Stormwater Interceptor

Stormwater runoff can range from low to very high flow rates…

stormwater install

Storm Water Storm Trooper (SWST) Interceptors

A high flow rate can be detrimental to a stormwater interceptor in that excessive flows tend to scour (stir up) the existing retained pollutants left from the previous storm event. The SWST controls high flow rates by utilizing a control manhole. The control manhole is engineered to divert the design flow through the interceptor while bypassing high flows to the storm sewer. Stormwater runoff flows into the inlet of the control manhole. Stormwater is then diverted from the bypass weir to the interceptor. The stormwater debris, oils, and sediments are filtered and separated. The flow is discharged via the outlet of the control manhole to the Municipal Separate Storm Sewer System (MS4). Stormwater runoff flows into the inlet of the control manhole.

Storm Water Storm Trooper (SWST) InterceptorsDuring high flow conditions, stormwater rises over the bypass weir and is discharged via the outlet of the control manhole to the Ms4. Trash is collected in the control manhole debris screen. As water enters the treatment chamber of the interceptor, trash and light debris are filtered through a screen; heavy oils immediately rise to the surface, Total Suspended Solids (TSS) sink to the bottom. The remaining oily water mixture flows through the second chamber. Both the smaller oil droplets the and finer TSS are progressively separated. Coalescing media is used to separate significant concentrations of hydrocarbons.

In the final stage, effluent is discharged at the bottom of the interceptor preventing collected pollutants from entering the outlet piping. Collected oils and solids will remain in the interceptor until removal.

Under the Storm Water Phase II Final Rule, urbanized areas where construction disturbs one acre or more must develop water quality controls. The Final Rule requires a water quality system design that will reduce TSS loadings by an average of 80% annually.

Storm Trooper system. End of pipe stormwater management

The Storm Trooper system is very easy to inspect and maintain, making it the best option for end of pipe stormwater management

A professional engineer must develop a Best Management Practice Plan (BMP) to obtain a NPDES number from permitting authorities. Typically, a designer utilizes site specific runoff coefficients and rainfall intensity rates to develop the hydrology calculations and structural control systems that become a Storm Water Quality Management Plan (SWQMP) or BMP. Using the “First Flush Principle” has become the acceptable means of determining treated stormwater flow rates. The initial runoff flow will be more polluted than the stormwater that runs off later, after the rainfall has “cleansed” the catchment area. The stormwater containing this high initial pollutant load will be treated with the StormTrooper Stormwater Interceptor®.  Most studies have found that significant concentration pollutant loads are retained when at least 90% of the storm events are treated.