1. We thank the Office of Research and Sponsored Programs for supporting this research, and Learning & Technology Services for printing this poster.
Nitrate Levels in Shallow and Deep Groundwater Wells
in Barron County, WI
Jesse Goss and Tristin Christopher | BSEPH Candidates, University of Wisconsin-Eau Claire Environmental Public Health
ENPH 441 Water and Wastewater
The Chetek area in Wisconsin has a history of unusually high
nitrate levels in transient non-community well systems. Nitrate
comes from nitrogen, a plant nutrient supplied by inorganic
fertilizer and animal manure. It also can come from
nonagricultural sources including lawn fertilizers, septic systems,
and domestic animals. Nitrate can easily migrate to ground water,
and eventually into well water (Nutrients National Synthesis
Project, 2015). This is a problem because nitrates can cause
health effects in immunocompromised individuals. Health effects
include shortness of breath and blue baby syndrome; when
consumed in too high of a concentration. The maximum
contaminate level (MCL) for nitrate is 10 mg/L or 10 ppm. This
level of protection is to prevent potential health problems (EPA,
2015). We will be exploring the nitrate levels at varying well
depths around Chetek, WI. If there is a difference in nitrate levels
between deep and shallow wells, that could help well drillers
decide how deep to drill wells that serve the public in the area.
INTRODUCTION RESULTS
METHODS
• Existing Wisconsin DNR databases were used to compile data
and analyze differences in nitrate levels by well depth.
• Well depth and nitrate data from 39 wells were collected and
compared.
• We defined a shallow well to be <100 ft. and a deep well > 100
ft.
• Student T-test using 2013 Microsoft Excel was used for data
analysis
DISCUSSION
REFERENCES
OBJECTIVES
• Explore nitrate levels at varying well depths
• Determine if there is a difference in nitrate concentrations
between shallow and deep wells
ACKNOWLEDGMENTS
• Center of Disease and Control. July 1, 2015. Nitrate and Drinking Water from Private Wells. Retrieved on
November 20th, 2015 from http://www.cdc.gov/healthywater/drinking/private/wells/disease/nitrate.html
• Department of Health. Nitrate Treatment Alternative for Small Water Systems. June 2005. Retrieved on
November 28th, 2015 from http://www.doh.wa.gov/portals/1/Documents/pubs/331-309.pdf
• Environmental Protection Agency. February 05, 2014. Basic Information about Nitrate in Drinking Water.
Retrieved on November 20th, 2015 from http://water.epa.gov/drink/contaminants/basicinformation/nitrate.cfm
• Nitrates and Drinking Water. (n.d.). Retrieved December 2, 2015, from http://www.bfhd.wa.gov/info/nitrate-
nitrite.php
• Nolan, B., Ruddy, B., Hitt, K., & Helsel, D. 2015, September 15. Nutrients National Synthesis Project. Retrieved
November 30, 2015, from http://water.usgs.gov/nawqa/nutrients/pubs/wcp_v39_no12/#FIG1
• WI DNR. DNR drinking water system/public water systems. Retrieved on November 21st, 2015 from
http://prodoasext.dnr.wi.gov/inter1/pws2$.startup
• WI DNR. Well Construction Reports. Retrieved on November 21st, 2015 from
http://prodoasext.dnr.wi.gov/inter1/watr$.startup
• Wisconsin Well Drillers Association. Retrieved on November 20th, 2015 from
http://www.wisconsinwaterwell.com/for-homeowners/faqs/
• Stacy Steinke – Water Supply Specialist with the
Wisconsin Department of Natural Resources
• Learning and Technology Services: University of
Wisconsin - Eau Claire
0
5
10
15
20
25
0 50 100 150 200 250 300
NitrateLevels(mg/L)
Well Depth (ft)
P-value = .0749
Mean well depth = 82.13 ft.
Well depth vs. Nitrate levels
Well Depth (ft.) Average Nitrate
Levels (mg/L)
<40 7.7
41-60 3.5
61-80 3.6
81-100 4.8
>100 .73
Figure 1: Location of all well samples, yellow dots
represent wells with a nitrate concentration less than
10 mg/L. Red dots represent wells with a nitrate
concentration greater than 10 mg/L.
Legend
= greater than
10 mg/L
= less than 10
mg/L
Figure 2: The chart shows the nitrate levels plotted at certain well
depths. The red line is to show the MCL at 10 mg/L.
• Results of t-test conclude there is no significant difference in nitrate
levels in deep and shallow wells
• The four wells, as indicated as red dots on the chart above, exceed the
MCL and are not in close proximity and have varying land use
practices. The furthest two wells are approximately 5 miles apart.
Figure 3
• The table above shows average nitrate levels at corresponding well
depths.
• There is a very low average nitrate level for wells greater than 100 ft.
• A higher average nitrate level was found at wells less than 40 ft.
• With our research we still recommend to have the wells tested at
least once a year
• High nitrate levels in Chetek, WI could be caused by the following:
• Fertilizer runoff from urban development of lake shore
• Upstream agricultural runoff
• Highly permeable soils
• Naturally occurring nitrogen deposits
• Confined animal feeding operations manure runoff
TREATMENT
• Ways to remove high nitrate levels include: ion exchange, reverse
osmosis, and electrodialysis.
• Ion Exchange is the most cost effective and is already widely used
around the U.S. (Department of Health, 2015).
• Non-treatment alternatives such as wellhead protection activities,
land use management, and location of septic system should always
be considered prior to focusing on treatment alternatives.
• Another long term option may be to find a new source of water such
as a new well or connecting to a public water supply system (Nitrates
and Drinking Water, 2015).
• Be sure to locate well away from possible nitrate contamination
sources
RESULTS, CON.
FUTURE INVESTIGATION
• With a larger collection sample, a significant difference could
possibly be reached showing wells over 100 ft. deep have lower
nitrate levels.
• Additional testing should be done with a larger collection sample
and area in order to see other trends including distance to lake,
land use, septic system placement, and geology of the soil.