6201 ASSOCIATED BLVD BASE FILE 2018-03-29

• Performance Laboratory Testing Fun Scale Laboratory Test Results Full reports available at www.contechstormwater.com Laboratory testing was conducted on a full scale Vortechs model Technical Bulletin 1: Removal Efficiencies for Selected Particle 2000.The 150 pm curve demonstrates the results of tests Gradations using particles that passed through a 60-mesh sieve and were Technical Bulletin 2: Particle Distribution of Sediments and the retained on a 100-mesh sieve.The 50 pm curve is based on Effect on Heavy Metal Removal tests of particles passing through a 200-mesh sieve and retained on a 400-mesh sieve(38-pm).A gradation with an average Technical Bulletin 3: Sizing for Net Annual Sediment Removal particle size(d50)of 80-pm,containing particles ranging from Technical Bulletin 3a: Determining Bypass Weir Elevation for Off- • 38-500-pm in diameter was used to represent typical stormwater solids.(Table 1) Line Systems Technical Bulletin 4: Modeling Long Term Load Reduction:The Particle Size Percentage of Sample Rational Rainfall Method Distribution (pm) Make-Up <63 42% Technical Bulletin 5: Oil Removal Efficiency 63- 75 4% Field Monitoring 75-100 9% Following are brief summaries of the field tests completed to 100- 150 7% date. 150-250 11% Full reports available at www.contechstormwater.com >250 27% Table 1: Particle gradation of typical urban runoff used for DeLorme Mapping Company efficiency curve Yarmouth,ME CONTECH Stormwater Solutions As shown,the Vortechs system maintains positive total Prior to this premier field test of the Vortechs system,CONTECH suspended solids(TSS),defined by the tested gradations, removal developed an extensive body of laboratory data to document efficiencies over the full range of operating rates.This allows total suspended solids(TSS)removal efficiency. CONTECH the system to effectively treat all runoff from large, infrequent performed this field study in order to compare the performance design storms,as well as runoff from more frequent low-intensity predicted using laboratory data to the performance of a correctly storms. sized system in the field. The study site was the headquarters of DeLorme Mapping in Yarmouth,Maine.The building,driveway, parking lot and 80% • ancillary facilities were constructed in 1996.A Vortechs model ~ • • 11000 was installed to treat runoff from the 300-space,4-acre 160% (1.62-ha)parking lot., W •. E 40%_ � Testing Period May 1999 to Dec 1999 • , #of Storms Sampled 20 20%- p • Mean Influent Concentration 328-mg/L r 0(0) 10(7) 20(+4) 30(20) 40(27) 55(34) 60(4+) 70(48) 90(54) 90(6+) 100(66) Mean Effluent Concentration 60-mg/L Operating Rate gpm/fl(Us/m') samicron _•••- typical gradation 150-miv0r, Removal Efficiency 82% Figure 1:Vortechs model 2000 Removal Efficiencies The main purpose of the DeLorme study was to verify that the Typical Vortechs systems are designed to treat peak flows from sizing methodology developed from our full-scale laboratory 1.6-cfs(45-L/s) up to 30-cfs(850-1/s)online without the need testing was valid and an accurate means of predicting field for bypass. However,external bypasses can be configured to performance.The results of the study confirmed our sizing convey peak flows around the system if treatment capacity is methodology. exceeded.The system can also be configured to direct low flows Village Marine Drainage from the last chamber of the system to polishing treatment Lake George, NY when more stringent water quality standards are imposed. In all • configurations, high removal efficiencies are achieved during the New York State Department of Environmental lower intensity storms,which constitute the majority of annual Conservation, Division of Water rainfall volume. The New York State DEC used funds obtained in a Section 319 grant to initiate a study of the effectiveness of the Vortechs Full report available at www.contechstormwater.com. system to remove sediment and other pollutants transported 4