Interagency Monitoring of Protected Visual Environments (IMPROVE)
Clean Air Status and Trends Network (CASTNET)
National Atmospheric Deposition Network (NADP)
National Air Toxics Assessment (NATA)
Only the SLAMS, NCore, PAMS, CSN and NATTS pertain to the information covered in the Handbook. The other networks described are for the benefit of the reader.
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State or Local Air Monitoring Stations (SLAMS) Network
Background The SLAMS make up the ambient air quality monitoring sites that are operated by State or local agencies for the primary purpose of comparison to the National Ambient Air Quality Standards (NAAQS), but may serve other purposes such as:
provide air pollution data to the general public in a timely manner;
support compliance with air quality standards and emissions strategy development; and
support air pollution research studies.
The SLAMS network includes stations classified as NCore, PAMS, and Speciation, and formerly categorized as NAMS, and does not include Special Purpose Monitors (SPM) and other monitors used for non-regulatory or industrial monitoring purposes.
In order to support the objectives, the monitoring networks are designed with a variety of monitoring sites that generally fall into the following categories which are used to determine:
the highest concentrations expected to occur in the area covered by the network;
typical concentrations in areas of high population density;
the impact on ambient pollution levels of significant sources or source categories;
the general background concentration levels;
the extent of regional pollutant transport among populated areas, and in support of secondary standards; and
air pollution impacts on visibility, vegetation damage, or other welfare- based impacts.
The monitoring aspects of the SLAMS program are found in the Code of Federal Regulations, Title 40, Parts 50, 53 and 58.
SLAMS must use approved Federal reference method (FRM), Federal equivalent method (FEM), or Approved Regional Method (ARM) monitors for ambient pollutant levels being compared to the NAAQS.
Background The NCore multi-pollutant stations are part of an overall strategy to integrate multiple monitoring networks and measurements. As required by the revised monitoring regulations promulgated in 2006, monitors at NCore multi-pollutant sites will measure particles (PM2.5, speciated PM2.5, PM10-2.5, speciated PM10-2.5), O3, SO2, CO, nitrogen oxides (NO/NO2/NOy), and basic meteorology. Monitors for all the gases except for O3 will be more sensitive than standard FRM/FEM monitors, so they could accurately report concentrations that are well below the respective NAAQS but that can be important in the formation of O3 and PM.
The objective is to locate sites in broadly representative urban (about 55 sites) and rural (about 20 sites) locations throughout the country to help characterize regional and urban patterns of air pollution. The NCore network must be fully operational by 2011. Many stations will be operational before that deadline.
In many cases, states will collocate these new stations with STN sites measuring speciated PM2.5 components, PAMS sites already measuring O3 precursors, and/or NATTS sites measuring air toxics. By combining these monitoring programs at a single location, EPA and its partners will maximize the multi-pollutant information available. This greatly enhances the foundation for future health studies, NAAQS revisions, validation of air quality models, assessment of emission reduction programs, and studies of ecosystem impacts of air pollution.
Background Section 182(c)(1) of the 1990 Clean Air Act Amendments (CAAA) require the Administrator to promulgate rules for the enhanced monitoring of ozone, oxides of nitrogen (NOx), and volatile organic compounds (VOC) to obtain more comprehensive and representative data on ozone air pollution. Immediately following the promulgation of such rules, the affected states were to commence such actions as were necessary to adopt and implement a program to improve ambient monitoring activities and the monitoring of emissions of NOx and VOC. Each State Implementation Plan (SIP) for the affected areas must contain measures to implement the ambient monitoring of such air pollutants. The subsequent revisions to Title 40, Code of Federal Regulations, Part 58 (40 CFR 58) required states to establish Photochemical Assessment Monitoring Stations (PAMS) as part of their SIP monitoring networks in ozone nonattainment areas classified as serious, severe, or extreme.
The chief objective of the enhanced ozone monitoring revisions is to provide an air quality database that will assist air pollution control agencies in evaluating, tracking the progress of, and, if necessary, refining control strategies for attaining the ozone NAAQS. Ambient concentrations of ozone and ozone precursors will be used to make attainment/nonattainment decisions, aid in tracking VOC and NOx emission inventory reductions, better characterize the nature and extent of the ozone problem, and prepare air quality trends. In addition, data from the PAMS will provide an improved database for evaluating photochemical model performance, especially for future control strategy mid-course corrections as part of the continuing air quality management process. The data will be particularly useful to states in ensuring the implementation of the most cost-effective regulatory controls.
Background As part of the effort to monitor particulate matter, EPA monitors and gathers data on the chemical makeup of these particles. EPA established a chemical speciation network consisting of approximately 300 monitoring sites. These sites are placed at various NAMS and SLAMS across the Nation. Fifty-four of these chemical speciation sites, the Speciation Trends Network (STN), will be used to determine, over a period of several years, trends in concentration levels of selected ions, metals, carbon species, and organic compounds in PM2.5. Further breakdown on the location or placement of the trends sites requires that approximately 20 of the monitoring sites be placed at existing Photochemical Assessment Monitoring Stations (PAMS). The placement of the remaining trends sites will be coordinated by EPA, the Regional offices, and the monitoring agencies. Locations will be primarily in or near larger Metropolitan Statistical Areas (MSAs). The remaining chemical speciation sites will be used to enhance the required trends network and to provide information for developing effective State Implementation Plans (SIPs).
The STN is a component of the National PM2.5 Monitoring Network. Although the STN is intended to complement the activities of the much larger gravimetric PM2.5 measurements network component (whose goal is to establish if NAAQS are being attained), STN data will not be used for attainment or nonattainment decisions. The programmatic objectives of the STN network are:
air quality trends analysis and tracking the progress of control programs;
compare the chemical speciation data set to the data collected from the IMPROVE network; and
development of emission control strategies.
Stakeholders in the STN will be those at EPA seeking to determine concentration trends of PM2.5 chemical species over a period of 3 or more years and decision-makers at tribal, state and local levels who will use the data as input to models and for development of emission control strategies and determination of their long-term effectiveness. Other users will be public health officials and epidemiological researchers. However, expectations for data sets from the STN must be put in context.
ions, metals, carbon species, and organic compounds
Network Design References
Quality System References
Data Management References
National Toxics Trends Network (NATTS)
Background There are currently 188 hazardous air pollutants (HAPs), or Air Toxics (AT), regulated under the
Clean Air Act (CAA) that have been associated with a wide variety of adverse health effects,
including cancer, neurological, reproductive and developmental effects, as well as eco-system effects. In 1999. EPA finalized the Urban Air Toxics Strategy (UATS). The UATS states that emissions data are needed to quantify the sources of air toxics impacts and aid in the development of control strategies, while ambient monitoring data are needed to understand the behavior of air toxics in the atmosphere after they are emitted. Part of this strategy included the development of the National Air Toxics Trends Stations (NATTS). Specifically, it is anticipated that the NATTS data will be used for:
tracking trends in ambient levels to facilitate tracking progress toward emission and risk reduction goals, which is the major objective of this program;
directly evaluating public exposure & environmental impacts in the vicinity of monitors;
Interagency Monitoring of Protected Visual Environments (IMPROVE)
Background The Interagency Monitoring of Protected Visual Environments (IMPROVE) program is a cooperative measurement effort governed by a steering committee composed of representatives from federal and regional-state organizations. The IMPROVE monitoring program was established in 1985 to aid the creation of Federal and State Implementation Plans for the protection of visibility in Class I areas (156 national parks and wilderness areas) as stipulated in the 1977 amendments to the Clean Air Act.
The objectives of IMPROVE are:
to establish current visibility and aerosol conditions in mandatory class I areas;
to identify chemical species and emission sources responsible for existing man-made visibility impairment;
to document long-term trends for assessing progress towards the national visibility goal;
and with the enactment of the Regional Haze Rule, to provided regional haze monitoring representing all visibility-protected federal class I areas where practical.
IMPROVE has also been a key participant in visibility-related research, including the advancement of monitoring instrumentation, analysis techniques, visibility modeling, policy formulation and source attribution field studies. In addition to 110 IMPROVE sites at visibility-protected areas, IMPROVE Protocol sites are operated identically at locations to serve the needs of state, tribes and federal agencies.
EPA, in coordination with the National Oceanic and Atmospheric Administration (NOAA), established CASTNET with the goal of assessing the impact and effectiveness of Title IV of the 1990 Clean Air Act Amendments (CAAA) through a large-scale monitoring network. CASTNET was designed to compile a sound scientific data base through routine environmental monitoring for the evaluation of air-quality management and control strategies. The network provides estimates of dry deposition using an inferential modeling method that relies on atmospheric concentrations, meteorological variables and other input as recorded at each site. The data record extends back to 1987, when routine field measurements first began under National Dry Deposition Network (NDDN). CASTNET currently consists of over 80 sites across the eastern and western United States and is cooperatively operated and funded with the National Park Service. CASTNET complements the National Atmospheric Deposition Program/National Trends Network (NADP/NTN) which provides information on precipitation chemistry and wet deposition values.
The main objective of the network is to:
track the effectiveness of national and regional scale emission control programs;
report high quality, publicly available data on the temporal and geographic patterns of air quality and atmospheric deposition trends; and
provide the necessary information for understanding the environmental effects in sensitive terrestrial and aquatic receptor areas associated with atmospheric loadings of pollutants.
-- weekly average atmospheric concentrations of sulfate, nitrate, ammonium, sulfur dioxide, nitric acid and base cations --hourly concentrations of ambient ozone levels --hourly averages of meteorological variables required for calculating dry deposition rates
Background 1The National Atmospheric Deposition Program (NADP) provides quality-assured data and information in support of research on the exposure of managed and natural ecosystems and cultural resources to acidic compounds, nutrients, base cations, and mercury in precipitation. 1NADP data serve science and education and support informed decisions on air quality issues related to precipitation chemistry.
1The NADP operates three precipitation chemistry networks: the 250-station National Trends Network (NTN), 7-station Atmospheric Integrated Research Monitoring Network (AIRMoN), and 100-station Mercury Deposition Network (MDN). The NTN provides the only long-term nationwide record of the wet deposition of acids, nutrients, and base cations. NTN stations collect one-week precipitation samples in 48 states, Puerto Rico, the Virgin Islands, and Quebec Province, Canada. Complementing the NTN is the 7-station AIRMoN. The daily precipitation samples collected at AIRMoN stations support continued research of atmospheric transport and removal of air pollutants and the development of computer simulations of these processes. The 100-station MDN offers the only regional measurements of mercury in North American precipitation. MDN data are used to quantify mercury deposition to water bodies that have fish and wildlife consumption advisories due to this toxic chemical. Presently, 48 states and 10 Canadian provinces list advisories warning people to limit fish consumption due to high mercury levels. Advisories also were issued for Atlantic Coastal waters from Maine to Rhode Island and North Carolina to Florida, for the entire U.S. Gulf Coast, and for Hawaii.
In addition to 1these long-term monitoring networks, the NADP is responsive to emerging issues requiring new or expanded measurements. Its measurement system is efficient, its data meet pre-defined data quality objectives, and its reports and products are designed to meet user needs.
Background NATA is a national-scale assessment of 33 air pollutants (a subset of 32 air toxics on the Clean Air Act's list of 188, plus diesel particulate matter). The assessment considers the year 1996 (an update to 1999 is in preparation), including:
compilation of a national emissions inventory of air toxics emissions from outdoor sources;
estimates of ambient concentrations across the contiguous United States;
estimates of population exposures; and
characterizations of potential public health risks including both cancer and non-cancer effects.
NATA identifies those air toxics which are of greatest potential concern, in terms of contribution to population risk. This information is relevant and useful in assessing risk for tribal programs.