and approved by EPA in 1994, and they are defined in detail in Sections I.B. and C., respectively, of the State Implementation Plan

- Specific Regulations for Nonattainment

- Attainment/Ma intenance Areas (Local Elements) Regulations (5 CCR 1001

- 20).

Control of Emissions from Stationary Sources Although there are no stationary sources located in the Pagosa Springs attainment/maintenance area, the State‘s comprehensive permit rules will lim it emissions from any new source that may, in the future, locate in the area. These rules are outlined in Table 1

.

As indicated above, emissions from new or modified major stationary sources emissions of PM 10 are controlled under AQCC Regulation No. 3's nonattainment

- area (NAA) new source review (NSR) permitting requirements. The NSR provisions require all new and modified major stationary sources to ap ply emission control equipment that achieves the "lowest achievable emission rate" (LAER) and to obtain emission offsets from other stationary sources of PM 10

.

The EPA approval of the original PM 10 Maintenance Plan, effective on 08/14/01, reinstates the

p revention of significant deterioration (PSD) permitting requirements in the Pagosa Springs Attainment/Maintenance area. The federal PSD requirements are considered a relaxation from the NAA NSR requirements, as LAER is no longer required and is replaced by the less stringent "best available control technology" (BACT), along with the removal of the requirement to offset

PM 10 emissions. The future reapplication of NAA NSR provisions appears unlikely in the Pagosa Springs Attainment/Maintenance area based on c urrent PM 10 monitoring trends.Voluntary and State

- Only Measures

In addition to the mandatory control measures discussed above, there are other activities that

result in the reduction of PM 10 emissions that are not classified as “federally enforceable control measures.” Some notable examples include:

The Town of Pagosa Springs has historically cleaned Highway 160 in town throughout the winter and spring using regenerative air vacuum sweepers. The frequency of this voluntary sweeping/cleaning has been about once after each street sanding deployment. The Town of Pagosa Springs is committed to regularly vacuum sweep/clean Highway 160 within four days of the roadway becoming free and clear of snow and ice following each street sanding deployment,

as weathe r, temperature, and street conditions permit, between the intersections of Highway 84 to the east and 14th street to the west. The town also street sweeps side streets regularly.

The Town of Pagosa Springs encourages private businesses to properly clean/s weep private parking lots on a regular basis. These strategies are considered to be voluntary local initiatives

intended to reduce PM 10 emissions. These strategies are not intended to be federally enforceable.

Archuleta County annually t r eats about 95 mi les of unpaved roadways that exceed 200 ADT with MgCl 2 to control dust and stabilize the road according to the County Public Works Director.

Windblown Dust from Disturbed Soils Pagosa Springs has a semi

- arid climate with approximately 17 inches of preci pitation annually. The town is located about 35 miles north of the New Mexico border at 7,000 feet. This area is considered a high desert plateau, creating an unusually mild climate. In winter and spring, regional windstorms are common, especially in dr ier years. It is during these high velocity windstorms that Pagosa Springs experiences PM 10 issues. Figure 1 illustrates potential areas of

local soil disturbance that have been evaluated by the Division.Figure 1 : Relative positions of Pagosa Springs PM 10 monitor and known or potential disturbed soil.

(Image from EPA)

Site A in Figure 1 shows a 1 acre vacant lot (southeast corner of U.S. Highway 160 and Main Street/Lewis Street) that previously contained a small convenience store which was torn down by the new owner between March and April of 2006. Division conversations with neighboring local business owners indicate the owner seeded the vacant lot (site A) with grass soon after demolishing the building. According to several nearby businesses and a court house clerk, the lot has been under continuous vegetative cover since the seeding in 2006. The grass is well maintained and is enclosed by a small fence (shown in Figure 2 ) to deter people from walking on the grass. Moreover, the lot is not used for parking or storage. As of August 2013, the lot is for sale. 

## D C A

BFigure 2 : Site A (August 2013)

Site B in Figure 1 (approximately 2 acres) shows part of The Springs Resort and Spa. The resort

underwent an expansion where construction began in June 2008 and was completed in May 2009. The construction project was awarded “Gold Status” (second highest award) for complying with the Leadership in Energy & Environmental Design (LEED ) 1 standards for New Construction V ersion 2.2 (Appendix B) . The LEED New Construction Standards require the developer to create (during the design phase of the project) and implement an Erosion Control and Sedimentation Control Plan to prevent polluting the air with particulat e matter during and after construction. Figure 3 shows the completed hotel addition as of August 2013. The Town of Pagosa Springs has provided Buildin g Inspection Reports ( Appendix A ) demonstrating that on February 27, 2009

, the exterior lath 2 was inspected. The building inspection report from April 29, 2009 ( Appendix A ) shows that the hotel was approved for temporary occupancy for 60 days. The final b uilding inspection was completed on June 18, 2009 (Appendix A)

. From the dates of the Town’s Building inspections it is clear that by April 2009, the entire construction site was paved and the building was completely constructed; the interior was just bein g finished.

1 LEED: http://www.usgbc.org/leed

2 Lath: weatherproofing material that covers the exterior of the building before stucco is appliedFigure 3 : Site B

- The Springs Resort and Spa (August 2013)

Site C in Figure 1 is a 35

- acre area of vacant land that is proposed for future expansion of the Springs Hotel and Spa . According to the Pagosa Springs Parks Department, the area is private property and is

enti rely naturally vegetated because of a continuous supply of ground water from the nearby stream. The Parks Department also indicates that off

- road recreational vehicles are prohibited on the property and signs are posted. The Parks Department is very aware of dust prevention practices and does not believe that the area is a significant source of dust during high winds. Figure 4 demonstrates that site C is fully vegetated as of August 2013. With regard to AQCC Regulation 1 requirements (Section III.D.2.b), the Division considers the natural vegetation with regular ground water availability due to the low

- lying terrain to be the appropriate available and p ractical method that is technologically feasible and economically reasonable in order to minimize fugitive particulate emissions for this lot at this time. Local sources, including the Pagosa Daily Post 3 , cite the proposed future 35

- acre hotel expansion (S ite C) to be projected to occur in several phases over a 10

- 15 year time period.

The Division has conduct ed appropriate outreach and compliance assistance so the hotel and County are aware of potentially applicable AQCC Regulation s, including Regulation 1 (Section III.D.2.b) and Regulation 3 (Construction Permit required if the project exceeds 25 acres and spans longer than 6 months in duration) requirements for future construction projects . The Division has specific Air Pollutant Emissions Notices (APEN s) for land development and associated guidance documents posted on its website for these type s of sources. Additionally, the Division has staff that conducts Small Business Assistance outreach as warranted. Compliance and enforcement inspectors from the Division are assigned regions throughout the state. As part of their workplans, they are required to be reasonably

3 http://www.pagosadailypost.com/news/8417/Springs_Resort_Sketch_Gets_Planning_Commission_Okay/(within one

- two business days) responsive to community and local government concerns and complaints

regarding air quality issues, including fugitive dust.

Figure 4 : Site C (August 2013)

Site D in Figure 1 is Yamaguchi Park, a 16

- acre park consisting of well

- maintained turf, irrigated grass, and some stabilized clay associated with a baseball field. The entire park is irrigated on a regular bas is to both maintain the vegetation and to mitigate dust. In the fall of 2008, Pagosa Springs hydro

- seeded the park which was watered on a regular basis to help the vegetation grow. In Figure 5 and Figure 6 , it is apparent that the park has well maintained vegetation and a small amount of stabilized c lay (on the baseball field). With regard to AQCC Regulation 1 requirements (Section III.D.2.b), the Division considers hydro

- seeding to be the appropriate available and practical method that is technologically feasible and economically reasonable in order to minimize fugitive particulate emissions for this magnitude of construction project.Figure 5 : Yamaguchi Park

- Google Image from 10

- 2011

Figure 6 : Site D Yamaguchi Park (August 2013)

The Division conducted thorough assessments to determine if the potential soil disturbances shown in Figure 1 were present during the 20 09 exceedances. During the course of these assessments, the Divisiondiscovered that these sites were reasonably controlled during the April 3 , 2009 high wind event.

Therefore, these sites were not significant contributors to fugitive dust in the Pagosa Springs area during

the April 3 , 2009 high wind event.

## Appendix A

- Building Inspection Reports for Expansion of The

Springs Resort and Spa from the Town of Pagosa SpringsBuilding Inspection Report from the Town of Pagosa Springs for the Expansion of The Springs

Resort and Spa

- 2/27/2009Building Inspection Report from the Town of Pagosa Springs for the Expansion of The Springs

Resort and Spa

- 4/29/2009Building Inspection Report from the Town of Pagosa Springs for the Expansion of The Springs

Resort and Spa

- 6/18/2009

## Appendix B

- LEED for New Construction and Major Renovations

Version 2.2