Using the IDEAL model with Flexstorm Filters

The creators of the IDEAL model made it very simple to input the characteristics of a Stormwater Manufactured Treatment Devices. FLEXSTORM Inlet filters qualify as a MTD Type 3 inlet filter. To use a FLEXSTORM filter with the IDEAL model:

1. Using the product configurator find the appropriate FLEXSTORM filter for your inlet. If you cannot find your exact inlet filter pick a filter using that is the closest to your inlet’s shape, B, & D dimensions. Write down your FLEXSTORM PART NUMBER (e.g. P-HD4-238-238-220-220-PC)

2. Submit a formal request in order to receive your spec sheet with your specific inlet’s FLEXSTORM ratings.

3. Fill out the General Characteristics field of the User Defined BMP input. Find your FLEXSTORM part number’s FLEXSTORM Ratings on your spec sheet PDF. Fill in the “Maximim flow rate before going into bypass mode (cfs)” with the PC/PC+ Flow Rate field. This field corresponds to the maximum amount of water the PC/PC+ or FX/FX+ bag can pass through (assuming 50% maximum flow) before the filter enters bypass mode. The “Maximum total volume of sediment the device can contain before going into bypass mode (ft^3) field correspond to “Bag Capacity (ft^3)”. Fill in both fields with their corresponding values.

FLEXSTORM does not have values for Maximum mass of dissolved nitrogen or maximum mass of dissolved phosphorus that can be trapped.

4. Fill out the Trapping Efficiency Characteristics fields of the User Defined BMP field. There are two types of Flexstorm bags that affect these fields:

- FX bag, Flexstorm's standard woven bag for temporary or permanent applications. For high flow rate and low maintenance applications. The FX bag has a TSS Trapping Efficiency (%) of 82% (See “Large-Scale Sediment Retention Device Testing of Flexstorm FX Filters”)

-PC bag, ‘Post Construction’ bag lined with Adsorb-it Filter fabric to specifically target small particle and hydrocarbon removal. The PC bag has a TSS Trapping Efficiency (%) of 99.01% (See “TSS Removal for OK-110 Silica Sand”)

Depending on your desired bag style input the Trapping Efficiency Characteristics into their specific trapping efficiency fields. These values are taken from Table 4 of “Greenville County Technical SpecificationWQ-10: Stormwater Manufactured Treatment Devices (MTDs).”

Trapping Efficiency / FX BAG / PC BAG
Gross TSS Removal / 82% / 99.01%
Clay (%) / 1.2 / 2
Silt (%) / 82 / 90
Sand (%) / 99 / 100
Small Aggregates (%) / 98 / 100
Large Aggregates (%) / 100 / 100

5. Click the OK button. The Flexstorm filter should now be integrated into your IDEAL model Simulation.