- View
- current air quality in Wisconsin.
- Find
- previous days air quality data reports.
- Check
- for current air quality advisories.
- Contact information
- For information on mercury monitoring in Wisconsin, contact:
- Mark Allen
Air monitoring chemist
608-266-8049
- Vid Grande
Air monitoring chemist
608-221-6374
Monitoring mercury in the air

Rural mercury monitoring station.
Mercury can enter Wisconsin's environment through atmospheric deposition, washed out of the air by rain or snow as "wet deposition" or deposited directly by particles as "dry deposition." Atmospheric deposition of mercury is a significant contributor to fish consumption advisories in our rivers and lakes.
There are three forms of mercury in the atmosphere: elemental mercury, oxidized mercury and particle-bound mercury. Both oxidized mercury and particle-bound mercury can be easily removed from the atmosphere while elemental mercury tends to stay in the atmosphere for a longer time (up to two years). Mercury is monitored by measuring its amount in collected rain or snow which is referred to as "deposition" monitoring, and measuring its concentration in air which is referred to as "ambient" monitoring.
Deposition monitoring
Since 1994, the DNR has monitored atmospheric deposition of mercury at a network of sites in Wisconsin. This work is conducted as part of the National Mercury Deposition Network [exit DNR]. The Wisconsin mercury deposition network currently consists of five monitoring stations - three operated by the department, one by the Forest County Potawatomi Community and one by the Lake Michigan Air Directors Consortium - designed to collect information on wet mercury deposition to the environment.
Ambient monitoring

Urban rooftop mercury monitor.
More than 99 percent of the mercury in the ambient air is elemental mercury. Less than one percent of mercury in the ambient air is oxidized mercury and particle-bound mercury. The DNR has conducted several short-term studies in urban and rural areas around the state to better understand ambient mercury concentrations in Wisconsin. Many studies are intentionally short-term since the mercury monitors are equipped with mobile trailers. The reports from these studies are technical in nature and include mainly the monitored ambient air concentrations of mercury, monitor site locations, and meteorology during the monitoring events. The reports make no determinations regarding any public health or wildlife effects associated with the sources that were monitored for mercury. Currently, long-term ambient mercury concentration information is monitored and collected in Milwaukee and Horicon areas by DNR and in Forest County by Forest County Potawatomi Community.
The ambient concentrations of mercury monitored by DNR in these studies do not exceed the air regulatory threshold levels for mercury. The ambient air quality standard for mercury is 300 nanograms per cubic meter (or 0.3 micrograms per cubic meter) on an annual average basis, as established in ch. NR 446, Wis. Adm. Code [PDF exit DNR]. The ambient background concentration for mercury is about 1-2 nanograms per cubic meter, based on data collected throughout the state.
Interactive map - Ambient mercury concentration studies
The following interactive map shows information about both active and inactive ambient air mercury monitors.
- To view information on a site, click on a pinpoint. You may need to zoom in on the map to differentiate between pinpoints, especially in the southeast area of the state.
- Orange pins represent inactive monitor sites; green pins represent active monitors.
- Each pinpoint contains information about the monitor and links to special studies, where available.
The information shown on these maps has been obtained from various sources, and are of varying age, reliability and resolution. These maps are not intended to be used for navigation, nor are these maps an authoritative source of information about legal land ownership or public access. Users of these maps should confirm the ownership of land through other means in order to avoid trespassing. No warranty, expressed or implied, is made regarding accuracy, applicability for a particular use, completeness or legality of the information depicted on this map.
Site: 16th St. Station
Site Status |
Inactive |
Type of Site |
Urban |
Mercury Specie Monitored |
Gaseous Elemental Mercury |
Study Time Period |
2003-2005; 2007; 2009; 2010 |
Report |
Email David.Grande@wisconsin.gov for reports |
-87.933333333
43.016667
orange
Site: FAA
Site Status |
Inactive |
Type of Site |
Urban |
Mercury Specie Monitored |
Gaseous Elemental Mercury |
Study Time Period |
2007 |
Report |
Email David.Grande@wisconsin.gov for reports |
-87.934167
42.955
orange
Site: National Guard Depot
Site Status |
Inactive |
Type of Site |
Urban |
Mercury Specie Monitored |
Gaseous Elemental Mercury |
Study Time Period |
2008 |
Report |
Email David.Grande@wisconsin.gov for reports |
-87.908722
43.096083
orange
Site: UW Milwaukee North
Site Status |
Inactive |
Type of Site |
Urban |
Mercury Specie Monitored |
Gaseous Elemental Mercury |
Study Time Period |
2004-2013 |
Report |
Email David.Grande@wisconsin.gov for reports |
-87.884444
43.075278
orange
Site: Bad River
Site Status |
Inactive |
Type of Site |
Remote |
Mercury Specie Monitored |
Gaseous Elemental Mercury; Gaseous Oxidized Mercury; Particle Bound Mercury |
Study Time Period |
2008; 2009; 2012; 2013 |
Report |
Email David.Grande@wisconsin.gov for reports |
-90.656153
46.602344
orange
Site: Chiwaukee Prairie
Site Status |
Inactive |
Type of Site |
Boundary |
Mercury Specie Monitored |
Gaseous Elemental Mercury; Gaseous Oxidized Mercury; Particle Bound Mercury |
Study Time Period |
2003; 2007; 2010 |
Report |
Report [PDF] |
-87.8111111
42.504722
orange
Site: Devils Lake
Site Status |
Inactive |
Type of Site |
Remote |
Mercury Specie Monitored |
Gaseous Elemental Mercury |
Study Time Period |
2003 |
Report |
Not available |
-89.680278
43.435556
orange
Site: Eau Claire
Site Status |
Inactive |
Type of Site |
Rural |
Mercury Specie Monitored |
Gaseous Elemental Mercury; Gaseous Oxidized Mercury; Particle Bound Mercury |
Study Time Period |
2011 |
Report |
Not available |
-91.413
44.761
orange
Site: La Crosse
Site Status |
Inactive |
Type of Site |
Source Specific |
Mercury Specie Monitored |
Gaseous Elemental Mercury |
Study Time Period |
2008 |
Report |
Email David.Grande@wisconsin.gov for reports |
-91.2333
43.8
orange
Site: Madison
Site Status |
Inactive |
Type of Site |
Source Specific |
Mercury Specie Monitored |
Gaseous Elemental Mercury |
Study Time Period |
2004; 2006-2008 |
Report |
Email David.Grande@wisconsin.gov for reports |
-89.35722
43.10083
orange
Site: Mayville
Site Status |
Inactive |
Type of Site |
Rural |
Mercury Specie Monitored |
Gaseous Elemental Mercury; Gaseous Oxidized Mercury; Particle Bound Mercury |
Study Time Period |
2004; 2009 |
Report |
Not available |
-88.527778
43.435
orange
Site: Port Edwards
Site Status |
Inactive |
Type of Site |
Source Specific |
Mercury Specie Monitored |
Gaseous Elemental Mercury |
Study Time Period |
2002; 2008-2011 |
Report |
|
-89.8787
44.399
orange
Site: Port Washington
Site Status |
Inactive |
Type of Site |
Source Specific |
Mercury Specie Monitored |
Gaseous Elemental Mercury |
Study Time Period |
2007 |
Report |
Email David.Grande@wisconsin.gov for reports |
-87.86666667
43.38333333
orange
Site: Union Grove
Site Status |
Inactive |
Type of Site |
Source Specific |
Mercury Specie Monitored |
Gaseous Elemental Mercury |
Study Time Period |
2002 |
Report |
Report [PDF] |
-88.076139
42.681472
orange
Site: UW Green Bay
Site Status |
Inactive |
Type of Site |
Rural |
Mercury Specie Monitored |
Gaseous Elemental Mercury |
Study Time Period |
2005 |
Report |
Not available |
-88.001111
44.523611
orange
Site: Woodland Dunes
Site Status |
Inactive |
Type of Site |
Rural |
Mercury Specie Monitored |
Gaseous Elemental Mercury; Gaseous Oxidized Mercury; Particle Bound Mercury |
Study Time Period |
2011 |
Report |
Not available |
-87.6161
44.138619
orange
Site: DNR SER HQ
Site Status |
Active |
Type of Site |
Urban |
Mercury Specie Monitored |
Gaseous Elemental Mercury |
Study Time Period |
8/22/2013 to Present |
Report |
Not Available |
-87.9125
43.06111
green
Site: Horicon
Site Status |
Active |
Type of Site |
Rural |
Mercury Specie Monitored |
Gaseous Elemental Mercury; Gaseous Oxidized Mercury; Particle Bound Mercury |
Study Time Period |
2010-Present |
Report |
Not available |
-88.621111
43.466111
green
Site: Potawatomi
Site Status |
Active |
Type of Site |
Remote |
Mercury Specie Monitored |
Gaseous Elemental Mercury |
Study Time Period |
2005-Present |
Report |
Email David.Grande@wisconsin.gov for reports |
-88.80859
45.56498
green
Site: Menomonee Valley
Site Status |
Active |
Type of Site |
Source Specific |
Mercury Specie Monitored |
Gaseous Elemental Mercury |
Study Time Period |
2003; 2004; 2005; 2007; 2010; 2014-Present |
Report |
Email David.Grande@wisconsin.gov for reports |
-87.93333333
43.01666667
green
Last revised: Tuesday November 29 2016