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Joseph Zachmann , Ph.D. Research Scientist Pesticide & Fertilizer Management Division. Pesticides & Risk. Pesticides control insect pests, weeds and diseases and may pose risk to human health and the environment Some pesticides leach to groundwater People are concerned about exposure risks - PowerPoint PPT Presentation
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Joseph Zachmann, Ph.D.Research Scientist
Pesticide & Fertilizer Management Division
Pesticides & Risk Pesticides control insect pests, weeds and diseases and
may pose risk to human health and the environment
Some pesticides leach to groundwater
People are concerned about exposure risks Are there pesticides in my drinking water? How high are the concentrations relative to known risk? Even if concentrations are low, what about unknown risks like
exposure to pesticides in mixtures, endocrine disruption and other concerns?
Groundwater Monitoring for Pesticides
MDA monitoring networks are designed for agricultural pesticides
Wells are located adjacent to operating farm fields
Central Sand Plain monitoring well nest
Far from non-agricultural contaminant sources; intersect water table to represent worst-case scenario
Southeast karst bedrock aquifers are monitored via springs
Extremely rare long-term data set – entering 29th year
Statewide Network
What are we looking for? In 2011
276 groundwater samples From 171 wells/sites
CWF helped purchase state-of-the-art LC/MS-MS equipment to:
Find pesticides at lower concentrations Increase number of pesticides & samples analyzed
Each sample analyzed for 110 different pesticides or degradates = 30,000 analyses annually
As new pesticides are registered they are reviewed for risk and may be added to the analytical list
What do we find?• 40 pesticides or degradates detected• Most are found in fewer than 4% of samples• Commonly detected in vulnerable areas:
AcetochlorAlachlorAtrazineMetolachlorMetribuzin
• No pesticide concentrations exceeded MDH drinking water risk levels
Metolachlor in Central Sands
• Atrazine and its degradates are frequently detected, but concentrations have decreased significantly in recent years
• Atrazine and degradate concentrations: 2000-2012
Atrazine and its Degradates in Central Sands
Atrazine in Southeast Karst
Year
Con
cent
ratio
n (p
pb)
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
0.1
0.2
0.3Atrazine + Deisopropylatrazine + Desethylatrazine
DNR Fish Hatchery Springs Median
ND
Year
Freq
uenc
y of
Det
ectio
n (%
)
2004
2005
2006
2007
2008
2009
2010
2011
2012
0
20
40
60
80
100
Atrazine Desethylatrazine Deisopropylatrazine
PMR 9
All springs
Uncertainties and Groundwater Risks
• Possible changes in pesticide use patterns & groundwater impacts due to:– New pesticide-resistant crop technologies– Weed resistance to current pesticides– Invasive species control– Climate change effects (warming) on economic crop
pests– Climate change effects on increased precipitation
intensity and greater leaching and runoff
All MDA monitoring data is:• Reviewed, compiled and reported annually• Submitted to MDH, MPCA and EPA for evaluation• Available and stored long-term in MPCA’s EQuIS database
QUESTIONS?Joseph Zachmann, Ph.D.Research ScientistPesticide Management UnitMinnesota Department of [email protected]
Nitrates in Groundwater within Agricultural Regions of Minnesota
Senate Legislative Briefing:Environment and Energy Committee
April 9, 2013
Bruce MontgomerySection Manager
Fertilizer Non-Point SectionPesticide and Fertilizer Management Division
MN Department of Agriculture
A groundwater/drinking water contaminate of major concern
NitrateNO3-N
Why the Concerns?Why the Concerns?
Jan-93 Oct-95 Jul-98 Apr-01 Jan-04 Oct-06 Jul-090
2
4
6
8
10
12
14
f(x) = 0.0012186044487809 x − 40.1144766920416R² = 0.687982949899093
PARK RAPIDS WELL 4
Nitr
ate-
N (m
g/L)
Nitrate Loading to Groundwater Can Be Significant In Sensitive Geologic Areas
These Areas Tend to Be Very Localized
1993 1998 2003 2008
Potentially Lost to Groundwater, Surface Water or Tile Drainage
Nitrate movement to groundwater, springs, and tile drainage waters can be appreciable
The Many Escape Routes of Nitrogen
What’s Grown on the Land Strongly Influences Nitrate
Loss to the Aquifer
Groundwater Stressors
Cropping Systems are NOT created
equal
Crops with Low N Loss Leaching Potential
Alfalfa and CloverVegetated Pasture
Native Prairie/CRP Plantings Perennial Crops
0
1
2
3
4
5
6
7
8
1921 1931 1941 1951 1961 1971 1981 1991 2001 2011
Mill
ions
of A
cres
Year
Hay Soybean
Acreage Trends in Minnesota’s “Legume” Crops (All Hay and Soybeans)
Soybeans
Alfalfa, Clover, etc
The Last 90 Years…..
Acreage Trends for Minnesota’s Major Nitrogen Demanding Crops
0
2
4
6
8
10
1920 1930 1940 1950 1960 1970 1980 1990 2000 2010
Mill
ions
of A
cres
Year
Corn
Small Grains
Potatoes
Sugarbeet
Sunflower
Edible Beans
All Small Grain Crops Cor
n
The Last 90 Years…..
Crops with High N Loss Leaching Potential
Potatoes
Edible Beans
Grain Corn
Silage Corn
Data Source: MDA, TVA, and AAPFCO
Commercial Nitrogen Fertilizer Sales Trends in U.S.& Minnesota: 1965-2011
0
2,000,000
4,000,000
6,000,000
8,000,000
10,000,000
12,000,000
14,000,000
0
100,000
200,000
300,000
400,000
500,000
600,000
700,000
800,000
900,000
MN Sales (left axis)
US Sales (right axis)
Tons
of N
Sold
in M
innes
ota
Tons
of N
Sold
in th
e U.
S.
1960’s 1970’s 1980’s 1990’s 2000’s 2010’s
0.40.60.81.01.21.4
Rat
io o
f Bus
hels
Pro
duce
d pe
r Lb
N
Fert
ilize
r Inp
ut
Statewide "NUE" on Corn Using the N Balance Method
MN Farmers Continue to Increase Efficiency from Their Nutrient Inputs
Bushels of Corn Produced per Lb of N Fertilizer
1992 to 2011
County Well Index DataNitrates in Private Drinking Wells
Most elevated conditions are found in the Central Sands region and Washington/Dakota Counties;
(Note that only wells with nitrate-N > than 3 mg/L are illustrated
here)
Two “Home Owner” Nitrate Monitoring Networks have been Recently Established
• Networks have been designed to provide low-cost nitrate trend information;
• Private wells selected on a pre-determined grid;
• Multi-Agency support;
• SWCD and/or Local Environmental Health shoulder much of work
Homeowner Participation is the Cornerstone of the Design
Nitrates in Private Drinking Wells in the Central Sands
• Home Owner Network Approach included 1,555 Minnesota families;
• This recent data (2011) suggests that about 5% > Health Standard (10 mg/L);
• Approx. 500-600 wells will be used for long-term trends
Southeast Nitrate Monitoring Network2008 to 2011
Data Source: MDH
This Type of Information will be Extremely Valuable to Future Generations
0
2
4
6
8
10
12
14
16
Feb'08 Aug'08 Feb'09 Aug'09 Aug'10 Aug'11
% Over 10 mg/L
Recent Analysis Suggests that between 200-300 Agricultural Townships Are at Potential Risk
(based upon GIS layering of sensitive surficial geology and row crop density)
Nitrates in Public Water Supplies
Nitrates in Public Water Supplies
Based upon MDH data, less that 1% of Minnesota’s public water supplies exceed the MCL;
(Note that only wells with nitrate-N > than 3 mg/L are illustrated here)
Figure 10. Distribution of public water supply wells in the County Well Index with nitrate-N greater than 3 mg/L
Data Source: MDH
Roughly 20-25 Public Water Suppliers in Agricultural Areas are Dealing with Nitrate Issues
Jan-93 Oct-95 Jul-98 Apr-01 Jan-04 Oct-06 Jul-090
2
4
6
8
10
12
14
f(x) = 0.0012186044487809 x − 40.1144766920416R² = 0.687982949899093
PARK RAPIDS WELL 4
Nitr
ate-
N (m
g/L)
Rapidly Increasing Nitrate Levels Are Not Uncommon in These Highly Sensitive
Landscapes
1993 1998 2003 2008
What’s at Stake for Community Water Suppliers Dealing with Nitrate Problems?
• Nitrate removal systems typically cost more than $3 Million for upfront construction costs and also maintenance costs
• Costs of drilling new and/or deeper wells;
• Costs of ‘blending” multiple wells to achieve get acceptable water quality;
• Consumer costs are 2-6 times higher than non-impacted water supplies
LESSONS LEARNED: MDA, MDH, and our partners have tools and case studies to share
http://www.mda.state.mn.us/protecting/waterprotection/drinkingwater.aspx