Examination of Thermal Impacts from Stormwater BMPs Funded by: USEPA Region 1 TMDL Program Project Team: The UNH Stormwater Center Robert Roseen, PhD, PE, D.WRE ; Nicholas DiGennaro, EIT; Alison Watts, PG, PhD; Thomas Ballestero, PE, PhD, PH, CGWP; James Houle, CPSWQ; Timothy Puls UNH Stormwater Center, Department of Civil Engineering University of New Hampshire Tuesday May 18, 2010 1
Heat Transfer: Function of the time of day. Thermal En nergy Air Input: Solar Radiation Thermal Energy Stormwater BMP Heat Transfer: Function of the mass of the system. Thermal Energy Output: Heat Ground Therm mal Energy Heat Transfer: Function of the depth of the system. 2
Project Objective Introduction To quantify the effect of Best Management Practices (BMPs, n=8) on the temperature of stormwater runoff in relation to established environmental indicators and lethality indices for fisheries and aquatic ecosystems Hypothesis Larger surface systems will see greater thermal variations Larger subsurface systems will see greater thermal buffering C th = m * C P C th = heat capacity of a system (J/ o C) m = mass of a system (kg) C P = specific heat (J/kg o C) 3
Systems Retention Pond Detention Pond Veg Swale Gravel Wetland Bioretention Unit Subsurface Infiltration Hydrodynamic Separator Isolator Row 4
Experimental Design CB T in Examination of Storms Stormwater BMP T out 40 Million Data Points 10 9 Farm Site 85.0 80.0 8 75.0 7 70.0 6 5 ` 4 3 2 1 0 J FMAMJ J ASONDJ FMAMJ JASONDJ FMAMJ J ASONDJ FMAMJ JASOND Runoff Retention Pond 85.0 Detention Pond Gravel Wetland Bioretention Vegetated Swale Hydrodynamic Separator ADS Infiltration System 80.0 StormTech Isolator Row 75.0 70.0 65.0 60.0 55.0 50.0 Event Mean Temperature ( o F) Even Mean Te mperature o ( F) Cumulative Probability (% 65.0 60.0 55.0 50.0 45.0 40.0 35.0 30.0 Runoff Retention Pond Detention Pond Gravel Wetland Bioretention Vegetated Swale Hydrodynamic ADS Infiltration StormTech Isolator Separator System Row 100% 90% 80% 70% 60% Runoff Retention Pond 50% Detention Pond Gravel Wetland Bioretention 40% Vegetated Swale HDS 30% ADS STIR 20% ΔT in o F (approximate change in stream temp) 100 80 60 40 20 0-20 10% 20% 25% 30% -40 40% 50% 60% 70% 75% 80% -60 90% 100% -80-100 -100-80 -60-40 -20 0 20 40 60 80 100 EMT in o F (relative to stream temp) 45.0 10% 40.0 35.0 30.0 Date 0% 30 35 40 45 50 55 60 65 70 75 80 85 Event Mean Temperature, EMT ( o F) 5
Performance Metric Event Mean Temperature, EMT ( o F) gpm) Flow ( Flow or Volume weighted temperature Calculated for each storm and each system 120 100 80 60 40 20 0 9:25 PM 120 Influent EMTs 11:25 PM 1:25 AM 3:25 AM 5:25 AM 7:25 AM Flow Temperature EMT 9:25 AM Date (3/10/07-3/1107) 11:25 AM 36.5 1:25 PM 3:25 PM 50 45 40 35 30 Temper ature ( o F) EMT EMT = T O = T t(t)q(t)dt O Vol q(t)dt * Temp Vol 6
70.0 65.0 60.0 55.0 50.0 45.0 40.0 35.0 30.0 85.0 80.0 75.0 70.0 65.0 60.0 55.0 50.0 45.0 40.0 35.0 30.0 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% Date Runoff Retention Pond Detention Pond Gravel Wetland Bioretention Vegetated Swale Hydrodynamic Separator ADS Infiltration System StormTech Isolator Row Runoff Retention Pond Detention Pond Gravel Wetland Bioretention Vegetated Swale Hydrodynamic Separator ADS Infiltration System Runoff Retention Pond Detention Pond Gravel Wetland Bioretention Vegetated Swale HDS ADS STIR StormTech Isolator Row 0% 30 35 40 45 50 55 60 65 70 75 80 85 Event Mean Temperature, EMT ( o F) 0.10 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0.00 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 Stormwater Temperature ( o F) Qualitative Analyses Annual and Seasonal Summer April through September 85.0 80.0 75.0 Winter November through March Time Series (EMT) Event Mean Temperature ( o F) Quartile Assessment (EMT) Even Mean Temperature ( o F) Cumulative Distribution Function (EMT) Histogram (Temperature) Thermal Loading Stream Mixing Cumulative Probability (% Normalized Frequency (Count/Total) 7
Environmental Indicators Temperature Indices Lower Optimum Limit (LOL) = 45 o F it Upper Optimum Limit (UOL) = 65 o F Lethal Limit (LL) = 80 o F Thermal Regimes Vary by stream Range and frequency of temperatures Mean July Temperatures Warmest month Groundwater Temperature As a base flow condition New Hampshire = 47 o F 8
Annual Time Series Runoff Retention Rt Pond ti Runoff Runoff Retention Retention Pond Pond 85.0 Detention Pond Gravel Wetland Bioretention Detention Pond Runoff Vegetated Gravel Wetland Swale Hydrodynamic Detention Pond Separator ADS Infiltration System 80.0 StormTech Bioretention Isolator Row Vegetated Swale LL 75.0 70.0 65.0 UOL 60.0 55.0 50.0 45.0 GW LOL 40.0 35.0 30.0 1/13/2005 1/13/2005 3/14/2005 3/14/2005 5/13/2005 5/13/2005 7/13/2005 7/13/2005 9/11/2005 9/11/2005 11/11/2005 11/11/2005 1/10/2006 1/10/2006 3/11/2006 3/11/2006 5/11/2006 5/11/2006 7/10/2006 7/10/2006 9/9/2006 9/9/2006 11/8/2006 11/8/2006 1/8/2007 1/8/2007 3/9/2007 3/9/2007 5/8/2007 5/8/2007 7/8/2007 7/8/2007 9/6/2007 9/6/2007 11/6/2007 11/6/2007 1/5/2008 1/5/2008 3/5/2008 3/5/2008 5/5/2008 5/5/2008 7/4/2008 7/4/2008 9/3/2008 9/3/2008 11/2/2008 11/2/2008 Dt Date 9 Event Mean Tem mperature o ( F)
Annual Cumulative Distribution Function 100% 1 LOL GW UOL LL 0.9 90% 0.8 08 80% 0.7 70% Cumulative Probabili lity (% (% 0.6 60% 0.5 50% 0.4 40% 0.3 30% 0.2 20% Runoff Retention Pond Detention Retention Pond Retention Gravel Pond Detention Wetland Pond Bioretention Runoff Detention Vegetated Gravel Wetland Pond Swale HDS Bioretention ADS Vegetated Vegetated Swale Swale STIR 0.1 10% 0 0% 30 30.0 35 35.0 40 40.0 45.0 50.0 55.0 60.0 65.0 70.0 75.0 80.0 85.0 EMT( Event Mean Temperature, o F) Event Mean Temperature, EMT ( o ( o F) F) 10
Summer CDF 100% LOL GW Summer (April - September) UOL LL 90% 80% lity (% Cu umulative Probabil 70% 60% 50% 40% 30% 20% 10% Runoff Retention Pond Detention Pond Gravel Wetland Bioretention Vegetated Swale HDS ADS STIR 0% 35.0 40.0 45.0 50.0 55.0 60.0 65.0 70.0 75.0 80.0 85.0 Event Mean Temperature, EMT ( o F) 11
Summer Quartile Assessment 85.0 80.0 LL 75.0 70.0 o ( F) Even nt Mean Temperature o ( 65.0 60.0 55.0 50.0 45.0 UOL GW LOL 40.0 35.0 30.00 Runoff Retention Pond Detention Pond Gravel Wetland Bioretention Vegetated Swale Hydrodynamic Separator ADS Infiltration System StormTech Isolator Row 12
Winter Quartile Assessment 85.0 80.0 75.0 70.0 Eve ent Mean Temperature o (F) 65.0 60.0 55.0 50.0 45.0 40.00 35.0 30.0 Runoff Retention Pond Detention Pond Gravel Wetland Bioretention Vegetated Swale Hydrodynamic ADS Infiltration StormTech Isolator Separator System Row 13
Annual Temperature Histogram 0.14 LOL GW UOL LL 0.12 Normalized Frequ uency (Count/Total l) 0.10 008 0.08 0.06 Runoff Retention Pond Gravel Wetland 0.04 0.02 0.00 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 Stormwater t Temperature ( o F) 14
Results Annual Assessments EMT ( o F) Runoff Retention Pond Detention Pond Gravel Wetland Bioretention Vegetated Swale HDS ADS STIR Median 52.4 48.1 52.8 47.3 51.8 57.3 56.6 49.2 47.6 Mean 53.55 50.9 52.3 48.7 51.9 54.8 54.1 51.55 49.0 Standard Deviation 12.7 14.6 15.1 12.0 13.1 12.6 13.6 9.7 9.2 Maximum 75.4 81.3 79.4 70.0 73.7 75.0 75.0 66.4 67.8 %N Non-Exceedance UOL (65 o F) 72.5% 79.0% 71.5% 87.0% 78.0% 72.5% 65.0% 95.0% 98.5% Summer Assessments EMT ( o F) Runoff Retention Pond Detention Pond Gravel Wetland Bioretention Vegetated Swale HDS ADS STIR Median 66.2 64.6 68.6 60.9 63.9 68.6 66.3 60.3 53.7 Mean 62.5 61.8 66.3 57.3 61.2 65.6 63.8 56.3 53.2 Standard Deviation Mean July Temperatures ( o F) %N Non-Exceedance UOL (65 o F) 9.8 11.8 7.8 10.1 8.7 7.3 9.1 9.3 7.9 67.1 77.9 72.2 66.0 67.7 70.3 69.0 63.4 58.5 42.0% 56.0% 37.0% 73.0% 58.5% 35.0% 34.0% 91.0% 96.0% 15
Summer Natural Streams 100% LOL GW UOL LL 90% 80% Non-E Exceedance Pro obability (%) 70% 60% 50% 40% 30% 20% 10% College Brook @DMP Wednesday Hill Brook Detention Pond Gravel Wetland Vegetated Swale StormTech Isolator Row 0% 30 35 40 45 50 55 60 65 70 75 80 85 Temperature ( o F) 16
Thermal Performance % Non-Exceedance Upper Optimum Limit 65*F 100 75 50 25 0 45 LOL 65 UOL 80 LL Mean July Temperature*F 17
Conclusions Infiltration practices allow greater buffering of stormwater temperature. The longer subsurface flow paths and mass, the greater the buffering. Bioretention Gravel Wetland ADS Infiltration System Conventional stormwater management designs that include ponding as a control measure, allow for additional increase in temperature. Permanent pools of water act as heat sinks during the warmer summer months. Vegetated Swale Detention Pond Retention Pond This data could be used to estimate the mixing of temperatures from the BMPs and receiving streams A predictive model could be developed based on mass and surface expression to determine required BMP characteristics (ie type and size) to be protective 18
Questions 19
Future Research Porous Asphalt Verify temperature readings System Size vs. Performance Expand data to include off-site systems Stream Mixing Determine thermal regimes for a variety of streams Model mixing behavior of temperature 20