Opti-Tool for Stormwater and Nutrient Management Mark Voorhees, US Environmental Protection Agency, Region 1

Transcription

1 Opti-Tool for Stormwater and Nutrient Management Mark Voorhees, US Environmental Protection Agency, Region 1 (voorhees.mark@epa.gov) What is Opti-Tool? Opti-Tool (Stormwater Management Optimization Tool) is a spreadsheet-based optimization tool that provides both a planning level and implementation level analysis. The tool helps planners determine the best mix of BMPs to provide the greatest benefit for achieving water resources goals while balancing costs. The Planning Level Analysis provides maximum possible load reduction for all feasible BMP opportunities or cost-effective single solution that meets the numeric load reduction target. The Implementation Level Analysis provides optimal combination of different BMP types, sizes and spatial locations or cost-effective solutions for a range of load reduction targets. Benefits of Opti-Tool Accessible to all users with Microsoft Excel 2013 software; Represents actual regional precipitation conditions; Incorporates best available information on stormwater urban runoff nutrient quality; Incorporates best available information for estimating long-term cumulative nutrient load and runoff volume reduction performances for 11 categories of structural stormwater controls; Incorporates representative stormwater control units cost information with scaling function to account for specific site conditions and development density; Includes flexibility to conduct either watershed planning level or detailed site specific design-level analyses; and Performs optimization analyses to determine most cost-effective selection of structural stormwater controls for achieving pollutant loading and runoff flow related reduction targets. Regional Specific Data Multiple datasets required as input for Opti-tool were customized for EPA Region 1. 1.Regionally calibrated BMP performance curves were developed based on University of New Hampshire Stormwater Center (UNHSC) BMP monitoring data. The BMP data was utilized to calibrate BMPs. 2.Charlies River Watershed Association and the UNHSC provided BMP cost estimates. 3.Compared weather stations from major urban areas across the New England states to determine Boston Logan Airport station is a representative precipitation data set for Region. 4.Long-term pollutant runoff time series for typical land uses in the region were updated. Storm water monitoring data was used to calibrate the buildup and washoff processes on impervious cover. The Run Single Scenario analysis can estimate the BMP Storage Capacity for any given runoff treatment depth from the BMP impervious drainage areas. The Run Optimize button will begin the performance optimization process. The optimization analyses are performed through Excel Solver. Landuse Type Agriculture Forest Highway Industrial Commercial High Density Residential Medium Density Residential Low Density Residential Open Land Agriculture Forest Developed A Developed B Developed C Developed C/D Developed D Planning Level Analysis Impervious/ Pervious Impervious Impervious Impervious Impervious Impervious Impervious Impervious Impervious Impervious Pervious Pervious Pervious Pervious Pervious Pervious Pervious The required information is separated into four different sections: management objective, optimization target, watershed information, and BMP information. The different scenario approaches calculates the BMP storage capacity (ft 3 ), BMP cost ($), treated impervious area (ac), annual operation and maintenance hours (hr), and pollutant load reduction (lbs) for the BMP defined with drainage area, from the BMP information step. Implementation Level Analysis The Implementation Level Analysis allows users to enter watershed and BMP design information through a series of customized forms and tables. The steps are tabled in order on the Implementation Level analysis interface. The user is responsible for defining the number of subbasins, junctions, land uses, BMPs, and pollutants under Watershed Information step. Then, throughout the step by step process, the user defines characteristics of each component. The View Results option allows users to provide a target value, and Opti-Tool searches for the nearest solution and provides the solution reduction percentage and the total cost. It also provides the BMP information for the BMPs defined in the project. The BMP information includes: BMP Type, BMP Area (ft 2 ), BMP Storage Depth (ft), Treated Impervious Area (ac), Annual Maintenance (hours), and BMP Cost($). The Cost-Effectiveness curve references the output files and provides the user an opportunity to have a meaningful interaction with the simulation results. Implementation level analysis yields a graph of all solutions and identification of the best solutions in a cost vs. % reduction graph. Solution Total Solution Reduction Target Reduction (%) Cost (Million $) (%) 52.1% % BMP ID BMP Type BMP Area (ft^2) BMP Storage Depth Treated Impervious Area (ft) (ac) Annual Maintenance (hours) Cost ($) BMP1 INFILTRATIONBASIN NOT ASSESSED 17,226,706 BMP2 INFILTRATIONBASIN NOT ASSESSED 14,480,419 BMP3 INFILTRATIONBASIN NOT ASSESSED 1,897,434 BMP4 BIORETENTION ,616 BMP5 BIORETENTION ,862,341 BMP6 BIORETENTION ,799,936 BMP7 BIORETENTION ,279,994 BMP8 ENHANCEDBIORETENTION NOT ASSESSED 7,175,105 BMP9 SUBSURFACEGRAVELWETLAND ,787,558 Cost saving of $47.5 million (56%) by lowering 10% of the numeric target (42.1%).

2 Stormwater Management with Opti-Tool U.S. EPA STORMWATER OUTREACH IN MASSACHUSETTS STORMWATER is a leading cause of poor water quality. Rain or melted snow runs down driveways, sidewalks and streets carrying oil, dirt and other pollutants into nearby waterways. Polluted runoff, which can cause erosion and flooding, runs into waterways and degrades plants, fish, shellfish and other wildlife. In water used for recreation, the runoff can lead to illness, and people who eat contaminated fish can also become sick. Untreated stormwater can also contaminate drinking water sources. This summer, EPA Region 1 will complete work on Opti-Tool. Opti-Tool is a spreadsheet-based stormwater best management practices optimization tool. Opti-Tool is designed for use by municipal SW managers and their consultants to assist in developing technically sound and optimized cost-effective SW management plans. Controlling and treating discharges of SW runoff, especially from highly developed urban areas, can be technically difficult and costly. Opti-Tool is designed to help SW managers navigate and overcome the planning and assessment challenges associated with retrofitting SW controls into existing developed landscapes. These SW controls are for the dual purposes of reducing pollutant loads of nutrients (TP, TN), sediments (TSS), and zinc (a surrogate for metals most commonly found in SW runoff), as well as addressing hydrologic imbalances. Benefits of the tool Accessible to all users with Microsoft Excel 2013 software. Represents actual regional precipitation conditions (long-term hourly data, ). Incorporates best available information on SW runoff nutrient quality, including build-up/wash off processes, especially important in New England where storms are predominantly small events (e.g., 50% < 0.3 in.; 70% < 0.6 in.; 80% < 0.8 in.; and 90% < 1.2 in.). Incorporates best available information for estimating long-term cumulative nutrient load and runoff volume reduction performances for 11 categories of structural SW controls - UNHSC is one of the best sources of data. Uses information which is being shared with other regional tool developers to promote the use of consistent and high quality data. Incorporates representative SW control units cost information with scaling function to account for site specific conditions and development density. Includes flexibility to conduct either watershed planning level or detailed site specific design-level analyses. Performs optimization analyses to determine most cost-effective selection of structural SW controls for achieving pollutant loading and runoff flow related reduction targets. continued > March 2016 t printed on 100% recycled paper, with a minimum of 50% post-consumer waste, using vegetable-based inks

3 TetraTech, Inc. Developed by TetraTech, Inc. for the U.S. EPA under contract. Microsoft Mention of commercial products, services or organizations does not constitute an endorsement by the U.S. EPA Provides results consistent with phosphorus source load rates and SW control reduction values in EPA Region 1 s new small MS4 general permits. What a User needs to do The user defines the targeted geographic area, land use distribution by impervious and pervious cover, pollutants of concern (or runoff volume), and follows user-friendly screen prompts for choices on characterizing watershed study area, soil, BMP types and hydraulic network/conduit information. Results After a given scenario simulation has run successfully, results are provided depending on the user s selection of a cost-effectiveness curve or a flow duration curve. Planning level scenarios yield optimal solution tables of different BMP types/sizes/o&m costs/and corresponding load reduction. Implementation level analysis yields a graph of all solutions and identification of the best solutions in a cost vs. % reduction graph. Coming Soon: A separate but compatible BMP Tracking and Accounting Tool (BATT) is being designed for use by small MS4 permittees for accounting, tracking and reporting on nutrient load reductions associated with BMP SW controls implemented and to demonstrate compliance with nutrient reduction requirements in EPA Region 1 s new stormwater permits for Massachusetts and New Hampshire.

4 Historical Overview Charles River P TMDLs, (Lower Upper/Middle ) Residual Designation Petition,~2007 SW Control Performance Analyses Pollutant Removal BMP Performance Curve: Gravel Wetland Land Use: Commercial 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% Depth of Runoff Treated (inches) TSS TP Zn MS4 Permits with TMDL Related Reductions Requirements MA Final (2016) NH Draft (2013,15) Accounting System Phosphorus Source Loads & Credible SW Control Reduction Credits ~ Stormwater Management Optimization Analysis, Low Cost SW Control Performance Analyses ~2013 Draft Residual Designation Permit, ~2010 Sustainable Funding Study & EPA Updated Optimization Analysis, Permitting Tools: Stormwater Management Optimization Tool Opti-Tool ( ), and BMP Accounting and Tracking Tool BATT ( )

5 SW Management in Developed Landscapes: Technical & Economic Feasibility Challenges/Opportunities CONCEPTS Comprehensive watershed planning vs. project by project Credible best estimates: IC source loadings SW Control cumulative reductions (all sizes) Costs Accounting System for planning & compliance Every little bit counts Optimization analyses

6 Stormwater Phosphorus & Nitrogen Phosphorus Highly associated with very fine particles ~ 40 microns Fine particles readily washed from impervious surfaces with small amounts of rainfall Stormwater controls must have filtration component to be effective Nitrogen N Oxides are readily washed off in early portion of rain events Organic nitrogen can be a significant part of N load High removals of SW nitrogen may require denitrification

7 100% of DIN mass in first 0.1 in runoff or 10% of WQV V ISR /WQV =0.1 90% of DIN mass in first 0.2 in runoff or 20% of WQV V ISR /WQV =0.2 Mass loading for DRO, Zn, NO3, TSS as a function of normalized storm volume for two storms: (a) a large 2.3 in rainfall over 1685 minutes; (b) a smaller 0.6 in storm depth over 490 minute. DRO=diesel range organics, Zn= zinc, NO3= nitrate, TSS= total suspended solids (Source: Dr. James Houle, UNHSC) 4

8 New England Region- Cumulative Precipitation, Runoff Volume, Total Nitrogen Load Delivery from Impervious Cover Cumulative Percent (%) Estimated Cumulative Percent (%) Runoff Volume and Total Nitrogen Load Delivery from Impervious Cover (IC) Based on Hourly Precipitation Data - Boston, MA ( ) and Median TN EMC data for Commercial/Industrial from NSQD - Rainfall Regions 1 & 2 (Pi 100% 90% 80% 75.9% 97.3% 98.0% 95.0% 70% 60% 50% 40% 30% 20% 10% 28.4% 0% 0% 45.1% 16.2% 29.1% 55.7% 74.6% cumulative % average annual runoff from IC cumulative % average annual TN Load from IC 0% Runoff Depth from Impervious Cover (IC), inches Runoff volumes calculated by assuming initial abstraction of 0.1 inch of rainfall depth per event 5

9 Importance of Impervious Area (IA) in SW Pollutant Loading Impervious cover (IC) generates much greater runoff volume than pervious areas, therefore in developed landscapes IC is typically the most significant contributor of overall SW pollutant loading and retrofits should focus on IC Typical range of urban SW TP concentrations Calculated annual phosphorus load export rates (PLER) based on various hydrologic conditions for a range of stormwater total phosphorus (TP) concentrations Watershed surface Description Annual Runoff Yield, MG/ha/yr Flow weighted SW TP conc., mg/l -----> Annual Phosphorus Load Export (PLE), kg/ha/yr Impervious surface impervious surface Pervious area HSG A well drained soils Pervious area HSG B moderately drained soils Pervious area HSG C limited permeability Pervious area HSG D poorly drained soils Annual Runoff yield by SWMM for hourly rainfall - Boston MA ( ), Flow-weighted SW TP conc. = total annual P load divided by total annual runoff volume. HSG= Hydrologic Soil Group, MG= million gallons, ha = hectare (1 ha= 2.47 acres)

10 EPA Region 1 s Proposed Phosphorus Load Export Phosphorus Load Accounted Land Surface Cover Use Rates for use in Stormwater Export Rate, Comments for in Opti- Permitting Process Kg/ha/yr Tool Table 1: Average Annual Phosphorus Load Export Rates for use in the MA MS4 Permit Phosphorus Source Category by Land Commercial (Com) and Industrial (Ind) Multi-Family (MFR) and High-Density Residential (HDR) Directly connected impervious Pervious Directly connected impervious Pervious 2.0 Derived using a combination of the Lower Charles USGS Loads study and NSWQ dataset. This PLER is approximately 75% of the HDR PLER and reflects the difference in the distributions of SW TP EMCs between Commercial/Industrial and Residential. See* DevPERV 2.6 Largely based on loading information from Charles USGS loads, SWMM HRU modeling, and NSWQ data set See* DevPERV Medium -Density Residential (MDR) Low Density Residential (LDR) - "Rural" Highway (HWY) Forest (For) Open Land (Open) Agriculture (Ag) *Developed Land Pervious (DevPERV)- Hydrologic Soil Group A *Developed Land Pervious (DevPERV)- Hydrologic Soil Group B *Developed Land Pervious (DevPERV) - Hydrologic Soil Group C *Developed Land Pervious (DevPERV) - Hydrologic Soil Group C/D *Developed Land Pervious (DevPERV) - Hydrologic Soil Group D Directly connected impervious 2.2 Largely based on loading information from Charles USGS loads, SWMM HRU modeling, Pervious Directly connected impervious Pervious See* DevPERV and NSWQ data set 1.7 Derived in part from Mattson Issac, HRU modeling, lawn runoff TP quality information from Chesapeake Bay and subsequent modeling to estimate PLER for DCIA (Table 14) to approximate literature reported composite rate 0.3 kg/ha/yr. See* DevPERV Directly connected impervious 1.5 Largely based on USGS highway runoff data, HRU modeling, information from Shaver et Pervious al and subsequent modeling to estimate PLER for DCIA for literature reported See* DevPERV composite rate 0.9 kg/ha/yr. Directly connected impervious 1.7 Derived from Mattson & Issac and subsequent modeling to estimate PLER for DCIA that Pervious corresponds with the literature reported composite rate of 0.13 kg/ha/yr (Table 14) Directly connected impervious Pervious Directly connected impervious Pervious Pervious Pervious Pervious Pervious Pervious Derived in part from Mattson Issac, HRU modeling, lawn runoff TP quality information from Chesapeake Bay and subsequent modeling to estimate PLER for DCIA (Table 14) to approximate literature reported composite rate 0.3 kg/ha/yr. See* DevPERV 1.7 Derived from Budd, L.F. and D.W. Meals and subsequent modeling to estimate PLER for DCIA to approximate reported composite PLER of 0.5 kg/ha/yr Derived from SWMM and P8 - Curve Number continuous simulation HRU modeling with assumed TP concentration of 0.2 mg/l for pervious runoff from developed lands. TP of 0.2 mg/l is based on TB-9 (CSN, 2011), and other PLER literature and assumes unfertilized condition due to the upcoming MA phosphorus fertilizer control legislation.

11 Cumulative Phosphorus Load Removal Runoff Volume Reduction 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% SW Control Long-term Cumulative Performance Curve Concept SW Control Performance Curves Surface Infiltration Practices rain gardens, swales, basins, etc. (Saturated Soil Infiltration Rate 0.52 in/hr) 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% Accounted for in Opti- Tool 0% Physical Storage Design Capacity, Impervious Surface Runoff Depth (inches) TP Volume 0% Small Rain Garden Larger Stormwater Basin

12 Unit Cost information for Various SW Controls SW Control Type Cost ($/ft 3 ) 2016 dollar Accounted for in Opti- Tool Bioretention $ Dry Pond $ 6.44 Enhanced Bioretention $ Infiltration Basin $ 5.91 Infiltration Chamber $ 60.4 Infiltration Trench $ Porous Pavement (Asphalt) $ 5.03 Porous Pavement (Concrete) $ 17.1 Sand Filter $ Subsurface Gravel Wetland $ 8.31 SW Control Development Type Cost Adjustment Factor New BMP in Undeveloped Area 1.00 New BMP in Partially Developed Area 1.50 New BMP in Developed Area 2.00 Difficult Installation in Highly Urban Settings 3.00 Estimates of hours of level of effort for Operation & Maintenance (O&M) has been estimated for each of the SW control types. Wet Pond $ 6.44 Unit cost is based on control s storage capacity (ft 3 ) to hold water (e.g., pond volume + void space volume) making it straight forward to integrate cost and performance information, (e.g., $ per pound of P removed). 9

13 Demonstration Project: Optimization Analysis for 3 Upper Charles Towns Conducted by Tetra Tech to evaluate broad SW Management Strategies to inform Permit Development Big Picture Key Findings: The range in estimated costs for implementation of SW controls watershed-wide to achieve a set phosphorus reduction target is HUGE Standardize sizing of controls (one size fits all) will be much more expensive (administrative ease may be unaffordable and unwise) Comprehensive optimization process will help identify the best combination of controls, design capacities and locations to achieve required load reduction at least cost

14 Demonstration Project: Optimization Analysis for 3 Upper Charles Towns Example Results All scenarios evaluated Total cost (million $) %, $98 Million 20 52%, $26 Million 52%, % 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% Annual average TP load reduction

15 Estimated Construction Cost, $ includes a 35% for engineering and contingencies Estimated Construction Costs for Structural Stormwater Controls to Achieve a 40 % Reduction in Phosphorus Load form the Charles River Watershed in Milford, Bellingham & Franklin based on Amount of Impervious Area Treated $250,000,000 $200,000,000 $193,788,094 $150,000,000 $151,722,468 $100,000,000 $114,715,944 $104,004,002 $97,826,021 $85,902,399 $50,000,000 60% 70% 80% 90% 100% Percentage of Impervious Area Treated in Charles River Watershed of Milford, Bellingham & Franklin, MA 10/25/

16 Weighted average capacity of structural controls inches of runoff from impervious cover Average Capacity of structural controls needed to achieve a phosphorus load reduction of 40% in the Charles River Watershed of Milford, Bellingham & Franklin, MA based on the treatment of varying amounts of impervious area % 60% 70% 80% 90% 100% Percentage of Impervious Area Treated in CRW of Milford, Bellingham, & Franklin MA 10/25/

17 Annual runoff volume recharged by Infiltration practices MG/yr 2800 Estimated annual stormwater recharge volume by infiltration practices for varying amounts of impervious area treated associated with achieving a 40% phosphorus load reduction from the Charles River Watershed within Milford, Bellingham & Franklin, MA 2548 MG/yr -Average annual potable water consumption for Milford, Bellingham and Franklin, MA % 65% 70% 75% 80% 85% 90% 95% 100% Percentage of impervious area treated in CRW of Milford, Bellingham & Franklin MA 10/25/

18 Opti-Tool: Introduction Overview of the planning and implementation options Khalid Alvi Environmental Engineer Tetra Tech, Incorporated Fairfax, Virginia

19 Project Background Small MS4 General Permit for MA and NH Phosphorus reduction requirement to meet the Waste Load Allocations for the impaired watershed Phosphorus Control Plan (PCP) To measure compliance with its phosphorus reduction requirement under the permit Opti-Tool A tool to facilitate storm water engineers to developing Nutrient Management Plans such as PCP. 16

20 Project Background cont. Proven benefits of optimization techniques in stormwater management Charles River watershed study Practical needs by stormwater practitioners BMP simulation BMP optimization Independent of ArcGIS Simple to use 17

21 Opti-Tool A spreadsheet-based BMP optimization tool Planning Level Analysis (EPA Region 1 BMP Performance Curves) Implementation Level Analysis (EPA SUSTAIN BMP Simulation and Optimization Engine) Customized for EPA Region 1 18

22 Opti-Tool: Planning and Implementation Options Excel Inputs Excel Outputs Planning Level Input: Target pollutant load reduction Watershed land use area BMP drainage area BMP Performance Curve Excel Solver Output Postprocessor: Cost-effectiveness solution Optimal management options BMP size and cost Treated impervious area Optimization method Implementation Level Input: Watershed, land use, pollutants Potential BMPs representation BMP treated area Input Text File SUSTAIN Optimization Engine Output Postprocessor: Cost-effectiveness curve Optimal management options Management objective BMP type, size, and cost

23 Opti-Tool: Example Applications Planning Level Analysis Maximum possible load reduction for all feasible BMP opportunities Watershed scale and/or site scale Aggregated BMP representation (grouping same BMP types as one unit) No BMP nesting (parallel BMPs) Cost-effective single solution meeting the numeric target Implementation Level Analysis Optimal combination of different BMP types, sizes, and spatial locations Watershed scale and/or site scale Aggregated and/or distributed BMP representation simple to complex BMP routing network (BMPs in parallel and/or in series) Cost-effective solutions (CE-curve) for a range of load reduction targets

24 Opti-Tool: Region Specific Data Precipitation Representation Long-term hourly data at Logan airport ( ) Land Representation Stormwater monitoring data to calibrate the buildup & washoff processes on impervious cover Long-term landuse specific annual average load export rates BMP Representation University of New Hampshire Stormwater Center (UNHSC) BMP monitoring data to calibrate flow and pollutant loss mechanism in BMPs Representative BMP cost information with scaling function 21

25 Opti-Tool: Precipitation Analysis Data Used 12 weather stations from major urban areas Represents climate regions in New England states NCDC hourly weather records Summary Results Average annual precipitation varies from 34 in. to 46 in. with average value of 42.3 in. Similar precipitation frequency distribution 48 percent of the events are < 0.1 inch 45 percent of the events are 0.1 to 1.0 inch 7 percent are > 1.0 inch Boston Logan Airport station is representative 22

26 Opti-Tool: Buildup & Washoff Calibration Data Used National Stormwater Quality Database (NSQD) Massachusetts and New Hampshire sites 100% impervious drainage areas Storm events smaller or equal than 1 inch Pollutants (TP and TN) Buildup & Washoff Parameterization Developed computer codes using GA algorithms to identify the parameter pattern that best fit the observed data Calibrated 21 sets of parameters representing different initial conditions Performed sensitivity analysis to identify the robust set of parameters 23

27 Buildup/Washoff: Calibration Plots for TP Reference: Technical Memos.pdf 24

28 Opti-Tool: HRU Timeseries Development Data Used Selected robust set of pollutant buildup & washoff parameters in calibrated SWMM model Regional representative landuse-based annual average pollutant load export rates (kg/ha/yr) Hourly precipitation and PET timeseries (1992 to 2014) Summary Results Adjusted buildup parameters to match the simulated long-term annual average pollutant loading rate (kg/ha/yr) Compared the simulated EMC distribution against the observed EMC distribution for impervious land use types Developed HRU hourly timeseries for flow, TP, TN, and TSS 25

29 Reference: Technical Memos.pdf 26

30 Opti-Tool: HRU Types 1. Commercial/Industrial 2. High-Density Residential 3. Medium-Density Residential 4. Low Density Residential 5. Highway 6. Open Land 7. Forest 8. Agriculture 9. Forest Pervious 10. Agriculture Pervious 11. Developed Land Pervious Hydrologic Soil Group A 12. Developed Land Pervious Hydrologic Soil Group B 13. Developed Land Pervious Hydrologic Soil Group C 14. Developed Land Pervious Hydrologic Soil Group C/D 15. Developed Land Pervious Hydrologic Soil Group D 27

31 Opti-Tool: BMP Calibration Data Used BMP design specifications (from the UNHSC) BMP monitoring data: flow and water quality (from the UNHSC) BMP Parameterization Developed SUSTAIN models Calibrated water quality parameters (1 st order decay and underdrain removal rate) Compared simulated BMP hydrograph and water quality performance against the observed BMP hydrograph and observed BMP efficiency Calibrated structural stormwater BMPs for flow, TP, TN, and TSS 28

32 Bioretention: Hydrology Calibration Observed Observed inflow inflow Generated Generated inflow to bio-retention inflow to bio-retention area area Observed Observed outflow outflow Calibrated Calibrated BMPDSS BMPDSS outflow outflow Flow (gpm) Flow (gpm) :40 20:00 21:00 20:20 21:20 20:40 21:40 21:00 22:00 21:20 22:20 21:40 22:40 22:00 23:00 22:20 23:20 22:40 23:40 23:00 0:00 23:20 0:20 23:40 0:40 0:00 1:00 0:20 1:20 0:40 1:40 1:00 2:00 1:20 2:20 1:40 2:40 2:00 3:00 2:20 2:40 3: :00 20:20 Time Time 29

33 Opti-Tool: BMP Performance Curve Data Used Calibrated SUSTAIN model Calibrated hourly HRUs timeseries (1992 to 2014) BMP Simulation Run BMP scenarios for a range of storage capacity and estimated the pollutant load reductions Developed BMP performance curve (pollutant load reduction vs storage capacity) Developed long-term cumulative pollutant load and runoff volume reduction performances for several categories of structural stormwater controls 30

34 31

35 Opti-Tool: BMP Types 1. Bio-filtration 2. Enhanced Bio-filtration with Internal Storage Reservoir 3. Dry Pond 4. Grass Swale 5. Gravel Wetland 6. Infiltration Basin 7. Infiltration Chambers 8. Infiltration Trench 9. Porous Pavement 10. Sand Filter 11. Wet Pond 32

36 Opti-Tool: BMP Cost Function Combination of the Charles River Watershed Association and UNHSC costs estimates Modified capital cost assessment (includes a fixed percentage for Design and Contingency Costs) Maintenance hours (from the UNHSC) BMP Type Cost ($/ft 3 ) 2016 Bioretention $ Dry Pond $ 6.8 Enhanced Bioretention $ Infiltration Basin $ 6.24 Infiltration Chamber $ Infiltration Trench $ Porous Pavement (Porous Asphalt Pavement) $ 5.32 Porous Pavement (Pervious Concrete) $ Sand Filter $ Subsurface Gravel Wetland $ 8.78 Wet Pond $ 6.8 Reference: Technical Memos.pdf 33

37 Opti-Tool: Interfaces

38 Planning Level: Two Approaches BMP Storage Capacity Evaluate the BMP performance for a design criterion (e.g., capture 1 inch storm size) Evaluate the changes in water quality benefits as the BMP sizes are changed Identify the most cost-effective BMP storage capacity that meets the target pollutant load reduction BMP Drainage Area Determine how much impervious drainage area would require treatment if specified BMP design capacities were selected Identify the extent of impervious area to be treated that can provide the target pollutant load reduction In this approach, both the BMP storage capacity and BMP cost are fixed.

39 Opti-Tool: Planning Level

40 Opti-Tool: Interfaces

41 Opti-Tool: Implementation Level 38

42 Cost (Million $) Opti-Tool: Model Results Solution Total Solution Reduction Target Reduction (%) Cost (Million $) (%) 52.1% % All Solutions Best Solutions Target Solution BMP Storage Depth Treated Impervious Area BMP ID BMP Type BMP Area (ft^2) Annual Maintenance (hours) Cost ($) (ft) (ac) BMP1 INFILTRATIONBASIN NOT ASSESSED 17,226,706 BMP2 INFILTRATIONBASIN NOT ASSESSED 14,480,419 BMP3 INFILTRATIONBASIN NOT ASSESSED 1,897,434 BMP4 BIORETENTION ,616 BMP5 BIORETENTION ,862,341 BMP6 BIORETENTION ,799,936 BMP7 BIORETENTION ,279,994 BMP8 ENHANCEDBIORETENTION NOT ASSESSED 7,175,105 BMP9 SUBSURFACEGRAVELWETLAND ,787,558 Cost $84.53 million to meet 52.1% average annual TP load reduction target Cost saving of $47.5 million (56%) by lowering 10% of the numeric target (42.1%) % 10% 20% 30% 40% 50% 60% % Reduction Annual Average Load

43 Benefits of Opti-Tool Accessible to all users with Microsoft Excel 2013 software Represents actual regional precipitation conditions Incorporates best available information on stormwater urban runoff nutrient quality Incorporates best available information for estimating long-term cumulative nutrient load and runoff volume reduction performances for 11 categories of structural stormwater controls Uses Information which is being shared with other regional tool developers to promote the use of consistent and high quality data

44 Benefits of Opti-Tool cont. Incorporates representative stormwater control units cost information with scaling function to account for specific conditions and development density Includes flexibility to conduct either watershed planning level or detailed site specific design-level analyses Performs optimization analyses to determine most cost-effective selection of structural stormwater controls for achieving pollutant loading and runoff flow related reduction targets

45 Flexible to Adapt for Other EPA Regions Develop local weather data Hourly precipitation Daily temperature (min and max) Run SWMM model (provided in the installation package) Local weather data input SWMM hourly HRU timeseries output Run HRU utility tool (provided in the installation package) SWMM hourly HRU timeseries input Opti-Tool hourly HRU timeseries output Update default data (provided in the installation package) HRU timeseries and local BMP cost function (optional)

46 Feedback and Other Presentations Questions or comments? Mark Voorhees Links to other presentations