- Related links
Platform with monitoring equipment at the Horicon monitoring site.
Air quality monitoring
Wisconsin's ambient air quality monitoring network provides timely access to air quality information, supports planning for air quality improvements and ensures program accountability. The network focuses on EPA's list of the most serious health-related air pollutants: ozone, particle pollution, sulfur dioxide, nitrogen dioxide and carbon monoxide. Using continuous monitoring data, DNR quickly informs the public when air pollution reaches unhealthy levels. Based on these notices, people may adjust their daily activities to minimize adverse health effects.
To see how Wisconsin's air quality compares with the rest of the nation, check out U.S. EPA AIRNOW.
The DNR periodically reviews its air monitoring network and provides an opportunity for public input on monitoring locations and pollutants to be monitored.
- Final 2017 Monitoring Network Plan - Revised Oct. 2016
- U.S. EPA approval of the 2017 network plan - Oct. 31, 2016
- June 2, 2016, public informational meeting re: proposed 2017 monitoring network plan
- Proposed 2017 Monitoring Network Plan
- Final 2016 Monitoring Network Plan - Dec. 2015
Five-year network assessment
Every five years, states are required to perform a more extensive assessment of its network to ensure the best possible use of available resources to meet policy, regulatory and technical needs. Wisconsin DNR staff cooperated with representatives from the States of Illinois, Indiana, Michigan, Minnesota and Ohio, local agencies, as well as U.S. EPA and the Lake Michigan Air Directors Consortium to develop a 5-Year Network Assessment that provides a broader, more comprehensive evaluation of the monitoring within the region. The regional assessment has been updated to include design value rank, population served, area served, correlation between sites, and site removal bias. The results of these analyses are offered in both graphical and tabular formats. Further, a review of sites eligible for shutdown and an analysis of revenue and operation costs are provided. This assessment is intended to provide information on whether monitoring networks still meet the monitoring objectives, whether new sites are needed, whether existing sites are no longer needed, and whether new technologies are appropriate.
Based on federal monitoring requirements and data analyses, the document provides detailed conclusions broadly consisting of key findings, new priorities and important issues including the recurring concern of sufficient funding. Although the recommendations are non-binding, Wisconsin's air monitoring program uses this as a tool for prioritizing monitoring operations and budgeting in upcoming annual network assessments.
Ambient air monitoring network configuration and siting criteria
The EPA sets minimum network requirements in federal code. Monitoring beyond federal minimum requirements is conducted to provide better documentation of air quality in a particular community. For example, adequately defining the ambient ozone problem in any given area, especially the larger urban areas, generally requires additional monitors. Federal grants fund the majority of the DNR air monitoring network.
Operating within funding constraints, Wisconsin's air program continues to:
- consolidate monitoring sites;
- increase automation;
- eliminate redundancies;
- upgrade to higher-sensitivity monitors for reactive nitrogen and carbon monoxide; and
- enhance the air toxics monitoring network.
We continue to work toward expanding network coverage in Wisconsin through partnerships with industry, Native American tribes and other entities.
Special monitoring studies
Here you will find special air monitoring studies of emissions from agricultural operations, urban air toxics, polychlorinated biphenyls (PCBs) and other hazardous air pollutants.
Livestock fenceline ammonia and hydrogen sulfide monitoring study
This 2010 study investigated concentrations of ammonia and hydrogen sulfide around several Animal Feeding Operations (AFOs) in south central Wisconsin, including a large poultry operation, three dairies and a small confined swine operation.
- Final Report
- Appendix A - Poultry
- Appendix B - Dairy 4
- Appendix C - Dairy 2
- Appendix D - Dairy Setback
- Appendix E - Swine
Dairy and livestock air emission/odor project
This 2009 project was a joint effort between the Wisconsin Department of Agriculture Trade and Consumer Protection (DATCP) and DNR, and was partially funded through a USDA Conservation Innovation Grant (CIG). The project was a three year, $1.6 million demonstration of current technologies that focused on control of odor and concentrations of ammonia and hydrogen sulfide from agricultural operations.
Polychlorinated biphenyls are a legacy pollutant, which means they are most often found in contaminated sediment. However, PCBs are commonly found in ambient air as well.
- Fox River Remediation Air Monitoring Report: Ambient PCBs During SMU 56/57, Demonstration Project, August-November 1999 (AM-310)
- Spatial Distribution of Airborne PCBs in Milwaukee (AM-342)
Urban air toxics
The Urban Air Toxics program monitors a variety of heavy metals and both volatile and semi-volatile organic compounds on an on-going basis.
- Green Bay Urban Air Toxics Monitoring Studies, 1991-96
- Wisconsin Urban Air Toxics Monitoring Studies, 1996-98
Volatile organic compounds (VOCs)
Vehicle exhaust is a major source of volatile organic compounds (VOCs), even in areas with a known major source.
- Evaluation of Passive Sampling Techniques for Monitoring Roadway and Neighborhood Exposures to Benzene and Other Mobile Source VOCs (AM-384) (2007)
- Benzene Monitoring in Waupaca - Final Report (2008)
Zip file that includes: studies on ambient atrazine; air quality forecasting; landfill monitoring at Portage, WI, and near Sarona, WI; June 20-25, 2002, ozone episode; urban leaf burning monitoring in Monona, WI; and ambient monitoring in Eagle River, WI.
U.S. Environmental Protection Agency near-road monitor program
Motor vehicle exhaust in the urban environment affects ambient concentrations of various pollutants and public health. To better understand this impact, the U.S. Environmental Protection Agency (EPA) developed a phased implementation approach to near-road monitoring by prioritizing near-road deployment to the largest metropolitan areas, including Milwaukee. This phased approach required state and local air monitoring agencies to install near-road nitrogen dioxide (NO2) monitoring stations at locations where peak hourly NO2 concentrations are expected to occur.
Near-road monitor establishment
Near-road monitor near I-94 and College Avenue in Milwaukee.
The EPA required Wisconsin to install and operate one near-road monitoring station within the Milwaukee Core Based Statistical Area. From May 2012 to January 2014, DNR considered and tested several locations. Based on traffic volumes and preliminary elevated precursor gas concentrations, the current College Avenue location was selected. Department staff prepared the site and installed an on-site shelter for housing the air monitoring instrumentation.
Wisconsin began operating its near-road monitoring station on January 1, 2014. The station is located in Milwaukee County in close proximity to Interstate Highway 94 near the College Avenue exit. The monitoring station measures NO2 and carbon monoxide (CO) as required by EPA. Supplementary measurements of wind direction, wind speed and temperature are also collected to support analysis of the pollution measurements. All measurement equipment is connected to an on-site data logger where monitoring data is collected, stored and transmitted at least once daily to DNR's central data system. Consistent with other monitoring stations, data from the site is certified by DNR and submitted to EPA quarterly.
The EPA sets National Ambient Air Quality Standards (NAAQS) that states must attain for certain pollutants known as criteria pollutants. The near-road site currently measures two criteria pollutants and tests for numerous additional non-criteria pollutants utilizing Special Purpose Monitors.
A view of I-94 from the roof of the near-road monitoring station, where air monitoring inlets collect ambient air samples.
Monitoring equipment inside the near-road monitoring station.
Nitrogen dioxide is one of a group of highly reactive gasses known as "oxides of nitrogen" (NOx). The EPA's NAAQS uses NO2 as the indicator for the larger group of nitrogen oxides. Nitrogen dioxide forms quickly from emissions from cars, trucks and buses, power plants, and off-road equipment. In addition to contributing to the formation of ground-level ozone and fine particle pollution, NO2 is linked with a number of adverse effects on the respiratory system.
Carbon monoxide is a colorless, odorless gas emitted from combustion processes. Nationally, and particularly in urban areas, the majority of CO emissions to ambient air comes from mobile sources. Carbon monoxide can cause harmful health effects by reducing oxygen delivery to the body's organs and tissues like the heart and the brain. At extremely high levels, CO can cause death.
Special Purpose Monitors (SPM)
The DNR also operates several Special Purpose Monitors (SPMs) at the near-road site. These SPMs measure black carbon (BC) , a by-product of combustion that may include diesel emissions, as well as ultraviolet-absorbing particulate matter (UVPM), ultrafine particulate matter (<PM1) and benzene and toluene concentrations. This data will be used by EPA to better assess the health impacts of the near-road environment.
Wisconsin near-road trends report
Air quality measurements to date at the near-road monitoring site indicate pollutant concentrations peak with morning and evening drive times.
Nitrogen dioxide and carbon monoxide trends - Wisconsin near-road
Since its establishment in 2014, the near-road monitoring site has not measured an exceedance of the NO or CO NAAQS. The maximum reported individual one-hour NO2 reading so far has been 60 parts per billion (ppb), well below EPA's national one-hour standard of 100 ppb.
Nitrogen dioxide and carbon monoxide - national trends
National data indicates that Wisconsin and other states with a near-road air monitoring station are below the NAAQS 1-hr standards for NO2 and CO. This means that across the nation near-road sites are reporting NO2 and CO values well below the NAAQS.
Sometimes naturally-occurring events such as forest fires or wind storms can result in a violation of a National Ambient Air Quality Standard. In these instances, emissions from anthropogenic sources such as cars, factories and power plants were not responsible for violation of the Air Quality Standard. The EPA then allows states to request to have the naturally-occurring event designated as an "exceptional event." If EPA approves the state's request, all high pollutant values associated with the event can be flagged by DNR and excluded from comparison with National Ambient Air Quality Standards.
On November 20, 2015, EPA proposed a revised Exceptional Events rule with new draft guidance.
The DNR conducted a thorough review of the new rule and guidance, and submitted comments to EPA on February 3, 2016. The comments are broken into four broad areas of concern:
- administrative burden on air agencies;
- consistency across EPA regions;
- EPA responsibilities and accountability; and
- insufficient and unclear requirements and definitions.
Pagami Creek fire event - September 2011
- DNR Addendum to Response to EPA Comments on an Exceptional Event Request (7/3/14)
- DNR Addendum to Response to EPA Comments on an Exceptional Event Request (10/12)
- DNR Response to EPA Comments on Exceptional Event Request (10/8/12)
- Final Report: Documentation in Support of a Request to Designate the PM2.5 Episode of Eastern Wisconsin September 13 - 14, 2011 as an Exceptional Event (10/5/12)
- EPA Initial Response to Exceptional Event Request (7/25/12)
The DNR provides support and technical expertise to facilities that are required to do ambient air monitoring as part of a permit condition. Air monitoring staff review ambient air monitoring plans (AAMPs) and monthly data reports. They also conduct data consolidation/archival audits as well as annual instrument audits.
A large portion of the current industrial monitoring network in Wisconsin is related to industrial sand mines. Additional information can be found on our sand mining web pages.
Guidance documents and tools
The links below include information and guidance regarding DNR audit procedures for high volume samplers. Additionally, industrial operators will find information about operation of samplers (calibrations, verifications and routine operations). Forms are provided to use as-is, or to modify and use to suit an industrial operator's needs.
- High Volume PM10/TSP Calibration/Verification/Audit Guidance - includes links to guidance on high-volume samplers (12/15/2014), high-volume audit form 121514 - blank, and high-volume audit form - examples
- Hi-vol MFC calibration - blank
- Hi-vol MFC calibration - examples