When to Use the StormTank Module vs. the Pack
The StormTank line provides two options for subsurface storage. Because of this, we often receive questions like: “When should I use the StormTank Module?” and “When is the StormTank Pack recommended?”
The StormTank Module 25 Series was introduced in 2007 as a solution for tight-footprint and high-capacity underground stormwater systems in North America. It features an open design with up to 97% void space and has the ability to support HS-25 loading due to its structural columns, which provide increased strength.
The Module 25 Series is great for areas where real estate is limited but is versatile enough to be utilized in large or small footprint scenarios. Along with the footprint flexibility, the product is also manufactured in five different heights and has the capability to be stacked up to six feet tall. It provides almost unlimited application range from detention basin to infiltration basin to rainwater harvesting and can even be installed under pervious pavements and bio-retention areas.
The StormTank Pack was introduced in 2014 as a light-duty alternative to underground storage products like the Module. It provides very high void space (95%) but less load capacity than standard box or arch structures.
The Pack’s design is ideal for residential systems. It provides adequate capacity for incidental passenger vehicle traffic or yard equipment, but it does not have the heavy-duty strength needed for larger truck traffic and the construction equipment typically used for commercial projects. When installed in a residential application, the Pack is buried with a minimum 24” cover and connects to the residence’s downspout network via a perforated pipe. This replaces traditional stone beds that can require large excavation because of the reduced void space (40%). The Pack is also ideal for use in bio-retention basins and rain gardens where vehicular traffic is limited. When the product is installed beneath the amended soils, surface ponding can be eliminated and storage capacity can be hidden. This eliminates common complaints about standing water and the associated issues, such as mosquitos.