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From the Pros to High School: Innovative Sports Field Construction12-30-08 | News

From the Pros to High School: Innovative Sports Field Construction

By Bret Shroyer, VP of Operations for Rehbein Environmental Solutions

Reliant Stadium opened in August of 2002 and is home to the Houston Texans, as well as other events like catered functions, exhibits, concerts and general sessions. It is the only NFL indoor/outdoor retractable roof, natural grass stadium that can be configured to utilize up to a 125,000 square foot space. Reliant Stadium features 1.9 million square feet with a seating capacity of 71,500 and 97,000 square feet of natural grass playing surface. What makes the field interesting is its portable modular turf system.

As public and private organizations continue to look for ways to save money and positively impact the environment, innovative construction and landscape design provides a great opportunity to balance difficult and sometimes conflicting goals. Sports field design and construction, in particular, presents the challenge of reducing costs and water use while still providing a quality field for athletics and other uses.

For several years, Rehbein Environmental Solutions, Inc. (RESI) has been on the cutting edge of this market, helping developers and groundskeepers solve unique challenges with several stadium and sports field projects.

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Reliant Stadium

In 2002, RESI was selected to install the turf system for the new Reliant Stadium in Houston, Texas. Reliant Stadium opened in August of 2002 and is home to the Houston Texans, as well as other events like catered functions, exhibits, concerts and general sessions.

The stadium required a new turf system that was natural and portable, since it would often have to be removed in order to make room for larger events such as concerts, rodeos and trade shows.

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Designers also had to keep in mind the effect of the turf on athletes, who require a forgiving, soft surface to help avoid injuries.

Each turf module is 7 1/2 inches deep and includes a metal drainage system. The modules incorporate a growing medium that is 4 1/2 inches deep and are reinforced with reflex mesh elements. The portable design of the modules, which includes an enhanced rootzone profile, also allow for the removal and replacement of any single module without adverse effects on surrounding modules. This easy exchange helps combat both the excessive wear that results from heavy usage on game days and long periods of shade to which the turf is subjected.

To meet these stringent requirements, a system was implemented that used 8-by-8 foot portable turf modules that are 7 1/2 inches deep and include a metal drainage system. The modules incorporate a growing medium that is 4 1/2 inches deep and are reinforced with reflex mesh elements.

The reflex mesh elements consist of small pieces of interlocking, three-dimensional poly-propylene mesh.

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Several times every year, each module of the field is removed to an outdoor nursery while the stadium hosts the Livestock Show and Rodeo and other events. The reflex mesh elements at Reliant Stadium give the turf surface ?EUR??,,????'?????<
The portable design of the modules, which includes an enhanced rootzone profile, also allow for the removal and replacement of any single module without adverse effects on surrounding modules. This easy exchange helps combat both the excessive wear that results from heavy usage on game days and long periods of shade to which the turf is subjected.

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The passive subsurface irrigation system (shown here during construction) installed at Vista del Lago uses capillary physics and gravity to deliver water and nutrients to the turf through an interconnected series of chambers and pans installed underground.

Vista del Lago High School

RESI is also involved with smaller-scale turf projects for schools and communities throughout the United States. When Vista del Lago High School in Folsom, Calif., needed a new natural turf soccer field in 2006 to complement its synthetic field for football, marching band, and other sports, they wanted to find a solution that would minimize the amount of water they would need to use.

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Vista del Lago High School in Folsom, Calif., installed a new irrigation system to grow a quality sports field turf that minimized the amount of water necessary for irrigation. With the cells full, capillary physics causes the water to move vertically to the surface and throughout the entire rootzone.

About the System

The passive subsurface irrigation system installed at Vista del Lago uses capillary physics and gravity to deliver water and nutrients to the turf through an interconnected series of chambers and pans. For the base preparation, the field was laser-leveled so that there was no crown.

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EPDM liner was installed to prevent water from soaking in to the subsoil and to keep soil contaminates out of the system and the turf above. As a result, the system can be used to repurpose brownfields like the natural asbestos site upon which the Vista del Lago field was built.

Next, headers were installed at both ends of the fields, one as an inlet for irrigation water and the other as a collection point. Between the two, near the middle of the field, they installed a 1,000 gallon recirculation tank, which was placed on a timer. Chambers were then positioned throughout the field and covered with sand to the surface.

Once every week, for about 23 hours, the tank pumps water to one header, at which point gravity takes over to irrigate the field. Water flows at a steady rate from the header to the first cell. Once the first cell is saturated, gravity causes the water to move to the next cell where the process repeats itself. Once each cell is saturated, remaining water returns to the collection point at the opposite end of the field and is deposited into the recirculation tank.

Because the system is run without sprinklers, no water evaporates in to the air or is wasted due to a poorly aimed sprinkler. ?EUR??,,????'?????<
Unfortunately, the school had already paid hook-up fees for their conventionally irrigated softball and baseball fields; otherwise they could have saved even more money.

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The field includes a safety feature: with no sprinkler heads to trip over, athletes reduce the risk of twisted ankles and scraped knees. There are no pressure lines to break and the field can be aerated without fear of puncturing anything since the sand bed provides a 7-inch barrier between the surface and the irrigation chambers.

Gray Water

The system at Vista del Lago can also use rainwater for irrigation. Because the field has such a high infiltration rate, it is capable of absorbing as much as 23 inches of rainwater in a 24-hour period. Once the field saturates to the 3-inch level, excess water filters through the sand profile and is removed to the underground recirculation tank, where it can be used again during the next irrigation process. A zone valve on the tank maintains a 2 foot deep water level in the tank at all times.

The Vista del Lago soccer field is also designed to use gray water from the local wastewater treatment facility to replenish the recirculation tank and irrigate the field.

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Sipaila said the school is quite happy with the installation.

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