Pollution in Door County, Wisconsin relates to the degree of pollution in the air, water, and land in Door County, Wisconsin. Pollution is defined as the addition of any substance (solid, liquid, or gas) or any form of energy (such as heat, sound, or radioactivity) to the environment at a faster rate than it can be dispersed, diluted, decomposed, recycled, or stored in some harmless form.
Air
Most air pollution reaching the monitor at Newport State Park comes from outside the county. This map shows how the air travels to the pollution monitor in Newport State Park.Photo of the monitoring station on p. 128 of Because the monitor is near the shore, only the red lines (which show the lower air currents) meaningfully depict the path of ozone to the monitor. As shown on the map, these lower currents carry polluted air from major urban areas. But further inland, the air from higher up mixes more, so all color lines are significant when tracing the path of air pollution further inland. These higher currents (shown in green and blue) blow in from cleaner, mostly rural areas.
Nitrous oxide concentrations measured by airplane over county waters are not significantly different than those measured closer to the Chicago area.Nitrogen dry deposition to Lake Superior and Lake Michigan by Theresa A. Foley and Eric A. Betterton, Journal of Great Lakes Research 45, 2019, page 230 (page 8 of the pdf)
In 2020, a traffic counter near the Bay View Bridge recorded an average of 12,500 daily vehicles.WisDOT Traffic Counts, Wisconsin Department of Transportation, June 20, 1972 Pollution modeling predicts the presence of locally generated air pollution associated with vehicular traffic in the city of Sturgeon Bay.EPA's EJScreen Mapping Tool. Partially reconstituted from original after deletion by the Trump Administration in 2025
In 2022, the Environmental Protection Agency decided that the northern part of the county met its standard for ozone.Air Plan Approval; Wisconsin; Redesignation of the Revised Door County (Partial) Area to Attainment of the 2015 Ozone Standard, federalregister.gov, April 29, 2022
Wells, soils, and surface waters 19th century Water-borne diseases were historically significant in the county. The Belgian migration to the county largely ceased after word of the 1856 cholera epidemic in Door County reached Europe. From 1859 to 1880, more than ten percent of all recorded deaths in the county were caused by dysentery or diarrhea. Death from dysentery or diarrhea was more common in the summer due food and water contamination.Pioneer Cemeteries: Door County Wisconsin by John M. Kahlert, 1981, Baileys Harbor, Wisconsin: Meadow Lane Publishers, pages 3–5
Aquifers and springs background Aquifers
Door County has three types of aquifers. The newest is in a relatively shallow layer of sand and gravel, but tends not to provide enough water except in the southeastern part of the county. Further down are layers of dolomite bedrock that are recharged by water percolating from the layer of sand and gravel. Past the dolomite is a layer of shale that typically does not contain water, although potentially it is a source of oil. Past the shale is a layer of sandstone that is also host to a bedrock aquifer. Only a few wells tap this deepest and oldest aquifer.Geology and ground water in Door County, Wisconsin, with emphasis on contamination potential in the Silurian dolomite by M.G. Sherrill Section: "Hydrologic Characteristics of Rock Units," 1978, U.S. Geological Survey Water-Supply Paper 2047, pp. 11–12 Due to the tilt of the layers and erosion, there are areas of the county missing certain layers. A study of three city wells serving Sturgeon Bay found that water from the surface fell anywhere from 13 to 115 feet per day from the surface down to the dolomite aquifer. When the snow melted in the spring, the water coming up from one well changed 9 days later to reflect the character of the new meltwater.Field Verification of Capture Zones for Municipal Wells at Sturgeon Bay, Wisconsin by Kenneth R. Bradbury, Todd W. Rayne, and Maureen A. Muldoon, 2002, Open-File Report 2001-01, p. 3
Springs Groundwater burbles up from the shallow aquifer through the fractured bedrock, forming fracture springs. It also may seep more slowly through the ground, forming seepage springs. Detailed measurements were taken of one fracture and three seepage springs during a 2014–2017 survey.Wisconsin Springs: Data, see the four points located in the county on the electronic map, Susan Swanson, Wisconsin Geological and Natural History Survey Although the fracture spring had large variations in output, it still had a greater flow rate than the other 409 springs surveyed. It had one of the highest specific conductance measurements (995 μS/cm) among the springs studied, due to the minerals dissolved in the water.An inventory of springs in Wisconsin by Susan K. Swanson, Grace E. Graham, and David J. Hart, Wisconsin Geological and Natural History Survey Bulletin 113, 2019, p. 8 (p. 14 of the pdf) and p. 13 (p. 19 of the pdf) A study of wells, springs, and surface waters in six county wetlands took samples from September 2017 to June 2018. Enterococci were found in all of the surface waters and six of the eight springs, but not either of the two wells.Water-quality indicators of human impacts to the wetlands of Door County, Wisconsin Technical Report by David Hart, Sarah Gatzke, Michael Grimm, and Nicole Van Helden, Wisconsin Geological and Natural History Survey Technical Report 006 2020, January 2021, Table 5: Water-quality indicators in sampled wetland springs, surface waters, and groundwater on pages 28-29, (pages 35-36 of the pdf), discussion on page 30 (page 37 of the pdf) An earlier study comparing spring water and well water from five springs and 47 wells in Sevastopol found that spring water was more turbid than well water and more likely to be contaminated by coliform bacteria. Nitrates, chloride, and specific conductance were not significantly different between the springs and wells.Hydrogeology and Groundwater Monitoring of Fractured Dolomite in the Upper Door Priority Watershed, Door County, Wisconsin by Bradbury, K.R., Muldoon, M.A., Wisconsin Geological & Natural History Survey # WOFR1992-02, January 1992
Wells
The combination of shallow soils and fractured bedrock makes well water contamination more likely. At any given time, at least one-third of private wells may contain bacteria, and in situations with quickly flowing underground water, wells may test clean one day but contaminated the next. Some household wells turn brown every spring from nearby manure applications.Protect the Water You Drink pamphlet, by Debbie Beyer, UW-Extension Basin Education Initiative; Shelby Giguere, and the Door County Soil and Water Conservation Department. See also Groundwater Quality Changes in a Karst Aquifer of Northeastern Wisconsin, USA: Reduction of Brown Water Incidence and Bacterial Contamination Resulting from Implementation of Regional Task Force Recommendations by Kevin Erb, Eric Ronk, Vikram Koundinya, and John Luczaj, published in Resources 2015, 4, 655–672; doi:10.3390/resources4030655 Bacterial contamination of wells is more likely in the summer due to the larger human population. In wells that are contaminated, bacterial concentrations peak during the following rains in the late summer and early fall.Geology and Ground Water in Door County, Wisconsin, with Emphasis on Contamination Potential in the Silurian Dolomite by M. G. Sherrill, Geological Survey Water-Supply Paper 2047, United States Government Printing Office, Washington, D.C., prepared in cooperation with the Wisconsin Department of Natural Resources, 1978, page 36 (page 42 of the pdf)
Nearly all soil types in the county which have received a rating for their overall suitability for septic systems are considered to be "very limited" in their utility for septic systems. Out of 292 different combinations of soil associations and types in the county, 124 soil classifications are assigned a "very limited" rating, 4 are assigned a "somewhat limited" rating, and 164 have not been rated. The four which are "somewhat limited" are uncommon in the county.Web Soil Survey, "Area of Interest: Door County, Wisconsin; Soil Reports: Sewage Disposal, including minor soils" Natural Resources Conservation Service, United States Department of Agriculture, accessed September 29, 2021 Additionally, certain soil types are especially prone to leeching contaminants into the groundwater. Out of the 74 different total soil types present in the county, 44 types are known to be more susceptible to leaching contaminants into groundwater than typical soils. Out of the 44 more susceptible types, 22 are more susceptible to leaching when the water table is less than 12 inches from the surface, 10 are more susceptible to leaching when the soil is less than 20 inches above the bedrock, and 14 are regarded to be highly permeable soils. Some of the 44 more susceptible soil types have a combination of these characteristics.Wisconsin Soil Classifications for Nutrient Management Planning - 2019 by the SnapPlus team directed by Laura Ward Good, University of Wisconsin-Madison, 2019
In 1968, 44 people on Washington Island were sickened with hepatitis, a food and water-borne disease, and one girl died.Environmental Geologic Aspects of Planning, Constructing, and Regulating Recreational Land Developments by Stephen M. Born and David A. Stephenson, published as an Inland Lake Renewal and Shoreland Management Demonstration Project Report funded by the Upper Great Lakes Regional Commission, January 1974, page 33
The porous and fractured dolomite bedrock was implicated as a factor in a June 2007 epidemic when 239 patrons and 18 employees2007 Annual Report: Door County Public Health Department by Rhonda Kolberg, page 57 (page 58 of the pdf) of the newly opened Log Den restaurant were sickened by a norovirus. Six were hospitalized. The virus was found to have traveled from a septic field 188 m (617 ft) away to the restaurant's well, contaminating their water.Norovirus outbreak caused by a new septic system in a dolomite aquifer, by Mark A. Borchardt, Kenneth R. Bradbury, Elizabeth C. Alexander, Rhonda J Kolberg, S Catherine. P Alexander, John R. Archer, Laurel A Braatz, Brian M. Forest, Jeffrey Alan Green, Susan K. Spencer, published in Ground Water. 2011 Jan-Feb;49(1):85–97. doi: 10.1111/j.1745-6584.2010.00686.x. From September to December 2007 a study was conducted in which dyes were placed into the septic system. The dyes traveled through the groundwater at about 2 miles per year, and researchers concluded that viral contaminants could travel "many miles in their life times."Plum Bottom Closed Depression Groundwater Trace Final Report by E. Calvin Alexander, Jr., Jeffrey A. Green, and Scott C. Alexander 25 January 2008 For transient non-community public wells such as the one supplying the restaurant, state only regulated for contaminants within a 200-foot radius unless flow studies had previously been done. Modeling research supporting this decision predicted that pathogens would be unlikely to travel more than 155 feet per year.Jay Y. Hodgson. (2002). Source Water Assessment Implementation Obstacles: Are Transient Noncommunity Wells Not As Important? Water Resources IMPACT, 4(2), page 18
In September 2014, 16 people fell ill from drinking wellwater after rainwater washed manure went down a sinkhole in Jacksonport.Residents seek answers after Jacksonport manure spill, December 4, 2014, Door County Advocate
Short-term rentals are thought to contaminate the groundwater whenever more people stay in a house or cottage than the septic system was designed to handle.Short-term-rental Eyes on Sevastopol by Debra Fitzgerald, Peninsula Pulse, May 7, 2021
Soils and groundwater