Linking Great Lakes Beach Water Quality to Land Use

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Linking Great Lakes Beach Water Quality to Land Use - Adam Mednick, WDNR

Nov 2010

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Linking Great Lakes Beach Water Quality to Land Use

  1. 1. Linking Great Lakes Beach Water-Quality to Land UseAdam C. MednickWisconsin Dept. of Natural ResourcesWAFSCM Conference, 11/4/10, Wisconsin Dells
  2. 2. OutlineI. Problem/ BackgroundII. Beach Water-Quality “Nowcasts”III. From Beach to WatershedIV. Modeling/ Decision-Support Framework
  3. 3. I. The Problem Elevated fecal indicator bacteria in nearshore recreational waters Public health impacts Escherichia coli Economic impacts In WI 2003-2009:  3,737 Swim Advisories  912 Beach Closures
  4. 4. Difficult to ID/ Mitigate Sources  Sources, pathways, and contributing factors vary from beach to beachSource: NOAA GLERL
  5. 5. Monitoring Challenges Standard methods take 18-24 hours  Collect/ transport water quality samples  Lab analysis Quanti-tray enumeration
  6. 6. Monitoring Errors (Type I) . Wisconsin 2003-2009:  63% of closings reflected false exceedances of state closure guideline (1,000 CFU/100 mL)  42% of advisories reflected false exceedances of the EPA freshwater standard (235 CFU/ 100 mL)
  7. 7. Monitoring Errors (Type II) Wisconsin 2003-2009:  3% of non-advisory days with water quality samples exceeded the state guideline (1,000 CFU); i.e. should have been closed  9%… exceeded the EPA standard (235 CFU); i.e., should have been posted
  8. 8. Beach Water-Quality “Nowcasts”Y = ϐ0 + (ϐ1*X 1) + (ϐ2*X 2) + … (ϐk *X k ) + ε FIB Concentration
  9. 9. X1 = Rainfall Source: NWS
  10. 10. X2 = Turbidity (NTU)
  11. 11. X3 = Wave Height Source: USGS Ohio Water Science Center Source: Racine Health Department
  12. 12. X4 = Sky Conditions Source: NOAA
  13. 13. X5 = Wind Speed*Direction Source: NOAA
  14. 14. X6 = Nearshore Current Grand River Plume (4/20/10) Grand Haven State Park, Michigan Source: NOAA GLERL
  15. 15. X6 = Nearshore Current Grand River Plume (4/20/10) Grand Haven State Park, Michigan Source: NOAA GLERL
  16. 16. X6 = Nearshore Current Grand River Plume (4/20/10) Grand Haven State Park, Michigan Source: NOAA GLERL
  17. 17. X7 = FIB loading Grand River Plume (4/20/10) Grand Haven State Park, Michigan Source: NOAA GLERL
  18. 18. First Operational “Nowcast” in WI Port Washington, 2009-2010  Explanatory Variables:  48-hour Rainfall  Turbidity (NTU)  24-hr Stream Flow (total discharge)  Wave Height  Water Temperature  Air Temperature  “Third Qtr” of Beach Season (Y/N)
  19. 19. E. Coli (CFU/100 mL) 20 07 20 .05 1 10 100 1000 10000 07 .29 20 .06 07 .17 20 .07 07 .04 20 .07 07 .21 20 .08 07 .09 20 .08 08 .26 20 .06 08 .12 20 .06 08 .29Date 20 .07 08 .15 20 .08 08 .02 "Combined Model" 20 .08 09 .18 20 .07 09 .02 20 .07 09 .30 .0 Predicted vs. Observed 2007-09 8. 27 - Nowcast - * R-sqr = 64% First Operational “Nowcast” in WI * MAE = 19 CFU Standard Predicted Observed
  20. 20. First Operational “Nowcast” in WI Sample date/time E. Coli E. Coli Units (Model) (Lab) Tues. 7/13/2010 8:30 4 23 MPN/ 100ml Wed. 7/14/2010 8:30 24 24 MPN/ 100ml Thurs. 7/15/2010 9:00 3,432 2,419 MPN/ 100ml Friday 7/16/2010 8:50 166 127 MPN/ 100ml
  21. 21. Expanded “Nowcast” Modeling Federal Great Lakes Restoration Initiative From 1 operational nowcast to 20 by 2013 59 candidate beaches Pt. Washington  Adequate data Study Area  High-priority and/or impaired
  22. 22. III. From Beach to Watershed
  23. 23. Root River, Racine Beach/Waterfront economically important Veryhigh number of closures and swim advisories prior to 2006 Inter-agency effort to address problem:  City Public Health Dept., Engineering Dept., Planning Dept.
  24. 24. Multi-Year Sanitary Survey 2003-present Intensive sampling of nearshore waters, stormwater outfalls, and Root River outlet Concurrent surveys of:  Beach conditions (e.g., # bathers, gulls, algae, litter…)  Nearshore currents, wave height, turbidity  Meteorological conditions
  25. 25. Site-Level Mitigation Redesigned stormwater outfall Constructed wetland cells Re-graded lower beach Modified grooming to increase aeration Ordinance against feeding gulls
  26. 26. Watershed Conditions Post-mitigation, contamination events primarily associated with major storm events/ Root River discharge Riverplumes often associated with elevated FIB at Great Lakes beaches, as well as Marine beaches (e.g. He & He 2008) Grand River at Grand Haven, MI Source: NOAA
  27. 27. Watershed Conditions Startingin 2007, weekly samples collected at 34 sites along lower Root River
  28. 28. 25 Open Water Sites
  29. 29. 9 Outfalls
  30. 30. Samples vs. Flow Conditions Flow Duration Curve (daily data 1963-2009) Wet Conditions Dry Conditions 10000 All Dates 1962-2009 1000 Sample Dates (N~75)Log of flow (cfs) 100 10 1 0 10 20 30 40 50 60 70 80 90 100 0.1 0.01 Percent of time flow rate exceeded
  31. 31. Applied-Research Questions Can we develop a modeling framework that links nearshore FIB concentrations to watershed conditions?  Land Use  Development Practices (LID) Ifso, can we translate this into a usable Planning-Support Tool?  Nowcasts for Public Health officials  Impact Assessment for Planners
  32. 32. Limited Research to date Kay and colleagues (2005) modeled real- time FIB fluxes for a coastal watershed discharging near recreational waters on the Irish Sea. Export coefficients based on percentages of different land uses Did not link outputs to nearshore FIB concentrations
  33. 33. IV. Modeling/ Decision-Support Framework Watershed modeling component Rainfall Beach “nowcast” componentLand Use Soils Rainfall Waves Wind Turbidity Current Runoff NPS Nearshore E. coli E. coli
  34. 34. Watershed Component Based on Long-Term Hydrologic Impact Assessment (“L-THIA”) Spatially-distributed automation of rainfall-runoff Curve Number (CN) method + event mean concentration (EMC) coefficients Simple model  Similar to PLOAD  Basis for runoff/NPS in the PSS software “INDEX”  Enables Web application
  35. 35. L-THIA (Online Version) https://engineering.purdue.edu/~lthia/
  36. 36. L-THIA (“Real-Time”)
  37. 37. Beach Component U.S. EPA’s “Virtual Beach”: Model-building/ decision-support tool Walks beach managers through the process of building and operating statistical models to predict real-time FIB concentrations
  38. 38. Initial Watershed Models Distributed CN’s based on 30m land use (NLCD 2001) and soils (SSURGO) Daily rainfall (2007-10) from Racine Airport CN’sadjusted for Antecedent Soil Moisture based on previous 5 days Daily direct runoff estimates per 30m cell
  39. 39. Root River Watershed2010 Land Use (NLCD) Open Water Developed, Open Space Developed, Low Intensity Developed, Medium Intensit Developed, High Intensity Barren Land Deciduous Forest Evergreen Forest Mixed Forest Shrub/Scrub Grassland/Herbaceous Pasture/Hay Cultivated Crops Woody Wetlands Emergent Wetlands0 5 Kilometers
  40. 40. Curve Numbers < 65 65 - 70 70 - 75 75 - 80 80 - 85 85 - 90 90+0 5 Kilometers
  41. 41. E. coli CoefficientsFor each land use, 4 different sets ofEMC coefficients for total coliforms,adjusted (EC = 0.625 * TC):1. L-THIA default EMCs2. WMM EMCs (Rouge River Natl. Wet Weather Demonstration Project 1998)3. PLOAD EMCs (U.S. EPA 2001)4. NSQD median values (Pitt el al. 2009)
  42. 42. Initial Beach Model #1 Rainfall + Clarity + Sky Conditions + Southerly Current R-square = 40.66%Variable Coefficient CFU/100 mL t-Statistic p-ValueConstant + 1.97 14.870 0.000(24-hr Rainfall [in]) -0.5 + 1.06 + 2.90 4.442 0.000Wave Height (ft.) + 0.33 + 1.39 2.823 0.005Water Clarity: "Somewhat Turbid" + 0.90 + 2.46 2.814 0.005Water Clarity: "Turbid" + 0.69 + 2.00 2.586 0.010Water Clarity: "Opaque" + 0.83 + 2.29 2.482 0.014Sky Conditions: "Overcast" + 0.49 + 1.63 2.978 0.003Stage-of-season: 3rd Qtr + 0.51 + 1.66 2.909 0.004Stage-of-season: 4th Qtr + 0.47 + 1.60 2.569 0.011(Southerly Surface Current [m/sec])-0.5 + 0.54 + 1.72 1.317 0.190
  43. 43. Initial Beach Model #2 24-hour Avg. Root River Discharge in place of rainfall R-square = 40.24%Variable Coefficient CFU/100 mL t-Statistic p-ValueConstant + 1.63 9.741 0.000(Root River Discharge) -0.5 + 0.03 + 1.03 4.281 0.000Wave Height (ft.) + 0.46 + 1.58 4.025 0.000Water Clarity: "Somewhat Turbid" + 1.02 + 2.77 3.206 0.002Water Clarity: "Turbid" + 0.55 + 1.73 2.011 0.046Water Clarity: "Opaque" + 0.76 + 2.14 2.273 0.024Sky Conditions: "Overcast" + 0.52 + 1.69 3.171 0.002Stage-of-season: 3rd Qtr + 0.71 + 2.04 3.886 0.000Stage-of-season: 4th Qtr + 0.67 + 1.96 3.553 0.000(Southerly Surface Current [m/sec])-0.5 + 0.69 + 1.99 1.639 0.103
  44. 44. Initial Beach Model #3 Estimated E. coli load in place of rainfall R-square = 38.71%Variable Coefficient CFU/100 mL t-Statistic p-ValueConstant + 2.04 15.298 0.000(Estimated E. coli load, WMM)-0.5 + 0.00 + 1.00 3.596 0.000Wave Height (ft.) + 0.38 + 1.47 3.308 0.001Water Clarity: "Somewhat Turbid" + 0.85 + 2.35 2.596 0.010Water Clarity: "Turbid" + 0.64 + 1.89 2.329 0.021Water Clarity: "Opaque" + 0.81 + 2.25 2.392 0.018Sky Conditions: "Overcast" + 0.50 + 1.65 2.982 0.003Stage-of-season: 3rd Qtr + 0.49 + 1.63 2.745 0.007Stage-of-season: 4th Qtr + 0.48 + 1.61 2.561 0.011(Southerly Surface Current [m/sec])-0.5 + 0.60 + 1.82 1.421 0.157
  45. 45. Forthcoming Watershed-specificEMC coefficients estimated Root River data  Data partitioned by flow regime and season Substitute lot-level land use for NLCD Calibrate curve numbers Validate E. coli estimates against sampling LID-adjusted curve numbers
  46. 46. Linking Great Lakes Beach Water-Quality to Land UseAdam C. MednickWisconsin Dept. of Natural ResourcesWAFSCM Conference, 11/4/10, Wisconsin Dells

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