Wild Rice Research Briefing Iron Mining Association Presentations to Range Cities October 1 and 2, 2014 1
Wild Rice Research Briefing MN CHAMBER ANALYSIS OF MPCA RESEARCH & PRELIMINARY DETERMINATIONS 2
Minnesota Chamber Review Team ENVIRON International Corporation University of Minnesota Scott Hall , Senior Manager, specializing in David Grigal, Ph.D., Professor Emeritus – – aquatic criteria development, served as Soil Water and Climate hydroponics testing project manager University of California Davis Robin Richards , REM, Principal – – Steve Grattan, Ph.D . Department of Soil – biochemist and plant physiologist, served Science, plant-water specialist in toxicity assessments and rulemaking Fort Environmental Labs guidance Mike Bock, Ph.D . Senior Manager – Douglas Fort, Ph.D . President, aquatic – – environmental statistician and terrestrial toxicology, developmental toxicology , toxicology/pharmacology Barr Engineering Co. ALLETE/Minnesota Power Rachel Walker, Ph.D. , Senior – Kurt Andersen , Environmental Audit Environmental Scientist – wild rice biology – and nutrient dynamics, wild rice surveys, Manager, aquatic toxicity assessment project management Mike Hansel , Senior Chemical Engineer – and Vice President – water quality rulemaking, environmental permitting John Borovsky , Senior Environmental – Scientist and Vice President – soils and groundwater interaction, environmental permitting Lindsey Tuominen , Ph.D., Biostatistician – – statistical analyses 3
Overview & Implication of NOT adjusting the current wild rice standard 1. Agreement: MPCA and Chamber hydroponic studies both confirm that sulfate does not directly affect wild rice up to 1,600 – 5,000 mg/L 2. Different view on toxicity of sulfide 3. Implications to cities & businesses if current standard is NOT adjusted 4
Toxicity Testing Fort Environmental Labs: Wild Rice Sulfate Toxicity Testing 5
MN Chamber’s Analysis of MPCA’s Research & Preliminary Determination From “TOXICITY OF SULFATE AND CHLORIDE TO EARLY LIFE-STAGES OF WILD RICE (ZIZANIA PALUSTRIS)” Journal of Environmental Toxicology and Chemistry, DOI 10.1002/etc.2744, September 2014 “Overall, results from this study suggest that sulfate did not adversely affect germination and early development of wild rice at concentrations below 5,000 mg /L over the 21-day hydroponic exposure. Some effects induced at high sulfate concentrations were also observed in osmotically equivalent chloride treatments, and some sulfate-specific stimulatory effects may be attributable to the effects of sulfate as a plant nutrient.” 6
MN Chamber’s Analysis of MPCA’s Research & Preliminary Determination Results agree with those of Dr. Pastor’s hydroponics test: direct toxicity of sulfate to wild rice occurs at sulfate concentrations far greater than 10 mg/L sulfate Dr. Pastor saw no adverse affects at 1,600 mg/L sulfate for rice germination and growth (maximum level tested) 7
MN Chamber’s Analysis of MPCA’s Research & Preliminary Determination MPCA developed two hypotheses on how sulfate may affect wild rice: – wild rice can be impacted by sulfate via the conversion of sulfate to sulfide in the rooting zone of the plants and – iron may mitigate the effects of sulfide production in the rooting zone of the sediment (emphasis added) 8
MN Chamber’s Analysis of MPCA Research & Preliminary Determination Unfortunately, MPCA research did not test the first hypothesis Only those portions NOT “in the rooting zone” were affected by low sulfide concentrations: “in all experiments, stem plus leaf lengths and total weights of juvenile seedlings declined significantly ( p < 0.05) at all nominal exposure concentrations greater than 9 μM sulfide “ 9
MN Chamber’s Analysis of MPCA Research & Preliminary Determination Portions of the plants “ in the rooting zone ”: – Roots; – Germinating Seeds; and – Mesocotyl Growth were unaffected by sulfide at concentrations of 90 µM (2,400 µg/L) 10
MN Chamber’s Technical Analysis of MPCA Hypotheses Field Survey found: – only 4 lakes with concentrations of porewater sulfide greater 90 µM (2,400 µg/L) and – only where naturally occurring iron concentrations are very low (e.g., less than 2 μM or 1,000 µg/L) These lakes are located in the Des Moines glacial lobe, which brought down high sulfur, low iron material from Canada 11
MN Chamber’s Technical Analysis of MPCA Hypotheses The relationships from the field surveys amply demonstrate that the MPCA’s hypothesis was well founded with respect to the role of naturally occurring iron mitigating the presence of free sulfide . The field surveys and the hydroponic studies demonstrate that the hypothesis that total sulfide in the rooting zone impacts rice is not supported. The relationships from the field surveys demonstrate that the hypothesis that surface water sulfate is a key determinant in the formation of sediment porewater free sulfide is not supported. 12
Sulfate & iron in groundwater, not surface water, determine sulfide formation Most of O O Des Minnesota x x Moines y y g g Lobe e e Areas n n Iron Iron If iron is present, it If iron is not present, prevents porewater porewater sulfide can Sulfate sulfide formation form Sulfate Sediment 13 13
MN Chamber’s Technical Analysis of MPCA Preliminary Determination The MPCA has attempted to show a correlation between porewater sulfide, surface water sulfate and wild rice growth. However, federal guidance and MPCA’s own rules require that the MPCA show with 95% confidence that there is causation – a dose-response relationship where sulfate, and not some other factor, affects wild rice. The MPCA must also have high confidence that reducing sulfate concentrations will result in the improvement and restoration of wild rice. 14
MPCA needs to consider ALL factors which affect wild rice The MPCA, MN DNR, WI DNR, WI Ag Extension Service, and tribal experts all note the following key factors most affect growth and restoration of wild rice: – Changes in natural hydrology – Invasive species – Competitive (native) species – Genetic engineering – Climate change – Shoreland development 15
HOW SHOULD RULEMAKING INCORPORATE RESEARCH? • A sulfate wild rice water quality standard does not appear necessary, given the high concentration of sulfate necessary to adversely affect the growth of wild rice, the weak correlation with porewater sulfide and the role which iron plays in mitigating sulfide. 16
HOW SHOULD RULEMAKING INCORPORATE RESEARCH? If a sulfide wild rice water quality standard is pursued by MPCA, all water and sediment factors influencing sulfide toxicity to wild rice have to be considered. 17
HOW SHOULD RULEMAKING INCORPORATE RESEARCH? Protecting wild rice waters To protect wild rice producing waters, a water quality standard really should address all key factors that negatively impact wild rice. 18
Wild Rice Research Briefing WHAT DOES THIS MEAN TO MN CITIES AND INDUSTRIES? 19
WHAT DOES THIS MEAN TO MN CITIES AND INDUSTRIES? If MPCA retains 10 mg/L standard, two things will happen: 1. Wild rice will not be better protected 2. Cities and industries will go bankrupt attempting to meet the 10 mg/L standard 20
Cost to comply with existing standard According to MPCA: – 150 cities & businesses have monitored for sulfate – 144 cities & businesses have sulfate > 10 mg/L Many cities and industries will need to provide additional treatment to meet the current standard Not just mines – data centers, food processors, manufacturers, refiners 21
Cost for cities to meet 10 mg sulfate/L standard The only technology which can meet the standard is reverse osmosis. City of St. Peter has built an RO system for their drinking water system (2,300 gpm, 3.3 MGD). Capital costs: $10.5 million. Annual O&M Costs: $0.5 million/year. Cost per household: $4.89/month, or $100/year 22
Cost for cities to meet 10 mg sulfate/L standard But system discharges brine to the river. To meet a 10 mg/L sulfate standard, one needs to evaporate & crystallize the brine. Additional Capital Costs: $19 million Additional O&M Costs: $5.7 million/year Additional Cost per household: $26.91/month or $323/year 23
Cost for cities to meet 10 mg sulfate/L standard Total cost for system to treat 2,300 gpm (3.3 MGD) = $31.83/month, or $382/year per household 24
Cost for cities to meet 10 mg sulfate/L standard Another example, for a Midwest city, including pre-treatment to protect membranes. Estimated costs for membrane reverse osmosis (with evaporation & crystallization of brine) for a large municipal plant (to reduce salt): $138.60/month per household, or $1,663/year per household. 25
Cost for cities to meet 10 mg sulfate/L standard Minnesota Public Facilities Authority (PFA) uses 1.4% of median household income as a wastewater costs affordability index for Minnesota communities. US Census Bureau says median household income (2008-2012) is $59,126. Monthly affordable cost would be $69/month 26
Cost for cities to meet 10 mg sulfate/L standard Can your residents afford an additional $400 - $1,600 per year On top of their current water and sewer charges? 27
Recommend
More recommend
