StormTreat Systems may be installed using a variety of configuration options provided they abide by StormTreat and state specific design specifications. Following are a couple common configuration options for reference purposes.
1. Conventional Detention can be provided in a traditional detention pond or in a subsurface storage structure (tanks, pipe, arch-shaped chambers, etc.). We recommend that influent stormwater be directed first to the StormTreat tanks for treatment. This assures that smaller storms and the first flush of larger storms containing the most pollutant laden runoff receive thorough treatment within the StormTreat System and is also advantageous as the bioretention plants receive maximum watering from each storm event increasing plant health and drought resistance. When the StormTreat System fills to six inches below the tank rim, influent is directed to the detention structure using an overflow/flow splitter device in the catch basin. (See Figure 1 Below)
2. The Backfill Detention and/or Infiltration option utilizes the stone filled excavation area surrounding a STS tank in order to detain and treat the water quality volume. As in option 1 above, influent stormwater is first directed to the STS tank. When stormwater reaches an elevation six inches below the tank rim the overflow discharge pipe within the STS tank directs flow to the surrounding backfill area for detention where it is either returned to the STS tank for treatment or allowed to infiltrate into native soils. If configured for infiltration the site must be assessed for soil permeability to assure a sufficient infiltration rate is available. Water discharged to the backfill area has already been treated in the sediment chamber and the bioretention area of the STS tank and will receive further treatment as it is either infiltrated to native soils or reintroduced into the STS tank. If water is to be reintroduced to the STS tank infiltration must be deterred either by impermeable soil type or by lining the backfill area with a "fish safe" liner. Also an additional inlet pipe fitted with a one-way check valve must be included to allow detained water to return to the tank. (See Figure 2 Below)