Wild Rice Sulfate Standard Study
& Preliminary Analysis
Laurentian Vision Partnership Meeting May 5, 2014
Shannon Lotthammer
Minnesota Pollution Control Agency
Wild Rice Sulfate Standard
Studies found correlation between lower sulfate and wild rice
Sulfate standard adopted in 1973 to protect wild rice production
“10 mg/L, applicable to water used for production of wild rice during periods when the rice may be susceptible to damage by high sulfate levels”
Implementing the Sulfate Standard
Additional information needed
Study protocol developed
2011 Legislation: $1.5 million for wild rice standards study from the
Clean Water, Land and Legacy Amendment
Advisory committee to provide input on study protocol, research results and rulemaking
MPCA to initiate rulemaking upon completing the study
Wild Rice Standards Study Advisory
Committee Kurt Anderson, Minnesota Power (ALLETE), wild rice
harvester
Leonard Anderson, wild rice harvester, citizen
Sara Barsel, citizen
Mike Appelwick, Northeast Technical Services
David Biesboer, University of Minnesota
Jennifer Engstrom, Minnesota DNR
Tracy Ekola, Minnesota Environmental Science and Economic Review Board (MESERB)
Ann Geisen, Minnesota DNR
Craig Johnson, League of Minnesota Cities
David Hatchett, Mesabi Mining
Kathryn Hoffman, Minnesota Center for Environmental Advocacy
Peter Lee, Lakehead University
John P. Lenczewski, Minnesota Trout Unlimited
Paula Maccabee, WaterLegacy
Joe Mayasich, Western Lake Superior Sanitary District
Anne Nelson, wild rice harvester, Wetlands and Water Committee of the Sierra Club
Beth Nelson, Minnesota Cultivated Wild Rice Council
Frank Ongaro, MiningMinnesota
Robert Pillsbury, University of Wisconsin Oshkosh
Raymie Porter, University of Minnesota
Robin Richards, ENVIRON International Corporation
Lloyd Grooms, Minnesota Chamber of Commerce
Shane Bowe, Red Lake Nation Foods and Red Lake Department of Natural Resources
Nancy Schuldt, Fond du Lac Band of Chippewa
Robert Shimek, wild rice harvester, member of Red Lake Band
David Skolasinski or Rob Beranek, Cliffs Natural Resources
David Smiga, U.S. Steel
Rod Ustipak, Minnesota Wild Rice Company, wild rice harvester
Rachel Walker, Barr Engineering
Darren Vogt, 1854 Treaty Authority
Wild Rice Standard Study
Goal: Enhance understanding of the effects of sulfate on wild rice; inform standard evaluation
Key avenues of investigation: Laboratory experiments
Field survey
Container experiments
Sediment experiments
Any standard modification will be based on multiple info. sources
Study Results and Preliminary Analysis
Data collection completed in December 2013
Reports posted
MPCA preliminary analysis posted March 12
Summarized MPCA analysis to date – further analysis ongoing
www.pca.state.mn.us/ktqh1083
Hydroponic Growth Tests (Dose-Response)
Germination Test (50 seeds per jar; 3 jars per treatment)
Juvenile Seedling Test (7 plants per bottle, 3 bottles per treatment)
Preliminary analysis: Sulfate treatments did not produce statistically-significant
impacts in hydroponic tests
Sulfide treatments (exposure level #2) did produce a statistically-significant reduction of seedling growth
Hydroponic seedling exposures
Maintaining exposure levels was a challenge, addressed in analysis
Method exposed whole seedling, which may or may not be an issue
Hydroponic Exposure Level #2 significantly reduced seedling growth
Effects not observed at 134 µg/L, observed at 309 µg/L
Regression Analysis of Hydroponic Sulfide Seedling Test Results
Effect concentration estimates can be used to interpret results
100 1,000 10,000
Mean Initial Sulfide Concentration (µg/L)
Change in
Weight (mg/day)
Field Survey
Can further inform understanding of sulfate-sulfide-wild rice relationship
Allows examination of other variables Iron, Others?
Targeted site selection Goal: Characterize
potential wild rice habitat across a range of sulfate
Comparing to other data
Wild Rice Field Survey Surface water
Na, K, Mg, Ca, Fe
SO4, Cl
Alkalinity, pH, conductivity, Total P, Total N,
Ammonia, Nitrate + Nitrite, transparency
Porewater
Sulfide
Na, K, Mg, Ca,
SO4, Cl
Total P, Total N, Silica
Ammonia, Nitrate + Nitrite
DOC (dissolved organic carbon)
Fe, Cu, Zn, Co, Ni, Mn, Mo, Se, As, B
Bulk Sediment Chemistry
Acid-Volatile Sulfide
Total carbon, phosphorus, nitrogen, sulfur
Phosphorus fractionation
Simultaneously-Extracted Metals:
Fe, Cu, Zn, Co, Ni, Mn, Mo, Se, As, B
Other Sediment Properties
Water
organic matter
carbonate content
Organic grain size
Wild rice phytolith presence/absence
Sediment coring at field site
Principal Components Analysis (PCA)
Tool to examine relationships among multiple variables measured at field sites
Additional analysis underway
Proportion of sites with at least 5% cover of wild rice declines with increasing porewater sulfide
• Field data consistent with observation that wild rice is less successful when porewater sulfide is above 150 to 300 µg/L
• May need to adopt a sediment porewater sulfide standard
Iron in porewater has a strong role in controlling sulfide in porewater
Sulfide and iron in porewater
Incorrect data point
Wild rice tends to grow where porewater is low in sulfide and high in iron
Because of iron, plots of sulfide on sulfate are wedge-shaped
Quantile Regression is an appropriate way to analyze pollutants whose effects
have multiple controls
• For example:
• wedge-shaped data between phosphorus and chlorophyll in streams (Fig. 22, Minnesota Nutrient Criteria Development for Rivers).
Quantile regression is a useful way to relate sulfide levels to surface water sulfate
Analysis continues
Preliminary Analysis, Summary
Although sulfate is not directly toxic to wild rice, it can be converted to sulfide, which can be toxic
Laboratory experiments showed reduced seedling growth when sulfide exceeded 150 to 300 µg/L Field data reinforced this
May need a sediment porewater sulfide standard
Preliminary Analysis, Cont.
Sulfide in the porewater is affected by sulfate in surface water and iron in porewater
Site-specific standards may be needed
Continue to examine if characteristics of water body type affect sulfide concentrations
Further explore “period of susceptibility” of wild rice to sulfate
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Next Steps
Feedback from Advisory Committee
Meetings with interested parties
Continue data analysis scientific review doc.
Expert scientific review – summer 2014
If MPCA recommends change to standard:
Develop Technical Support Document
Initiate formal rulemaking
Informal and formal comment opportunities
Also exploring implementation & policy questions
More about Scientific Peer Review
Contracted with independent company -- ERG
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Activity Date/Timeframe DRAFT
MPCA continues to refine the analysis, considering feedback received
April – May 2014
MPCA review document and technical charge sent to peer reviewers and Advisory Committee
Early June 2014
Advisory Committee members submit feedback on review document; ERG sends this feedback to peer reviewers for their consideration
Late June/Early July 2014
Peer review meeting held Early August 2014
Final meeting summary from ERG Early September 2014