There's no reason why athletic fields can't moonlight as infiltration systems. The only thing that's stopping them is lack of imagination and creative thinking, says Mike Kelly, director of new product development of Tiller Corp. in Maple Grove, Minn.

Built properly - with a drainage system underneath that sends excess water to a nearby watershed - athletic fields can be active biofilters for large storm events. The key to creating a sporty infiltration area is sand.

"Sandy areas can sock water and prevent flooding," says Kelly. A mass of sand, roots, vegetables, and microorganisms can provide the perfect properties for cleaning, detaining, cooling, and storing water, while also reducing the urban heat island effect.

This is not a new concept, says Kelly, who has designed and worked on sports fields for nearly 20 years. The golf industry has been building green fields with sandy soil for years . "The technology is there, we just need to use it on the civil engineering side."

When designing athletic fields to double as stormwater systems, Kelly often uses EPIC System, by Minneapolis-based Rehben Environmental Solutions Inc.. Once installed as an underground drainage system, it is as durable as any sand-based field. No catch basins are needed.

The infiltration system uses the properties of capillary attraction (the flow of liquids through porous media) to provide subsurface irrigation and drainage. It consists of three elements: the liner pan that catches and retains water, the chamber (a 4-foot pipe with large inlet holes that drains excess water quickly) that rests in the pan, and the sand fill that covers and surrounds the first two components. The only moving part in the system is water that's forced by gravity to travel throughout the system in a predetermined order. The largest component of the system is sand.

The system consumes 50% to 85% less water than traditional surface or drip irrigation systems. It absorbs natural runoff and effluents, storing it for later reuse or slowly releasing it in a controlled manner to keep the sand moist for grass to grow - an ideal solution for drought-stricken areas, as it can collect rainfall over a period of time and reuse the water during the dry season.

Session: Athletic Field or Dry Storm Pond?
Mike Kelly, New Product Development, Tiller Corp., Maple Grove, Minn.
Sun., Sept. 13, 2009
2-2:50 p.m.