# CHAPTER 3
Air Quality Setting

3.1 Weather and Climate ......................................................................................... 3-1
3.2 Air Quality and Ar ea Designati ons ..................................................................... 3-1

3.3 PM 10 

### Air Qua lity ................................................................................................. 3-3 3.3.1 Health Impacts of PM 10 

### .................................................................... 3-3 3.3.2 Owens Lake Health Advisory Progr am ............................................. 3-3 3.3.3 Monitoring Sites and Data Collection ................................................ 3-4 3.3.3.1 PM 10 

### Monitoring Ne twork ................................................. 3-4 3.3.3.2 Dust Transport Study ....................................................... 3-5 3.3.3.3 PM 2.5 

### Monitoring at Keeler ................................................. 3-5 3.3.4 PM 10 

### Data Summa ry ........................................................................ 3-6 3.3.4.1 Number of 24-hour Exceedanc es ..................................... 3-6 3.3.4.2 Annual Average PM 10 

### Concentrati ons .............................. 3-6 3.3.4.3 Peak PM 10 

### Concentrati ons ................................................ 3-6 3.3.4.4 PM 10 

### Trends ...................................................................... 3-7

3.4 Cancer Risk Due to Owens Lake Dust St orms .................................................. 3-7
3.5 Visibility and Sensit ive Airsheds ....................................................................... 3-8

3.6 Off-Lake PM 10 

### Violati ons ................................................................................... 3-9

3.7 Referenc es ....................................................................................................... 3-9

### FIGURES Following Page
Figure 3.1 Boundaries of the federal PM 10 

### non-attainment area .............................. 3-2
Figure 3.2 Locations of PM 10 

### monitor sites near Owens Lak e ................................. 3-4
Figure 3.3 Annual trend for the number of exc eedances ......................................... 3-6
Figure 3.4 Annual average concentrations measured at each site using TEOM monitors.

................................................................................................. 3-6
Figure 3.5 Yearly comparison of highest Owens Lake PM 10 

### concentrations with Highest nationwide va lues, 1995 to 2006 ............................................... 3-6
Figure 3.6 Daily 24-hour maximum TEOM PM 10 

### values at Owens Lake, 2001 to 2006. .......................................................................................... 3-6
Figure 3.7 Locations of sensit ive airsheds near the OVPA ...................................... 3-8

TABLES Page or Following Page

Table 3.1 California and national ambient air quality standards .............................. 3-2
Table 3.2 Summary of the particulate matte r monitoring history for each site ........ 3-6
Table 3.3 Annual Ranking of Owens Lake PM 10 

### in U.S. ......................................... 3-6

Table 3.4 Cancer risk at Keeler due to Owens Lake dus t storms. .......................... 3-7

Table 3.5 Sensitive airsheds and t heir PSD classifi cations. ................................... 3-83-1 

# CHAPTER 3
Air Quality Setting

3.1 WEATHER AND CLIMATE The Owens Valley Planning Area (OVPA) is located in the southern end of the Owens Valley in Inyo County, California. Owens Lake is bounded by the Inyo Mountains to the east, and the Sierra Nevada to the west, which rise over 10,000 feet above the lake bed surface. Because it is in the rain shadow of the Sierra Nevada, annual rainfall is very low in the project area. Owens Lake averages approximately 4 inches of rainfall per year with the majority of that falling from November through April. Temperatures range from around 18oF to 70oF during winter, and 45oF to 112oF during summer. Hourly average wind speeds in the area can exceed 40 mph asmeasured at a 33-foot height. These winds are generally associated with the passage of lowpressure systems during winter and spring months. The leading edges of these low-pressure systems are usually cold fronts that initially produce winds from the south as the colder air mass approaches, under-running and displacing the warmer air in its path. As the leading edge of the front passes, the wind direction shifts, often resulting in converging winds from the south along the east side of the valley and from the north along the west side. Cold winds from the north typically follow the passage of the low-pressure system as high pressure begins to build back over the area.

3.2 AIR QUALITY AND AREA DESIGNATIONS Air quality is regulated through federal, state and local requirements and standards in the project area. Under the Federal Clean Air Act, the U.S. Environmental Protection Agency (USEPA) has set ambient air quality standards to protect public health and welfare. National ambient air quality standards (NAAQS) have been set for the following criteria pollutants; particulate matter less than 10 microns (PM 10 

### ), particulate matter less than 2.5 microns (PM 2.5 

### ), ozone, carbon monoxide, oxides of nitrogen, sulfur dioxide, and lead. In addition, California has set air quality standards for these pollutants, which are usually more stringent, and has added to this list standards for vinyl chloride, hydrogen sulfide, sulfates and visibility-reducing particles. Table 3.1 shows the current California and national ambient air quality standards.

The OVPA has been designated by the state and the USEPA as non-attainment for the state and federal 24-hour average PM 10 

### standards. The boundaries of the federal PM 10 

### nonattainment area are shown in Figure 3.1. The area is designated as “attainment” or “unclassified” for all other federal ambient air quality standards. Monitoring and research conducted for more than 20 years, as well as three previous State Implementation Plans (SIPs), has determined that wind-blown dust from the dry bed of Owens Lake is the dominant cause of NAAQS violations for PM 10 

### in the non-attainment area.

The USEPA designated the Owens Valley as a “serious” non-attainment area due to the frequent violations of the NAAQS for PM 10 

### and the inability of the area to attain the standard by December 31, 1995. For serious PM 10 

### non-attainment areas, the federal Clean Air Act Amendments of 1990 (CAAA) required the submittal of a SIP by February 8, 1997 that wouldAir Quality Setting

3-2 

### bring the area into attainment with the NAAQS by December 31, 2001, if practicable. In November 1998, the District adopted the 1998 SIP, which was approved by the USEPA on August 19, 1999 (Federal Register, 1999). That 1998 SIP required the City of Los Angeles (City), the entity responsible for diverting the Lake’s water and exposing the emissive lake bed, to use Best Available Control Measures (BACM), which consisted of Shallow Flooding, Managed Vegetation, and Gravel Blanket, to reduce PM 10 

### emissions on 16.5 square miles of the Owens Lake bed by 2003. The 1998 SIP also provided a five-year extension of the deadline for attainment, and committed to a SIP Revision in 2003 that would determine the final control strategy to attain the NAAQS by December 31, 2006 (GBUAPCD, 1998a).

On November 13, 2003, the District approved th e 2003 Revised State Implementation Plan for the Owens Valley Planning Area (2003 SIP), which was approved by the CARB in February 2004. The 2003 SIP is currently implemented under Board Order #031113-01. The 2003 SIP control strategy required the City to continue to use BACM to control emissions on a total of 29.8 square miles of the lake bed. The 2003 SIP also required the District to continue to monitor PM 10 

### emissions and to require the City to implement additional controls beyond the 29.8 square miles, if necessary. (GBUAPCD, 2003)

In December 2005, a dispute arose between the District and the City regarding requirements to control dust from additional areas at Owens Lake beyond the 29.8 square miles identified in the 2003 SIP (Schade, 2005 and Schade, 2006). On December 4, 2006 a Settlement Agreement was approved by both parties to resolve this dispute (GBUAPCD, 2006b). Under the provisions of this agreement, the City agreed to implement dust control measures on an additional 13.2 square miles of the lake bed by April 1, 2010 and the District agreed to revise the 2003 SIP before March 1, 2008 to incorporate the provisions of the Settlement Agreement.

On March 23, 2007, the USEPA published a finding that the Owens Valley Planning Area did not attain the 24-hour NAAQS for PM 10 

### by December 31, 2006 as mandated by the CAAA (USEPA, 2007a). As a result of this finding, the Owens Valley SIP must be revised to include a control strategy that will provide for attainment in the Owens Valley Planning Area as soon as practicable, by achieving at least a 5 percent reduction in PM 10 

### emissions per year. The 2008 SIP must demonstrate that the NAAQS can be attained by March 23, 2012, unless the USEPA grants an extension which could extend the deadline up to March 23, 2017 (CAAA §179(d)(3)). The USEPA may consider the severity of nonattainment and the feasibility of applying available control measures in deciding if an extension should be granted. In accordance with CAAA §189(d), the revised SIP must be submitted to the USEPA by December 31, 2007.

At the time the 2003 SIP was approved by the District and the CARB in November 2003, the USEPA policy direction on PM 10 

### attainment demonstrations was that the control measures that were needed to demonstrate attainment must be implemented by December 31, 2006. After the 2003 SIP was adopted, the USEPA policy direction ch anged to require three continuous years of air quality data without violations prior to December 31, 2006 to demonstrate attainment. This change in policy direction effectively made th e 2003 SIP attainment demonstration deficient, since all the control measures should have been implemented before the end of 2003 to meet the attainment deadline. Because it takes two to three years to implement the Shallow Flooding and Managed Vegetation control measures, the construction of the 2003 SIP dust control measures were not completed until the end of 2006. Numerous NAAQS violations occurred during theConcentration 3 Method 4 Primary 3,5 Secondary 3,6 Method 7

1 Hour 0.09 ppm (180 μg/m 3 )

—

8 Hour 0.070 ppm (137 μg/m 3 ) 0.08 ppm (157 μg/m 3 )

24 Hour 50 μg/m 3 150 μg/m 3

Annual Arithmetic Mean 20 μg/m 3

—

24 Hour 35 μg/m 3

Annual Arithmetic Mean 12 μg/m 3 Gravimetric or Beta Attenuation 15 μg/m 3

8 Hour 9.0 ppm (10mg/m 3 ) 9 ppm (10 mg/m 3 )

1 Hour 20 ppm (23 mg/m 3 ) 35 ppm (40 mg/m 3 )

8 Hour (Lake Tahoe) 6 ppm (7 mg/m 3 )

— ——
Annual Arithmetic Mean 0.030 ppm (56 μg/m3) 0.053 ppm (100 μg/m 3 )

1 Hour 0.18 ppm (338 μg/m 3 )

—
Annual Arithmetic Mean — 0.030 ppm (80 μg/m 3 )

—

24 Hour 0.04 ppm (105 μg/m 3 ) 0.14 ppm (365 μg/m 3 )

—

3 Hour — — 0.5 ppm (1300 μg/m 3 )

1 Hour 0.25 ppm (655 μg/m 3 )

— ——
30 Day Average 1.5 μg/m 3

— ——

Calendar Quarter — 1.5 μg/m 3 Same as Primary Standard High Volume Sampler and Atomic Absorption



### No

Sulfates 24 Hour 25 μg/m 3 Ion Chromatography 

### Federal

Hydrogen

Sulfide 1 Hour 0.03 ppm (42 μg/m 3 ) Ultraviolet Fluorescence 

### Standards Vinyl Chloride 8 24 Hour 0.01 ppm (26 μg/m 3 ) Gas Chromatography

For more information please call ARB-PIO at (916) 322-2990 California Air Resources Board (02/22/07) Inertial Separation and Gravimetric Analysis 

# Ambient Air Quality Standards

Pollutant Averaging Time

Ozone (O 3 ) Ultraviolet Photometry Ultraviolet Photometry California Standards 1 Federal Standards 2

Respirable Particulate Matter (PM10)

Atomic Absorption

* The Nitrogen Dioxide ambient air quality standard was amended on February 22, 2007, to lower the 1-hr standard to 0.18 ppm and establish a new annual standard of 0.030 ppm. These changes become effective after regulatory changes are submitted and approved by the Office of Administrative Law, expected later this year. Gas Phase Chemiluminescence Nitrogen Dioxide (NO 2 ) * Same as Primary Standard Gas Phase Chemiluminescence

Lead 8 Spectrophotometry (Pararosaniline Method)

Extinction coefficient of 0.23 per kilometer — visibility of ten miles or more (0.07 — 30 miles or more for Lake Tahoe) due to particles when relative humidity is less than 70 percent. Method: Beta Attenuation and Transmittance through Filter Tape. 8 Hour Visibility Reducing Particles

See footnotes on next page ... Same as Primary Standard

Sulfur Dioxide

(SO 2 ) Ultraviolet Fluorescence Same as Primary Standard No Separate State Standard Same as Primary Standard

Carbon Monoxide (CO) Fine Particulate Matter (PM2.5) Gravimetric or Beta Attenuation

Inertial Separation and Gravimetric Analysis

Non-Dispersive Infrared Photometry (NDIR) None Non-Dispersive Infrared Photometry (NDIR) 

### Table 3.1 - California and National Ambient Air Quality Standards

### 1. California standards for ozone, carbon monoxide (except Lake Tahoe), sulfur dioxide (1 and 24 hour), nitrogen dioxide, suspended particulate matter—PM10, PM2.5, and visibility reducing particles, are values that are not to be exceeded. All others are not to be equaled or exceeded. California ambient air quality standards are listed in the Table of Standards in Section 70200 of Title 17 of the California Code of Regulations.

2. National standards (other than ozone, particulate matter, and those based on annual averages or annual arithmetic mean) are not to be exceeded more than once a year. The ozone standard i s attained when the fourth highest eight hour concentration in a year, averaged over three years, is equal to or less than the standard. For PM10, the 24 hour standard is attained when the expected number of days per calender year with a 24-hour average concentration above 150 μg/m 3 

### is equal to or less than one. For PM2.5, the 24 hour standard is attained when 98 percent of the dail y concentrations, averaged over three years, are equal to or less than the standard

. Contact U.S. EPA for further clarification and current federal policies.

3. Concentration expressed first in units in which it was promulgated. Equivalent units given in
p arentheses are based upon a reference temperature of 25°C and a reference pressure of 760 torr. Most measurements of air quality are to be corrected to a reference temperature of 25°C and a reference pressure of 760 torr; ppm in this table refers to ppm by volume, or micromoles o f
p ollutant per mole of gas.

4. Any equivalent procedure which can be shown to the satisfaction of the ARB to give equivalent results at or near the level of the air quality standard may be used

. 5. National Primary Standards: The levels of air quality necessary, with an adequate margin of safety t o p rotect the public health.

6. National Secondary Standards: The levels of air quality necessary to protect the public welfare from any known or anticipated adverse effects of a pollutant

. 7. Reference method as described by the EPA. An “equivalent method” of measurement may be used b ut must have a “consistent relationship to the reference method” and must be approved by the EPA

. 8. The ARB has identified lead and vinyl chloride as 'toxic air contaminants' with no threshold level of exposure for adverse health effects determined. These actions allow for the implementation of control measures at levels below the ambient concentrations specified for these pollutants

.

For more information please call ARB-PIO at (916) 322-2990 

### California Air Resources Board (02/22/07)

##  	

     

### 

	
	

### BLANK PAGEAir Quality Setting

3-3 

### 3-year attainment demonstration period. As a result, the USEPA made the finding that the Owens Valley failed to attain the standard as required under CAAA §189(d).

The USEPA did not take action on the approval or disapproval of the 2003 SIP, but it has been approved by both the District and the state and is currently enforced by the District. By December 31, 2006, the City had implemented dust control measures on all 29.8 square miles of the lake bed as required in the 2003 SIP.

This 2008 SIP revises the 2003 SIP and includes an updated analysis of the particulate matter air pollution problem in the Owens Valley and a revised control strategy to bring the area into attainment with the federal air quality standard for particulate matter as soon as practicable. This 2008 SIP also incorporates provisions of the Settle ment Agreement between the District and the City to expand dust control measures to additional areas at Owens Lake in order to attain the NAAQS as soon as practicable (GBUAPCD, 2006b).

3.3 PM 10 

### AIR QUALITY 3.3.1 Health Impacts of PM 10 

### Particulate pollution is generally associated with dust, smoke and haze and can be measured as PM 10 

### , which indicates particulate matter less than 10 microns in average aerodynamic diameter. These particles are extremely small, one-seventh the diameter of a human hair or 400 times smaller than the period at the end of this senten ce. Because of their small size, the particles can easily penetrate into the lungs. Breathing PM 10 

### can cause a variety of health problems. It can increase the number and severity of asthma and bronchitis attacks. It can cause breathing difficulties in people with heart or lung disease, and it can increase the risk for, or complicate, existing respiratory infections. Children, the elderly and people with existing heart and lung problems are especially sensitive to elevated levels of PM 10 

### . Even healthy people can be adversely affected by dust at extremely high concentrations. The USEPA has set an episode level of 600 μg/m 3 

### (averaged over 24 hours) as the level that can pose a significant risk of harm to the health of the general public (40 CFR 51.151).
3.3.2 Owens Lake Health Advisory Program The NAAQS for PM 10 

### is frequently violated in the Owens Valley Planning Area because of wind-blown dust from Owens Lake. Wind speeds greater than about 17 mph have the potential to cause significant wind erosion from the barren lake bed. Ambient PM 10 

### readings are the highest measured in the country (USEPA, 2007a). Prior to implementing dust control measures on the lake bed, twenty-four-hour average PM 10 

### concentrations measured at the Dirty Socks monitor site at times exceeded 12,000 μg/m 3 

### —more than 80 times higher than the 24-hour NAAQS of 150 μg/m 3



### . In 1995, the District instituted a program to advise the public when unhealthful levels of particulate pollution occur in the Owens Valley area. Under this program, the District issues Air Pollution Health Advisories when dust storms from Owens Lake cause PM 10 

### concentrations that exceed selected trigger levels. Health Advisory notices are faxed to schools and doctor’s offices in the area and to local news media.Air Quality Setting

3-4 

### • Stage 1 Air Pollution Health Advisories are issued when hourly PM 10 

### levels exceed 400 μg/m 3 

### . The Stage 1 Health Advisory recommends children, the elderly, and people with heart or lung problems refrain from strenuous outdoor activities in dust-impacted areas.

• Stage 2 Air Pollution Health Advisories are issued when hourly PM 10 

### levels exceed 800 μg/m 3 

### , and recommends that everyone refrain from strenuous outdoor activities in dustimpacted areas.

From fall of 1995 through spring of 2007, over 150 advisories were issued as part of the Owens Lake Air Pollution Health Advisory program. This program is not intended to replace the need to control the dust problem at Owens Lake, but is intended to help reduce adverse health effects until dust control measures are in place. The health advisory program will remain in effect until dust control measures are fully implemented at Owens Lake and PM 10 

### levels no longer violate the NAAQS.
3.3.3 Monitoring Sites and Data Collection 3.3.3.1 PM 10 

### Monitoring Network Ambient PM 10 

### measurements to determine compliance with the federal PM 10 

### standard have been taken at Keeler, Olancha and Lone Pine for ove r 20 years (Figure 3.2). Meteorological data are also collected at each of these permanent monitoring sites to provide wind speed, wind direction, and temperature information. An upper air profiler was operated from March to May 2000 and January to September 2001 at Dirty Socks and from October 2001 to June 2003 at the Mill Site to measure upper level wind speeds and temperature profiles. Precipitation data are collected at the Keeler site and humidity and barometric pressure are recorded at the Olancha site. Four additional PM 10 

### sites were set up on the shoreline of Owens Lake as part of the Owens Lake Dust Identification Program. These are Dirty Socks (Summer 1999), Shell Cut and Flat Rock (both set up in January 2001) and the Bill Stanley site (March 2002). Other sites that were or still are monitored for PM 10 

### from Owens Lake include the Navy 1 site at the Coso Known Geothermal Resource Area and the Coso Junction site. These sites are about 10 miles south of the Owens Valley planning area. The Coso Junction PM 10 

### monitor is currently providing hourly PM 10 

### measurements and the Navy 1 monitor was discontinued in 1998.

The Lone Pine Paiute-Shoshone Tribe installed a PM 10 

### monitor on the Lone Pine reservation in 2002 and a PM 2.5 

### monitor in 2006. Both monitors are Tapered Element Oscillating Microbalance (TEOM) monitors that provide hourly concentration data. They are operated in accordance with federal monitoring guidelines (40 CFR, Part 58). The monitor site is located southeast of the District’s Lone Pine monitor site. Data from the Lone Pine Tribe’s PM 10 

### TEOM have closely paralleled the values recorded by the District’s Lone Pine TEOM, although specific dust plumes may cause high values at one of these TEOMs and yet miss the other.

Currently, all the PM 10 

### monitor sites in the planning area are equipped with TEOM continuous PM 10 

### samplers ( EPA Manual Reference Method: EQPM-1090-079) that provide hourly and daily PM 10 

### concentrations. TEOMs are USEPA equivalent method particulate monitors. Some of the monitoring sites began collecting PM 10 

### data with High-Volume (Hi-Vol) samplers (Wedding [RFPS-1087-062] or Graseby [RFPS-1287-063]). Change s in primary sampler type, from HiVols to TEOMs, are indicated in Table 3.2. All Owens Lake monitoring sites, except the Bill Stanley site were also equipped with Partisol PM 10 

### samplers (RFPS-1298-126 and RFPS-1298- 127), which are filter-based USEPA-approved reference method samplers that were operated to

# 

	



		





	 
	 

 

#  	



		


	

	

		



	 

#       




## 


  !" #$
  !	"	

	!#	 !$

### BLANK PAGEAir Quality Setting


### provide 24-hour average PM 10 

### concentrations. The Partisol samplers confirm the 24-hour averages of the TEOM samplers (Parker, 2003). Table 3.2 summarizes the particulate matter monitoring history at each site in the Planning Area.

The District performed a detailed study of different types of PM 10 

### monitors and found significant differences in the concentrations measured by collocated monitors of different types. The District’s analysis showed that TEOM and Partisol samplers provide the most consistent measurements at Owens Lake, and that they are the most suitable monitors for measuring PM 10 

### caused by wind-blown dust (Ono, et al ., 2000).
3.3.3.2 Dust Transport Study Historically, the permanent PM 10 

### monitoring stations were operated on a one-in-six day schedule to sample PM 10 

### , and did not sample on the other five off-schedule days. This was changed for a period from March 1993 to June 1995 to collect data to assess the PM 10 

### impacts downwind from Owens Lake toward the City of Ridgecrest. A special-purpose monitoring network was set upadding the southern communities of Pearsonville, Inyokern and Ridgecrest. During the specialpurpose monitoring period, samplers at both Owens Lake and the southern sites were operated on days when Owens Lake dust events were forecast to have impacts toward the south. The results of this study showed that Owens Lake dust plumes caused exceedances of the PM 10 

### NAAQS as far as Ridgecrest, 60 miles south of the lake. The 1998 SIP (GBUAPCD, 1998a) includes the monitoring data from this episode-monitoring program.

About 40,000 permanent residents from Ridgecrest to Bishop are affected by the dust from Owens Lake. In addition, many visitors spend time in this dust-impacted area, to enjoy the many recreational opportunities the Eastern Sierra and hi gh desert have to offer. Lone Pine annually hosts the Lone Pine film festival, which draws thousands of visitors from outside the area. The National Park Service is concerned about the health hazard posed to the 86,000 people that annually visit the Manzanar National Historic Site, 15 miles north of Owens Lake. The Park Service is concerned because a high percentage of the visitors to Manzanar are older visitors who are more prone to airborne respiratory thr eats, and that they will spend 3 to 4 hours outdoors in a potentially harmful environment (Hopkins, 1997).

3.3.3.3 PM 2.5 

### Monitoring at Keeler Monitoring of fine particulate matter (PM 2.5 

### ) on a 1-in-3-day schedule was initiated in 1999 at Keeler. Eight years of PM 2.5 

### data show a rough correspondence between PM 2.5 

### levels and PM 10 

### levels at the Keeler site. A high value of 193 μg/m 3 

### , recorded on December 28, 2006, indicates that a serious fine particulate pollution problem may exist at this site. However, the current PM 2.5 

### NAAQS is 35 μg/m 3 

### for the 98 th 

### percentile value at a monitor in a calendar year. This allows seven exceedances of the 35 μg/m 3 

### standard per year without violating the standard. Therefore, there was not a violation of the PM 2.5 

### NAAQS at Keeler for 2006 because the 98 th 

### percentile (eighth highest) value was below 35 μg/m 3 

### , despite this one high value. To date, no violations of the PM 2.5 

### NAAQS have been documented in Keeler.

In the near future, the District is planning to upgrade to daily PM 2.5 

### monitoring at Keeler in an effort to better characterize fine particulate levels there.

3-5Air Quality Setting

3-6 

### 3.3.4 PM 10 

### Data Summary 3.3.4.1 Number of 24-hour Exceedances From 1993 through 2006, almost daily PM 10 

### sampling recorded 208 PM 10 

### exceedances at Keeler. This averages about 15 exceedances of the PM 10 

### NAAQS per year. The Dirty Socks monitor recorded 205 PM 10 

### exceedance days over a seven year period from January 2000 to December 2006. Dirty Socks averaged over 29 exceedances per year and had the highest concentrations of the seven sites monitored. Figure 3.3 shows the number of exceedances from 1994 through 2006 at each site. All six monitor sites were in violation of the 24-hour average PM 10 

### NAAQS, which allows no more than one exceedance per year over a three year period.
3.3.4.2 Annual Average PM 10 

### Concentrations Figure 3.4 shows the annual PM 10 

### concentration trend for six Owens Lake sites from 1994 through 2002. Although the USEPA eliminated an annual PM 10 

### NAAQS in 2006, it is instructive to track annual PM 10 

### averages in order to observe trends (Prior to its elimination, the annual PM 10 

### NAAQS was 50 μg/m 3 

### ). Since the installation of a PM 10 

### monitor at Dirty Socks in 1999, this monitor site has consistently registered the highest concentrations measured at Owens Lake. The three-year annual average for Dirty Socks was estimated at 157 μg/m 3 

### for the years 2000- 2002. Only once (2005) in seven years of operation has the annual average PM 10 

### concentration in Dirty Socks monitoring site dropped below 50 μg/m 3 

### . The Shell Cut monitoring site has produced an annual average above 50 μg/m 3 

### for the years 2002 through 2006, as well.

3.3.4.3 Peak PM 10 

### Concentrations The 24-hour average PM 10 

### measurements from Owens Lake sites are consistently listed as the highest concentrations in the United States on the USEPA’s AIRData website (USEPA, 2007c). PM 10 

### concentrations exceeding 20,000 μg/m 3 

### have been measured at the Dirty Socks monitor site using a partisol PM 10 

### monitor. This is more than 133 times higher than the 24-hour NAAQS of 150 μg/m 3 

### . Partisols are Federal Reference Method monitors that collect samples on a filter that are weighed in the lab and are operated once every third day. However, note that most of the PM 10 

### data shown in Table 3.2 are based on automated TEOM PM 10 

### measurements which provide hourly and daily concentrations and are another federally approved PM 10 

### monitor. Table 3.3 compares Owens Lake values with the rest of the United States.

In the data available on the USEPA’s AIRData website, Owens Lake has produced the highest PM 10 

### reading in the nation in all but one of the past eleven years. As shown graphically in Figure 3.5, Owens Lake concentrations have consistently dwarfed values reported from the rest of the nation since 2000. Table 3.3 also contains PM 10 

### values measured at Mono Lake, which is in the District to the north of the Owens Valley PM 10 

### Planning Area. Mono Lake has also consistently exceeded all PM 10 

### readings in the rest of the nation since 2000. Mono Lake PM 10 

### exceedances are also caused by the City of Los Angeles’ Ea stern Sierra water diversions (GBUAPCD, 1995).

The highest PM 10 

### concentration for any of the PM 10 

### monitor sites at Owens Lake on each date for a six-year period is shown in Figure 3.6. PM 10 

### concentrations are shown on a logarithmic scale due to the extreme concentration range. The seasonal nature of the dust events can also be seen in this figure. Most dust events occur during winter and spring. There are few violations recorded during summer and fall months.0 5 10 15 20 25 30 35 40 45

1994 1996 1998 2000 2002 2004 2006
YEAR# of PM-10 Exceedances/Year Keeler Lone Pine
Olancha Dirty Socks
Flat Rock Shell Cut Bill Stanley



### Figure 3.3 - All seven Owens Lake monitoring sites have violated the NAAQS (150 μg/m 3 

### ) by averaging more than one exceedance per year of the 24-hour standard.

0 50 100 150 200 250

1994 1996 1998 2000 2002 2004 2006
YEARAnnual Avg. PM-10 (μg/m3) Keeler Lone Pine

Olancha Dirty Socks

Flat Rock Shell Cut



### Figure 3.4 - The 3-year annual average PM 10 

### concentrattions measured at Dirty Socks and Shell Cut both violated the PM 10 

### annual NAAQS of 50 μg/m 3



### .0 5000 10000 15000 20000 All Other U.S. PM-10
Owens Lake 2006

2005

2004

2003

2002

2001

2000

1999

1998

1997

1996

1995



### Figure 3.5 - Yearly comparison of highest Owens Lake PM 10 

### concentrations with highest concentrations at all U.S. PM 10 

### monitoring sites outside the GBUAPCD10 100 1000 10000 100000 

### 2001 (43 Exceedances)

10 100 1000 10000 100000 

### 2002 ( 46 Exceedances )

10 100 1000 10000 100000 

### 2003 ( 37 Exceedances )

10 100 1000 10000 100000 

### 2004 ( 34 Exceedances )

10 100 1000 10000 100000 

### 2005 (26 Exceedances)

10 100 1000 10000 100000 

### 2006 (36 Exceedances)

Figure 3.6 - Daily 24-hour maximum PM-10 values at Owens Lake monitoring sites, 2001 - 2006Table 3.2 Summary of the particulate matter monitoring history for each site

Peak Number Adjusted Number 24-Hour of # of Annual 3-Year Sample Primary Site Year Value Exceeds Exceeds Average Average Days Monitor
KEELER 1987 672 4 24 46.70 60 Hi Vol
KEELER 1988 394 2 12 31.75 58 Hi Vol
KEELER 1989 1861 4 Invalid 55 Hi Vol
KEELER 1990 858 2 Invalid 20 Hi Vol
KEELER 1991 181 1 Invalid 47 Hi Vol
KEELER 1992 526 3 18 37.34 59 Hi Vol
KEELER 1993 781 1 6 43.16 58 Hi Vol
KEELER 1994 1381 20 Invalid 297 TEOM
KEELER 1995 3929 23 Invalid 311 TEOM
KEELER 1996 862 15 15 Invalid 309 TEOM
KEELER 1997 835 12 12 30.81 341 TEOM
KEELER 1998 1464 17 17 35.08 353 TEOM
KEELER 1999 2569 19 19 50.41 38.76 364 TEOM
KEELER 2000 1101 18 18 42.56 42.68 365 TEOM
KEELER 2001 1400 9 9 40.16 44.38 353 TEOM
KEELER 2002 1077 13 13 14.75 39.86 365 TEOM
KEELER 2003 1209 11 11 29.87 35.63 364 TEOM
KEELER 2004 3322 14 14 39.46 35.40 363 TEOM
KEELER 2005 1441 7 7 26.99 32.11 364 TEOM
KEELER 2006 2101 11 11 33.18 33.21 365 TEOM

LONE PINE 1987 178 1 6 23.27 58 Hi Vol
LONE PINE 1988 172 1 6 21.60 60 Hi Vol
LONE PINE 1989 126 0 0 22.73 22.53 61 Hi Vol
LONE PINE 1990 68 0 0 17.15 20.49 61 Hi Vol
LONE PINE 1991 82 0 0 17.90 19.26 59 Hi Vol
LONE PINE 1992 63 0 0 17.15 17.40 57 Hi Vol
LONE PINE 1993 170 1 5 17.02 17.36 117 Hi Vol
LONE PINE 1994 499 3 3 22.23 18.80 352 TEOM
LONE PINE 1995 392 5 5 23.12 20.79 363 TEOM
LONE PINE 1996 166 1 1 17.71 21.02 336 TEOM
LONE PINE 1997 123 0 0 16.86 19.23 360 TEOM
LONE PINE 1998 472 5 5 23.62 19.40 346 TEOM
LONE PINE 1999 325 3 3 22.18 20.89 350 TEOM
LONE PINE 2000 180 2 2 19.30 21.70 360 TEOM
LONE PINE 2001 260 2 18.94 20.14 332 TEOM
LONE PINE 2002 315 7 7 26.59 21.61 365 TEOM
LONE PINE 2003 724 4 4 21.57 22.37 365 TEOM
LONE PINE 2004 349 1 1 20.27 22.81 355 TEOM
LONE PINE 2005 262 1 1 17.20 19.68 364 TEOM
LONE PINE 2006 293 2 2 20.33 19.26 361 TEOMTable 3.2 Continued

Peak Number Adjusted Number 24-Hour of # of Annual 3-Year Sample Primary Site Year Value Exceeds Exceeds Average Average Days Monitor
OLANCHA 1987 31 0 Invalid 31 Hi Vol
OLANCHA 1988 55 0 0 19.00 57 Hi Vol
OLANCHA 1989 109 0 Invalid 52 Hi Vol
OLANCHA 1990 200 2 12 23.19 61 Hi Vol
OLANCHA 1991 181 1 6 18.04 59 Hi Vol
OLANCHA 1992 366 2 6 19.66 20.30 60 Hi Vol
OLANCHA 1993 346 3 Invalid 36 Hi Vol
OLANCHA 1994 362 2 Invalid 94 Hi Vol
OLANCHA 1995 2252 4 Invalid 207 TEOM
OLANCHA 1996 2383 8 8 33.22 354 TEOM
OLANCHA 1997 2229 12 12 36.52 350 TEOM
OLANCHA 1998 327 5 5 19.38 29.71 358 TEOM
OLANCHA 1999 353 5 5 23.07 26.32 356 TEOM
OLANCHA 2000 417 5 5 20.54 21.00 365 TEOM
OLANCHA 2001 1545 3 3 25.37 22.99 352 TEOM
OLANCHA 2002 905 7 7 31.86 25.92 365 TEOM
OLANCHA 2003 1062 5 5 23.23 26.82 359 TEOM
OLANCHA 2004 408 6 6 22.24 25.78 365 TEOM
OLANCHA 2005 288 5 5 19.64 21.71 363 TEOM
OLANCHA 2006 428 2 2 22.94 21.61 364 TEOM

DIRTY SOCKS 1999 2182 10 Invalid 185 TEOM
DIRTY SOCKS 2000 10549 33 33 141.21 365 TEOM
DIRTY SOCKS 2001 12153 41 41 229.11 339 TEOM
DIRTY SOCKS 2002 6702 40 40 130.90 167.07 365 TEOM
DIRTY SOCKS 2003 10933 32 32 135.77 165.26 365 TEOM
DIRTY SOCKS 2004 4472 21 21 85.77 117.48 365 TEOM
DIRTY SOCKS 2005 3087 19 19 43.99 88.51 365 TEOM
DIRTY SOCKS 2006 4169 18 18 63.39 64.38 364 TEOM

FLAT ROCK 2001 1779 8 8 28.00 354 TEOM
FLAT ROCK 2002 759 6 6 25.89 359 TEOM
FLAT ROCK 2003 395 3 3 16.98 23.62 363 TEOM
FLAT ROCK 2004 626 4 4 20.04 20.97 348 TEOM
FLAT ROCK 2005 346 2 2 15.52 17.51 365 TEOM
FLAT ROCK 2006 6171 6 6 36.73 24.10 364 TEOM

SHELL CUT 2001 2660 14 14 35.08 351 TEOM
SHELL CUT 2002 2840 19 19 68.44 361 TEOM
SHELL CUT 2003 9162 17 17 75.87 59.80 342 TEOM
SHELL CUT 2004 2990 20 20 58.89 67.73 366 TEOM
SHELL CUT 2005 3989 13 13 55.08 63.28 359 TEOM
SHELL CUT 2006 6847 12 12 58.20 57.39 365 TEOMTable 3.2 Continued

Peak Number Adjusted Number 24-Hour of # of Annual 3-Year Sample Primary Site Year Value Exceeds Exceeds Average Average Days Monitor
COSO JUNCTION 1987 196 1 6 33.53 59 Hi Vol
COSO JUNCTION 1988 92 0 0 33.53 59 Hi Vol
COSO JUNCTION 1989 227 1 6 27.13 27.43 61 Hi Vol
COSO JUNCTION 1990 866 1 6 29.38 26.05 60 Hi Vol
COSO JUNCTION 1991 93 0 0 18.80 25.10 60 Hi Vol
COSO JUNCTION 1992 38 0 Invalid 36 Hi Vol
COSO JUNCTION 1993 254 2 Invalid 51 Hi Vol
COSO JUNCTION 1994 388 1 Invalid 49 Hi Vol
COSO JUNCTION 1995 692 2 12 18.60 55 Hi Vol
COSO JUNCTION 1996 309 1 Invalid 47 Hi Vol
COSO JUNCTION 1997 92 0 Invalid 54 Hi Vol
COSO JUNCTION 1998 409 1 6 22.81 59 Hi Vol
COSO JUNCTION 1999 46 0 0 13.96 114 Hi Vol
COSO JUNCTION 2000 74 0 0 14.56 17.11 110 Hi Vol
COSO JUNCTION 2001 100 0 0 11.42 13.31 122 Hi Vol
COSO JUNCTION 2002 175 1 3 17.63 14.53 112 Hi Vol
COSO JUNCTION 2003 484 1 3 20.10 16.38 110 Hi Vol
COSO JUNCTION 2004 66 0 0 14.40 17.37 121 Hi Vol
COSO JUNCTION 2005 97 0 0 17.89 17.46 119 Hi Vol
COSO JUNCTION 2006 296 1 1 19.09 17.12 273 TEOM

BILL STANLEY 2002 539 1 Invalid 154 TEOM
BILL STANLEY 2003 2196 3 Invalid 92 TEOM
BILL STANLEY 2004 191 2 Invalid 166 TEOM
BILL STANLEY 2005 880 1 Invalid 261 TEOM
BILL STANLEY 2006 322 3 3 17.69 356 TEOM

Notes: (1) Number of samples 150 μg/m 3 or more.
(2) If not daily sampling, number of exceeds is divided by sampling frequency (e.g., divide by 1/6 for 1-in-six-day sampling). (3) Annual average is invalid if less than 75% of scheduled samples are collected in each of four quarters. (4) One quarter (3rd) at 73% data capture. District views data as valid.

### Table 3.3 – Annual Ranking of Owens Lake PM 10 

### in U.S.

YEAR Owens Lake Highest in

U.S.? Highest Owens Lake Value Highest Mono Lake Value Highest non-GBUAPCD Value 1995 Yes 3,929 - 384 1996 Yes 2,383 - 1,715 1997 Yes 2,229 - 1,264 1998 No 1,464 - 1,477 1999 Yes 2,901 - 442 2000 Yes 10,842 10,466 508 2001 Yes 20,754 4,482 610 2002 Yes 7,915 6,505 590 2003 Yes 16,619 5,745 590 2004 Yes 5,225 987 625 2005 Yes 3,989 2,108 760 2006 Yes 8,299 4,300 1,079

### BLANK PAGEAir Quality Setting


### For days when the 24-hour PM 10 

### standard is violated, peak hourly wind speeds at the Owens Lake monitoring sites have been measured up to 50 mph. However, violations have also been recorded when the hourly wind speed peaked at a more modest 20 mph. The daily average wind speed when the 24-hour PM 10 

### standard is violated ranges from 5 to 33 mph, since many violations occur with winds that last only a few hours.

3.3.4.4 PM 10 

### Trends Although dust control measures were in place on 29.8 square miles of lake bed by the end of 2006, PM 10 

### levels at Owens Lake have remained high at the monitoring sites. Monitoring of PM 10 

### levels beginning in 2007 will be necessary to establish the overall air quality improvements resulting from the first phases of dust control measure implementation. Some improvement in exceedances per year (Figure 3.3) and in annual average PM 10 

### concentration (Figure 3.4) at Keeler and Dirty Socks may indicate signs of im provement, but are yet to show that the NAAQS are being met. At Keeler, the average TEOM value for the years 1993 through 2000 was 45 μg/m 3 

### . This was prior to the construction of dust control measures on the nearby North Sand Sheet. The average TEOM value for the years 2002 through 2006, after dust control measures on the North Sand Sheet were operational, was 34 μg/m 3 

### . The inter-year comparisons in Figure 3.6 indicate an overall reduction in exceedances per year and a reduction in daily peak values at Owens Lake monitors. Keeler and Dirty Sock s appear to be trending toward significant reductions in PM 10 

### levels, but the other sites have yet to show significant improvements.

3.4 CANCER RISK DUE TO OWENS LAKE DUST STORMS In addition to the high levels of fine particulate matter, Owens Lake dust also contains cadmium, arsenic and other toxic metals that are at levels above those in soils in the Owens Valley due to natural concentration in the terminal lake. These metals pose a significant risk for additional cancer cases in the areas of greatest dust impact. Table 3.4 shows that the cancer risk at Keeler, associated with cadmium and arsenic in the Owens Lake dust, is estimated at 23 additional cases in a million. This is based on an annual concentration average of 45 μg/m 3 

### from the dust storms, breathed over a 70-year period. The value of 45 μg/m 3 

### is taken from the seven-year average of PM 10 

### concentrations measured using a TEOM at Keeler (1993-2000). This average represents the annual average prior to the implementation of controls.

Under the District’s adopted air toxics policy, a toxic risk greater than one in a million additional cancer cases is considered to be significant. This policy requires implementation of controls on sources that pose a risk greater than one in a million in order to reduce the risk, and it prohibits the issuance of a permit to sources that exceed a risk of 10 in a million (GBUAPCD, 1987). A revised cancer risk from arsenic and cadmium, using the reduced average dust concentration of 34 μg/m 3 

### at Keeler, would result in 17 cases per million, a significant reduction in cancer risk. Model calculations project an average Keeler PM 10 

### concentration of 21 μg/m 3 

### after all dust control measures are operational. This would result in even greater reduction in cancer risk. Since this residual dust would contain a smaller fraction of lake bed-derived material than under pre-dust-control conditions, the benefits for reduction in cancer risk would be compounded.

3-7Air Quality Setting

3-8 

### Table 3.4 Inhalation cancer risk at Keeler due to Owens Lake dust storms


### Cancer Toxic Metal Toxic Potency Concentration Inhalation Metal (μg/m 3 

### ) -1 

### (parts per million) Cancer Risk

Cadmium 4.2 x 10 -3 

### 29 5 per million

Arsenic 3.3 x 10 -3 

### 118 18 per million
Lifetime Cancer Risk = 23 per million

• Cancer potency from the Air Toxics Hot Spots Program (OEHHA, 2002).

• Dust samples are taken from Keeler PM 10 filters, with concentrations measured by x-ray fluorescence (Chester LabNet, 1996).

• 70-year cancer risk at PM 10 = 45 μ g/m 3 (Keeler annual average from 1993-2000).



### 3.5 VISIBILITY AND SENSITIVE AIRSHEDS Under normal conditions, visibility in the Owens Valley generally ranges from 37 to 93 miles, with the best visibility occurring during winter. Visibility is most limited from May through September and during days when Owens Lake dust storms occur. Owens Lake dust storms can reduce visibility to near zero at Owens Lake and obscure visibility 150 miles away from the lake bed. The main cause of visibility degradation in the Owens Valley is fine particles in the atmosphere. In addition to dust from Owens Lake, visibility degradation results from transport of air pollutants from the San Joaquin Valley and South Coast air basins, and from forest fires. Most of the visibility degradation can be attributed to inter-basin transport of air pollutants. On days when Owens Lake dust storms do not occur, emissions of fine particulate matter from gasoline and diesel fueled vehicles and equipment within the Owens Valley are local man-made contributors to visibility degradation. However, these local sources have an insignificant impact on the area’s visibility. Nitrogen dioxide, a light-absorbing gas formed during local fuel combustion, contributes less than five percent to the overall visibility degradation. Other local man-made sources of visibility degrading emissions represent less than five percent of the overall reduction in visibility (Trijonis, et al ., 1988).

There are 11 sensitive airsheds in the region, including wilderness areas, national parks, national forests, a national historic site, and the R-2508 military airspace. Figure 3.7 shows the locations of these sensitive airsheds. Four of these airsheds are designated as Class I PSD (Prevention of Significant Deterioration) areas, which are afforded more stringent protection from visibility degradation and for impacts from air pollutants: John Muir and Domeland Wilderness Areas, Kings Canyon and Sequoia National Parks. These sensitive areas and their classifications are shown in Table 3.5.

The R-2508 military air space, which includes the China Lake Naval Air Weapons Station, is a sensitive site for visibility impacts from Owens Lake dust events. Good visibility is needed for some military operations, such as an air-to-air test (an air-launched target whose target is also in

##    

  

   

   

                                                              

! " ! ! # ! $ ! %     !

     

                  

  

       

       

       



###    

        !    "           

                

#  $            

###  %     &  

      '     $   

 %     &  

          $   

 (  %  )      

###    * 

+      "           

,  +      

        )   )               

)   - +              $    #              

     $    #    ,             

     $    #   

. +    $   

      $    / 0 1 2

3 / 2

1 4 3 0 5

/ 0 1

1 4 3 0 5

3 6 3 6)78154&    9        

:          3 5                 

### &     '

%  (      3 5                Table 3.5 – Sensitive airsheds and their PSD classifications. Sensitive Airshe d PSD Airshed Classification

* Wilderness Areas in National Forests: Domeland Class I Golden Trout Class II John Mui r Class I South Sierra Class II

* National Parks: Death Valley Class II Kings Canyon Class I Sequoia Class I

* National Historic Site: Manzana r Class II

* National Forests: Inyo Class I&II Sequoia Class I&II

* Military Base: China Lake NAWS Class II
Source: MHA Environmental Consulting, Inc., 1994.Air Quality Setting


### the air), which relies on high-speed cameras to record time and position information. Owens Lake events can reduce the visibility to less than one to two miles at China Lake. The Department of the Navy has stated that cancellation of a test costs the Range and/or its customer approximately $10,000 to $50,000. Owens Lake dust events can lead to cancellations of several tests per day and can last for one to two days, or occasionally longer (Stevenson, 1996).

3.6 OFF-LAKE PM 10 

### VIOLATIONS

Analysis of exceedances of the PM 10 

### NAAQS at Owens Lake shoreline monitors indicates that some of the high PM 10 

### days would have resulted in exceedances, even if emissions from the lake bed were reduced to zero (Kiddoo, et al. , 2007). Winds from off-lake directions carry windblown dust from the Keeler dunes, northeast of the lake bed, and from the Olancha dunes, south of the lake bed, toward shoreline monitors. In the period from January 2000 through December 2006, the Keeler dunes are estimated to have caused five violations of the PM 10 

### NAAQS at Keeler per year. In the same period, the Olancha dunes are estimated to have caused one violation of the PM 10 

### NAAQS per year at each of the Shell Cut and Flat Rock monitors. At the Dirty Socks monitor, 30 violations can be attributed to southerly wind directions, but it appears that many of these violations may have resulted from erosion of emissive areas on the lake bed, but south of the Dirty Socks monitor. Dust cont rols in this area immediately south of the Dirty Socks monitor were completed at the end of 2006, and it is expected that violations there due to southerly wind directions will be reduced to levels similar to those observed at Flat Rock and Shell Cut (see Kiddoo, et al., 2007, for details of this analysis).

After all the lake bed sources in the 2003 and 2008 dust control areas are controlled, the Keeler dunes area is expected to be the only remaining dust source that is causing exceedances of the standard in the planning area. The Olancha dunes are natural dunes that were present prior to the City’s water gathering activities in the Owens Valley. If PM 10 

### violations are attributed to the Olancha dunes, these violations will be treated as natural events and a Natural Events Action Plan will be developed and implemented in accordance with the USEPA rule on Exceptional Events (see Section 2.2.3.3).

3.7 REFERENCES Chester LabNet, 1996. Chester LabNet - Portland, report on chemical analysis of ambient filters, Report #95-085, prepared for Great Basin Unifie d Air Pollution Control District, Tigard, Oregon, June 18, 1996.

Federal Register, 1999. Approval and Promulgation of Implementation Plans: California – Owens Valley Nonattainment Area; PM 10 

### , Federal Register , Volume 64, No. 171, pp. 48305-48307, September 3, 1999.

GBUAPCD, 1987. Great Basin Unified Air Polluti on Control District, Adopted Toxic Risk Policy, GBUAPCD, Bishop, California, 1987.

GBUAPCD, 1995. Great Basin Unified Air Pollution Control District, Mono Basin Planning Area PM 10 

### State Implementation Plan (Final) , GBUAPCD, Bishop, California, May, 1995.

3-9Air Quality Setting

3-10 

### GBUAPCD, 1998a. Great Basin Unified Air Pollution Control District, Owens Valley PM 10 

### Planning Area Demonstration of Attainment State Implementation Plan , GBUAPCD, Bishop, California, November 16, 1998.

GBUAPCD, 2003. Great Basin Unified Air Pollution Control District, Owens Valley PM 10 

### Planning Area Demonstration of Attainment State Implementation Plan - 2003 Revision
, GBUAPCD, Bishop, California, November 13, 2003.

GBUAPCD, 2006b. Great Basin Unified Air Polluti on Control District, Settlement Agreement between the District and the City to resolve the City’s challenge to the District’s Supplemental Control Requirement determination issued on December 21, 2005 and modified on April 4, 2006, GBUAPCD, Bishop, California, December 4, 2006.

Hopkins, 1997. Hopkins, Ross, letter from National Park Service, Manzanar National Historic Site, Superintendent, to Ellen Hardebeck, Great Basin Unified Air Pollution Control District, regarding the Owens Lake air pollution problem, January 3, 1997.

Kiddoo, et al. , 2007. Kidoo, Phill, Jim Parker, Duane Ono, Off-Lake PM 10 

### Exceedances at Owens Lake, January 1, 2000 – June 30, 2007.

OEHHA, 2002. Office of Environmental Health Hazard Assessment, Air Toxics Hot Spots Program Risk Assessment Guidelines, Part II, Technical Support Document for Describing Available Cancer Potency Factors , Sacramento, California, December 2002.

Ono, et al ., 2000. Ono, Duane, Ellen Hardebeck, Jim Parker, B.G. Cox, Systematic Biases in Measured PM 10 

### Values with U.S. Environmental Protection Agency-Approved Samplers at Owens Lake, California, J.Air & Waste Manage. Assoc. , Pittsburgh, PA, 50:1144- 1156, July 2000.

Parker, 2003. Parker, James, Comparison of TEOM and Partisol Monitors at Owens Lake, California , Great Basin Unified Air Pollution Control District, June 2003.

Schade, 2005. Great Basin Unified Air Pollution Cont rol District, Owens Lake Dust Control: Air Pollution Control Officer’s 2004-2005 Determination Requiring the City of Los Angeles to Implement, Operate and Maintain Air Pollution Control Measures on Additional Areas of the Owens Lake Bed, Letter from Theodore D. Schade, Air Pollution Control Officer, GBUAPCD, Bishop, California to Ronald Deaton, General Manager, Los Angeles Department of Water and Power, Los Angeles, California, December 21, 2005.

Schade, 2006. Great Basin Unified Air Pollution C ontrol District, Modified Determination and Response to the City of Los Angeles’ Altern ative Analysis of the Air Pollution Control Officer’s 2004-2005 Supplemental Control Requirements Determination, Letter from Theodore D. Schade, Air Pollution Contro l Officer, GBUAPCD, Bishop, California to Ronald Deaton, General Manager, Los Angeles Department of Water and Power, Los Angeles, California, April 2, 2006.Air Quality Setting

3-11 

### Stevenson, 1996. Stevenson, C.A., letter from U.S. Department of the Navy, Naval Air Weapons Station, Commanding Officer, to Ellen Hard ebeck, Great Basin Unified Air Pollution Control District, regarding impact of Owens Lake dust on China Lake, May 9, 1996.

Trijonis, J. et al. , 1988. Trijonis, John, Michael McGown, Marc Pitchford, Donald Blumenthal, Paul Roberts, Warren White, Edward Macias, Raymond Weiss, Alan Waggoner, John Watson, Judith Chow, Robert Flocchini, RESOLVE Project Final Report - Visibility Conditions and Causes of Visibility Degradation in the Mojave Desert of California
, Naval Weapons Center, China Lake, California, July 1988.

USEPA, 2007a. United States Environmental Protection Agency, Proposed Finding of Failure to Attain; State of California, Owens Valley Nonattainment Area; Particulate Matter of 10 Microns or Less, EPA-R09-OAR-2007-0091, FRL-8291-1, Federal Register , Volume 72, No. 56, March 23, 2007, pp 13723-13726.

USEPA, 2007c. United States Environmenta l Protection Agency, AirData website, http://www.epa.gov/air/data/monvals.html , August, 2007.

### BLANK PAGE