Options for Meeting Water Quality Standards Lake Pepin Technical Conference September 23, 28 Lake Pepin Photo by Guy Schmickle
Overview Role of modeling in the TMDL Main features of UMR-LP Model Reductions to meet turbidity standard Reductions to meet eutrophication standard Impacts of reductions on in-filling of Lake Pepin Impact of reductions on submerged aquatic vegetation (SAV) growth
Why model? Inform management decisions Answer questions, such as What conditions lead to impairment? i How extensive is the impairment? What is contributing to the impairment? What are appropriate goals to attain? What changes are needed to attain goals? Where, when and how much???
What is a model? Models attempt to simulate cause-and-effect relationships If then $ BUDGET MODEL $ Income Expenses Balance? Interest If I have given income, expenses, and interest rates, then what will my balance be? 4
What is a model? Models attempt to simulate cause-and-effect relationships If then $ BUDGET MODEL $ Income? Expenses? Balance Interest How do I need to adjust income or expenses to meet a goal for my balance? 5
Water quality models Use mathematical formulas to represent complex natural processes C = f (loads, physics, chemistry, biology) Are constructed by developing a mass balance relationship for each parameter of concern Load Upstream transport Transport downstream Concentration Processes
Spring Lake Turbidity Nutrient Impairment Impairment Lake Pepin
UMR-LP Domain Spring Lake Lake Pepin
Loading Sources Represented in UMR-LP Tributary Sources: Upper Mississippi River (Lock & Dam 1) Minnesota River St. Croix River Cannon River Vermillion River Rush River Minor tributary t loadings to Lake Pepin (MN/WI) Urban/suburban loadings for the Metro area Direct WWTP Sources: Pool 2: Metro Plant, Empire, Eagles Point Pool 3: Hastings, Prescott Pool 4: Red Wing, Lake City
WWTP Tributary Spring Lake Lake Pepin
The Model Development Process Clarify Objectives / Set Goals Review Available Data and Model Design Conceptual Modeling Strategy Recommend Additional Data Develop Model Evaluate Model Apply Model Ongoing Communication and Review MPCA Staff Stakeholder Advisory Committee Science Advisory Panel
UMR-LP Model Framework Boundary conditions & loads: upstream tribs point source Boundary conditions & loads: upstream tribs point source Fine Scale Bathymetry Other Species-specific Parameters flows Water Level Hydrodynamic and Sediment Transport temperature sediment transport Water Quality Light Extinction Water Temperature SAV 32 Water Quality State Variables Algal l species (3 functional groups) Nutrients Turbidity Suspended sediments Dissolved oxygen et cetera Two SAV Species Wild Celery Sago Pondweed Model Output Biomass Areal Coverage
The Model Development Process Clarify Objectives / Set Goals Review Available Data and Model Design Conceptual Modeling Strategy Recommend Additional Data Develop Model Evaluate Model Apply Model Ongoing Communication and Review MPCA Staff Stakeholder Advisory Committee Science Advisory Panel
Model-Data Comparison for Lake Pepin Chlorophyll (Jun-Sept)
Using the model to answer: What happens when we reduce loads? Developed 19 scenarios, including combinations of the following: Reduce Mississippi River loads at LD1 by 2% and 5% Reduce Minnesota River loads by 2%, 5%, and 8% Reduce Cannon River loads by 5% Reduce St. Croix River and other tributary loads by 2% Reduce Direct WWTP loads from 1 mg/l TP to.3 mg/l, maintain permitted flows Reduce resuspension in Pool 2 Reduce to natural background conditions 9% reductions
Historical TSS Loads T/d) TSS Load (M 9, 8 8, 7, 6, 5, 4, 3, 2, 1, May to September Avg. TSS load Minnesota Upper Mississippi St. CroixRiver Cannon/ Vermillion Metro WWTP Other Sources Need to replace with May 15 Sep 15 rather than annual 1985 1986 1987 1988 1989 199 1991 1992 1993 1994 1995 1996 1997 1998 1999 2 21 22 23 24 25 26
Historical TSS Loads May to September Avg. TSS load Minnesota Upper Mississippi St. CroixRiver Cannon/ Vermillion Metro WWTP Other Sources T/d) TSS Load (M 9, 8 8, 7, 6, 5, 4, 3, Need to replace with May 15 Sep 15 rather than annual 22 is a 9 th percentile flow condition 2, 1, 1985 1986 1987 1988 1989 199 1991 1992 1993 1994 1995 1996 1997 1998 1999 2 21 22 23 24 25 26
Historical Turbidity, LD2, May 15- September 15 6 Avg. Turbidity Data (May 15 Sept 15) at LD2 LTRM MP Turbidity (NTRU) 5 4 3 2 1 25 2 15 1 5 ES Turbidity (NTU) MC 85 86 87 88 89 9 91 92 93 94 95 96 97 98 99 1 2 3 4 5 6
Historical Turbidity, LD2, May 15- September 15 Avg. Turbidity Data (May 15 Sept 15) at LD2 LTRM MP Turbidity (NTRU) 6 5 4 3 2 1 22 is a 9 th percentile flow condition 25 2 15 1 5 ES Turbidity (NTU) MC 85 86 87 88 89 9 91 92 93 94 95 96 97 98 99 1 2 3 4 5 6
Effect of Solids Reductions on Turbidity at LD2, 22 Conditions, May 15-Sept. 15 LTRMP Tur rbidity (NT TRU) 6 5 4 3 2 1 5 1, 2, 3, 4, 5, TSS Load to LD2 (Metric tons/day) 25 2 15 1 MCES Tur rbidity (NT TU)
Effect of Solids Reductions on Turbidity at LD2, 22 Conditions, May 15-Sept. 15 LTRMP Tur rbidity (NT TRU) 6 5 4 3 2 1 5 1, 2, 3, 4, 5, TSS Load to LD2 (Metric tons/day) 25 2 15 1 MCES Tur rbidity (NT TU)
Effect of Solids Reductions on Turbidity at LD2, 22 Conditions, May 15-Sept. 15 LT TRMP Tur rbidity (NT TRU) 6 5 4 3 2 1 Also consider reduced resuspension of soft sediments 1, 2, 3, 4, 5, TSS Load to LD2 (Metric tons/day) 25 2 15 1 5 MCES Tur rbidity (NT TU)
Effect of Solids Reductions on Turbidity at LD2, 22 Conditions, May 15-Sept. 15 LT TRMP Tur rbidity (NT TRU) 6 5 4 3 2 1 5 1, 2, 3, 4, 5, TSS Load to LD2 (Metric tons/day) 25 2 15 1 MCES Tur rbidity (NT TU)
Effect of Solids Reductions on Turbidity at LD2, 22 Conditions, May 15-Sept. 15 LT TRMP Tur rbidity (NT TRU) 6 5 4 3 2 1 Scenario 17 25 2 15 1 5 MCES Tur rbidity (NT TU) 1, 2, 3, 4, 5, TSS Load to LD2 (Metric tons/day)
Scenario 17 Reductions on an Annual Basis, 22 Conditions Load (Metr ric tons/day y) TSS 25 2 15 1 5 Upper Mississippi River Minnesota River St. Croix Bar chart, TSS load, Baseline vs River 17 Baseline Scenario 17 Cannon & Vermillion Rivers Other Direct WWTPs Scenario 17 reductions: 2% in Upper Miss. River 5% in Minnesota River 2% in St. Croix River 5% in Cannon River 2% in other tributaries Direct WWTPs at permitted flows and TSS Reduced resuspension in Pool 2
Effect of Scenario 17 Reductions over 22-Year Period, LD2 Avgerage Turbidity (May 15 Sept 15) at LD2 6 Baseline Scenario 17 Reductions ity (NTRU) LTR RMP Turbid 5 4 3 2 1 Bar chart, 22-years, Baseline side-by-side with 17, 2-4 highlightedhli ht 25. 2. 15. 1. 5. 85 86 87 88 89 9 91 92 93 94 95 96 97 98 99 1 2 3 4 5 6.
Effect of Scenario 17 Reductions over 22-Year Period, LD3 Avgerage Turbidity (May 15 Sept 15) at LD3 6 Baseline Scenario 17 Reductions LTRM MP Turbidi ity (NTRU) 5 4 3 2 1 Bar chart, 22-years, Baseline side-by-side with 17, 2-4 highlightedhli ht 25. 2. 15. 1. 5. 85 86 87 88 89 9 91 92 93 94 95 96 97 98 99 1 2 3 4 5 6.
Historical Total Phosphorus Loads
Historical Total Phosphorus Loads 1987, 1989, and 26 represent 1 th percentile flow conditions
Historical TP Concentrations, Lake Pepin Average, June-Sept. Average TP (model) in Lake Pepin.3 hosphorus s (mg/l) Total P.25.2.15.1.5. 85 86 87 88 89 9 91 92 93 94 95 96 97 98 99 1 2 3 4 5 6
Historical Chl-a Concentrations, Lake Pepin Average, June-Sept. 45 Average Chl a (model) in Lake Pepin 4 hlorophyll a (ug/l) C 35 3 25 2 15 1 5 85 86 87 88 89 9 91 92 93 94 95 96 97 98 99 1 2 3 4 5 6
Historical Chl-a Concentrations Daily Chlorophyll a h ll in Lake Pepin 26 1989 1987 Chloro ophyll a (ug g/l) 8 7 6 5 4 3 2 1 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Effect of TP Reductions on Chl-a, Lake Pepin Average, Low-Flow Conditions, June - Sept. Lake Pepin All Scenarios 1987 26 1989 4 Chl lorophyll (u ug/l) 3 2 1..5.1.15.2.25 Total Phosphorus (mg/l)
Effect of TP Reductions on Chl-a, Lake Pepin Average, Low-Flow Conditions, June - Sept. Lake Pepin All Scenarios 1987 26 1989 4 Chl lorophyll (u ug/l) 3 2 1..5.1.15.2.25 Total Phosphorus (mg/l)
Effect of TP Reductions on Chl-a, Lake Pepin Average, Low-Flow Conditions, June - Sept. Lake Pepin All Scenarios 1987 26 1989 4 Chl lorophyll (u ug/l) 3 2 1..5.1.15.2.25 Total Phosphorus (mg/l)
Effect of TP Reductions on Chl-a, Lake Pepin Average, Low-Flow Conditions, June - Sept. Lake Pepin All Scenarios 1987 26 1989 4 Chl lorophyll (u ug/l) 3 2 1 Scenario 17..5.1.15.2.25 Total Phosphorus (mg/l)
Effect of TP Reductions on Chl-a, # of days > 5 ug/l, Low-Flow Conditions, June - Sept. Lake Pepin All Scenarios 1987 26 1989 3 # of da ays Chl a >5 5 ug/l 2 1 Scenario 17..5.1.15.2.25 Total Phosphorus (mg/l)
Scenario 17 Reductions on an Annual Basis, 26 Conditions Load (Metr ric tons/yr) TP 3 25 2 15 1 5 Upper Mississippi River Minnesota River St. Croix Bar chart, TSS load, Baseline vs River 17 Baseline Scenario 17 Cannon & Vermillion Rivers Other Direct WWTPs Scenario 17 reductions: 2% in Upper Miss. River 5% in Minnesota River 2% in St. Croix River 5% in Cannon River 2% in other tributaries Direct WWTPs at permitted flows and.3 mg/l TP Reduced resuspension in Pool 2
Effect of Solids Reductions on In-filling of Lake Pepin
Effect of Solids Reductions on In-filling of Lake Pepin 1 1. Depositio on Rate (c cm/yr).8.6.4.2. 5 1, 1,5 2, 2,5 3, TSS Load to Lake Pepin (Metric tons/day)
Effect of Solids Reductions on In-filling of Lake Pepin Depositio on Rate (c cm/yr) 1 1..8.6.4.2 Natural Background Historical (85-6) Scenario 17. 5 1, 1,5 2, 2,5 3, TSS Load to Lake Pepin (Metric tons/day)
Effects of Solids Reductions on Submerged Aquatic Vegetation (SAV) Sago Pondweed Lower Pool 4 Scenario 2 Darker colors (orange, red) indicate higher plant density Scenario 18
Findings to date Reductions in solids and phosphorus loads on the order of: 2% in the Mississippi River 5% in the Minnesota River 2% in the St. Croix River 5% in the Cannon River 2% in other tributaries 7% from permitted levels at direct WWTPs are about sufficient i to meet current turbidity and nutrient goals
Next Steps Further assessment of model scenarios and goals Final modeling report September 3 th Further apply model and integrate with other modeling efforts in watershed to inform TMDL
Contact: Hans Holmberg, LimnoTech Phone: 715-549-674 email: hholmberg@limno.com www.limno.com