Clean Air Status and Trends Network
2005 Annual Report
Air Quality Measurements
Long-Term Trends
Environmental Results
- Dry Sulfur Deposition
- Dry Nitrogen Deposition
Year
Prepared for:
U.S. Environmental Protection Agency
Office of Air and Radiation
Clean Air Markets Division
Washington, DC
December 2006
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Clean Air Status and Trends Network
(CASTNET)
2005 Annual Report
Prepared by:
MACTEC Engineering and Consulting, Inc.
Prepared for:
U.S. Environmental Protection Agency
Office of Air and Radiation
Clean Air Markets Division
Washington, D.C.
December 2006
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Table of Contents
Executive Summary ii
Chapter 1 CASTNET Overview 1
Locations of Monitoring Sites 3
CASTNET Monitoring Sites on Tribal Lands 4
Measurements Collected at CASTNET Sites 5
Calculating Dry Deposition 6
CASTNET Reference Sites 7
SO2 and NOX Emissions 8
Chapter 2 Atmospheric Concentrations 10
Sulfur Dioxide 10
Particulate Sulfate 12
Total Nitrate 13
Particulate Ammonium 15
Continuous Measurements of Trace Concentrations of CO, NOy, and SO2 16
Chapter 3 Atmospheric Deposition 17
Sulfur Deposition 18
Contributors to Atmospheric Deposition 22
Nitrogen Deposition 23
Chapter 4 Ozone Concentrations 26
National Ambient Air Quality Standards for Ozone 27
Eight-Hour Ozone Concentrations 28
Sixteen-Year Trends 30
Nitrogen Oxides and Ozone 32
Trends in Ozone Concentrations along the Washington, D.C. to Coastal Maine Corridor 36
Chapter 5 Data Quality 38
Precision 39
Accuracy 44
Completeness 46
Laboratory Intercomparison Studies 47
Conclusion 48
References R-l
Appendix A Significant Events During 2005
Appendix B Locational and Operational Characteristics of CASTNET Sites
Appendix C Acronyms and Abbreviations
On the cover:
The site pictured is Parsons, WV (PAR107).
The graph depicts mean dry deposition values from the 34 CASTNET reference sites (see page 7).
CASTNET Annual Report - 2005
Table of Contents
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Executive Summary
Created by the Environmental Protection Agency (EPA) to establish long-term monitoring of air
quality and meteorological conditions in rural areas, the Clean Air Status and Trends Network
(CASTNET) began operation in 1991. CASTNET measures rural, regionally representative
concentrations of sulfur and nitrogen species and ozone in order to evaluate the effectiveness of
national and regional air pollution control programs.
Key Results through 2005
t Mean annual sulfur dioxide (SO2) and particulate sulfate (SO24") concentrations aggregated
over the 34 eastern reference sites have declined significantly over the 16-year period
1990 through 2005.
t Over the 16-year period, wet, dry, and total deposition of atmospheric sulfur have
declined.
t Mean annual concentrations of total nitrate (nitric acid plus particulate nitrate) showed
almost no change from 1990 through 2000. Since then, total nitrate has declined
approximately 10 percent.
t Estimates of wet, dry, and total nitrogen deposition show no significant trend over the 16
years. However, the data suggest a slight decline in dry nitrogen deposition and in mean
nitrogen concentrations in precipitation since 1999.
t The median fourth highest daily maximum 8-hour ozone concentration for 2005 was the
second lowest in the history of the network despite the return to normal weather
conditions during the ozone season. The recent decline in rural ozone and nitrate levels
has been attributed to the documented decline in nitrogen oxides (NOX) emissions as well
as weather conditions. Nitrogen oxides emissions in the eastern United States have
declined over the last several years because of the Acid Rain Program, EPA's NOX State
Implementation Plan (SIP) Call, and several other NOX control programs.
Significant operational events during 2005 are listed in Appendix A. The location and
operational characteristics of each site by state is provided in Appendix B. Appendix C provides
a list of acronyms and abbreviations.
Mackville, KY (MCK131/231)
CASTNET Annual Report - 2005 - ii - Executive Summary
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Initiated:
Number of Sites:
(as of December 2005)
Sampling Schedule:
Ambient Measurements:
Gaseous:
Particulate:
Meteorological
Parameters:
(Hourly averages)
Land Surface Features:
Network Summary
1987
87
Filters exposed over seven days to produce 7-day averages
(Tuesday to Tuesday)
Sulfur Dioxide (SO2), Nitric Acid (HNO3), Ozone (O3) [hourly]
Sulfate (SO24-), Nitrate (NOj), Ammonium (NH+4), Other
relevant ions
Temperature (2 and 9 meters), Wind Speed and Direction,
Standard Deviation of Wind Direction (Sigma Theta), Solar
Radiation, Relative Humidity, Precipitation, Surface Wetness
Leaf Area Index and Vegetation, Land Use, Terrain
Note:
The National Dry Deposition Network (NDDN) was established in 1986 and field measurements began in 1987. With the passage of the
1990 Clean Air Act Amendments, NDDN was subsumed by CASTNET in 1991.
CASTNET Annual Report - 2005
Executive Summary
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Chapter 1: CASTNET Overview
Perkinstown, WI (PRK134)
The 1990 Clean Air Act Amendments (CAAA) mandated significant reductions in sulfur dioxide
(SO2) and nitrogen oxides (NOX) emissions from electric utility plants. In addition, the CAAA
directed that a national air monitoring network be established to track real-world environmental
results as the reductions were implemented. The Clean Air Status and Trends Network
(CASTNET) is a national air monitoring network that provides data for determining relationships
between emissions, air quality, deposition, and ecological effects. This report summarizes
CASTNET monitoring activities and the resulting concentration and deposition data for 2005.
CASTNET started as the National Dry Deposition Network (NDDN), which began operation in
1986. The 50 NDDN sites were transferred to CASTNET in 1991. One of the major strengths of
CASTNET is the long-term data record with more than 40 sites operating since the late 1980s.
The network, as of December 2005, included 87 monitoring stations at 83 site locations
throughout the continental United States and Alaska. CASTNET sites measure rural, regionally
representative concentrations of sulfur and nitrogen species and ozone (O3) in order to detect and
quantify trends, define the spatial distribution of rural pollutants, and estimate dry deposition
fluxes. The goal of estimating dry deposition also requires the measurement of several
meteorological parameters and information on vegetation and land use.
CASTNET Annual Report - 2005
Chapter 1: CASTNET Overview
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To satisfy the CASTNET objectives and to support the investigation of the relationships between
emissions and concentrations/depositions, efforts were made to select regionally representative
sites, especially in the eastern United States. "Regionally representative" refers to the overall
similarity - in terms of air pollutant concentrations and land use - of the site to a characteristic
area, typically 100 kilometers (km) by 100 km, surrounding the site. For the western United
States, the limited number of sites and higher geographic diversity preclude rigorous
determination of spatial patterns. Therefore, site selection focused on locations where specific
research issues could be addressed and where natural resources were at risk (e.g., national parks).
CASTNET is sponsored by the Environmental Protection Agency (EPA) and the National Park
Service (NFS). NFS began its participation in CASTNET in 1994 under an agreement with EPA.
NFS is responsible for the protection and enhancement of air quality and related values in
national parks and wilderness areas. The number of NPS-sponsored CASTNET sites was 27 as
of the end of 2005. In addition to EPA and NFS, the principal sponsors, CASTNET operates in
partnership with other rural long-term monitoring networks:
* National Atmospheric Deposition Program/National Trends Network (NADP/NTN)
operates monitoring stations with wet deposition samplers to measure the concentrations
and deposition rates of air pollutants that are removed from the atmosphere by
precipitation. NADP/NTN operates wet deposition samplers at or near virtually every
CASTNET site.
* The Canadian Air and Precipitation Monitoring Network (CAPMoN) operates 28
measurement sites throughout Canada and one in the United States. CASTNET and
CAPMoN both operate samplers at monitoring stations in Ontario, Canada and also at
Pennsylvania State University.
* The Interagency Monitoring of Protected Visual Environments (IMPROVE)
measures aerosol pollutants near more than 30 CASTNET sites. IMPROVE measures
particulate air pollutants that affect visibility and visual air quality.
* Mercury Deposition Network (MDN) samplers are operated at multiple CASTNET
sites. MDN samplers measure mercury in precipitation.
State agencies also operate special purpose air pollutant measurement devices at some
CASTNET sites. EPA uses CASTNET in conjunction with these other long-term monitoring
networks to assess the effectiveness of national and regional air pollution control programs.
Additional information, previous annual reports, and other CASTNET documents can be found
on the EPA Web site, www.epa.gov/castnet. The CASTNET database is also available to the
public by accessing the "Data" link on EPA's CASTNET Web page. The Web site provides
archives of the concentration and deposition data. Fully validated data are generally available
approximately ten months following collection.
CASTNET Annual Report - 2005 2 Chapter 1: CASTNET Overview
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Locations of Monitoring Sites
Figure 1-1 shows the locations of CASTNET monitoring sites as of December 2005. Eighty-
seven sites were operational at 83 distinct locations. Most CASTNET sites are located in rural or
remote locations away from pollution emission sources and heavily populated areas. Appendix B
provides the location and operational characteristics of each site by state, including information
on start date, latitude, longitude, elevation, and the types of measurements taken at each site. For
the purposes of this report, CASTNET sites are called "western" or "eastern" depending on
whether they are west or east of 100 degrees west longitude. The line runs north to south
dividing the states of North and South Dakota, Nebraska, Kansas, Oklahoma, and Texas.
Figure 1-1 CASTNET Sites as of December 2005
PIN414 CAN407
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ALH1S7 VIN140
CKT136 vp|120
MCK131. MCK231 -
GRC474
CON186
PET427
JOT403
FSP1?7
PE01M
GRS420'ซ CND125 BFT142
COW137
SND152
GAS1S3
EPA Sponsored
NPS Sponsored
Collocated Pair
.
IRL141
CASTNET Annual Report - 2005
Chapter 1: CASTNET Overview
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CASTNET Monitoring Sites on Tribal Lands
Three CASTNET monitoring sites are located on tribal
lands as a result of a unique cooperative effort among EPA
Headquarters (HQ), EPA Regions, tribal governments, and
the Inter-Tribal Environmental Council (ITEC), a non-profit
agency which provides member tribes with technical
support and training in environmental fields. This
collaborative effort has resulted in monitoring sites
operating on the tribal lands of the Cherokee Nation in
eastern Oklahoma (CHE185), the Alabama-Coushatta in
eastern Texas (ALC188), and the Santee Sioux in northern
Nebraska (SAN189).
All three tribes initially received grants from EPA Regions 6
and 7 to establish sites and purchase monitoring equipment.
EPA Regional staff and ITEC then worked with the local
tribal environmental staff to help with the installation of the
site, operation of instruments, and the interpretation of results. EPA HQ and Regions continue to
support the tribes in the operation, instrument calibration, and maintenance of each site as part of
CASTNET.
Having CASTNET monitoring sites on tribal lands provides benefits to both tribes and EPA. For
the tribes involved, it enhances their ability to develop and run their own environmental
programs that help to protect their communities and environment. Locating these sites on tribal
lands also helps EPA (both HQ and Regions) obtain regional data that are used to monitor long-
term trends in air pollution and understand the behavior of atmospheric pollutants.
- . - r, " '
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Paynes Prairie State Park, FL
CASTNET Annual Report - 2005
Chapter 1: CASTNET Overview
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Measurements Collected at CASTNET Sites
CASTNET was designed primarily to measure seasonal and annual average concentrations and
depositions over many years. Consequently, measurement of weekly average concentrations was
selected as the basic sampling strategy. Over the course of the week, air is drawn through a
three-stage filter pack (Figure 1-2) at a controlled flow rate to collect air pollutants in the form of
gases and particles. The first stage of the filter pack encloses a Teflonฎ filter, the second a nylon
filter, and the third holds two potassium carbonate (K2CO3)-impregnated cellulose filters. The
filter pack is changed out each Tuesday and shipped to the analytical chemistry laboratory
for analysis.
Figure 1-2 Three-Stage Filter Pack
CASTNET measures concentrations of sulfur in the form of
sulfur dioxide (SO2) and sulfate (SO2;) and nitrogen as
nitrate (NO3), nitric acid (FINO3), and ammonium (NH+4). In
addition, it measures concentrations of chloride (Cl ~),
calcium (Ca2+), sodium (Na+), magnesium (Mg2+), and
potassium (K+). Sulfate, NFT4, NO3, Cl", and the earth
metals are collected on the Teflonฎ filter. The nylon filter
collects FDSTO3and some SO2. The cellulose filters collect
the remaining SO2.
Previous studies have suggested that the CASTNET filter
pack system overestimates FDSTO3 and underestimates
particulate NO3 and NH4. This suggestion is based on the
hypothesis that typically a fraction of the ammonium nitrate
(NH4NO3) collected on the Teflonฎ filter dissociates to
ammonia (NH3). Also, NH4NO3 can react with acid sulfate
particles on the Teflonฎ filter to produce HNO3. Data from
CASTNET and three other measurement programs
CASTNET Ambient
Measurements
Sulfur dioxide (SO2)
Particulate sulfate (SO2;)
Paniculate nitrate (NO,)
Nitric acid (HNO3)
Particulate ammonium (NH*)
Paniculate calcium (Ca2+)
Paniculate sodium (Na+)
Paniculate magnesium (Mg2+)
Paniculate potassium (K+)
Paniculate chloride (CO
Ozone (O3)
Meteorological variables and
information on land use and
vegetation
CASTNET Annual Report - 2005
Chapter 1: CASTNET Overview
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(e.g., Ames, et al, 2001) are being used to address this hypothesis and to estimate uncertainties
in CASTNET filter pack measurements of HNO3, NO"3, and MT4 on a seasonal, annual, and
geographic basis. Information from these analyses will be available in late 2006. Preliminary
results (Rogers, et al., 2006b) indicate that total nitrogen measurements are comparable among
different monitoring programs but that differences exist among measurements of individual
species (e.g., NO3).
CASTNET also measures ozone, one of the major components of smog. In addition to the air
pollutants, CASTNET sites record meteorological measurements of temperature, solar radiation,
relative humidity, precipitation, wind speed and direction, and surface wetness. These
meteorological measurements are used to gauge the transport of air pollutants and as input to the
mathematical model (the Multi-Layer Model or MLM) used for estimating dry deposition to
ecosystems in the atmospheric boundary layer. The ozone and meteorological measurements are
recorded continuously and archived as hourly averages.
Calculating Dry Deposition
The original network design was based on the assumption that dry deposition or flux could be
estimated as the linear product of measured pollutant concentration (C) and modeled deposition
velocity (V
-------
Figure 1-3 Multi-Layer Model
Flux = C X V d
1
1
-+ra
rcut+rb ra_soil+ rsoi
= turbulence
., = turbulence near soil
rb = thin layer at surface ฃ ^ Wind Speed,
r cuticular ' " Sigma Theta
rs stomatal
rsoll = soil
Temp
SR,
1
^1 lrb
LAI' ~* s K^X rcut
l"a, soil
CW^'?T^ f rsoil-^| Wetaess.
1
1
CASTNET Reference Sites
Chapters 2 through 4 present maps
illustrating the magnitude of pollutant
concentrations and deposition fluxes across
the United States. In addition,
measurements from 34 CASTNET
reference sites (Figure 1-4) were analyzed
for each pollutant in order to determine
trends in concentrations and trends in rates
of dry, wet, and total deposition. These 34
sites have been reporting CASTNET
measurements since at least 1990 and are
used for determining long-term trends. The
reference sites were selected using criteria
similar to those used by EPA in its
National Air Quality and Emission Trends
Report (2000). The criteria include site
longevity and data completeness. EPA's
procedures to interpolate and extrapolate
quarterly mean data were also used. In
chapters 2 through 4, the data from the 34
reference sites were aggregated and then
presented using box plots for the period
1990 through 2005.
Figure 1-4 CASTNET Reference Sites
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.
"<ป -CN012S ,,;-"
Reference Sites
CASTNET Annual Report - 2005
Chapter 1: CASTNET Overview
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SO2 and NOX Emissions
The Acid Rain program (ARP), established under Title IV of the 1990 Clean Air Act
Amendments, requires major reductions of sulfur dioxide (SO2) and nitrogen oxides (NOX)
emissions from the electric power industry. The SO2 program sets a permanent cap on the total
amount of SO2 that may be emitted by electric generating units in the contiguous United States.
The program began in 1995 and is being phased in, with the final 2010 SO2 cap set at 8.95
million tons, a level equal to about one-half of the emissions from the power sector in 1980.
Using a market-based cap and trade mechanism to reduce SO2 emissions allows flexibility for
individual combustion units to select their own methods of compliance. Currently, one allowance
provides a regulated unit limited authorization to emit one ton of SO2. The Clean Air Act
allocates allowances to regulated units based on historic fuel consumption and specific emission
rates prior to the start of the program. The total allowances allocated for each year equal the SO2
emission cap. The program encourages early reductions by allowing sources to bank unused
allowances in one year and use them in a later year.
The ARP has closer to a traditional approach to achieve NOX emission reductions. Rate-based
limits apply to most of the coal-fired electric utility boilers subject to the ARP. No nationwide
cap has been placed on NOX emissions. Other NOX emissions control programs have resulted in
significant reductions in NOX emissions during the ozone season (see Chapter 4). Two prominent
control programs are the Ozone Transport Commission (OTC) NOX Budget (1999-2002), and the
NOX State Implementation Plan (SIP) Call, which began in 2003 and will continue through 2007.
The ARP is composed of two phases for SO2 and NOX. Phase I applied primarily to the largest
coal-fired electric generation sources from 1995 through 1999 for SO2 and from 1996 through
1999 for NOX. Phase II for both pollutants began in 2000. In 2005, the SO2 Phase II requirements
applied to 3,456 operating units; the Phase IINOX requirements applied to 982 of those operating
units that are > 25 megawatts and burned coal between 1990 and 1995 (EPA, 2005a).
Figure 1-5 presents state-by-state total annual SO2 and NOX emissions for Phase I and Phase II
electric utility plants for 2005. The heaviest emissions occurred in the eastern United States with
major SO2 sources centered around the Ohio River Valley.
CASTNET Annual Report - 2005 8 Chapter 1: CASTNET Overview
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Figure 1-5 Annual Utility SO2 and NOX Emissions (Phase I and Phase II Plants only) for 2005
2005 Annual Emissions
(thousand short tons)
1,000
D Sulfur Dioxide
D Nitrogen Oxide
CASTNET Annual Report - 2005
Chapter 1: CASTNET Overview
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Chapter 2:
Atmospheric Concentrations
Cedar Creek State Park, WV (CDR119)
CASTNET uses filter pack technology to measure concentrations of sulfur dioxide (SO2),
sulfate (SO24"), nitric acid (HNO3), nitrate (NOj), ammonium (NH^), chloride (CP), and
several earth metals. Since 1990, measured concentrations of sulfur species have generally
decreased. However, annual mean SO2 and SO24" concentrations increased in 2005 relative
to 2004. There were no concurrent increases in electric utility emissions in the eastern
United States. Concentrations of nitrogen species remained relatively steady from 1990
until 2000 when they began a slow decline. However, mean annual total nitrate and NFt,
concentrations increased in 2005.
This chapter presents maps illustrating the geographic distribution and magnitude of annual
mean concentrations across the United States. Maps are provided for sulfur dioxide (SO2), sulfate
(SO24"), total nitrate (NO3), and ammonium (NFt,) concentrations. Maps of other filter pack
measurements are provided in CASTNET quarterly reports (MACTEC, 2005b; 2005c; 2006a;
2006c). In addition, concentration data from the 34 CASTNET reference sites (Figure 1-4) were
analyzed to determine any trends in concentrations over the period 1990-2005. The data from
the 34 reference sites are presented using box plots for each year of the 16-year period.
Sulfur Dioxide
Figure 2-1 presents annual mean sulfur dioxide (SO2) concentrations for 2005. The map shows a
large region in the eastern United States with concentrations greater than or equal to
5.0 micrograms per cubic meter (|j,g/m3). The region extends from southwestern Illinois and
western Kentucky to eastern Michigan to New Jersey, Maryland, and Virginia. Concentrations
above 5.0 ng/m3 were also observed at Sand Mountain, AL (SND152) and Georgia Station, GA
(GAS 153). Several sites along and downwind of the Ohio River Valley recorded SO2
concentrations in excess of 10.0 |J,g/m3. The Ohio River Valley is the major SO2 emission source
region (see Figure 1-5) in the United States. The single highest SO2 concentration (16.2 ng/m3)
was measured in eastern Ohio at Quaker City (QAK172). Only three western sites (i.e., sites
west of 100 degrees west longitude) measured an annual mean SO2 concentration greater than
CASTNET Annual Report - 2005 10 Chapter 2: Atmospheric Concentrations
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1.0 Lig/m . These sites include Theodore Roosevelt National Park, ND (THR422), Petrified
Forest National Park, AZ (PET427), and Sequoia National Park, CA (SEK430).
Figure 2-2 provides box plots that show the 1990-2005 trend in annual mean SO2 concentrations
aggregated over the 34 reference sites. The diagram shows an overall downward trend with some
interannual changes. The 2005 mean concentration was slightly higher than the 2004 level.
Three-year means for 1990-1992 and 2003-2005 were 9.0 Lig/m3 and 5.9 Lig/m3, respectively.
This change demonstrates a significant reduction of 34 percent in annual mean SO2
concentrations.
Figure 2-1 Annual Mean SO2 Concentrations (iig/m3) for 2005
Site not pictured:
DEN417. AK 0.5
Concentration
High: 16.2
8 _, Low : 0.2
Figure 2-2 Trend in Annual Mean SO2 Concentrations (iig/m3) - Eastern United States
20
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8
ง 8 +
O
90th Percentile
75th Percentile
Median
Mean
25th Percentile
10th Percentile
CASTNET Annual Report - 2005
11
Chapter 2: Atmospheric Concentrations
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Paniculate Sulfate
A map of annual mean sulfate (SO24") concentrations for 2005 is presented in Figure 2-3. The map
shows a region of concentrations greater than or equal to 5.0 |J,g/m3 along the Ohio River Valley
from western Kentucky to southwestern Pennsylvania. An annual concentration of 5.1 |J,g/m3
also was recorded at SND152, AL. Sulfate concentrations were generally higher in 2005 than in
2004. In 2004 only one site recorded a value above 5.0 ng/m3. That site was QAK172, OH,
which also recorded the highest concentration of 5.6 ng/m3 in 2005. Sulfate concentrations
greater than or equal to 1.0 ng/m3 were measured at five sites in California and along the
southern tier to Chiricahua National Monument, AZ (CHA467) and Big Bend National Park, TX
(BBE401). The CASTNET site in North Dakota (THR422) also measured a SO2; level of
1.0 |J,g/m3. The five relatively high SO24" concentrations in California were higher than the
respective SO2 levels for the same sites.
Figure 2-4 provides box plots of 2005 annual mean SO2" data from the CASTNET eastern
reference sites in order to illustrate the trend in atmospheric sulfate. Overall, the figure depicts a
significant reduction in SO2" over the last 16 years with some interannual changes. The 2005
mean level was higher than the 2004 value. The difference between 3-year means at the
beginning and end of the period is 23 percent, a change from 5.4 |J,g/m3 for 1990-1992 to
4.2 ng/m3 for 2003-2005.
Figure 2-3 Annual Mean SO2" Concentrations (ng/m3) for 2005
1.5
Site not pictured:
DEN417, AK 0.3
CASTNET Annual Report - 2005
12
Chapter 2: Atmospheric Concentrations
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Figure 2-4 Trend in Annual Mean SO24" Concentrations (|j,g/m3) - Eastern United States
7-
i51
o
04 --
3
*--*
90th Percentile
75th Percentile
Median
Mean
25th Percentile
10th Percentile
8
CM CM CM CM CM CM
Total Nitrate
Figure 2-5 provides a map of annual mean total nitrate (NOj) concentrations for 2005. Total NOj
is defined as the sum of gaseous nitric acid (HNO3) and particulate NO3. Total NO3 better
measures the response to changes in nitrogen oxides (NOX) emissions than either of its
constituents alone. Also, the individual constituents are thought to include measurement
uncertainties. EPA is currently sponsoring a work assignment to investigate the uncertainties in
CASTNET HNO3 and NO3 measurements and to compare CASTNET measurements with
nitrogen data from other networks. Final results of this study will be presented in the CASTNET
2006 Annual Report and in a separate project report and/or paper.
The map in Figure 2-5 shows a complex pattern of total nitrate concentrations along the
Appalachian chain from Georgia to eastern Ohio and Pennsylvania. Mean concentrations ranged
from 0.8 ng/m3 at the CASTNET site at Coweeta, NC (COW137) to 3.5 ng/m3 at QAK172, OH.
The geographic variability in concentrations is caused by changes in the elevations of the
monitoring stations and the associated differences in deposition velocities, inversion heights, and
exposure to fresh nitric oxide emissions. The highest annual mean total nitrate values were
recorded in Illinois, Indiana, and Ohio. Seven sites measured concentrations greater than or equal
to 4.0 ng/m3. Concentrations greater than or equal to 4.0 ng/m3 were also observed at
Arendtsville, PA (ARE128) and Blackwater Wildlife Refuge, MD (BWR139). Three CASTNET
sites in California measured total nitrate concentrations above 3.0 ng/rn3. One of these sites,
SEK430, is located in the Sierra Nevada Mountains adjacent to the agricultural Central Valley.
The other two sites Converse Station (CON186) and Joshua Tree National Monument
(JOT403) are located downwind of the Los Angeles Basin.
Box plots of annual total nitrate values from the 34 CASTNET reference sites are provided in
Figure 2-6. The data show a decline from 2000 to 2004 but a slight increase in 2005. The overall
trend depicts a 12 percent reduction in total nitrate from 1990-1992 to 2003-2005.
CASTNET Annual Report - 2005
13
Chapter 2: Atmospheric Concentrations
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Figure 2-5 Annual Mean Total Nitrate (NO3 + HNO3) Concentrations (ng/m3) for 2005
ซ 0.3.
Site not pictured:
DEN417. AK 0.2
Figure 2-6 Trend in Annual Total Nitrate (NOj + HNO) Concentrations (ng/m3)
Eastern United States
6 --
c
o
c
o
O
2
mm
83 83 83
83
90th Percentile
75th Percentile
Median
Mean
25th Percentile
10th Percentile
888
CASTNET Annual Report - 2005
14
Chapter 2: Atmospheric Concentrations
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Paniculate Ammonium
A map of annual mean ammonium (NFT4) concentrations is presented in Figure 2-7. The map
shows annual levels greater than or equal to 2.0 |J,g/m3 in the agricultural states of Illinois,
Indiana, and Ohio and also at three sites representative of agricultural areas in Pennsylvania,
Kentucky, and Alabama - Penn State University, PA (PSU106); Mackville, KY (MCK13 1); and
SND152, AL. The NFt, concentrations measured at western sites were relatively low with all
sites measuring concentrations below 1.0
The trend diagram for annual mean NFt, values is provided in Figure 2-8. The box plots show a
16 percent decline in NFt, concentrations from the 3 -year period 1990-1992 to the three years at
the end of the period (1.79 |J,g/m3 to 1.49 |j,g/m3). However, the 2005 mean was higher than the
2004 value. This increase might be related to relatively higher SO24" and NO3 concentrations in
2005 and the resulting higher ammonium sulfate [(NH4)2SO4] and ammonium nitrate (NH4NO3)
concentrations.
Figure 2-7 Annual Mean NFT4 Concentrations (ng/m3) for 2005
Site not pictured:
DEN417. AK 0.1
CASTNET Annual Report - 2005
15
Chapter 2: Atmospheric Concentrations
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Figure 2-8 Trend in Annual Mean NH^, Concentrations (|j,g/m3) - Eastern United States
3-
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1 --
90th Percentile
75th Percentile
Median
Mean
25th Percentile
10th Percentile
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05050505050505050505000000
Continuous Measurements of Trace Concentrations of
CO, NOy, and SO2
In addition to filter pack measurements, continuous measurements of low-concentration
(i.e., trace) carbon monoxide (CO), total reactive oxides of nitrogen (NOy), and sulfur
dioxide (SO2) are collected at the CASTNET Beltsville, MD (BEL 116) site. Data from
these continuous gas analyzers were extracted from the entire 7-month database and
plotted. The data show some interesting results. The following figure is a plot of hourly
CO, NOy, and SO2 data from the low-concentration analyzers for the first two weeks of
November 2005. Separate scales are provided for each pollutant. The CO and NOy
measurements are correlated, suggesting an urban source of these two pollutants. The SO2
measurements are unrelated to the CO and NOy data. This result suggests that the SO2
sources are not collocated with the urban sources of the CO and NOy. These simple
interpretations suggest that the low-concentration measurements could be utilized for other
types of analyses and also for the evaluation of filter pack measurements.
LU
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CASTNET Annual Report - 2005
16
Chapter 2: Atmospheric Concentrations
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Chapter 3:
-iTi
Lassen Volcanic National Park, CA (LAV410)
CASTNET was designed to estimate dry deposition as the product of measured pollutant
concentrations and modeled deposition velocities. The Multi-Layer Model (MLM) is the
computer model used to calculate hourly deposition velocities based on meteorological
measurements and information on vegetation and its annual evolution. Total deposition is
the sum of estimated dry deposition and measured wet deposition. Since 1990, total sulfur
deposition has declined significantly. The data show a 27 percent reduction in 3-year mean
sulfur fluxes over the period from 1990-1992 to 2003-2005. Total nitrate deposition
declined by 9 percent over the same period. Dry deposition is responsible from
approximately 20 to 80 percent of total deposition depending on location and climate. The
percentage is higher in major source regions. Typical percentages are 40 percent for dry
sulfur and 30 percent for dry nitrogen deposition.
Gaseous and aerosol sulfur and nitrogen pollutants are deposited into ecosystems through dry and
wet atmospheric processes. One of the most critical and unique components of CASTNET
involves estimation of the rate, or flux, of dry deposition from measured environmental
conditions. Measured concentration data are combined with modeled dry deposition velocities to
develop the flux estimates. For this report, wet deposition measurements were obtained from
NADP/NTN and combined with CASTNET's dry deposition data to estimate total deposition.
Total sulfur and nitrogen deposition rates decreased during 2005. Precipitation-weighted mean
concentrations in precipitation of total atmospheric sulfur remained about the same in 2005 as
2004, while nitrogen concentrations in precipitation continued the slow decline that began
in 1998.
Dry deposition processes were simulated using the MLM (Figure 1-3) as described by
Meyers et al. (1998) and Finkelstein et al. (2000). An improved version of the MLM (Schwede,
2006) will be provided to MACTEC in 2006. For this report, the MLM was run using CASTNET
meteorological measurements and information on land use, vegetation, and surface conditions to
calculate deposition velocities for sulfur dioxide (SO2), nitric acid (HNO3), ozone (O3), and the
particles, sulfate (SO24"), nitrate (NO3), and ammonium (NFT4). The deposition velocities were
assumed to be identical for all particle species. Deposition velocity values were calculated for
CASTNET Annual Report - 2005 17 Chapter 3: Atmospheric Deposition
-------
each hour with valid meteorological data for each CASTNET site for the entire period 1990
through 2005. For a deposition velocity to be estimated, temperature, solar radiation, relative
humidity, wind speed, and standard deviation of the wind direction (sigma theta) must all be valid
for the hour. Aggregation rules for CASTNET require three valid quarters for the calculation of
an annual value. If an annual value is not available for a specific site, results are not included on
maps presented in this chapter. For trends analyses, missing values are replaced by interpolation
or extrapolation using valid annual estimates. The MLM has been evaluated for a limited number
of vegetation types, terrain settings, and time periods (summarized by Baumgardner et a/., 2002).
Sulfur Deposition
MLM simulations were done separately for sulfur dioxide (SO2) and sulfate (SO24"). The model
calculations were summed to obtain estimates of dry sulfur deposition [as sulfur (S)] for 2005,
which are shown in Figure 3-1. The magnitude of a deposition rate is illustrated by the size of the
circle. The map shows a narrow region with fluxes greater than 5.0 kilograms per hectare per year
(kg/ha/yr) centered around and downwind of the Ohio River Valley from southern Indiana to
New Jersey. The highest deposition rate was estimated for Quaker City, OH (QAK172) with a
flux of 13.3 kg/ha/yr. The highest dry sulfur deposition rates were coincidental to the major SO2
source region (Figure 1-5) and declined sharply with distance.
Figure 3-1 Dry Sulfur (SO2 + SO2;) Deposition (as S) (kg/ha/yr) for 2005
Sites not pictured:
DEN417.AK 0.1
The dry deposition rates for the western sites were all less than 1.0 kg/ha/yr with the majority of
sites less than 0.5 kg/ha/yr. The MLM was not run for those sites in Figure 3-1 having no
numerical value adjacent to the site location because of incomplete data.
CASTNET Annual Report - 2005
18
Chapter 3: Atmospheric Deposition
-------
Wet deposition values used in these analyses represent a combination of historical CASTNET wet
deposition data with NADP/NTN wet deposition data. For CASTNET sites where wet
concentrations were measured prior to January 1999 (when responsibility for wet deposition
monitoring activities at CASTNET sites was transferred to NADP/NTN), those values were used
in the data set. For sites where no wet concentrations were measured and for all sites after January
1999, values were obtained from a grid of concentration estimates derived from available
NADP/NTN sites by using an inverse distance weighting function. Estimated concentrations were
multiplied by the precipitation measured at the CASTNET sites to obtain estimates of
wet deposition.
Figure 3-2 provides a map of estimates of total sulfur deposition. The map was constructed by
adding dry and wet deposition. The circles in the figure illustrate the magnitude of total sulfur
deposition and also the relative contributions from wet and dry deposition. The dark shading
(blue) signifies wet deposition and the light shading (tan) shows dry deposition. For 2005, a
region with total (dry + wet) sulfur deposition (kg/ha/yr) greater than 10.0 kg/ha/yr extended from
southwestern Indiana and central Kentucky, along the Ohio River into Ohio, West Virginia,
Virginia, Maryland, New Jersey, Pennsylvania, and New York. Sulfur deposition at western sites
was less than 2.0 kg/ha/yr. The contribution of dry deposition was much more significant in and
near major source regions. For example, the contribution of dry sulfur deposition ranged from
about half of total sulfur deposition at Vincennes, IN (VIN140) to only a small fraction at sites
in Florida.
Figure 3-2 Total (Dry + Wet) Sulfur Deposition (as S) (kg/ha/yr) for 2005
Sites not pictured:
DEN417.AK 0.9
Total Deposition
16
8
1.6
HI Dry Deposition
Wet Deposition
CASTNET Annual Report - 2005
19
Chapter 3: Atmospheric Deposition
-------
Figure 3-3 presents box plots that show the trend in dry sulfur deposition (as S), and Figure 3-4
shows the trend in annual total (dry + wet) sulfur deposition (as S) over the 16 years, 1990
through 2005. The box plots were based on data obtained from the 34 eastern CASTNET
reference sites (Figure 1-4). Sulfur deposition at these sites declined significantly over the
16 years, although the dry fluxes have been relatively constant for the last five years. Figure 3-4
shows a decline in total sulfur deposition over the last two years. Figure 3-5 presents estimates of
trends in dry, wet, and total deposition of sulfur (as S) on the same diagram. The trend line for
mean sulfur concentrations in precipitation shows a continuing decrease over the last several
years with a small increase in 2005. The influence of precipitation on total sulfur deposition is
illustrated by comparing the solid (top) line to the dotted blue line in Figure 3-5. The solid line
shows total deposition, which depends on sulfur concentrations in precipitation and precipitation
amounts. The dotted line shows concentrations in precipitation, which reflect changes in SO2
emissions. Total sulfur deposition declined from a 1990-1992 mean of 13.5 kg/ha/yr to a
2003-2005 mean of 9.9, a 27 percent reduction.
Figure 3-3 Trend in Dry Sulfur Deposition (as S) (kg/ha/yr) - Eastern United States
\
-------
Figure 3-4 Trend in Total (Dry + Wet) Sulfur Deposition (as S) (kg/ha/yr) -
Eastern United States
25
20
15
o
Q.
ฐ> -in
o TU
5
90th Percentile
75th Percentile
Median
Mean
25th Percentile
10th Percentile
O5O5O5O5O5O5O5O5O5O5
O5O5O5O5O5O5O5O5O5O5
OOOOOO
OOOOOO
CMCMCMCMCMCM
Figure 3-5 Trend in Dry, Wet, and Total Sulfur Deposition (as S) (kg/ha/yr) with Precipitation-
Weighted Mean Concentrations in Precipitation (mg/L) - Eastern United States
16
14
12
C10
o
W Q
O O
Q.
-------
Contributors to Atmospheric Deposition
1990-1992: CASTNET Eastern Reference Sites
Sulfur
Nitrogen
D DrySO2
Deposition
(as Sulfur)
D DrySO42-
Deposition
(as Sulfur)
WetSO42-
Deposition
(as Sulfur)
13.5 kg/ha 7.9 kg/ha
2003-2005: CASTNET Eastern Reference Sites
D Dry HNO3
Deposition
(as Nitrogen)
D Dry NCV
Deposition
(as Nitrogen)
D Dry NH4*
Deposition
(as Nitrogen)
Wet NO3~
Deposition
(as Nitrogen)
Wet NH4*
Deposition
(as Nitrogen)
D DrySO2
Deposition
(as Sulfur)
D DrySO42-
Deposition
(as Sulfur)
WetSO42-
Deposition
(as Sulfur)
9.9 kg/ha
7.2 kg/ha
D Dry HNO3
Deposition
(as Nitrogen)
D Dry NCV
Deposition
(as Nitrogen)
n Dry NH4*
Deposition
(as Nitrogen)
Wet NCV
Deposition
(as Nitrogen)
H Wet NH4*
Deposition
(as Nitrogen)
The four pie charts illustrate mean total (wet + dry) sulfur and nitrogen deposition rates for two
3-year periods, 1990 to 1992 and 2003 to 2005. The mean values were obtained for the 34 reference
sites. The pie charts show a significant decline in mean total sulfur deposition from about 13.5 to
9.9 kg/ha/yr from the beginning to the ending three years. The charts show a relatively small decline
in total nitrogen deposition, from 7.9 to 7.2 kg/ha/yr from the beginning three years to the final three
years of the 16-year period. The data show that wet SO24 deposition was the major contributor to
total sulfur deposition, followed by dry SO2 and a much smaller contribution from dry SO24. The
percentage of dry deposition in total deposition changed from 41 percent to 39 percent over the 16
years. Wet NO3 deposition was the major contributor to total nitrogen deposition followed by wet
NH+4, dry HNO3, dry NH4, and dry NO"3. The percentage of dry nitrogen deposition changed slightly
from 29 percent to 27 percent over the 16 years. For both sulfur and nitrogen, dry deposition
contributed from about 20 to 80 percent of total deposition at individual CASTNET sites, depending
on location and climate. Typical deposition percentages are about 40 percent for dry sulfur and
30 percent for dry nitrogen.
CASTNET Annual Report - 2005
22
Chapter 3: Atmospheric Deposition
-------
Nitrogen Deposition
Figure 3-6 presents a map of dry fluxes of nitrogen [as nitrogen (N)] for 2005. Nitrogen fluxes are
comprised of nitric acid (HNO3) + nitrate (NO3) + ammonium (NFC,). This map was constructed
by summing the individual MLM simulations for the three species. Almost all of the CASTNET
sites in the eastern United States had estimated dry nitrogen deposition rates greater than
1.0 kg/ha/yr. The nitrogen fluxes were more uniform than the sulfur fluxes, reflecting a wider
distribution of NOX sources. The flux values ranged from 0.5 kg/ha/yr in New Hampshire and
Maine to 3.6 kg/ha/yr in eastern Ohio. The values at the western sites ranged from 0.2 kg/ha/yr at
North Cascades National Park, WA (NCS415) to 3.0 kg/ha/yr at Converse Station, CA
(CON186).
Figure 3-6 Dry Nitrogen (HNO3 + NO3 + NFF^ Deposition (as N) (kg/ha/yr) for 2005
Sites not pictured:
DEN417.AK 0.1
A map (Figure 3-7) of total nitrogen deposition (as N) for 2005 was constructed by summing the
estimates of dry (light shading) and wet (dark shading) deposition. The figure shows that a large
majority of the eastern sites recorded deposition rates greater than 5.0 kg/ha/yr. No values above
10.0 kg/ha/yr were observed in 2005. Lower fluxes were recorded along the periphery of the
network (e.g., in New England and Florida and throughout the West). The values at the western
sites ranged from 1.3 kg/ha/yr in central California at Yosemite National Park (YOS430) and in
Wyoming at Yellowstone National Park (YEL408) to 5.0 kg/ha/yr in southern California
at CON186. The contributions of dry nitrogen deposition to total nitrogen were lower than the
corresponding contributions of dry sulfur deposition. Dry nitrogen deposition typically
contributed less than 50 percent of total deposition in the East. Interestingly, dry nitrogen
CASTNET Annual Report - 2005
23
Chapter 3: Atmospheric Deposition
-------
deposition contributed more than half of total nitrogen deposition in southern California, a region
with elevated concentrations of nitrogen species and limited rainfall. The CASTNET site at
QAK172, OH had the distinction of measuring the highest total sulfur and nitrogen
deposition rates.
Figure 3-7 Total (Dry + Wet) Nitrogen Deposition (as N) (kg/ha/yr) for 2005
Total Deposition
10
Sites not pictured:
DEN417.AK 0.4
HI Dry Deposition
D Wet Deposition
Figure 3-8 presents box plots that show the trend in dry nitrogen deposition (as N), and Figure 3-9
shows the trend in annual total (dry + wet) nitrogen deposition over the 16 years, 1990 through
2005. The box plots in Figure 3-8 show little overall trend although the data suggest a decline in
dry nitrogen deposition since 1999. Total nitrogen deposition (Figure 3-9) decreased since 2003.
Figure 3-8 Trend in Dry Nitrogen Deposition (as N) (kg/ha/yr) - Eastern United States
90th Percentile
75th Percentile
Median
Mean
25th Percentile
10th Percentile
O5O5O5O5O5O5O5O5
O5O5O5O5O5O5O5O5
CN CN CN CN
CASTNET Annual Report - 2005
24
Chapter 3: Atmospheric Deposition
-------
Figure 3-9 Trend in Total (Dry + Wet) Nitrogen Deposition (as N) (kg/ha/yr)
Eastern United States
14
12
.2 10
o
Q.
a>a>a>a>a>a>
CDCDCDCDCDCDCDCD
a>a>
(J>(J>
- 0.8
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-0.4
g
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- 0.2
0.0
000000
o o o o o o
CASTNET Annual Report - 2005
25
Chapter 3: Atmospheric Deposition
-------
Chapter 4:
Ozone Concentrations
Death Valley National Park, CA (DEV412)
CASTNET provides the primary means for monitoring rural ozone (O3) concentrations
in the United States. The median fourth highest daily maximum 8-hour O3 concentration
for 2005 was the second lowest in the history of the network despite the return to
normal weather conditions during the ozone season (May through September). The
decline in rural ozone levels over the last few years has been attributed to the
documented decline in NOX emissions, as well as weather conditions not conducive to
ozone formation during some of those years.
CASTNET ozone (O3) measurements provide information on geographic patterns in regional O3.
Each monitoring site operates an ozone analyzer to measure O3 concentrations continuously.
Ozone data are recorded and archived as hourly averages.
The CASTNET O3 database constitutes a long-term
record of O3 levels in rural areas with more than 40 sites
operating since the late 1980s. While CASTNET is not a
compliance network, the 8-hour O3 standard is a useful
metric in assessing status and trends in rural O3. The
analyses presented in this section examine trends in the
fourth highest daily maximum 8-hour average O3
concentrations, consistent with the metric used in the
8-hour standard (see call out box on following page).
During the period 2003-2005, 3-year averages of the
fourth highest daily maximum 8-hour O3 concentrations
were greater than or equal to 85 parts per billion (ppb) at
seven sites in California, Maryland, New Jersey, and
Tennessee. Measurements of 8-hour concentrations
during 2005 were somewhat higher than 2003 and 2004
but were considerably lower than concentrations measured over the period 1990-2002. Ozone
levels measured in 2005 continue to show a downward trend that began in 2002.
CASTNET Annual Report - 2005
26
Chapter 4: Ozone Concentrations
-------
National Ambient Air Quality Standard for Ozone
8-Hour Ozone Standard
To better protect public health, EPA (1997) revised its national air quality standards for
ozone in 1997, establishing an 8-hour standard. The 8-hour standard is 0.08 parts per
million (ppm). An area meets the standard if the 3-year average of the annual fourth
highest daily maximum 8-hour average concentration is less than or equal to 0.08 ppm.
For more information on the 8-hour ozone standard and ozone nonattainment areas in
the United States, visit www.epa.gov/air/oaqups/glo/designations/index.htm.
What Does It Mean?
EPA collects ozone data on an hourly basis. Essentially, 8-hour average ozone
concentrations at a monitor cannot exceed 0.08 ppm more than three days per year. For
compliance purposes:
* Hourly ozone measurements are used to compute 8-hour average concentrations.
* The daily maximum 8-hour average is recorded for each day.
* For each year, the fourth highest daily maximum concentration is calculated.
* These annual fourth highest daily maximum concentrations are averaged over three-
year periods.
* If the average exceeds 0.084 ppm (0.085 rounds up to 0.09 thus exceeding the
standard criteria) or 85 ppb in practice, the area is designated as a "nonattainment
area."
CASTNET Annual Report - 2005 27 Chapter 4: Ozone Concentrations
-------
Eight-Hour Ozone Concentrations
Figure 4-1 presents 3-year averages of the fourth highest daily maximum 8-hour O3
concentrations for 2003-2005. The sites with concentration levels greater than or equal to 85 ppb
are listed in a table next to the map in Figure 4-1. Three eastern and four sites in California
measured 3-year average concentrations greater than or equal to 85 ppb. These 3-year average
concentrations constitute current design values for achieving the 8-hour National Ambient Air
Quality Standard (NAAQS) for O3. For example, the estimated value of 124 ppb at CON186
would have to be reduced to 84 ppb to achieve the standard. Design values change as a new
3-year database becomes available.
For comparison, 3-year averages of the fourth highest daily maximum 8-hour O3 concentrations
for the previous 3-year period, 2002-2004 are presented in Figure 4-2. The area with standard
exceedances was larger during this earlier period. Six eastern and the same four California sites
recorded 3-year averages greater than or equal to 85 ppb. The period 2003-2005 represents an
improvement in air quality.
Fourth highest daily maximum 8-hour O3 concentrations for 2005 are shown in Figure 4-3.
Concentrations greater than or equal to 85 ppb were recorded along the East Coast in the
Washington, D.C. to Boston corridor; Great Smoky Mountains National Park, TN (GRS420);
and Alhambra, IL (ALH157). In addition, five California CASTNET sites monitored
exceedances of the 8-hour ozone NAAQS. The California sites include Converse Station
(CON186), Sequoia National Park (SEK430), Joshua Tree National Monument (JOT403), Death
Valley National Monument (DEV412), and Yosemite National Park (YOS404). The 8-hour level
of 123 ppb at CON186 was the highest value that was measured in the network during 2005.
Rocky Mountains National Park, CO (ROM406/206)
CASTNET Annual Report - 2005
28
Chapter 4: Ozone Concentrations
-------
Figure 4-1 Fourth Highest Daily Maximum 8-Hour Ozone Concentrations (ppb) for
2003-2005
Concenlralion
High: 124
Site ID
CON 186, CA
SEK430, CA
JOT403, CA
YOS404, CA
BWR139, MD
WSP144, NJ
GRS420, TN
Cone > 85
Ppb
124
107
106
88
88
86
86
Site not pictured:
OEN417. AK 52
Figure 4-2 Fourth Highest Daily Maximum 8-Hour Ozone Concentrations (ppb) for
2002-2004
Site not pictured.
DEN417. AK S3
S3
Site ID
CON 186, CA
JOT403, CA
SEK430, CA
WSP144, NJ
BWR139, MD
GRS420, TN
YOS404, CA
ARE128, PA
ABT147, CT
LYK123, OH
Cone > 85
ppb
125
107
103
93
92
91
91
89
86
86
Figure 4-3 Fourth Highest Daily Maximum 8-Hour Ozone Concentrations (ppb) for 2005
Site not pictured:
OEN417. AK 51
Concentration
High 123
Site ID
CON 186, CA
SEK430, CA
JOT403, CA
WSP144,NJ
ALH157, IL
BWR139, MD
ABT147, CT
GRS420, TN
DEV412, CA
YOS404, CA
Cone > 85
ppb
123
107
104
89
88
87
87
86
85
ฃ
CASTNET Annual Report - 2005
29
Chapter 4: Ozone Concentrations
-------
Sixteen-Year Trends
Since 2002, CASTNET ozone measurements have shown a significant decline in annual fourth
highest daily maximum 8-hour concentrations throughout the 34 eastern reference sites (Figure
1-4) used to track trends in concentrations. During 2002, 24 of the reference sites measured
fourth highest daily maximum 8-hour O3 concentrations greater than or equal to 85 ppb. The
number of reference sites with exceedances was reduced to six in 2003, followed by further
reduction to none in 2004. As shown in Figure 4-3, five eastern reference sites recorded elevated
8-hour concentrations in 2005.
Figure 4-4 shows the 16-year trend in 8-hour O3 concentrations aggregated over the 34 reference
stations. The box plots show a significant decline from 2002 to 2003 and a further decline in
2004. The 2005 data show a small increase. Median values for the aggregated measurements for
the four years 2002 through 2005 were 88 ppb, 79 ppb, 70 ppb, and 76 ppb, respectively. Trends
in temperature, solar radiation, and precipitation for the reference sites are shown in Figures 4-5
though 4-7. These box plots were produced for the ozone season, May through September, when
sunlight and warm weather promote the chemical reactions that form ozone. The meteorological
influence on O3 concentrations is evident from the three figures. The 2003 and 2004 ozone
seasons, which measured significantly lower concentrations of ozone than the preceding years
(1990-2002), were unusually cool, cloudy, and wet. For example, total precipitation measured in
2003 and 2004 was well above the amounts recorded during the previous 13 years. Interestingly,
ozone season weather returned to normal in 2005. Yet the median 8-hour O3 concentration was
the second lowest in the 16-year period.
Figure 4-4 Trend in Fourth Highest Daily Maximum 8-Hour Ozone Concentrations (ppb) -
Eastern United States
120
100 --
O 80
60
90th Percentile
75th Percentile
Median
Mean
25th Percentile
10th Percentile
o
o
o
CM CO
O O
O O
LO
O O
O O
CM CM CM CM CM CM
CASTNET Annual Report - 2005
30
Chapter 4: Ozone Concentrations
-------
Figure 4-5 Trend in Mean Seasonal (May through September) Temperature (ฐC) -
Eastern United States
30
25 --
2.20
E
15 --
10
90th Percentile
75th Percentile
Median
Mean
25th Percentile
10th Percentile
o T CM co =* in
o o o o o o
o o o o o o
CM CM CM CM CM CM
Figure 4-6 Trend in Mean Seasonal (May through September) Solar Radiation (W/m2)
Eastern United States
300
CASTNET Annual Report - 2005
31
Chapter 4: Ozone Concentrations
-------
Figure 4-7 Trend in Total Precipitation (mm) (May through September)
Eastern United States
1200
90th Percentile
75th Percentile
Median
Mean
25th Percentile
10th Percentile
200
CDCDCDCDCDCDCDCD
CDCDCDCDCDCDCDCD
CD CD
CD CD
O T- CM CO "3- LO
O O O O O O
O O O O O O
CM CM CM CM CM CM
Nitrogen Oxides and Ozone
EPA recently analyzed changes in NOX emissions and O3 concentrations. The findings were
published in two excellent reports (EPA, 2005b and 2006), which evaluated the effectiveness of
NOX and volatile organic compound (VOC) emission control programs in the eastern United
States and reported subsequent changes in ozone levels. Figure 4-8, which was taken from the
2006 EPA report, depicts annual NOX and VOC emissions in the eastern United States from 1990
through 2005. Figure 4-9 shows ozone season NOX emissions for five baseline years during this
time period. The figure illustrates emissions from large electric generating and industrial sources
in the NOX Budget Trading Program (NBP) region, which is illustrated in light green in
Figure 4-10. The region includes 19 eastern states and the District of Columbia. The emissions
were totaled for 2,570 units in the region. The decline in NOX emissions over the last several
years is evident in the figures. In the report, EPA attributed the decline in emissions to several
effective control programs:
I Mobile source controls,
I VOC Reasonably Available Control Technology (RACT) and Maximum Available
Control Technology (MACT),
I New Source Review,
a Acid Rain Program,
S Ozone Transport Commission (OTC) NOX Budget (1999-2002), and
NOX State Implementation Plan (SIP) Call (2003 - current).
CASTNET Annual Report - 2005
32
Chapter 4: Ozone Concentrations
-------
Figure 4-8 Annual Emissions in the Eastern United States, 1990-1995 and 1997-2005
1
.1 10
3 6
1990
1991
1992 1993
Year
1994
1995
1997
1999
2001
Year
2003
2005
NO,
-VOCs
Figure 4-9 NBP NOX Emissions in the Eastern United States, Ozone Season
(May through September), 1990-2005
2,000
1990
2000
2003
2004
2005
Ozone Season (May 1 -September 30)
Figure 4-10, which was taken from the 2006 EPA report, shows the relationship between
emission reductions from power industry sources and changes in O3 concentrations at CASTNET
and EPA Air Quality System sites in the eastern United States over the period 2002 through
2005. The figure shows declines in ozone concentrations in all NBP states.
CASTNET Annual Report - 2005
33
Chapter 4: Ozone Concentrations
-------
Figure 4-10 NOX Emission Reductions and Changes in 8-hour Ozone, 2002-2005
Increase Less Than 1,000
Decrease Less Than 25.000
Decrease Between 25,000 and 50.000
Decrease Between 50,000 and 75.000
Between 75,000 and 105.000
Ozone Season 8-Hour Ozone
Percent Reduced
Increase Between 15% and 22%
Increase Between 5% and 15%
Increase Less Than 5%
Decrease Less Tnan 5%
Decrease Between 5% and 15%
Decrease Sefrveeri 15% and 23%
Margin of error is +/ 5 percent.
Note:
Shaded region shows areas affected under the NBP as of 2005. Source: EPA
Trends in CASTNET measurements of total nitrate concentrations (Figure 4-11) show a
relationship between the decline in ozone and a decline in atmospheric nitrogen (Rogers etal,
2006a). The box plots show a significant reduction in total nitrate concentrations during the
ozone season since 1999. Figure 4-12 illustrates this decline by comparing ozone season mean
total nitrate concentrations for 2000 and 2005 for the CASTNET reference sites. Both weather
and a reduction in NOX emissions and total nitrate concentrations contributed to the decline in O3
concentrations.
Figure 4-11 Trend in Ozone Season (May through September) Mean Total Nitrate
(NO~3 + HNO3) Concentrations (|ag/m3) - Eastern United States
6 -
5 --
o
co 4
"c
O Q
ฃ= ฐ
O
O
2 -
1 -
^D T CNI CO ^~ LO
^D ^D ^D ^D ^D ^D
CM CM CM CM CM CM
CASTNET Annual Report - 2005
34
Chapter 4: Ozone Concentrations
-------
Figure 4-12 2000 and 2005 Ozone Season (May through September) Mean Total Nitrate
^+ HNO3) Concentrations (ng/m3) - CASTNET Eastern Reference Sites
36.UI6.b \
9/3.-8 3.8 hi 4.1/3.
5/0.4
CASTNET Annual Report - 2005
35
Chapter 4: Ozone Concentrations
-------
Trends in Ozone Concentrations along the
Washington, D.C. to Coastal Maine Corridor
Historically, elevated ozone
concentrations have been recorded along
the East Coast from metropolitan
Washington, D.C. to Acadia National
Park in Maine. Within the last five years,
3-year averages of the fourth highest
daily maximum O3 concentrations have
been more than 90 ppb at the CASTNET
sites in Maryland, eastern Pennsylvania,
New Jersey, and Connecticut and as high
as 87 ppb in Maine. Recent studies by
EPA (2005b) demonstrated a decline in
O3 concentrations in the eastern United
States that is related to the decline in NOx
emissions, which resulted from a number
of NOx emission control programs. The
analyses discussed by Rogers et al.
(2006a) together with the analyses in this
chapter demonstrate a significant
reduction in O3 levels at the 34 eastern
CASTNET reference sites. This
reduction is attributed to the significant
decline in NOx emissions, as manifested
by the decline in total nitrate
concentrations, and cool, cloudy, and wet
weather conditions during the "ozone
season" (i.e., May through September) of
2003 and 2004. More typical ozone
season weather was observed in 2005.
550 E
D Total Nitrate
CASTNET Annual Report - 2005
36
Chapter 4: Ozone Concentrations
-------
Fourth highest daily maximum O3 concentrations measured at six CASTNET sites indicate
that ozone peaked in 2002, and the lowest concentrations occurred during the last three
years. The trend was calculated from 1990-2005 measurements from Beltsville, MD
(BEL 116); Blackwater Wildlife Refuge, MD (BWR139); Arendtsville, PA (ARE 128);
Washington's Crossing State Park, NJ (WSP144); Abington, CT (ABT147); and Acadia
National Park, ME (ACA416). The data were aggregated over the six sites. Ozone season
temperature, solar radiation, and precipitation data show that the 2002 O3 peak was
observed during an exceptionally warm, sunny, and dry summer. Much lower O3
concentrations were recorded in 2003 and 2004. The weather conditions during these two
ozone seasons were cool, cloudy, and wet. Weather conditions returned to normal during
the 2005 O3 season. Yet O3 concentrations remained low.
Ozone season mean nitrate concentrations have shown a significant decline in atmospheric
nitrogen along the East Coast since 1999. The trend in total nitrate concentrations along the
East Coast is comparable to the trend in total nitrate levels for the 34 reference sites
(Figure 4-11), but the decline in concentrations along the East Coast is more significant.
The 3-year mean total NO3 level for 1990-1992 of 4.4 |ig/m3 declined to 3.2 ng/m3 in
2002-2005, a 27 percent reduction. The 1999 peak in mean nitrate was 4.5 |J,g/m3. EPA has
estimated about a 25 percent reduction in annual NOX emissions in the eastern United
States over the period 1997-2004 (see Figure 4-9) and an approximate 50 percent decline
in power industry NOX emissions during the ozone season for the same period. The
relationship between low ozone along the East Coast and weather is clear from the trends.
The decline in ozone, especially in 2005, is also related to the decline in NOX emissions
and the corresponding decline in nitrate concentrations.
CASTNET Annual Report - 2005 37 Chapter 4: Ozone Concentrations
-------
Chapter 5:
Data Quality
Joshua Trees in Nevada
The CASTNET quality assurance program is based on specified data quality objectives,
which are evaluated using data quality indicators (DQI). Historical data and measurements for
2005 can be used with confidence since CASTNET measurements are continually evaluated
through the use of DQI and their associated measurement criteria. CASTNET has produced
and continues to produce data of the highest quality.
The CASTNET Quality Assurance (QA) program was designed to ensure that all reported data
are of known and documented quality in order to meet CASTNET objectives and to be
reproducible and comparable with data from other monitoring networks and laboratories. The
QA program elements are documented in the Quality Assurance Project Plan (QAPP), Revision
2.1, (MACTEC, 2003b). The QAPP is comprehensive and includes standards and policies for all
components of project operation from site selection through final data reporting.
Estimating dry deposition requires the measurement of several meteorological parameters and
information on vegetation and land use. The CASTNET data collection process and QA efforts
were designed to ensure that the data collected meet program objectives.
Data quality indicators (DQI) are quantitative statistics and qualitative descriptors used in
interpreting the degree of acceptability and utility of the data collected. The DQI for CASTNET
are precision, accuracy, completeness, bias, representativeness, and comparability. Precision,
accuracy, and completeness for CASTNET 2005 data were analyzed and compared with
historical data collected during the period 1990-2004. The information in this report is
supplemented by analyses that are discussed in quarterly CASTNET Quality Assurance Reports
(e.g., MACTEC, 2006b). These QA reports are produced four times per year with the fourth
quarter report including an annual summary. Both historical and current data can be used with
confidence since CASTNET data are always verified and validated through the use of the DQI
and associated measurement criteria. CASTNET has produced and continues to produce data of
the highest quality.
CASTNET Annual Report - 2005
38
Chapter 5: Data Quality
-------
Figure 5-1 Historical and 2005 Precision Data for Atmospheric Concentrations
Overall-1990 to 2004
DMackville, KY-2005
D Rocky Mtn, CO - 2005
HNO,
NO,
NH4+
Precision
Exposed Filter Concentrations
Figure 5-1 provides a bar chart in which the bars represent precision statistics for each
CASTNET analyte in terms of mean absolute relative percent difference (MARPD) for both the
historical (1990-2004) and the 2005 data for the collocated sites at Mackville, KY
(MCK131/231) and Rocky Mountain National Park, CO (ROM406/206). Trace cations and
chloride are excluded from this figure but are shown later in Figure 5-2. The historical results
vary from about 4 percent for particulate sulfate (SO24") to about 12 percent for particulate nitrate
(NO3). The historical MARPD for SO4 met the criterion for the CASTNET laboratory
measurements shown in Table 5-1. The historical results for sulfur dioxide (SO2), nitric acid
(HNO3), and ammonium (NFT4) were above the 5 percent criterion but were considered
reasonable. The results for NO3 were significantly above the 5 percent goal. Historically, the
precision of NO3 measurements has been consistently worse than for the other analytes, possibly
because NO3 concentrations are the lowest of all the pollutants, and nitrate species include
sampling artifacts (Harding ESE, 2003).
The 2005 precision results shown in Figure 5-1 indicate that the results for MCK131/231 were
below (i.e., better than) the historical results for all five parameters. Four parameters (SO2, SO24",
HNO3, and NH4) met precision criteria. The precision results for ROM406/206 were better than
historical results for one parameter, HNO3. Only the result for NH4 met the DQI criterion.
Overall, the filter pack precision results for 2005 were about the same as 2004.
CASTNET Annual Report - 2005
39
Chapter 5: Data Quality
-------
Table 5-1 Data Quality Indicator Criteria for CASTNET Laboratory Measurements
Analyte
Ammonium (NH4)
Sodium (Na+)
Potassium (K+)
Magnesium (Mg )
Calcium (Ca2+)
Chloride (CL)
Nitrate (NO"3)
Sulfate (SO24")
Method
Automated colorimetry
ICP-AES
ICP-AES
ICP-AES
ICP-AES
Ion chromatography
Ion chromatography
Ion chromatography
Precision1
(MARPD)
10
5
5
5
5
5
5
5
Accuracy2
(%)
90-
95-
95-
95-
95-
95-
95-
95-
110
105
105
105
105
105
105
105
Note: This column lists precision goals for both network precision calculated from collocated filter samples
Nominal
Reporting Limits
0,
0,
0,
0,
0,
0,
0,
0,
.020 mg-N/L
.005 mg/L
.005 mg/L
.003 mg/L
.003 mg/L
.020 mg/L
.008 mg-N/L
.040 mg/L
and laboratory precision based
on replicate samples. The goal for the ICP-AES precision RPD criterion changed from 10 percent to 5 percent at the onset of the new
contract beginning on July 30, 2003. The precision criterion is applied as described below:
QC conditions: (vl = initial response; v2 = replicate response; RL = nominal reporting limit)
Condition 1: if (v 1 or v2 < RL and the absolute value of (v 1 - v2) < RL) = OK
Condition 2: if (vl-v2) < RL and vl < 5 x RL) = OK
Condition 3: if (vl > 5*RL and RPD < 5%) = OK
Status: one of the conditions is OK = Precision QC Passes
This column lists laboratory accuracy goals based on reference standards and continuing calibration verification spikes. The goal for
the ICP-AES accuracy criterion changed from 90 - 110 percent to 95-105 percent for continuing calibration verification spikes at
the onset of the new contract beginning on July 30, 2003. The criterion remains 90 - 110 percent for ICP-AES reference standards.
ICP-AES = inductively coupled plasma-atomic emission spectrometry
MARPD = mean absolute relative percent difference
N = as nitrogen
For more information on analytical methods and associated precision and accuracy criteria, see the CASTNET Quality Assurance Project Plan -
Revision 2.1 (MACTEC, 2003b).
Precision statistics for 2005 for four cations and chloride (Cl~), based on collocated ambient
concentrations, are summarized in Figure 5-2. The historical MARPD statistics for both
MCK131/231 and ROM406/206 do not meet the DQI criterion of 5 percent, except for Cl",
which had a MARPD of approximately 5 percent. As discussed in the CASTNET 2002 QA
Report (MACTEC, 2004) and in the CASTNET 2002 Annual Report (MACTEC, 2003a), the
very high historical MARPD for sodium (Na+) was the result of sample bottle contamination.
These bottles are no longer purchased. Also, acceptance testing of the Teflonฎ filter was
instituted for the trace cations and CP in 2003. The 2005 precision results for cations and Cl~
show that potassium (K+), Na+, and CP met the precision criterion at MCK131/231 and that Cl~
met the criterion at ROM406/206. The MARPD for potassium measured by the two filter packs
at ROM406/206 was about 18 percent. This relatively poor precision was caused by very low K +
concentrations at the park. Potassium is analyzed at a wavelength of 766.4 nanometers (nm) by
the inductively coupled plasma-atomic emission spectrometry (ICP-AES) instrument. This is a
difficult wavelength for the ICP-AES instrument because it is close to the wavelength of the
carrier gas. Low concentration levels show more noise for K+and lower precision through
repeatability as a result.
CASTNET Annual Report - 2005 40 Chapter 5: Data Quality
-------
Table 5-2 summarizes 2005 precision results by quarter for the two sets of collocated sites. The
results indicate comparable performance in 2005 precision versus 2004 for MCK131/231 and a
slight decline in precision for ROM406/206 2005 values versus 2004 (MACTEC, 2005a).
Figure 5-2 Precision Data for Cation and Cl~ Concentrations
25
20 -
Overall-2000 to 2004
DMackville, KY - 2005
D Rocky Mtn, CO - 2005
15 -
D
Q_
o:
10 -
cr
Table 5-2 Collocated Precision Results for 2005 by Quarter (MARPD)
Site Pairs
so2,
NO3
NH4
Ca2
Mg2+
Na +
K
HNO3
Total
SO2 NO3 Cl
MCK 131/231, KY
Quarter 1
Quarter 2
Quarter 3
Quarter 4
2005
2.16
2.29
2.43
3.68
2.64
8.50
8.34
14.38
8.93
10.04
3.60
2.15
3.41
3.30
3.12
19.38
6.74
5.39
7.62
9.79
8.78
6.88
5.58
11.16
8.10
4.84
2.64
7.47
5.31
5.07
5.42
4.52
4.86
5.77
5.14
7.74
3.08
3.32
4.06
4.55
4.97 4.24 5.38
1.64 4.05 0.76
2.64 4.46 0.76
3.01 5.23 7.58
3.07 4.50 3.62
ROM 406/206, CO
Quarter 1
Quarter 2
Quarter 3
Quarter 4
2005
4.41
7.08
7.67
5.49
6.16
13.65
11.78
15.89
12.69
13.50
3.40
7.87
7.22
5.50
6.00
9.77
8.08
10.28
12.31
10.11
13.81
8.15
11.62
9.13
10.68
6.18
8.83
8.51
7.75
7.82
26.70
8.77
15.04
21.17
17.92
5.64
6.92
2.63
5.37
5.14
9.10 4.76 2.93
10.95 6.18 2.89
7.17 3.25 2.59
8.43 4.89 5.18
8.91 4.77 3.40
CASTNET Annual Report - 2005
41
Chapter 5: Data Quality
-------
The 2005 analytical precision results for five analytes and the three filter types are presented in
Figure 5-3. The results were based on analysis of five percent of the samples that were randomly
selected for replication in each batch. The results of in-run replicate analyses were compared
to the results of the original concentrations. The laboratory precision data met the 5 percent
measurement criterion listed in Table 5-1.
Figure 5-3 Precision Results for Laboratory Replicate Samples (2005)
4 -
3 -
Nylon Cellulose Teflon
SO42" SO42" SO42"
contribute to SO 2
Nylon Teflon
Teflon
NH4*
Teflon
Na*
Teflon Teflon Teflon
K* Mg2* Ca2*
Teflon
CI"
Ozone Concentrations
CASTNET QA procedures for the EPA-sponsored ozone (O3) analyzers are different from the
EPA QA requirements for State and Local Monitoring Stations (SLAMS) monitoring
(EPA, 1998). The QA procedures for the O3 analyzers at the NPS-sponsored sites also do not
meet the SLAMS requirements. While NPS utilizes the appropriate procedures and equipment,
the NPS sites are calibrated twice per year versus the SLAMS requirements of four times per
year. In any event, the operation of the collocated O3 analyzers at ROM406/206, CO provides an
opportunity to evaluate the precision of the independent systems. Table 5-3 provides the DQI
criteria for the CASTNET continuous measurements including O3. The precision criterion for the
collocated O3 data is 10 percent.
CASTNET Annual Report - 2005
42
Chapter 5: Data Quality
-------
Table 5-3 Data Quality Indicator Criteria for CASTNET Field Measurements
Measurement
Parameter
Wind Speed
Wind Direction
Sigma Theta
Relative Humidity
Solar Radiation
Precipitation
Ambient Temperature
Delta Temperature
Surface Wetness
Ozone
Filter Pack Flow
Method
Anemometer
Wind Vane
Wind Vane
Thin Film Capacitor
Pyranometer
Tipping Bucket Rain Gauge
Platinum RTD
Platinum RTD
Conductivity Bridge
UV Absorbance
Mass Flow Controller
Criteria*
Precision
ฑ 0.5 m/s
ฑ5ฐ
Undefined
ฑ 10% (of full scale)
ฑ 10% (of reading taken at local
noon)
ฑ 10% (of reading)
ฑ 1.0ฐC
ฑ0.5ฐC
Undefined
ฑ 10% (of reading)
ฑ 10%
Accuracy
The greater of ฑ 0.5 m/s for winds < 5
m/s or ฑ 5% for winds > 5 m/s
ฑ5ฐ
Undefined
ฑ 5%, relative humidity > 85%
ฑ 20%, relative humidity < 85%
ฑ 10%
ฑ 0.05 inclvj-
ฑ0.5ฐC
ฑ0.5ฐC
Undefined
ฑ 10%
ฑ5%
Note:
ฐC = degrees Celsius
m/s = meters per second
RTD = resistance-temperature device
UV = ultraviolet
Precision criteria apply to collocated instruments, and accuracy criteria apply to calibration of instruments.
For target value of 0.50 inch.
MCK131/231,KY
ROM406/206, CO
MARPD statistics were calculated from hourly O3 measurements obtained from the collocated
sites MCK131/231, KY and ROM406/206, CO during 2005. In addition, quarterly historical
precision statistics were compiled for all collocated sites. Quarterly precision results are
summarized in Figure 5-4. The data show the historical results met the 10 percent criterion. The
2005 precision data also met the 10 percent criterion for all four quarters for both MCK131/231
and ROM406/206. The results for ROM406/206 indicate that the two independently operated O3
analyzers with different QA/quality control (QC) procedures produce nearly identical results.
CASTNET Annual Report - 2005
43
Chapter 5: Data Quality
-------
Figure 5-4 Historical and 2005 Precision Data by Quarter for Ozone Concentrations
Overall-1990 to 2004
DMackville, KY-2005
D Rocky Mtn, CO - 2005
First
Quarter
Second
Quarter
Third
Quarter
Fourth
Quarter
Accuracy
Laboratory Filter Concentrations
Accuracy of laboratory measurements is assessed through the analysis of reference samples and
continuing verification samples (CVS). Reference samples and CVS are procured from
independent suppliers and are National Institute of Standards and Technology (NIST) traceable.
Reference samples are analyzed at the beginning and end of each analytical batch to verify the
accuracy and stability of the calibration curve. The target value of the CVS solution is set to
the midrange of the calibration curve. The CVS in 2005 were analyzed every tenth sample to
verify no drift in the calibration curve. Table 5-4 presents the percent recoveries and standard
deviations for reference samples and CVS relative to target concentrations. The table shows
that the DQI goals (see Table 5-1) were met in 2005. Table 5-4 also lists the precision results
that were shown in Figure 5-3.
Shenandoah National Park, VA Photo: NFS
CASTNET Annual Report - 2005
44
Chapter 5: Data Quality
-------
Table 5-4 Filter Pack QC Summary for 2005
1i
a.
ฃ
_
o>
+J
E
Teflonฎ
Nylon
Cellulose
Parameter
so2;
NO;
NH+4
Ca2+
Mg2+
Na+
K+
cr
so2;
NO;
so2;
Reference
Sample1 Recovery (%R)
ซ
85%) relative humidity
at 80.3 percent and solar radiation at 86.6 percent. However, these results did not adversely
affect data collection because data are not considered invalid unless criteria are exceeded by
more than two times the criterion. Using the two times standard, relative humidity passed with
95 percent frequency and solar radiation passed with 97 percent frequency. During 2006, a
portable relative humidity chamber will be used as the calibration transfer for testing the
accuracy of the relative humidity sensors. Using a humidity chamber instead of transfer salts will
provide a better gauge of the relative humidity sensor performance.
CASTNET Annual Report - 2005
45
Chapter 5: Data Quality
-------
Table 5-5 Accuracy Results for 2005 Field Measurements
Parameter Percent Within Criterion
Temperature (0ฐC) 95 percent
Temperature (ambient) 97 percent
Delta Temperature (0ฐC) 96 percent
Delta Temperature (ambient) 95 percent
*Relative Humidity > 85% 80 percent
Relative Humidity < 50% 98 percent
* Solar Radiation 87 percent
Wind Direction North 92 percent
Wind Direction South 94 percent
Wind Speed < 5 m/s 99 percent
Wind Speed > 5 m/s 98 percent
Precipitation 100 percent
Wetness (w/in 0.5 volts) 99 percent
Ozone Slope 97 percent
Ozone Intercept 99 percent
Flow Rate 94 percent
Note: ฐC = degrees Celsius.
m/s = meters per second.
* = Per CASTNET project protocols, data are flagged as "suspect" (S) but still considered valid if the calibration criterion is not
exceeded by more than its magnitude (i.e., if within 2x the criterion). The percent within 2x criterion for relative humidity
> 85 percent was 95.1 percent. The percent within 2x criterion for solar radiation was 96.6 percent.
Completeness
Completeness is defined as the percentage of valid data points obtained from a measurement
system relative to total possible data points expected to be obtained. The CASTNET
measurement criterion for completeness requires a minimum completeness of 90 percent for
every measurement for each quarter. In addition, data aggregation procedures require
approximately 70 percent completeness for hourly fluxes and weekly concentrations/fluxes.
Figure 5-5 presents historical and 2005 completeness data for all sites for measured filter
concentrations, continuous measurements, and calculated parameters. The figure shows that the
2005 direct measurements met the 90 percent goal. The 2005 results show that data completeness
exceeded 95 percent for six parameters, including filter pack flow. The four parameters derived
from model results exceeded 75 percent completeness for 2005. Historical results are better for
atmospheric concentrations, wind speed, temperature, ozone, and annual mean atmospheric
concentrations.
CASTNET Annual Report - 2005 46 Chapter 5: Data Quality
-------
Figure 5-5 Historical* and 2005 Percent Completeness of Measurements and Modeled
Estimates
Atmospheric Concentrations
Vector Wind Speed
Scalar Wind Speed
Wind Direction
Sigma Theta
Relative Humidity
Solar Radiation
Meteorological Precipitation
Parameters
Ambient Temperature
Delta Temperature
Ozone
Filter Pack Flow
Surface Wetness
Hourly Flux Estimates
Model Annual Mean Atm. Concentrations
Results Annual Mean Deposition Velocities
Annually Aggregated Flux Estimates
'
=3
=Ln
1,
,
i
^
1 -^ | DQI Measurement Criterion | ^
L- 1 ,
' il ,
^^^=
^
J
65
70
75
Note:
* Black bars represent 1990-2004 data
80 85
Percent Completeness
90
95
100
Laboratory Intercomparison Studies
MACTEC participates in the U.S. Geological Survey (USGS) interlaboratory comparison
program. Overall, eight laboratories participate in the program, receiving four samples for
chemical analysis from USGS every two weeks. The samples are a mix of synthetically
prepared samples, deionized water, and natural wet deposition samples. MACTEC
reported the eight parameters of interest for CASTNET for 104 USGS samples during
2005. MACTEC 2005 median values for all of the parameters analyzed were within
10 percent of the target values.
MACTEC generally participates in two studies by the National Water Research Institute
(NWRI) of Canada's Proficiency Testing QA Program each year in addition to
interlaboratory comparison studies for the USGS. During the 2005 studies, MACTEC's
laboratory achieved the "Ideal" rating (i.e., results were within two standard deviations of
the study's assigned value) for seven of the eight CASTNET parameters tested with one
sample result for sulfate listed between two and three standard deviations. The
performance of the laboratory was rated as being free of systematic bias for all eight
parameters. MACTEC was ranked number 5 out of 39 participating laboratories as of the
end of 2005.
CASTNET Annual Report - 2005
47
Chapter 5: Data Quality
-------
Conclusion
DQI results demonstrate that field and laboratory processes were adequately monitored through
QA/QC procedures and generally free of systematic bias during 2005. Accuracy data met the
established criteria for field and laboratory parameters with the exception of relative humidity
> 85 percent and solar radiation. However, since the criterion was exceeded by a value less than
its own magnitude, the associated continuous data collected are considered valid.
Precision data for sulfur constituents and ammonium are considered acceptable. Precision data
for nitrate analyses of collocated field samples have not met the established criterion due, most
likely, to the low concentrations generally measured and the unpredictable nature of the
gas-particle equilibrium of the nitrate species. Completeness criteria were met for all parameters
in 2005.
CASTNET Annual Report - 2005 48 Chapter 5: Data Quality
-------
References
Ames, R.B. and Malm, W.C. 2001. Comparison of Sulfate and Nitrate Particle Mass
Concentrations Measured by IMPROVE and the CDN. Atmospheric Environment.
Vol. 35(5)905-916.
Baumgardner Jr., R.E., Lavery, T.F., Rogers, C.M., and Isil, S.S. 2002. Estimates of the
Atmospheric Deposition of Sulfur and Nitrogen Species: Clean Air Status and Trends
Network, 1990-2000. Environmental Science and Technology. 36(12):2,614-2,629.
Finkelstein, P.L., Ellestad, T.G., Clarke, J.F., Meyers, T.P., Schwede, D.B., Hebert, E.G., and
Neal, J.A. 2000. Ozone and Sulfur Dioxide Dry Deposition to Forests: Observations and
Model Evaluation. J. Geophys. Res. 105:D12:15,365-15,377.
Harding ESE, Inc., now known as MACTEC Engineering and Consulting, Inc. (MACTEC).
2003. Clean Air Status and Trends Network (CASTNET) 2001 Quality Assurance Report.
Prepared for U.S. Environmental Protection Agency (EPA), Office of Air and Radiation,
Research Triangle Park, NC, Contract No. 68-D-98-112. Gainesville, FL.
MACTEC Engineering and Consulting, Inc. (MACTEC). 2006a. Clean Air Status and Trends
Network (CASTNET) Fourth Quarter 2005 Data Report. Prepared for U. S.
Environmental Protection Agency (EPA), Office of Air and Radiation, Clean Air Markets
Division, Washington, D.C. Contract No. 68-D-03-052. Gainesville, FL.
MACTEC Engineering and Consulting, Inc. (MACTEC). 2006b. Clean Air Status and Trends
Network (CASTNET) Quality Assurance Report: Fourth Quarter 2005 (October-
December) with 2005 Annual Summary. Prepared for U. S. Environmental Protection
Agency (EPA), Office of Air and Radiation, Clean Air Markets Division, Washington,
D.C. Contract No. 68-D-03-052. Gainesville, FL.
MACTEC Engineering and Consulting, Inc. (MACTEC). 2006c. Clean Air Status and Trends
Network (CASTNET) Third Quarter 2005 Data Report. Prepared for U. S. Environmental
Protection Agency (EPA), Office of Air and Radiation, Clean Air Markets Division,
Washington, D.C. Contract No. 68-D-03-052. Gainesville, FL.
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References (continued)
MACTEC Engineering and Consulting, Inc. (MACTEC). 2005a. Clean Air Status and Trends
Network (CASTNET) 2004 Annual Report. Prepared for U.S. Environmental Protection
Agency (EPA), Office of Air and Radiation, Clean Air Markets Division, Washington,
D.C. Contract No. 68-D-03-052. Gainesville, FL.
MACTEC Engineering and Consulting, Inc. (MACTEC). 2005b. Clean Air Status and Trends
Network (CASTNET) First Quarter 2005 Data Report. Prepared for U.S. Environmental
Protection Agency (EPA), Office of Air and Radiation, Clean Air Markets Division,
Washington, D.C. Contract No. 68-D-03-052. Gainesville, FL.
MACTEC Engineering and Consulting, Inc. (MACTEC). 2005c. Clean Air Status and Trends
Network (CASTNET) Second Quarter 2005 Data Report. Prepared for U. S.
Environmental Protection Agency (EPA), Office of Air and Radiation, Clean Air Markets
Division, Washington, D.C. Contract No. 68-D-03-052. Gainesville, FL.
MACTEC Engineering and Consulting, Inc. (MACTEC). 2004. Clean Air Status and Trends
Network (CASTNET) 2002 Quality Assurance Report. Prepared for U. S. Environmental
Protection Agency (EPA), Research Triangle Park, NC, Contract No. 68-D-03-052.
Gainesville, FL.
MACTEC Engineering and Consulting, Inc. (MACTEC). 2003a. Clean Air Status and Trends
Network (CASTNET) 2002 Annual Report. Prepared for U.S. Environmental Protection
Agency (EPA), Research Triangle Park, NC, Contract No. 68-D-03-052. Gainesville, FL.
MACTEC Engineering and Consulting, Inc. (MACTEC). 2003b. Clean Air Status and Trends
Network (CASTNET) Quality Assurance Project Plan (QAPP), Revision 2.1. Prepared
for U.S. Environmental Protection Agency (EPA), Research Triangle Park, NC, Contract
No. 68-D-98-112. Gainesville, FL.
Meyers, T. P., Finkelstein, P., Clarke, J., Ellestad, T.G., and Sims, P.F. 1998. A Multilayer
Model for Inferring Dry Deposition Using Standard Meteorological Measurements.
J. Geophys.Res. 103017:22,645-22,661.
Rogers, C.M., Howell, H.K., and Lavery, T.F. 2006a. The Surprising Decline in Rural Ozone
Concentrations in the Eastern United States. Electric Utility Environmental Conference.
Tucson, January 22-25.
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References (continued)
Rogers, C.M., Howell, H.K., and Lavery, T.F. 2006b. Uncertainties in CASTNETNO'3 and
HNO3Measurements. Paper # 06-C-858-AWMA. Air & Waste Management
Association (AWMA) 99th Annual Conference. New Orleans, June 20-23.
Schwede, D.B. 2006. A Comparison of the Deposition Velocity Estimates from the CASTNET
and CAPMoNNetworks. (Working paper). Research Triangle Park, NC.
U. S. Department of Energy (DOE). 1997. The Effects of Title IV of the Clean Air Act
Amendments of 1990 on Electric Utilities: An Update. Energy Information
Administration, Office of Coal, Nuclear, Electric and Alternate Fuels, U.S. Department
of Energy, Washington, DC. DOE/EIA-0582(97).
U.S. Environmental Protection Agency (EPA). 2006. NOX Budget Trading Program. 2005
Program Compliance and Environmental Results. EPA430-R-06-013. September 2006.
U.S. Environmental Protection Agency (EPA). 2005a. Acid Rain Program 2004 Progress
Report. EPA430-R-05-012. October 2005.
U.S. Environmental Protection Agency (EPA). 2005b. Evaluating Ozone Control Programs in
the Eastern United States. EPA454-K-05-001. August 2005.
U.S. Environmental Protection Agency (EPA). 2000. National Air Quality and Emissions
Trends Report, 1998. EPA-454-R-00-003. OAQPS, RTF, NC 27711.
U.S. Environmental Protection Agency (EPA). 1998. Quality Assurance Requirements for State
and Local Air Monitoring Stations (SLAMS). 40 CFR 50, Appendix L.
U.S. Environmental Protection Agency (EPA). 1997. National Ambient Air Quality Standards
for Ozone. 40 CFR 50.
CASTNET Annual Report - 2005 R-3 References
-------
Appendix A
Significant Events During 2005
-------
Significant Events During 2005
January
Ozone monitoring was discontinued at NFS-sponsored site EVE419, FL beginning January 1, 2005.
February
NFS-sponsored site SEK402, CA temporarily stopped sampling on February 24, 2005, when the site was dismantled
and relocated.
NFS-sponsored site OLY421, WA stopped all sampling at the end of February 2005.
April
NFS-sponsored site SEK402, CA was moved to another location in Sequoia National Park and resumed sampling on
April 7, 2005 with the new designation of SEK430.
June
Low-power ozone analyzers were installed at the solar-powered sites, LYE145, VT and CAT175, NY.
The first two Monitoring Instruments for Aerosols and Gases (MARGA) were installed at the BEL116, MD site.
July
An independent audit of the CASTNET field operations center in Gainesville, FL was conducted by Environmental
Forward Observer, LLC. CASTNET operations were judged as satisfactory.
Preliminary, screened data became available within 48 hours of collection on the CASTNET web page:
www.epa.gov/castnet
August
The annual "floor-to-ceiling audit of CASTNET property was conducted by EPA and the Defense Contract
Management Agency at MACTEC's Gainesville, FL location. The property management system was approved
by the audit.
Hurricane Katrina damaged a CASTNET site in Mississippi (CVL151).
September
Hurricane Rita damaged a CASTNET site in Texas (ALC188).
KVA428, AK stopped all sampling at the end of September 2005.
October
External audits of EPA- and NPS-sponsored CASTNET sites began.
Hurricane Wilma damaged CASTNET sites in Florida (EVE419 and IRL141).
December
After testing and evaluation, a new laboratory information management system (LIMS) was approved for use with
CASTNET data.
CASTNET Annual Report - 2005 Appendix A
-------
Appendix B
Locational and Operational Characteristics of CASTNET Sites
-------
Table B-l. Locational and Operational Characteristics of CASTNET Sites
Site ID
Site Name
Start date
Latitude (ฐN)
Longitude (ฐW)
Elevation (m)
O>
i . i f
1 =1 1 1
S ซ 2 ง ฃ
1> 11 2 a
II li 1 1
Terrain
Representative to
the MLM3
s*
0
^
=
0
o.
VI
Alabama
SND152
Sand Mountain
12/27/88
34.2894
85.9704
352
Agri.
Rolling
Y
EPA
Alaska
DEN417
Denali National Park
10/06/98
63.7258
148.9633
661
Forested
Complex
N
NPS
Arizona
CHA467
GRC474
PET427
Chiricahua National Monument
Grand Canyon National Park
Petrified Forest National Park
04/25/89
05/16/89
09/24/02
32.0092
36.0597
34.8225
109.3892
112.1822
109.8919
1570
2073
1723
0 Range
Forested
Desert
Complex
Complex
Flat
N
M
Y
NPS
NPS
NPS
Arkansas
CAD150
Caddo Valley
10/04/88
34.1792
93.0989
71
Forested
Rolling
N
EPA
California
CON186
DEV412
JOT403
LAV410
PIN414
SEK430
YOS404
Converse Station
Death Valley National Monument
Joshua Tree National Monument
Lassen Volcanic National Park
Pinnacles National Monument
Sequoia National Park
Yosemite National Park
06/17/03
02/21/95
02/16/95
07/25/95
05/16/95
04/07/05
09/25/95
34.1941
36.5092
34.0714
40.5403
36.4850
36.4894
37.7133
116.9130
116.8481
116.3906
121.5764
121.1556
118.8269
119.7061
1837
125
1244
1756
335
457
1605
Agri./Forested
Desert
Desert
Forested
Forested
Forested
Forested
Complex
Complex
Complex
Complex
Complex
Mountaintop
Complex
N
Y
M
M
M
N
N
EPA
NPS
NPS
NPS
NPS
NPS
NPS
CASTNET Annual Report- 2005
B-1
Appendix B
-------
Table B-l. Locational and Operational Characteristics of CASTNET Sites
Site ID
Site Name
Start date
Latitude (ฐN)
Longitude (ฐW)
Elevation (m)
0ป
i . g s
1 it ! 1
1 ซ2 & fc-
1> 11 2 a
II li 1 1
Terrain
Representative to
the MLM3
s*
0
^
=
0
o.
to
Colorado
GTH161
MEV405
ROM206
ROM406
Gothic
Mesa Verde National Park
Rocky Mountain National Park
Rocky Mountain National Park
05/16/89
01/10/95
07/03/01
12/20/94
38.9573
37.1983
40.2778
40.2778
106.9854
108.4903
105.5453
105.5453
2926
2165
2743
2743
0 Range
Forested
Forested
Forested
Complex
Complex
Complex
Complex
N
M
M
M
EPA
NPS
EPA
NPS
Connecticut
ABT147
Abington
12/28/93
41.8402
72.0111
209
0 Urban-Agri.
Rolling
M
EPA
Florida
EVE419
IRL141
SUM156
Everglades National Park
Indian River Lagoon
Sumatra
10/06/98
07/09/01
12/28/88
25.3911
30.1065
30.1065
80.6806
80.4554
84.9938
2
2
14
ซ4 Swamp
Beach
0 Forested
Flat
Flat
Flat
Y
Y
Y
NPS
SJRWMD
EPA
Georgia
GAS153
Georgia Station
06/28/88
33.1812
84.4100
270
Agri.
Rolling
M
EPA
Illinois
ALH157
BVL130
STK138
Alhambra
Bondville
Stockton
06/28/88
02/09/88
12/28/93
38.8690
40.0520
42.2872
89.6229
88.3725
89.9998
164
212
274
0 Agri.
Agri.
Agri.
Flat
Flat
Rolling
Y
Y
M
EPA
EPA
EPA
CASTNET Annual Report- 2005
B-2
Appendix B
-------
Table B-l. Locational and Operational Characteristics of CASTNET Sites
Site ID
Site Name
o>
"S
a
ฃ
S
ft!
tude (ฐN)
3
ฃ
o
o>
a
s
a
5
=
_o
03
ฃ
S
, *
' ^
5 N 0 "3
^ ^ '5 ง
i if 1 i
S-3* S S ซ g
II II 1 1
=
S
o>
H
resentative to
MLM3
8- a
K 5
0
a
0
c.
VI
Indiana
SAL133
VIN140
Salamonie Reservoir
Vincennes
06/28/88
08/04/87
40.8164
38.7406
85.6608
87.4844
250
134
Agri.
Agri.
Flat
Rolling
Y
M
EPA
EPA
Kansas
KNZ184
Konza Prairie
03/26/02
39.1021
96.6096
348
Prairie
Flat
Y
EPA
Kentucky
CDZ171
CKT136
MAC426
MCK131
Cadiz
Crockett
Mammoth Cave National Park
Mackville
10/01/93
08/24/93
07/24/02
07/31/90
36.7841
37.9211
37.1319
37.7044
87.8500
83.0658
86.1478
85.0483
189
455
243
353
Agri.
Agri.
Agri./Forested
Agri.
Rolling
Rolling
Rolling
Rolling
M
Y
M
M
EPA
EPA
NPS
EPA
Maine
ACA416
ASH135
HOW132
Acadia National Park
Ashland
Howland
12/01/98
12/20/88
11/24/92
44.3769
46.6039
45.2158
68.2608
68.4142
68.7085
158
235
69
Forested
Agri.
Forested
Complex
Flat
Rolling
M
Y
Y
NPS
EPA
EPA
Maryland
BEL116
BWR139
Beltsville
Blackwater National Wildlife Refuge
11/01/88
07/04/95
39.0283
38.4448
76.8175
76.1115
46
4
Urban-Agri.
Forest-Marsh
Flat
Coastal
N
M
EPA
EPA
CASTNET Annual Report- 2005
B-3
Appendix B
-------
Table B-l. Locational and Operational Characteristics of CASTNET Sites
Site ID
Site Name
ฃ
o. ^
1 1
S ซ
tt -J
Longitude (ฐW)
Elevation (m)
o>
sซ H^
1 ซ 2 1 ฃ>
1> 11 2 a
II li 1 1
Terrain
Representative to
the MLM3
0
a
0
o.
Michigan
ANA115
HOX148
UVL124
Ann Arbor
Hoxeyville
Unionville
06/28/88 42.4164
10/31/00 44.1809
06/28/88 43.6139
83.9019
85.7390
83.3597
267
298
201
0 Forested
Forested
0 Agri.
Flat
Flat
Flat
M
Y
Y
EPA
EPA
EPA
Minnesota
VOY413
Voyageurs National Park
06/13/96 48.4128
92.8292
429
Forested
Rolling
M
NPS
Mississippi
CVL151
Coffeeville
12/27/88 34.0028
89.7989
134
Forested
Rolling
M
EPA
Montana
GLR468
Glacier National Park
12/27/88 48.5103
113.9956
976
Forested
Complex
N
NPS
Nevada
GRB411
Great Basin National Park
05/16/95 39.0053
114.2158
2060
Forested
Complex
M
NPS
New Hampshire
WST109 Woodstock
12/27/88 43.9446
71.7008
258
Forested
Complex
N
EPA
New Jersey
WSP144
Washington's Crossing
12/27/88 40.3133
74.8726
61
Urban -Agri.
Rolling
M
EPA
CASTNET Annual Report- 2005
B-4
Appendix B
-------
Table B-l. Locational and Operational Characteristics of CASTNET Sites
Site ID
Site Name
o>
"03
ซ
S
to
<ฃ
a
a
a
B
*^
3
^
o
o
a
s
a
3
g
=
o
^
5
O)
*"" ^
1 ง -9
t^ ^j *P ^"
s ง o i ^
2 5 "3 & >?
^ ^ 0* O O 03
o^ a 01 M a
o. o 0*3 -5 S
% -S3 rs *a f? ซ"
CJ PL ^^ ^j &. PL
=
2
O)
H
3
o
-t^
S <>
^H
o. ^
4, ^
o
o
c.
New York
CAT175
CTH110
HWF187
Claryville
Connecticut Hill
Huntington Wildlife Forest
05/10/94
09/28/87
05/28/02
41.9423
42.4010
43.9732
74.5519
76.6535
74.2232
765
515
502
ซ5 Forested
0 Forested
Forested
Complex
Rolling
Complex
N
N
N
EPA
EPA
EPA
North Carolina
BFT142
CND125
COW137
PNF126
Beaufort
Candor
Coweeta
Cranberry
12/28/93
09/25/90
11/04/87
12/27/88
34.8843
35.2643
35.0605
36.1040
76.6213
79.8382
83.4302
82.0448
2
198
686
1250
0 Agri.
0 Forested
Forested
0 Forested
Flat
Rolling
Complex
Mountaintop
Y
M
N
M
EPA
EPA
EPA
EPA
North Dakota
THR422
Theodore Roosevelt National Park
10/06/98
46.8947
103.3778
850
Range
Rolling
Y
NPS
Ohio
DCP114
LYK123
OXF122
QAK172
Deer Creek State Park
Lykens
Oxford
Quaker City
09/28/88
01/10/89
08/18/87
09/28/93
39.6358
40.9169
39.5314
39.9431
83.2600
82.9981
84.7231
81.3378
267
303
284
372
0 Agri.
0 Agri.
Agri.
Agri.
Rolling
Flat
Rolling
Rolling
Y
M
N
M
EPA
EPA
EPA
EPA
Oklahoma
CHE185
Cherokee Nation
04/02/02
35.7507
94.6700
299
Agri.
Rolling
Y
EPA
Ontario
EGB181
Egbert, Ontario
12/27/94
44.2317
79.7840
251
6 ซ4 Agri.
Rolling
Y
EPA
CASTNET Annual Report- 2005
B-5
Appendix B
-------
Table B-l. Locational and Operational Characteristics of CASTNET Sites
Site ID
Site Name
o>
"S
a
ฃ
S
ft!
tude (ฐN)
3
ฃ
o
o>
a
s
a
5
=
_o
03
ฃ
S
, *
' ^
S N 0 "3
^ ^ '5 ง
i if 1 i
S-3* S B ซ |
II II 1 1
=
ฃ
o>
H
resentative to
MLM3
8- a
K 5
0
a
0
c.
VI
Pennsylvania
ARE128
KEF112
LRL117
MKG113
PSU106
Arendtsville
Kane Experimental Forest
Laurel Hill State Park
M.K. Goddard State Park
Penn. State University
06/28/88
01/03/89
12/15/87
01/12/88
01/06/87
39.9231
41.5981
39.9883
41.4250
40.7209
77.3078
78.7683
79.2522
80.1447
77.9316
269
622
615
384
376
0 Agri.
Forested
Forested
Forested
Agri.
Rolling
Rolling
Complex
Rolling
Rolling
M
Y
N
N
M
EPA
EPA
EPA
EPA
EPA
South Dakota
WNC429
Wind Cave National Park
11/18/03
43.5578
103.4839
1292
Prairie
Rolling
M
NPS
Tennessee
ESP127
GRS420
SPD111
Edgar Evins State Park
Great Smoky Mountains National Park
Speedwell
03/22/88
10/06/98
06/12/89
36.0389
35.6331
36.4698
85.7330
83.9422
83.8265
302
793
361
Forested
Forested
0 Agri.
Rolling
Complex
Rolling
N
N
Y
EPA
NPS
EPA
Texas
ALC188
BBE401
Alabama-Coushatta
Big Bend National Park
04/02/04
07/18/95
30.4210
29.3022
94.4045
103.1772
101
1052
Forested
Forested
Rolling
Complex
Y
M
EPA
NPS
Utah
CAN407
Canyonlands National Park
01/24/95
38.4586
109.8211
1809
Desert
Complex
M
NPS
Vermont
LYE145
Lye Brook
03/30/94
43.0510
73.0613
730
ซ5 0 Forested
Mountaintop
N
EPA
CASTNET Annual Report- 2005
B-6
Appendix B
-------
Table B-l. Locational and Operational Characteristics of CASTNET Sites
Site ID
Site Name
o>
"S
a
ฃ
S
ft!
tude (ฐN)
3
ฃ
o
o>
a
s
a
5
=
_o
03
ฃ
S
, *
' ^
S N 0 "3
^ ^ '5 ง
i if 1 i
S-3* S S ซ g
II II 1 1
=
S
o>
H
resentative to
MLM3
8- a
K 5
0
a
0
c.
VI
Virginia
PED108
SHN418
VPI120
Prince Edward
Shenandoah National Park
Morton Station
11/03/87
06/28/88
06/02/87
37.1653
38.5231
37.3300
78.3070
78.4347
80.5573
150
1073
920
0 Forested
Forested
Forested
Rolling
Mountaintop
Mountaintop
M
M
N
EPA
NPS
EPA
Washington
MOR409
NCS415
Mount Rainier National Park
North Cascades National Park
08/29/95
02/14/96
46.7583
48.5397
122.1244
121.4472
415
109
Forested
Forested
Complex
Complex
N
M
NPS
NPS
West Virginia
CDR119
PAR107
Cedar Creek State Park
Parsons
11/10/87
01/19/88
38.8794
39.0906
80.8478
79.6614
234
510
0 Forested
Forested
Complex
Complex
N
N
EPA
EPA
Wisconsin
PRK134
Perkinstown
09/27/88
45.2066
90.5972
472
0 Agri.
Rolling
M
EPA
Wyoming
CNT169
PND165
YEL408
Centennial
Pinedale
Yellowstone National Park
08/19/91
12/27/88
06/26/96
41.3722
42.9214
44.5597
106.2422
109.7900
110.4006
3178
2388
2400
Range
Range
Forested
Complex
Rolling
Rolling
M
M
N
EPA
EPA
NPS
CASTNET Annual Report- 2005
B-7
Appendix B
-------
The dry deposition filters are analyzed for the following constituents!
Teflonฎ = SO2, NO3, NH*4, Cl", K+, Na+, Mg2*, Ca2*
Nylon = SO2, NO3 (reported as HNO3)
Cellulose = SO2 (reported as SO2)
Meteorological sensors: temperature, delta temperature, relative humidity, solar radiation,
vector wind speed, scalar wind speed, wind direction, sigma theta, surface wetness, and
precipitation via tipping bucket rain gauge.
N = No; Y = Yes; M = Marginal; N/A = Not Applicable.
O3 not measured.
Solar-powered sites.
Composite filter pack, day filter pack, and night filter pack.
Indicates current monitoring.
0 Indicates discontinued monitoring.
Measurements were discontinued at the various sites because of several reasons
including:
(1) rotate limited number of instruments;
(2) redundant measurements (e.g., with IMPROVE and NADP/NTN); and
(3) funding limitations.
100 and 200 series = EPA - Operated Sites
400 series = NPS - Operated Sites
141 site = St. Johns River Water Management District (SJRWMD)
CASTNET'AnnualReport- 2005
B-8
Appendix B
-------
c
Acronyms and Abbreviations
-------
List of Acronyms and Abbreviations
ARP Acid Rain Program
ฐC degrees Celsius
Ca2+ paniculate calcium ion
CAAA Clean Air Act Amendments
CAPMoN Canadian Air and Precipitation Monitoring Network
CASTNET Clean Air Status and Trends Network
Cl" paniculate chloride ion
CO carbon monoxide
CVS continuing verification samples
DQI data quality indicator
EPA U.S. Environmental Protection Agency
HNO3 nitric acid
HQ EPA Headquarters
ICP-AES inductively coupled plasma-atomic emission spectrometry
IMPROVE Interagency Monitoring of Protected Visual Environments
ITEC Inter-Tribal Environmental Council
K+ paniculate potassium ion
K2CO3 potassium carbonate
kg/ha/yr kilograms per hectare per year
km kilometer
LAI leaf area index
LEVIS laboratory information management system
MACT maximum available control technology
MACTEC MACTEC Engineering and Consulting, Inc.
MARGA monitoring instrument for aerosols and gases
MARPD mean absolute relative percent difference
MDN Mercury Deposition Network
Mg2+ particulate magnesium ion
mg/L milligrams per liter
MLM Multi-Layer Model
mm millimeter
N nitrogen
Na+ particulate sodium ion
NAAQS National Ambient Air Quality Standards
NADP/NTN National Atmospheric Deposition Program/National Trends Network
CASTNET Annual Report - 2005
C-l
Appendix C
-------
List of Acronyms and Abbreviations (continued)
NBP
NDDN
NH3
NH4
NH4NO3
(NH4)2SO4
NIST
nm
NO3"
NOX
NOy
NFS
NWRI
O3
OTC
ppb
ppm
QA
QAPP
QC
RACT
S
SIP
SLAMS
SO2
SO24"
total NO3
USGS
Vd
VOC
W/m2
NOX Budget Trading Program
National Dry Deposition Network
ammonia
particulate ammonium
ammonium nitrate
ammonium sulfate
National Institute of Standards and Technology
nanometer
particulate nitrate
nitrogen oxides
total reactive oxides of nitrogen
National Park Service
National Water Research Institute
ozone
Ozone Transport Commission
parts per billion
parts per million
quality assurance
Quality Assurance Project Plan
quality control
reasonably available control technology
sulfur
State Implementation Plan
State and Local Monitoring Stations
sulfur dioxide
particulate sulfate
gaseous nitric acid (HNO3) + particulate nitrate (NO3)
micrograms per cubic meter
U.S. Geological Survey
deposition velocity
volatile organic compounds
watts per square meter
CASTNET'Annual Report - 2005
C-2
Appendix C
-------
For More Information
U.S. Environmental Protection Agency
Office of Air and Radiation
Clean Air Markets Division
Washington, D.C.
On the Web:
CASTNET Home Page:
Clean Air Markets
Division Home Page:
EPA Home Page:
www.epa.gov/castnet www.epa.gov/airmarkets
www.epa.gov
------- |