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MUSIC User Guide - StormTech Tank Systems
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Gross Pollutant Traps (GPT)
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Stormwater Harvesting (SWH) Retention System -
Rainwater Tank
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Stormwater Infiltration Tank
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Stormwater Detention Tank
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Contact
Content copyright 2017 © Cubic M3 Pty Ltd.
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MUSIC – Model for Urban Stormwater Improvement Conceptualisation – software predicts the performance of stormwater quality management systems. It is intended to help organisations plan and design (at a conceptual level) appropriate urban stormwater management systems for their catchments. This MUSIC user guide explains how to incorporate a StormTech system into a MUSIC model for the following stormwater applications: 1. 2. 3. 4.
Gross Pollutant Traps Rainwater Tanks (Stormwater Harvesting) Infiltration Systems Detention Systems
StormTech Subsurface Stormwater Management System The StormTech arch was developed by world-renowned experts of buried drainage structures. The rigorous design process included structural testing and evaluation of short and long term loading. This includes traffic loads well in excess of the loading requirements in AS5100. StormTech offers a wide range of arch sizes to suit the project and site conditions. Designed to meet the most stringent industry standards, StormTech has been successfully installed in thousands of projects around the world over the past 15 years. Cubic M3 has 15 years plus experience designing StormTech tanks in Australia, Ireland, UK, UAE and NZ.
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TYPICAL STORMTECH SYSTEM CROSS SECTION The StormTech system incorporates the internal Isolator Row which is an internal gross pollutant trap (GPT). Therefore StormTech modelling will incorporate a GPT node for each type of tank application. Its efficiency will change depending on the way the system is plumbed to suit your project and council requirements. Stormwater is distributed into the tank via the open bottom chambers and is self-levelling throughout the tank.
INPUT PARAMETERS SPECIFIC TO STORMTECH All StormTech tanks incorporate an Isolator Row which is an internal GPT. This traps 96 per cent of total suspended solids (TSS) from the inlet water down to 100mm. The Isolator Row is FILTERED WATER DISTRIBUTION a row of StormTech chambers, surrounded with filter fabrics and connected to the inlet pit. The fabric wrapped chambers provide for settling and filtration of sediment as stormwater enters the Isolator Row and ultimately passes through the filter fabrics. The Isolator Row(s) should be long enough to allow the water to distribute into the storage rows. Depending on the StormTech chamber selected, the required length can be calculated by dividing the inflow rate by the rate of exfiltration from each chamber. Number of SC310 chambers = Inflow rate = 9L/s/ch Number of SC740 chambers = Inflow rate = 14L/s/ch Number of MC3500 chambers = Inflow rate 21L/s/ch Number of MC4500 chambers = Inflow rate 13L/s/ch
…………. SC310 Chambers (each SC310 is 2.2m long) …………. SC740 Chambers (each SC740 is 2.2m long) = ……… MC3500 Chambers (each MC3500 is 2.2m long) = ……… MC4500 Chambers (each MC4500 is 1.2m long)
The minimum tank length can be calculated from the number of chambers above. If there is insufficient room for this length, simply distribute the inflows into multiple rows.
SINGLE ISOLATOR ROW
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MULTIPLE ISOLATOR ROW
When a GPT is required on your project to capture sediments, a StormTech tank with an Isolator Row only can be used. Model layout is:
Sediments are captured in the Isolator Row, protecting the tank from sediment accumulation. Annual inspections of the sediment build-up through the inlet pit or inspection port, will determine the need for cleanout. Once the sediment reaches approx. 75mm, the Isolator Row should be jetted out via the use of a JetVac truck. This flushes pollutants back to the inlet pit to be vacuumed out.
GROSS POLLUTANT TRAP (ISOLATOR ROW)
For Total Suspended Solids:
Edit end point (right click on point and click edit) on graph and change Output Value to 200 (i.e. isolator row will detain 80% of Total Suspended Solids)
For Gross Pollutants:
Edit end point (right click on point and click edit) on graph and change output value to 0 (i.e. isolator row will detain 100% of gross pollutants.)
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Note: Total Nitrogen and Total Phosphorus transfer functions should not be changed as gross pollutant traps are not capable of treating soluble pollutants. For further information regarding input parameters for StormTech, technical papers, design volume spreadsheet or for assistance tailoring StormTech to your site, please contact your local Cubic M3 representative.  
When incorporating a StormTech stormwater harvesting system into your project, use the Rainwater Tank node and the GPT node.
Ensure the Isolator Row has sufficient capacity to distribute the inflows into the tank (as per above). The tank is plumbed so the overflow comes from the row next to the Isolator Row and therefore all water is treated by the Isolator Row before continuing.
RAINWATER TANK (SWH) + GPT
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Input Parameters: Tank Volume* *Note: Refer to Stormtech Design Guidelines on detention and infiltration to determine the tank volume which accounts for volume lost due to rock backfill. Typical backfill stone porosity is 40% (i.e. 40% void space). Make sure to account for void space lost by rock backfill. Set by designer Tank base area Set by designer (typically 0-50% of tank volume) For further information regarding input parameters for StormTech, technical papers, design volume spreadsheet or for assistance tailoring StormTech to your site, please contact your local Cubic M3 representative on 1300 428 242.  
When incorporating a StormTech system into an infiltration application, use the Infiltration System node and the GPT node.
Ensure the Isolator Row has sufficient capacity to distribute the inflows into the tank (as per above). The tank is plumbed so any overflow comes from the row next to the Isolator Row and therefore all water is treated by the Isolator Row before continuing.
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INFILTRATION SYSTEM + GPT
Input Parameters: Tank base area Extended Detention Depth = Actual Tank Volume* “Pond Surface Area” *Note: Make sure to account for void space lost by rock backfill Tank base area Perimeter of tank | Set to low figure (e.g. 0.01) as this is negligible Set to 0 as there is little to no evapo-transpiration in a closed tank system Notes: ▷▷ Stormtech arch tanks act as rainwater storage to allow more time for water to infiltrate into the ground. The tanks act in the same way as an Extended Detention Depth. ▷▷ Other nodes such as On-Site Detention and Pond can be used to replicate the same outcome. For further information regarding input parameters for StormTech, technical papers, design volume spreadsheet or for assistance tailoring StormTech to your site, please contact your local Cubic M3 representative.
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When incorporating a StormTech system into a detention tank application, use the Detention Basin node and the GPT node.
Ensure the Isolator Row has sufficient capacity to distribute the inflows into the tank (as per above). The tank is generally plumbed so overflow comes from the top of the inlet pit. All low flow rain events will be 100% treated in the Isolator Row. During heavy rain events the first flush will be treated. A restricted outlet or orifice can be installed in the outlet pit.
DETENTION TANK + GPT
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Input Parameters: Tank base area Extended Detention Depth = Actual Tank Volume* “Pond Surface Area� *Note: Make sure to account for void space lost by rock backfill Set to 0 if the tank system is lined otherwise specify hydraulic conductivity (mm/hr) at base of tank) Set to 0 as there is little to no evaporation in a closed tank system Set by designer
Typical Exfiltration Rates: 0 to 0.36 mm/hr for heavy clay 0.36 to 3.6 mm/hr for medium clay 3.6 to 36 mm/hr for sandy clay 36 to 180 mm/hr for sandy loam 180 to 360 mm/hr for sand 360 to 3600 mm/hr for course sand It is recommended that Exfiltration Rates (i.e. Saturated Hydraulic Conductivity) be obtained from a geotechnical investigation. The above rates can be used if the soil profile is known.
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CONTACT For more information: info@cubicm3.com.au 1300 428 242 For any questions on StormTech input parameters, technical papers, design volume spreadsheets or assistance tailoring StormTech to your site, please contact your local Cubic M3 representative.
New South Wales & ACT Branch 0431 261 575 NSWorders@cubicm3.com.au
Northern Territory Branch 0402 191 135 NTorders@cubicm3.com.au
Queensland & Northern NSW Branch 0431 326 967 QLDorders@cubicm3.com.au
South Australia Branch 0431 581 901 SAorders@cubicm3.com.au
Victoria & Tasmania Branch 0413 173 353 VICorders@cubicm3.com.au
Victorian Regional & Irrigation Branch 0427 188 290 VICREGorders@cubicm3.com.au
Western Australia Branch 0432 184 470 WAorders@cubicm3.com.au
New Zealand Branch +61 413 173 353 NZorders@cubicm3.com.au
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