PEAIP Tracking, Quantifying, and Reporting for Phase II MS4 Permit - PowerPoint PPT Presentation

PEAIP Tracking, Quantifying, and Reporting for Phase II MS4 Permit Compliance Avery Blackwell, P.E Geosyntec Consultants, Santa Barbara, CA Cathleen Garnand County of Santa Barbara, Project Clean Water Program 1

Discussion Topics • Requirements, Local Context, and Model Objectives • LPR Model Overview and Lessons Learned • LPR Model Benefits • Questions 2

Phase II MS4 Permit Requirements • “Quantification of pollutant loads and pollutant load reductions achieved by the program as a whole” (Section E.14.a.ii.a.6) • “Assess BMP and program effectiveness in terms of the following Outcome Levels: 4) Pollutant load reductions” (Sections E.14.a.ii.b.4) • “Quantitatively assess BMP performance at reducing pollutant loads wherever feasible, using … science-based estimates of pollutant load removal for BMPs where direct measurement of pollutant removal is overly challenging” (Sections E.14.a.ii.d.2) 3

Central Coast Regional Board Requirements July 2014 June 2016 • Quantify Pollutant Loads • Catchment delineation to and Load Reductions (Yr 2) support catchment scale stormwater volume and  Evaluate and select flow and pollutant loading models; pollutant loading (Aug 2016)  Prioritize load quantification by • Structural BMP Inventory (Yr 3) catchment; and • Volume and Pollutant Loading,  Provide schedule for Catchment Ranking, without completing pollutant load quantification to inform BMPs (Yr 3) submittal of Stormwater • Structural BMP Assessment, Program Modifications by Year Volume and Pollutant Loading, 5 Catchment Ranking with BMPs • Map stormdrain system (Yr 5) (Yr 2) 4

Santa Barbara County Context 5

Primary Model Objectives Perform minimum requirements from Permit and Central Ease of use Low cost Coast Regional Board No models existed that could fulfill all these objectives, therefore it was necessary to create a new model Customizable with Reflect County- County-specific specific water quality datasets priorities 6

Load, Prioritization, and Reduction Model (LPR Model) 7

LPR Model Components • Quantify baseline annual average wet weather pollutant loads and runoff volumes; • Prioritize MS4 catchments; • Track BMP implementation details; • Quantify non-structural and structural BMP pollutant load and runoff volume reductions; and • Summarize, format, and graphically present all results for easy reporting. 8

Quantify Runoff Volumes and Pollutant Loads 9

Estimate Runoff Volume • Runoff coefficients developed using:  detailed land use (to estimate imperviousness)  hydrologic soil group • Average annual precipitation • Drainage areas catchments 1. MS4 Permit Area 2. Watershed 3. to BMPs 4. 10

Estimate Runoff Volume Lesson Learned: Land use data should be verified 11

Calibration of Runoff Volumes Model-Predicted Runoff Volume Observed Flow Data Annual Precipitation Data Atascadero Land use and Creek USGS Modeled Runoff Soil GIS data Flow Gauge Coefficients Statistical Comparison of Observed Annual Runoff Modeled Annual Runoff Runoff Volumes Volume (ac-ft) Volume (ac-ft) 25,000 25,000 20,000 20,000 15,000 15,000 Calibrated 10,000 10,000 Runoff Volume 5,000 5,000 Multiplier 0 0 1980 1990 2000 2010 2020 1980 1990 2000 2010 2020 12

Catchment and Land Use Loads MS4 Permit Area – by Land Use 13

Watershed Loads Lesson Learned GIS analysis removed IGP parcels and Caltrans by MS4 & non-MS4 areas 14

Prioritize Catchments 15

Catchment Prioritization Pollutant of Concern All pollutants Identification Pollutants with available land use EMC data (Modelable pollutants) Modelable pollutants that have land use EMCs above Basin Plan objectives or related TMDL WLAs for MS4 dischargers (Pollutants of Concern [POCs]) Pollutant-specific catchment priority rankings are calculated for each Modelable Pollutant of Concern pollutant Prioritization POCs are assigned weighting factors based on watershed-specific 303(d) listings and TMDLs Final catchment priorities are made based on combined weighted POC-specific rankings Areas of highest priority to the Permittees 16

Pollutant of Concern Identification Diss Tot Cu Tot Pb Diss Tot Zn Fecal TSS TP DP NH3 NO3 TKN Cu Zn Col. Land Use #/100 mg/L mg/L mg/L mg/L mg/L mg/L ug/L ug/L ug/L ug/L ug/L mL Single-Family 124.2 0.4 0.32 0.49 0.78 2.96 9.4 18.7 11.3 27.5 71.9 15,600 MS4 Area Land Uses Residential Commercial 67 0.4 0.29 1.21 0.55 3.44 12.3 31.4 12.4 153.4 237.1 5,510 Industrial 219.2 0.39 0.26 0.60 0.87 2.87 15.2 34.5 16.4 422.1 537.4 18,700 Education 99.6 0.3 0.26 0.40 0.61 1.71 12.2 19.9 3.6 75.4 117.6 11,800 Transportation 77.8 0.68 0.56 0.37 0.74 1.84 32.4 52.2 9.2 222 292.9 1,680 Multi-Family 0.50 39.9 0.23 0.2 1.51 1.8 7.4 12.1 4.5 77.5 125.1 11,800 Residential Agriculture 999.2 3.34 1.41 1.65 34.4 7.32 22.5 100.1 30.2 40.1 274.8 24,800 Open Space 216.6 0.12 0.09 0.11 1.17 0.96 0.6 10.6 3.0 28.1 26.3 484 BPO or typical WLA: 0.3* 8* 13** 14** 82** 120** 120** 400* Cells highlighted yellow have Land use EMCs that exceed BPO or typical WLAs * SMR Nutrient /Bacteria TMDL wet weather WLA for MS4 dischargers ** CTR default value (acute freshwater criteria, hardness -100 mg/l) 17

Pollutant of Concern Prioritization 18

Catchment Prioritization Maps Multi- pollutant Lesson Learned: 50% of the top ranked catchments are different if prioritized using County-specific water quality priorities instead of traditional surrogates TSS only 19

BMP Tracking and Reductions 20

Model Framework 21

BMP Reductions Table 7. BMP Reductions (Additional BMPs may be added to the next empty row) *Note: units shown under pollutants represent concentration. Unit reductions are in units specified in Table 2 and percent reductions are in %. Diss Tot Cu Tot PbDiss Zn Tot Zn Fecal Pollut Pollut Pollut Volume TSS Tot P Diss P NH3 NO3 TKN Cu Col. ant ant ant Reduction % BMP Type Method* Capture ug/L #/100 cu ft mg/L mg/L mg/L mg/L mg/L mg/L ug/L ug/L ug/L ug/L unit unit unit mL 85th – Redevelopment (100% Infiltration) E 89% 100% 18.1 0.14 0.07 0.18 0.37 0.98 8.3 8.8 4.2 34.7 37.6 5,890 85th – Redevelopment (50% Infiltration) E 89% 50% 18.1 0.14 0.07 0.18 0.37 0.98 8.3 8.8 4.2 34.7 37.6 5,890 85th – Redevelopment (100% Treatment) E 89% 0% 18.1 0.14 0.07 0.18 0.37 0.98 8.3 8.8 4.2 34.7 37.6 5,890 95th – Redevelopment (100% Infiltration) E 100% 100% 18.1 0.14 0.07 0.18 0.37 0.98 8.3 8.8 4.2 34.7 37.6 5,890 Brake Pad Copper Phase-out Legislation p 100% 0.0275 0.0275 Other Non-structural BMPs (CBSM) P 100% 0.05 Other Non-structural BMPs (WAAP BMPs - Tanglewood & Orcutt only) P 100% 0.1 0.1 0.1 0.1 0.1 0.1 * Percent Load Reduction (P) or Effluent Concentration (E) Lesson Learned: It was important to incorporate advanced logic to accurately estimate BMP reductions when multiple BMPs treat the same area 22

BMP Reductions 23

LPR Model Benefits 24

Future LPR Model Uses • Prioritize catchments (or land uses) for MS4 cleaning, street sweeping, outreach, structural BMP placement, etc. • Prioritize BMPs – e.g., compare relative cost-benefit of different BMP options • Support grant applications and/or Stormwater Resource Plans • Use maps as educational tools for public, PW managers, and/or elected officials • Forecast long-term cost of compliance (TMDL WLAs, etc.) • Identify/prioritize potential BMP retrofit opportunity sites • Quantify water supply benefits of structural BMPs 25

Key Benefits of the LPR Model a non-proprietary Excel ability to model 12 water a simple to navigate model owned by the quality parameters for interface and report jurisdictions reduces current or planned BMP ready figures provide long-term cost of Permit implementation exceeds a user-friendly compliance and other Permit requirements experience modeling requirements capacity for streamlined meaningful catchment updates and modification prioritization and BMP to GIS data and all pre- reductions are based on populated datasets locally important water provides maximum quality concerns customization 26

For More Information http://centralcoastbmploadmodel.net Download: • Approach Memo - discusses the modeling approach and the default model values • Guidance Document - describes the model organization, how users can add new BMPs and extract model results for future annual reports, how to modify model defaults, and how model calculations are performed • CASQA presentation – Available for download next week 27

http://centralcoastbmploadmodel.net Cathleen Garnand - cgarnan@cosbpw.net Avery Blackwell - ablackwell@geosyntec.com 28