1 University of Massachusetts, Amherst, © 2005 Storm Water Best Management Practices Evaluation, Testing and Technology Transfer New England Stormwater Technology Workshop June 14, 2005 Eric Winkler Ph.D. University of Massachusetts – Amherst

2 University of Massachusetts, Amherst, © 2005 Massachusetts Department of Environmental Protection University of Massachusetts at Amherst MA Stormwater Technology Evaluation Project S319 Non-Point Source Pollution Program

3 University of Massachusetts, Amherst, © 2005 Factors Affecting Stormwater Sampling Rainfall and pollutants Sampling challenges Site-related issues Solids sampling Particle size issues Technology design limits

4 University of Massachusetts, Amherst, © 2005 Regional Rainfall Differences

5 University of Massachusetts, Amherst, © 2005 Recurrence vs. Precipitation Depth

6 University of Massachusetts, Amherst, © 2005 Sampling Criteria: Pollutant Load Decreases Over Event

7 University of Massachusetts, Amherst, © 2005 Sample Composition Sampling location is key Avoid bed load sampling – sampling at the bottom of the collection or piping network Ensure sample is mixed by sampling one or more locations along pipe cross section that best represent all of the flow Potential bias in performance efficiency Pollutant specific sampling techniques Solids sampling may be affected by inlet velocity of sampling equipment Want samples to reflect the load in all flow

8 University of Massachusetts, Amherst, © 2005 Particle Size Issues Removal efficiencies can vary greatly with particle size distribution (PSD) Poorly graded solids scheme can exaggerate performance claims Well-graded distributions present the most accurate performance data Sample volume must be considered in order to collect for PSD

9 University of Massachusetts, Amherst, © % -55% -35% -15% 5% 45% 65% 85% Evaluating TSS Removal Rates Based on Concentration Removal Efficiency (%) Influent Concentration (mg/L)

10 University of Massachusetts, Amherst, © 2005 Detail of Data Generation and Acquisition Requirements (Quality Assurance Project Plan) 1. Sampling process design (experimental design) 2. Sampling method requirements 3. Sample handling and custody requirements 4. Analytical methods requirements 5. Quality control requirements 6. Instrument/equipment testing, inspection, and maintenance requirements 7. Instrument calibration and frequency 8. Inspection/acceptance requirements for supplies and consumables 9. Data acquisition requirements (non-direct measurements) 10. Data management

11 University of Massachusetts, Amherst, © 2005 Protocol Minimum Criteria Identifying Qualifying Storm Event (Section and Section , TARP Tier II Protocol) Minimum rainfall event depth is 0.1 inch. Minimum inter-event duration of 6 hours (duration beginning a cessation of flow to unit). Base flow should not be sampled. Identification of qualifying event needs to verify flow to the unit and rainfall concurrently. TARP:

12 University of Massachusetts, Amherst, © 2005 Qualifying Event Sample TARP Tier II Protocol Criteria 10 water quality samples per event 10 influent and 10 effluent If composite - 2 composites, 5 sub-samples Data for flow rate and flow volume At least 50% of the total annual rainfall CA – monitor 80-90% of rainfall.

13 University of Massachusetts, Amherst, © 2005 Qualifying Event Sample (continued) Preferably 20 storms, 15 minimum Sampling over the course of a full year of sampling to account for seasonal variation Compositing flow-weighted samples cover at least 70% of storm flow (and as much of the first 20% as possible) Examples of variation within TARP community: PA - Temporary BMPs sized using 2 year event NJ – Water Quality design based on volume from a 1.25 inch event.

14 University of Massachusetts, Amherst, © 2005 Efficiency Ratio (ER) TARP Protocol Recommended Method Where Event Mean Concentration (EMC): V=volume of flow during period i n=total number of events C=average concentration associated with period j m=number of events measured

15 University of Massachusetts, Amherst, © 2005 Efficiency Ratio Interpretation EMCs weight all storms equally. Most useful when loads are directly proportional to the relative magnitude of the storm – accuracy varies with BMP type. Minimizes impacts of smaller/cleaner storms. Allows for use of data where portions of data are missing – would not significantly effect the average EMC. Can apply log normalization to avoid equal weighting of events.

16 University of Massachusetts, Amherst, © 2005 Variation in Performance Values Removal Efficiencies for all Events: Removal Efficiency by Efficiency Ratio: 57% Removal Efficiency by Summation of Loads: 44% Removal Efficiency by Regression of Loads: 40% Removal Efficiency by Efficiency of Individual Storm Events: 59%

17 University of Massachusetts, Amherst, © 2005 System Efficiency v. Unit Efficiency BMP 1 BMP2 BMP3 (Unit)10% 25% 80% (Removal)10% 22.5% 54% (Passing)90% 67.5% 13.5% System Efficiency = 10% % + 54% = 86.5%

18 University of Massachusetts, Amherst, © 2005 System Efficiency v. Unit Efficiency BMP 1 BMP2 BMP3 (Unit)10% 25% 70% (Removal)10% 22.5% 47.25% (Passing)90% 67.5% 20.25% System Efficiency = 10% % % = 79.75%

19 University of Massachusetts, Amherst, © 2005 Stormwater Database Project Project Goal: Provide technology transfer information about innovative stormwater Best Management Practices (BMPs) to MADEP, conservation commissions, local officials, and other BMP users to help them make appropriate technology implementation decisions. Project Scope of Work: Needs survey, develop searchable database, develop screening tool, evaluate technologies, provide fact sheets for TARP Tier II qualified technologies.

20 University of Massachusetts, Amherst, © 2005 Category 0Technology entry is in process or incomplete. Category 1There is sufficient reliable data on this technology to be able to provide a scientifically valid evaluation Category 2Studies are underway that offer promise for reliable data in the near future Category 3There is insufficient reliable data with which to evaluate this technology Stormwater Database Entry Protocol

21 University of Massachusetts, Amherst, © 2005

22 University of Massachusetts, Amherst, © 2005

23 University of Massachusetts, Amherst, © 2005 Contact: Eric Winkler, Ph.D. University of Massachusetts MASTEP – NSF International – International Stormwater BMP Database – WA Dep. of Ecology - New Jersey Corporation for Advanced Technology (CAT) – Environmental Technology Verification Program (ETV) - Resources :