Choosing BMPs and Monitoring Them James Houle and Tim Puls, UNH Stormwater Center
Choosing BMPs
Both Willow Brook and this reach of the Cocheco River are listed as impaired for aquatic life(ph) and Primary Contact (E.coli) uses. It Depends.
Welcome to Willow Brook 2515 acres impaired for aquatic life (ph) Primary Contact (E.coli) uses
Distribution of Land Use Type
IC Targets Over Time for WB Implementation Rates Current (0.79 Ac/yr) 50 Yr (3.0 Ac/yr) 40 Yr (3.75 Ac/yr) 30 Yr (5.0 Ac/yr) 20 Yr (7.75 Ac/yr) 10 Yr (15.0 Ac/yr) 2012 Impervious Cover Beginning 15.91% 15.91% 15.91% 15.91% 15.91% 15.91% Yrs to Implementation Total % IC Disconnected Per Year Total Acres Treated Per Year 189 50 40 30 20 10 0.03% 0.12% 0.15% 0.20% 0.31% 0.60% 0.79 3.0 3.75 5.0 7.75 15.0
Use Updated Resources
RLBCI (Red Lake Band of Lake Superior Chippewa). 2008 Nonpoint Source Assessment of Streams, Lakes and Wetlands. Red Lake Band of Chippewa Indians, Red Lake, MN.
Synthesis
Plan Implement Monitor
Pre and Post BMP Monitoring University of New Hampshire Stormwater Center Timothy Puls, James Houle, Thomas Ballestero
Establishing an Approach Objective of Monitoring Time, Money, and Resources Available Equipment Selection
Monitoring Objectives What are the parameters or pollutants of concern? What are the intended treatment goals? What level of sophistication is required to establish evidence of success?
Available Resources Personnel Time Personnel Experience Level Budget
Equipment Selection Wide Range of Available Options Addressing first two questions will help narrow down equipment options Simple to Complex
The UNH Stormwater Center 7
UNH WEST EDGE LOT Watershed Boundary Main UNH SC Research Facility TREE FILTER POROUS ASPHALT 8
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POROUS ASPHALT TREE FILTER 10
TREATMENT STRATEGIES: Conventional Devices Retention Pond 2004 to 2006 Detention Pond 2006 to present Rock Lined Swale 2004 2005 Vegetated Swale 2005 2006 Veg Swale with Engineered Filter Berm 2006 2007 Rip Rap Swale Retention Pond 11
TREATMENT STRATEGIES: Manufactured Devices Tested 2004 2006: ADS Subsurface Detention System, Aqua Swirl and Aqua Filter; VortSentry, CDS, V2b1, ADS Isolator row Tested 2006 present: Stormtech Isolator Row; HIL Up Flo Filter, HIL Downstream Defender, VortSentry, Deep Sump Catch Basin Hydrodynamic Separator Subsurface Infiltration Unit Filter Unit 12
Infiltration and Filtration Systems Porous Asphalt Pervious Concrete Gravel Wetland Sand Filter Bioretention Cell Tree Filter Subsurface Infiltration Unit 13
BMP Monitoring: How We Do It QAPP Governed Protocol 1. Runoff is sampled 2. Influent enters distribution chamber 3. Equal volumes flow out to systems 4. Influent flows through systems 5. Effluent leaves system 6. Effluent enters sampling gallery
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Real Time Automated Samplers 16
Site Considerations Power Outfall Type: Pipe, Box Culvert, Tidal, etc. Rural or Urban Vandalism and Security Equipment Access Seasonal Accessibility
Site Monitoring Real Time Precipitation Flow ph Temperature Conductivity Dissolved Oxygen Turbidity Discrete Samples Metals Petroleum Hydrocarbons Sediment Anions and Cations Nutrients Microorganisms 18
Remote Monitoring
Flow weighted composites Freeze or send for analysis Flow weighted composites
Know Hydrology Understand the runoff (rain, snowmelt, etc.) characteristics of the watershed to the location of monitoring Time of concentration Lag CN Unit hydrograph peak discharge Base flow Land use 21
Flowlink Graph
Water Quality Estimate the water quality characteristics of what you are attempting to monitor Maximum Minimum Median Variance Memory Sources 23
Measurement Know the analytical capabilities of equipment/lab Detection level Accuracy Precision Reliability 24
Data Build and maintain the data vault Access Entry Logs QA 25
Objectives Bad Examples Will this impair the creek? Too vague Possibly many other causes of impairments How is this answered? Is this a good design? Is monitoring a necessity to answer? Non quantifiable statement Units of measure When answered? 26
Objectives Good Examples Is the design meeting the infiltration goal? Infiltration goal established (say equal to predevelopment) At what point in time is question answered? Is stormwater meeting compliance (for some target contaminant)? Simple metric At what point in time is question answered? 27
DO NOT THINK LIGHTLY ABOUT FLOW MEASUREMENT Discharge is considered a no brainer Reality is that accuracy is problematic Cannot do a good mass balance without excellent flow monitoring Often measure water level or depth and convert 28
Effective Sample Collection BE PREPARED!! Clean containers Purging Representative Preservation Chain of Custody If you really want to understand the importance of each sample, ask yourself, What is it worth to me for this sample to be lost? 29
Expect the unexpected
Quality Assurance Duplicates Spikes Double checks QA officer Review Data Frequently 31
Dissemination Final report Project updates Public presentations Professional presentations 32
Questions