Constructed Wetlands Removal Efficiency: 65-80% average 80% MassDEP TSS Removal Credit Key Features: Large area Peak flow control Biological treatment Maintenance: low to moderate Cost: marginally higher than wet ponds Source: MassDEP, Massachusetts Stormwater Handbook 2002
Extended Detention Basins TSS Removal Efficiency: 60-80% average 50% MassDEP TSS Removal Credit Key Features: Large area Peak flow control Maintenance: low Cost: low to moderate Source: MassDEP, Massachusetts Stormwater Handbook
Water Quality Swales Removal Efficiency: average 70% MassDEP TSS Removal Credit Key Features: Higher pollutant removal rates than drainage channels Transport peak runoff and provide some infiltration Maintenance: low to moderate Cost: low to moderate Source: MassDEP, Massachusetts Stormwater Handbook
Deep Sump Catch Basins Removal Efficiency: 9-35% average 25% MassDEP TSS Removal Credit Design Features: Debris removal Pretreatment Maintenance: moderate to high Cost: low to high Source: MassDEP, Massachusetts Stormwater Handbook
Innovative BMPs – Media Filtration Removal Efficiency: 50-80% average Design rate: case by case evaluation Design Features: small area Oil and Grease control Maintenance: moderate Cost: moderate Massachusetts Stormwater Technology Evaluation Project, UMass Stormwater Management Inc, 2002
Innovative BMPs - Hydrodynamic Removal Efficiency: No treatment to 35% Design rate: case by case evaluation Design Features: small area Oil and Grease control Maintenance: moderate Cost: moderate Vortechs Inc, 2002
Address technology review and approval barriers in policy and regulations; Accept the performance tests and data from partners review to reduce subsequent review and approval time; Use the Protocol for state-led initiatives, grants, and verification or certification programs; and Share technology information with potential users in the public and private sectors using existing state supported programs CA IL MA MD NJ NY PA VA TX TARP- Technology Acceptance Reciprocity Program
Performance Verification - TARP Storm Event Criteria to Sample More than 0.1 inch of total rainfall. A minimum inter-event period of 6 hours, where cessation of flow from the system begins the inter-event period. Obtain flow-weighted composite samples covering a minimum of 70 % of the total storm flow, including as much of the first 20 % of the storm as possible. A minimum of 10 water quality samples (i.e., 10 influent and 10 effluent samples) should be collected per storm event. Determining a Representative Data Set At least 50 % of the total annual rainfall must be sampled, for a minimum of 15 inches of precipitation and at least 15, but preferably 20, storms. Massachusetts Stormwater Technology Evaluation Project, UMass
Performance Verification - TARP Stormwater Sampling Locations Sampling locations for stormwater BMPs should be taken at inlet and outlet. Sampling Methods Programmable automatic flow samplers with continuous flow measurements should be used Grab samples used for: pH, temperature, cyanide, total phenols, residual chlorine, oil and grease, total petroleum hydrocarbons (TPH), E coli, total coliform, fecal coliform and streptococci, and enterococci. Stormwater Flow Measurement Methods Primary and secondary flow measurement devices are required.
Is There Enough Data? Field Studies 15+ storms 15 inches of rainfall Lab Studies 15 test runs
Are the Data Representative? Weather conditions Topography, land use Soils, sediments
Are the Data Representative?, Weather, Flows Multiple samples per event Field Studies: must include high flow/intensity storms Consecutive storms Sample all year Lab Studies: Flow rates: 25%, 50%, 75%, 100%, 125%
Particle size: mean < 100 microns; distribution 55% sand, 40% silt, 5% clay Influent concentration 100 – 300 mg/l Are the Data Representative? Sediment
Impact of Particle Size on Performance
Impact of Particle Size on Performance
Quality Control tests, data Standardized methods Are Results Accurate, Repeatable?
MASTEP Rating System Category 0: MASTEP has not yet reviewed performance data for this technology. Category 1: TARP-compliant field study or equivalent lab study data available for this product Cat. 2: Sound field or lab study data available – some caveats Cat. 3: Data of moderate scientific validity exists – significant caveats Cat. 4: Reliable performance lacking
Higher rating does NOT mean better performance MASTEP evaluates quality of performance DATA NOT BMP Performance Results
Lab vs. Field Tests Lab Relatively inexpensive Standardized – best for comparing 2 BMPs Ideal conditions, not real world – simplified Short term Field Real world. Problems are encountered Cant control conditions Expensive Long Duration
Contact Jerry Schoen MASTEP Project Manager Blaisdell House UMass Amherst MA Massachusetts Stormwater Technology Evaluation Project
The effectiveness of Proprietary BMPs varies with the size of the unit, flow requirements, and specific site conditions. The UMass Stormwater Technologies Clearinghouse database evaluates the quality of proprietary BMP effectiveness studies. MassDEP urges Conservation Commissions to use this database when verifying the effectiveness of Proprietary BMPs: -Excerpt from MA Stormwater Handbook Volume 2 Chapter 4
Two Ways to Approve or Deny the Use of Proprietary Stormwater BMPs 1. MassDEP has reviewed the performance of a technology as determined by TARP or STEP and assigned a TSS removal efficiency. If the conditions under which it is proposed to be used are similar to those in the performance testing, presume that the proprietary BMP achieves the assigned TSS removal rate. Look at sizing, flow and site conditions. 2. Issuing Authority makes a case-by-case assessment of a specific proposed use of a proprietary technology at a particular site and assigns a TSS removal efficiency. Proponent must submit reports or studies showing effectiveness of BMP. MassDEP strongly recommends using UMass Stormwater Technologies Clearinghouse database to ensure that reports and studies are of high quality (www.mastep.net). Look at sizing, flow and site conditions. For ultra-urban and constrained sites, proprietary BMPs may be the best choice.