Groundwater Issues in Wisconsin
• Water Quantity
• Water Quality
http://pubs.usgs.gov/circ/circ1186/pdf/circ1186.pdf
Water quantity issues in Wisconsin:
• Concentrated pumping of
groundwater threatens
health of nearby streams
and lakes.
• Communities have had to
locate alternative sources
of water because of
contamination in existing
aquifers.
• Some communities have
trouble extracting
sufficient groundwater
because of local geologic
conditions.
Water quantity issues in Wisconsin:
• Concentrated pumping of
groundwater threatens
health of nearby streams
and lakes.
• Communities have had to
locate alternative sources
of water because of
contamination in existing
aquifers.
• Some communities have
trouble extracting
sufficient groundwater
because of local geologic
conditions.
Water quantity issues in Wisconsin:
• Concentrated pumping of
groundwater threatens
health of nearby streams
and lakes.
• Communities have had to
locate alternative sources
of water because of
contamination in existing
aquifers.
• Some communities have
trouble extracting
sufficient groundwater
because of local geologic
conditions.
Water quantity issues in Wisconsin:
• Concentrated pumping of
groundwater threatens
health of nearby streams
and lakes.
• Communities have had to
locate alternative sources
of water because of
contamination in existing
aquifers.
• Some communities have
trouble extracting
sufficient groundwater
because of local geologic
conditions.
water basics
• “Universal Solvent”
• Naturally has “stuff”
dissolved in it.
– Impurities depend on rocks,
minerals, land-use, plumbing,
packaging, and other materials
that water comes in contact
with.
• Can also treat water to
take “stuff” out
pO
H
H
p+
Contamination Susceptibility
 Susceptibility is related
to the type of soil and the
local geology.
 Land-use ultimately
determines if
groundwater becomes
contaminated from
human activities.
Soil
Generate Wastewater
Some settling/conversion
Reactions
Reactions/adsorption
Septic System
•
•
•
When properly constructed and maintained, it is
capable of nearly complete removal of suspended
solids, bio-degradable organic compounds and
fecal coliforms.
Soil adsorbs some contaminants.
Many contaminants particularly those that do not
adsorb to soil can eventually find there way into
groundwater (and nearby surface waters):
–
–
–
–
–
•
Nitrate (definitely)
Chloride (definitely)
Phosphorus (to some extent)
Viruses
Endocrine disruptors
Contaminants expected to be diluted as effluent
plume travels along flowpath.
Nitrate – ACTIVE SYSTEM
40 mg/l
Robertson and Harman
1999
Nitrogen
Waste
Concentration
Drinking Water
Standard
Surface Water
Standard
30-60 mg/l
10 mg/l Nitrate
Varies
Phosphorus
5-20 mg/l
None
Varies/Lakes >
0.02 mg/l often
considered
eutrophic
Chloride
40-100 mg/l
(considerable
range w/
softening)
None
Secondary 250
mg/l for salty
taste
359 mg/l in
Wisconsin
Sources include: EPA/625/R-00/008
Phosphorus – ACTIVE
1 mg/l
Langton Site: operated 1947-1994 (1991 results)
200 student school, medium sand, 3 meters unsaturated
70 meter plume,
Recharge Area for Municipal Well
Recharge area - land area that contributes water and
pollutants to the water supply
Sauk County 2-D model
Sun Prairie 3-D model
Ten- year capture zones
Data Courtesy of Gotkowitz, WGNHS
Private vs. Public Water Supplies
Public Water Supplies
Regularly tested and
regulated by drinking water
standards.
Private Wells
Not required to be regularly
tested.
Not required to take
corrective action
Owners must take special
precautions to ensure safe
drinking water.
Tests Important to Health
Contaminant
Which wells should be
tested?
Frequency
Coliform Bacteria
Every well
Annually
Nitrate
All wells
Test at least once
Used by pregnant women
Test before pregnancy
Levels close to 10 ppm
Test annually
Pesticides
Within ¼ mile of agricultural
fields
Consider testing at least
once every 5-10 years
Lead
Homes with brass fixtures or
copper plumbing installed
before 1985
Consider one time test
Copper
Homes with copper plumbing Consider one time test
Arsenic
All wells
Consider one time test
http://dnr.wi.gov/org/water/dwg/private/waterproblems.htm
http://dsps.wi.gov/php/sb-ppalopp/contam_alpha_list.php
http://www.uwsp.edu/cnr-ap/watershed/Pages/ResidentialWaterUse.aspx
Comparing Land-use Impacts
Corn1
(per acre)
Prairie1
(per acre)
Septic 2
System
Total Nitrogen Inputs (lb)
169
9
20-25
Nitrogen Leaching Loss (lb)
36
0.04
16-20
Amount N lost to leaching (%)
20
0.4
80-90
Using these numbers: 36 septic systems on 20 acres (0.55 acre lots) needed to achieve
same impact to water quality as 20 acres of corn
1 Data from Masarik, on a silt-loam soil, 2003
2 Data from Tri-State Water Quality Council, 2005 and EPA 625/R-00/008
36 lbs
36 lbs
36 lbs
36 lbs
36 lbs
36 lbs
36 lbs
36 lbs
36 lbs
36 lbs
36 lbs
36 lbs
36 lbs
36 lbs
36 lbs
36 lbs
36 lbs
36 lbs
36 lbs
36 lbs
20 lbs
20 acres
20 acres
Comparing Land-use Impacts
20 lbs/septic system x 1 septic systems = 20 lbs
1/36th the impact on water quality
0.44 mg/L
Assuming 10 inches of recharge -
36 lbs/ac x 20 acres = 720 lbs
16 mg/L
Comparing Land-use Impacts
20 acres
36 lbs
36 lbs
36 lbs
36 lbs
36 lbs
36 lbs
36 lbs
36 lbs
36 lbs
36 lbs
36 lbs
36 lbs
36 lbs
36 lbs
36 lbs
36 lbs
36 lbs
36 lbs
36 lbs
36 lbs/ac x 20 acres = 720 lbs
20 acres
36 lbs
20 lbs
20 lbs
20 lbs
20 lbs
20 lbs
20 lbs
20 lbs
20 lbs
20 lbs
20 lbs
20 lbs
20 lbs
20 lbs
20 lbs
20 lbs
20 lbs
20 lbs
20 lbs
20 lbs
20 lbs
20 lbs
20 lbs
20 lbs
20 lbs
20 lbs
20 lbs
20 lbs
20 lbs
20 lbs
20 lbs
20 lbs
20 lbs
20 lbs
20 lbs
20 lbs
20 lbs
20 lbs/septic system x 36 septic systems = 720 lbs
Using these numbers: 36 septic systems on 20 acres (0.55 acre lots) needed to achieve
same impact to water quality as 20 acres of corn