BMP Trains 2020 Model SFWMD Professional Staff Education and Training

Transcription

1 An introduction to BMP TRAINS 2020 with example stormwater BMPs BMP Trains 2020 Model SFWMD Professional Staff Education and Training By: Marty Wanielista, Ikiensinma Gogo-Abite, Antony Rios and Christelle Dasny April 3,

2 BMP Trains 2020 MODEL BMP Trains 2020: a C++ and VB based model for estimating annual removal effectiveness. The acronym is derived from the analysis of stormwater BMPs in series The model is used to evaluate Best Management Practice Treatment options for Removal on an Annual basis by those Interested in Nutrients in Stormwater. Mailing list for updates: 2 Locations for the manual and the program: Credit and thanks for the programming and technical skills of: Dr. Ron Eaglin, Dr. Mike Hardin, Dr. Harvey Harper, Dr. Ikiensinma Gogo-Abite, Eric Livingston, Rich Magee and Chris Kuzlo

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4 Learning Objectives 1. What is BMP Trains 2020? 2. Improvements to existing model. 3. Navigation of BMP Trains Site Information Worksheet. 5. Catchment Worksheet. DCIA and CN calculations. 6. Treatment Options Worksheet. 7. Single catchment examples with one of more BMPs. 8. Groundwater recharge, loading and average annual concentration. 9. Report Options. 4

5 BACKGROUND INFORMATION (WHY a Model?) 1. The need for consistency in assessment of any stormwater management plan and in particular for ERP and BMAP applications. 2. Incorporate creative solutions and establish credit for creative designs. Some examples are green roofs, depression storage (rain gardens), pervious pavements, filters, swales, harvesting, exfiltration trench, vegetated filter strips (VFS), tree wells. 3. Need for Florida based applications, not something for a different climate or enforcement program (Effectiveness is annual basis). 4. Professional discovery and understanding of hydrologic events leading to better design, example would be disconnected impervious areas. 5

6 Some considerations in the choice of a model to evaluate BMP systems Uses Florida Rainfall. Uses Florida soils and physical land use conditions. Uses event mean concentration data from Florida based studies. Incorporates removal effectiveness for many structural BMPs and LIDs. Evaluates the effectiveness of BMPs in series and parallel. Peer reviewed by professionals and passed administrative hearings. Be available in the open literature (no cost to purchase). Acceptable to many practicing professionals. Acceptable to the local, regional (WMD), Department of Transportation (FDOT), and FDEP regulatory and review professionals. BMP Trains provides all of the above. 6

7 The BMPTRAINS EXCEL model 7

8 Improvements to BMPTRAINS (EXCEL model) to a stand-alone BMP Trains 2020 (in C++) Why Easier to read input/output; so called Need more than 3 BMPs in one catchment. Now have up to 4 BMPs. EX #1: pervious pave to rain garden to wet detention to filtration. EX #2 Depression storage to swale to wet detention to harvesting. Provide for more than 4 catchments per run. EXCEL required the transfer of data manually among topologies if more than 4 catchments. C++ has an unlimited number of catchments, tested up to 10. At least 50 different topologies (catchment arrangements) have been tested. Provide annual recharge volume and average annual concentration estimates for discharges from BMPs to the ground. Did not have an estimate of concentration or volume per year when using the EXCEL version. Stand alone model not dependent on other proprietary platforms. It runs on a PC and a MAC with a PC emulator. Best on Windows 10 or protected Windows 7. 8

9 Input and Testing of BMPTRAINS BMP Trains 2020 Testing so that 2020 model Reproduce existing solutions Had Continued input from the FDEP, WMDs, and FDOT and consider input from consultants With new BMP combinations, such as, BMP after wet detention tools to calculate runoff and design parameters Provides for more accurate CN calculations that are based on annual runoff volume. 9

10 Improvements to BMP Trains 2020 Testing and Manual Documentation and example problems available Up to 4 BMPs per catchment With many catchments and configurations (topologies) All calculation routines tested. Example problems use data for surface and groundwater loading and recharge volumes validation. 10

11 Start using the BMP Trains 2020 model 11

12 Navigation and Structure of the Program Worksheets to enter data and retrieve results Drop Down Menu Choices limited Navigation Buttons Data Cells Unlimited Entries 12

13 General Site Info Worksheet- BMPTrains2020 Support Information Drop Down Menu Can change any input without having to reload Net Improvement Specify Efficiencies BMP Analysis 10% less than Pre 13

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15 Changing Input Data easy to do Example Change Zone 15

16 ENTER DATA AS SHOWN THEN HIT CALCULATE BUTTON 16

17 ENTER DATA AS SHOWN For other BMPs, runoff and loadings will be calculated 17

18 Directly Connected Impervious area (DCIA) or averaging the CNs not a good idea Natural Condition: All pervious, represented by a Curve Number (CN) = 60 Developed Condition: 55% NDCIA, 45% DCIA CCN = 60 x x 0.45 = 77 (traditional flood control calculations) for flood control: CN for impervious area typically is 98, for small volume annual storms CN=95 or R>0 when P=0.1. and CCN = 60 x x 0.45 = 76 (annual runoff calculation) Zone 4: R=50 inches Annual Runoff inches and traditional units Ac-FT = in x acres / 12(in/ft) 55% Pervious 45% DCIA Total Area =4.75 Ac Wet pond = 0.25 Acres Calculate Runoff with composite Curve Number, CCN = 77 R = # x 50 = 5.48 inches ( ac-ft per acre) And for 4.75 acres = Ac-Ft # Annual runoff coefficient from Harper and Baker (2007) Calculate Runoff with composite Curve Number, CCN = 76 R = # x 50 = 5.14 inches ( ac-ft per acre) And for 4.75 acres = Ac-Ft # Annual runoff coefficient from Harper and Baker (2007) 18

19 Annual Runoff Volume Fraction (C) Zone 4 CN DCIA Based on 45 rainfall sites in the State using hourly data DCIA= By linear interpolation Calculation Tools Note: At 100% DCIA, there is initial abstraction and for small storm events there is little to no runoff. This is the annual runoff from a DCIA. 19

20 Use Directly Connected Impervious area (DCIA) averaging the CNs not a good idea Natural Condition: All pervious, represented by a Curve Number (CN) = 60 Developed Condition: 55% NDCIA, 45% DCIA CCN = 60 x x 0.45 = 77 (traditional flood control calculations) for flood control: CN for impervious area typically is 98, for small volume annual storms CN=95 or R>0 when P=0.1. and CCN = 60 x x 0.45 = 76 (annual runoff calculation) Zone 4: R=50 inches Annual Runoff inches and traditional units Ac-FT = in x acres / 12(in/ft) 55% Pervious 45% DCIA Total Area =4.75 Ac Wet pond = 0.25 Acres Calculate Runoff with composite Curve Number, CCN = 76 R = # x 50 = 5.14 inches ( ac-ft per acre) And for 4.75 acres = Ac-Ft # Annual runoff coefficient from Harper and Baker (2007) BUT: FOR DCIA = 45% For DCIA alone: Runoff = # x 50 = inches And for impervious area = x.45(4.75) / 12 = 7.33 Ac-Ft # Annual runoff coefficient from Harper and Baker (2007) USE DCIA not a CCN based on simple average or area weight Annual DCIA + Pervious 7.78 Ac-ft 20

21 CCN for Area with different soil and ground cover CCN is based on the weighted annual runoff for the areas Example Condition: 25 Acres, 7 different land use and soil types. No DCIA, but impervious area More accurate with annual runoff (C) for areas of each soil/cover crop with Ann their Run CNs. Area (ac) CN fraction Area and CN values are: Zone Acres soil/cover sum avg run= Discharge to a potential BMP area If average of CN= 60.7 weighted on area = 65 Ann Run Acre fract ~81 NDCIA CN % DCIA

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23 CN Based on area weighting would be 74 23

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27 14 Treatment BMP Options Each BMP Design Found in User Manual For a design other than the 13 listed, consult the review agency and enter as User Defined Calculating tools helpful for design For more than one BMP in the same catchment 27

28 To change to Groundwater Discharge Analysis 28

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32 Unlimited Catchments and Topology User can add catchments and their routing 32

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34 With no media TN = Kg/yr Avg Conc = mg/l < 0.35 m/l Recharge = MG/Y TN = 0.87 Kg/yr Avg Conc = 0.29 mg/l 34

35 At end of a run.. Save Data (.bmpt file), new. 35

36 BMP Trains 2020 Single catchment with more than one BMP in the same catchment BMP Trains 2020 Model By: Marty Wanielista April 3,

37 Retention BMPs Treating Runoff from the Same Catchment Area BMP Efficiency Determination For multiple retention BMPs used within a single catchment the overall efficiency is determined by adding up the total volume retained to obtain the associated treatment efficiency Treatment efficiency(%): Retention Efficiency Plot Efficiency Curve: System Efficiency (N $ P) CAT 1: System Efficiency (N $ P) CAT 2: System Efficiency (N $ P) CAT 3: System Efficiency (N $ P) CAT 4: Retention depth (inch): 37

38 Example for Two Retention BMPs in Series BMP Efficiency Determination Assume two retention BMPs in series first captures 0.5 in and the second captures 0.5 in 50% + 50% = 100% X Add the volume retained 0.5in + 0.5in = 1in 70% Treatment efficiency(%): Retention Efficiency Plot Efficiency Curve: System Efficiency (N $ P) CAT 1: System Efficiency (N $ P) CAT 2: System Efficiency (N $ P) CAT 3: System Efficiency (N $ P) CAT 4: Retention depth (inch): The avg annual cumulative rainfall for a given retention depth or rainfall volume. 38

39 Detention BMPs Treating Runoff from the Same Catchment Area BMP Efficiency Determination Based on the residence time a treatment efficiency can be determined and note Different removals for N & P At 50 days residence time, N removal is 40%, P removal is 70%. Treatment Efficiency (%): Detention Efficiency Plot Average Annual Residence Time (days): Efficiency Curve (P) System Efficiency (P) CAT 1 System Efficiency (P) CAT 2 System Efficiency (P) CAT 3 System Efficiency (P) CAT 4 Efficiency Curve (N) System Efficiency (N) CAT 1 System Efficiency (N) CAT 2 System Efficiency (N) CAT 3 System Efficiency (N) CAT 4 39

40 Example for Detention BMPs in Series BMP Efficiency Determination Assume two detention BMPs in series each have a 50 day retention time N=40%; P=70% N 40% + 40% = 80% X P 70% + 70% = 140% X N 50d + 50d = 100d ~ 43% 10 P 50d + 50d = 100d ~ 74% 0 Treatment Efficiency (%): Detention Efficiency Plot Average Annual Residence Time (days): Efficiency Curve (P) System Efficiency (P) CAT 1 System Efficiency (P) CAT 2 System Efficiency (P) CAT 3 System Efficiency (P) CAT 4 Efficiency Curve (N) System Efficiency (N) CAT 1 System Efficiency (N) CAT 2 System Efficiency (N) CAT 3 System Efficiency (N) CAT 4 40

41 BMPs not Related Example: Wet detention followed by filtration BMP 1 BMP mg 40% 60 mg 50% 30 mg 40 mg 30 mg Note this results in a 70% removal efficiency Not 90%, and never can have over 100% removal 41

42 Examples: Pre-Treat, Street Sweeping & FFL (user defined treatment and filtration) NOTE: For Surface Discharge Analysis If problem 7 saved, rain gardens has a color 42

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45 BMP Trains 2020 Example Problem 12 Single Catchment (wet detention and side-bank filter) BMP Trains 2020 Model By: Ikiensinma Gogo-Abite, PhD. April 3,

46 Example Problem 12 Stormwater Wet Detention and Filtration Average annual removal of a wet detention pond in series with a side-bank filter Net improvement analysis Located on the Southwest side of Florida, in meteorological zone 4 Mean annual rainfall is 52 inches Wet Pond area is 1.0 acre and permanent pool volume is 5.0 acre-feet Catchment configuration Pre-development Post-development Area (acres) Land-use Agricultural - Citrus Single-Family Non-DCIA CN DCIA (%)

47 Example Problem 12 contd. Input data for watershed and catchment area 47

48 Example Problem 12 contd. Input data for wet detention pond 48

49 Example Problem 12 contd. Input data for surface filtration 49

50 Calculation for Filter Media Surface Area Equating Generated volume to Treated volume Minimum Surface area (SF) based on removal in 3 days AA ffff = EEEEEE TTTT QQ ffff aa Usually the flow-through treatment rate (QQ ffff aa) is reduced by 50% to provide a safety factor. Available in BMP TRAINS 2020 as a calculator in the Tool menu

51 Calculation for Filter Media Surface Area Inputs are: Catchment characteristics, filtration rate and treatment depth Catchment characteristics and Treatment depth Same values are applied in the Surface Water Filtration Tab Filter Media Flow Rate Multiply the filter media permeability by the conversion factor Flow rate conversion factor from iiii hrr gggggg ffff 2 1 iiii hrr = gggggg ffff 2 Examples B&G CTS media: 5 iiii hrr gggggg ffff 2 & AA ffff = EEEEEE TTTT B&G ECT media: 96 iiii hrr gggggg ffff 2 & AA ffff = EEEEEE TTTT For EIA = Acres, TD = inches, and AA ffff = Square Feet (SF)

52 Example Problem 12 contd. Input data for surface area Check for drawdown time and size the filter to accommodate drawdown. Use acceptable methodologies by the FDOT and WMDs. Estimate the service life of filter media increase filter size to achieve longer service life. Minimum Filter Area = 2, SF 52

53 Example Problem 12 contd. Input treatment option 53

54 Example Problem 12 contd. Output TN: Discharged Load = 4.63 kg/yr Load Removed = kg/yr TP: Discharged Load = 0.10 kg/yr Load Removed = 4.22 kg/yr 54

55 Questions: Service Life Calculations 1. How long before it becomes ineffective? 2. How often will the filter media be replaced? 3. How can I determine the replacement cycle? Responses: Nitrate conversion is a biological process Orthophosphate (OP) is by adsorption Loading rate of OP OP is a fraction of TP (site-specific parameter) Sorption rate: 0.2 mg of OP per gram of moist filter media ( oz. of OP per pound of moist filter media) 55

56 Service Life Calculations Contd. Parameters Parameters required to calculate the Service Life of media Annual Runoff (RROO yyyy ) Actual size of the bank filter (> min of 2400 SF), and 6.5 x 371 = 2411 SF By code or regulation, depth of flow = 2 or more Runoff Capture Efficiency TP Concentration (TTPP cccccccc ) Reported Removal Efficiency of the media (TTPP EEEEEE ) Fraction of TP, in Dissolved form, in Runoff (OOOO ffffffff ) site specific Type of Media Volume of Media (VV ffff ) from previous calculations [AA ffff ffff 2 dd ffff ] Dry Unit Weight of Filter Media (γγ dd.ffff ) from design 56

57 Service Life Calculations contd. Calculation Steps: 1. Concentration of OP OOOO cccccccc = TTTT cccccccc mmmm LL OOOO ffffffff Or OOOO cccccccc = TTTT mmmmmmmm dddddddddddddddddddd RRRR aaaaaaaaaaaa 2. Weight of Media WW ffff = γγ dd.ffff 11 + ww (use when in series) VV ffff 3. OP Capacity of Media FFFF OOOO.cccccc = WW ffff OOOO SSSS 4. OP Loading Rate OOOO LLLL = RROO cccccccccccccc OOOO cccccccc 5. Annual OP Removal OOOO yyyy = OOOO LLLL OOOO EEEEEE 6. Service Life SSSS ffff = FFFF OOOO.cccccc OOOO yyyy 57

58 Example Problem 12 contd. Bold & Gold CTS Filtration Media PARAMETER Value Treatment Depth (in) 1.75 Volume of CTS Media (CF) 4,823 Concentration of OP (mg/l) Weight of Media (grams) 273,459,500 OP Capacity of Media (mg) 54,691,900 Runoff Capture Efficiency (%) 94 Annual Runoff Capture (L/yr.) 12,435,347 Annual OP Loading Rate (mg/yr.) 874,205 Removal Efficiency (%) 89 Annual OP Removal Rate (mg/yr.) 778,042 Service Life (yr.) 70 Inputs 1. Pond slope 4H:1V 2. Pond treatment depth 1.5 feet 3. Filter media depth 2, length = 371 width = Moist density of filter media 100 pcf 5. OP sorption rate 0.2 mg/g of media Service Life = OP Removal Capacity of Media divided by the OP supplied to the filter per year. Service Life = 54,691,900 mg/778,042 mg/yr. Service Life = 70 yr. 58

59 BMP Trains 2020 Example Problem 6 Cost Example Single Catchment BMP Trains 2020 Model By: Marty Wanielista April 3,

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61 Example Input Cost Data 61

62 Example Output Cost Analysis 62

63 BMP Trains 2020 REPORTS, Copy, Print, Save BMP Trains 2020 Model By: Marty Wanielista April 3,

64 REPORT GENERATION and DATA for REVIEW Many options to print, copy or create electronic files Bragging point: Was able to secure the extender Namely.BMPT Electronic Files 64

65 REVIEW PROCESS: USE COPIES OR PRINT OUTS REPORT GENERATION and DATA for REVIEW 65

66 REPORT GENERATION and DATA for REVIEW Many options to print, copy or create electronic files 66

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68 Summary Reports and Information 68

69 Learning Summary 1. Navigation of the BMP Trains 2020 model is by buttons with drop down menus and data input cells. There are support information and a user s manual. Go to: 2. BMP Trains is used to estimate average annual nutrient removal effectiveness. There is flexibility to account for regional rain, soil, DCIA, catchment configurations and design parameters. 3. The average annual effectiveness is site and BMP specific and can be calculated for both surface discharge and groundwater annual recharge, loadings and concentrations. 4. BMP Trains can evaluate annual effectiveness and provide cost comparisons for 14 BMPs and accepts user defined options.

70 An introduction to BMP Trains 2020 Single Catchment with applications Comments and Discussion April 2019 By Marty Wanielista, 70

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72 BMP Trains 2020 Model Understanding Multiple Catchments BMP Trains 2020 Model By: Marty Wanielista, April 3,

73 Learning Objectives 1. What is a catchment? 2. Disconnecting areas in a catchment. 3. Calculation Tools. 4. Configure Catchments Worksheet or Multiple Catchment set-up. 5. Comingling and delay time. 6. Efficiency vs. BMP Size for discovery of BMP options to aid in design and assessment. 7. Groundwater Discharge analysis

74 CATCHMENT Identification and Examples A catchment is defined by an area that contributes runoff water and there is a potential for a BMP. It is frequently called a contributing area. Series Ex: Greenroof Pervious Pave Wet Detention A BMP is usually associated with a catchment area but can be removed for evaluating various BMP combinations A 1 A - Single Catchment NOTE: Up to 4 BMPs at each catchment provided same catchment area into each BMP. Example: a retention area overflowing into a swale and to a wet detention pond and finally a filter. NOTE: the catchment area remains the same. BUT.. some of the particulate matter is removed before it gets to the wet detention pond. BMP Trains makes the adjustment in % effectiveness when a retention area is in front of wet detention.

75 Retention before Detention Retention BMP removes settling solids prior to detention BMP Partial removal credit for detention BMP Will vary depending on the removal achieved by upstream retention Treatment Efficiency (%): Settling fractions: N = 12% and P = 22% Average Annual Residence Time (days): Efficiency Curve (P) System Efficiency (P) CAT 1 System Efficiency (P) CAT 2 System Efficiency (P) CAT 3 System Efficiency (P) CAT 4 Efficiency Curve (N) System Efficiency (N) CAT 1 System Efficiency (N) CAT 2 System Efficiency (N) CAT 3 System Efficiency (N) CAT 4 75

76 Can have any combination of catchment configurations (you create your own). roof Parking lot 1 2 B - 2 Catchment-Series 1 2 C - 2 Catchment-Parallel 3 E - 3 Catchment-Parallel F F - Mixed-3 Catchment-2 Series-Parallel (A) G 1 2 Tested up to 10 catchments and all in series. It is impossible to test all configurations. Pond Pond Pond D - 3 Catchment-Series 3 G - Mixed-3 Catchment-2 Series-Parallel (B) H 1 2 H - 4 Catchment-Series 3 4 When to use more than one catchment? When treatment (ex: roof treatment or VFS are physically separated from remainder of watershed) or flow conditions (pond routing) dictate separation. 76

77 BMP Trains 2020 Disconnecting Areas BMP Trains 2020 Model By: Marty Wanielista, April 3,

78 CATCHMENTS Dis-connecting Areas Series Parallel A catchment is defined by an area that contributes runoff water and there is a potential for a BMP. It is frequently called a contributing area. A dis-connected area is one from which there is no annual runoff for 4 inches of rain. Why 4 inches? Marginal increases in annual mass loadings for rainfall over 4 inches. AND near 99% removal. 4

79 Treatment efficiency(%) A depression area with 4 inch storage over the catchment area (CA) (AVG annual Treatment efficiency = AVG annual capture volume) 80 In BMP Trains, Retention Removal Curves are defined for up to 4 inches of storage 70 Curve from BMP Trains Retention depth (inch) >98% 4.0 inch over the CA, usually NOTE: If Storage is = or > 4 inches, the CN number is the lowest or 30, which implies that the annual capture volume > 99% The CA for depression storage can be removed from the total area if treat depth = or >4.0

80 TOOLS (assistance in calculations and discovery) 80

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82 Retention Efficiency Discovery and Calculator 82

83 BMP Trains 2020 Multiple Configuration of Catchments BMP Trains 2020 Model By: Marty Wanielista, April 3,

84 Description of Example Problems in the Manual 1. Swale, Net Improvement, zone 1, and conduct a groundwater analysis 2. Comingling, Retention, BMP Analysis, zone 2 3. Retention, specify removal eff at 75%, zone 4 4. Wet detention with littoral zone and harvesting, net improvement, zone 5 5. Wet detention in series with retention, specify removal, zone 5 6. Multi BMP Cost Analysis, net improvement, zone 2 7. Rain gardens (a.k.a. depression storage), net improvement, zone 4, and conduct a groundwater analysis 8. VFS, net improvement for surface water, groundwater analysis, zone catchments in series, retention &wet detention, net improvement, zone catchments, in parallel and series, net improvement, zone 2 with harvesting 11.User defined baffle box with filter, Up-flow filter, zone 2 12.Wet detention and side bank filter, with filter size, zone 4 13.Impervious to pervious retention in zone 2. 84

85 BMP Trains 2020 can model many catchments in any configuration Previously limited to 4 catchments: User Define Previously had to run the model twice (4 catchments and two catchment). Then by repetitive solving of two models to achieve a target removal. With BMP Trains 2020 run the model once to determine the average annual removal or target levels. 85

86 Many catchments in any configuration catchment configuration, series and parallel 5 Catchment and treatment data must be added 86

87 6 Catchments, new site Add a catchment catchment configuration

88 BMP Trains 2020 Option to Comingle (mix with an existing BMP) BMP Trains 2020 Model By: Marty Wanielista, April 3,

89 Comingling, Wet pond BMP analysis, zone 2 An existing wet pond for one catchment has an adjacent catchment area that is not treated. Thus, two distinct catchments or possible control at both. The question is: by routing the adjacent area flow into the existing wet pond, is the sum of average annual removal with comingling greater than that without treating the adjacent site. Existing Pond Not treated Approximately a 58% increase in TN mass removal when combining versus no treatment of the adjacent site. The cost was lower compared to removing an equivalent amount using another BMP Also, can a side-bank BAM filter be added to improve the annual mass removal and gain additional credit for the municipality in their BMAP program? 89

90 Comingling, Existing Wet pond + Filter, No Treatment at the adjacent catchment, catchments in series 90

91 Comingling, Wet Detention BMP example: from 100 days to 50 days residence time Phosphorus Efficiency decrease is ~8% But input load increased ~ 100% Nitrogen Efficiency decrease is ~2% But input load increased ~ 100% 91

92 Comingling, Retention BMP example from 1.25 to inch retention depth Efficiency decrease is ~21% But input load increased ~ 100% 92

93 Ex Problem #2 Comingling, Retention, net improvement, zone 2 An existing retention basin serving a 2-acre highway with an option to by-pass or treat runoff from an equivalent offsite area. The offsite 2 acres with 50% directly connected impervious roadway owned by another transportation entry has the option to by-pass or be treated with the existing onsite retention basin. The site is located in Marion County, near Ocala FL, with 50 inches of annual rainfall on Hydrologic Soil Group C. A non-dcia Curve Number (CN) of 80 describes the soil conditions of both areas. Thus, the rainfall excess is the same from each roadway. Both treated Comingling OFF ON By-Pass ON OFF 93

94 Ex Problem #2 BMP analysis, zone 2, 50 inches rain 94

95 Ex Problem #2 Catchment 1 Conditions 95

96 Ex Problem #2 Navigate to Treatment Options 96

97 Ex Problem #2 Retention Basin Option 97

98 Ex Problem #2 Comingling, Retention, Depth of Treatment 98

99 Ex Problem #2 Retention Plot (efficiency vs. depth) 99

100 If groundwater discharge concerns: Plot Information Capture and Effectiveness with retention and a reactive media Treatment efficiency(%) 100 Capture Eff. Curve 90 Pond Capture Eff CAT 1 Pond Capture Eff CAT 2 80 Pond Capture Eff CAT 3 70 Surface Capture Pond Capture Eff CAT 4 60 Eff. Curve(N) P Removal before GW discharge 50 Eff. Curve(P) Sys. Eff. (N) CAT 1 40 N Removal Sys. Eff. before (N) CAT 2 GW discharge 30 Sys. Eff. (N) CAT 3 20 Sys. Eff. (N) CAT 4 10 Sys. Eff. (P) CAT 1 0 No Removal Sys. Eff. for (P) CAT natural 2 sandy soils Retention depth (inch) Sys. Eff. (P) CAT 3 Sys. Eff. (P) CAT 4 100

101 Example: Tree Well Sizing and Groundwater discharge analysis Note: there are 9 choices of media that will produce two separate removal curves in addition to the volume capture. Type of media mixes: View Media Mixes 101

102 Ex Problem #2 Go Back-Back to the site worksheet 102

103 Ex Problem #2 Must Enter the Configuration information 103

104 Ex Problem #2 Single Catchment, Retention, to Discharge (0) 104

105 Ex Problem #2 Summary Treatment Information 105

106 Ex Problem #2 Retention on-site only Summary 81% Removal and pounds of TN removed per year 106

107 Ex Problem #2 Add a Catchment 107

108 Ex Problem #2 Adding catchments. 108

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111 Ex Problem #2 Comingling of off-site with existing on-site Summary 63% TN removal but the mass of TN removed per year is pounds Note: If no delay time from catchment one to catchment two, the efficiency decreases from 63 to 61%. 111

112 Ex #2 Retention on-site no treatment off-site (BY-PASS Summary) 40% Removal and pounds of TN Per year removed Note TN % removal in this parallel treatment option is only 40% and pounds/yr TN removed compared to 63% and pounds/yr TN removed with comingling. Thus, mass removal has increased with comingling. This may not always be the result as EMCs, runoff volumes, design sizes and other factors may be such that comingling is not always the best. 112

113 Learning Summary 1. Annual Effectiveness of multiple catchments are in BMP Trains Effectiveness of wet detention is decreased by upstream retention. All configurations are possible and with any number of catchments. 2. Catchment areas can be reduced by providing for at least 4 inches of retention in specific areas. 3. Comingling of off-site with existing on-site treatment can be done using multiple catchments as well as by-pass analysis. 4. The removal curves for retention as a function of retention depth and wet detention as a function of annual residence time is important to discover options for additional treatment. 5. Groundwater discharge analysis is another assessment option.

114 Dynamic and Continuing Efforts Continue to make changes based on user input. This workshop input is important. Incorporation of this BMP information into local codes and state design manuals. All model updates posted on: stars.library.ucf.edu/bmptrains/ For BMP Trains 2020 Version February

115 BMP Trains 2020 Understanding Multiple Catchments (navigation and examples) Comments and Discussion April 2019 By Marty Wanielista, 115