Low-Profile Chambers Solve Athletic Field Site Constraints

The public school district in Hingham, Massachusetts, is comprised of six schools, including Hingham High School, which aims to graduate students with the academic, civic, social and personal skills necessary to become productive, responsible members of a democratic and ever-changing global society. With the support and involvement of the community, Hingham engages students in a challenging, well-balanced educational program complemented by co-curricular activities.
As part of the co-curricular activity offerings, the school touts a number of athletic teams, including football, boys’ and girls’ soccer, track and field, cross country, softball and baseball. In an effort to upgrade the athletic facilities, Hingham High School’s traditional grass fields were reconstructed and replaced with synthetic turf fields. The permitting process for the renovation took place in late 2012 and early 2013, and the actual construction ran from June through August 2013.
GETTING THE LAY OF THE LAND
Hingham High School’s new turf fields, which include lights for night games and an additional parking area, will primarily be utilized by the school’s football and soccer programs. Part of the process for designing and installing the new fields included the design of a new subsurface stormwater management system. Engineers at Gale Associates collaborated with contractors from R.A.D. Sports to design and install a subsurface system that would effectively provide retention and detention to the site.
During the initial planning phase, engineers were faced with a couple of challenges. A seasonal high-water table was an initial design constraint. In Massachusetts, sites without proper clearance from the water table require additional storage to provide detention, and infiltration cannot be included as part of a model during a larger storm event.
“When designing the system, we had to be mindful of the high water table, as well as a 100-year flood elevation area, which is situated just outside the site,” says Peter Spanos, Gale Associates engineer. “We were able to use CULTEC’s StormGenie® drawing program and the HydroCAD® Stormwater Modeling System to easily generate an accurate system layout and design. Using these tools we dramatically cut down our design time and determined that CULTEC’s Contactor 100HD® chamber was ideal for this project because of its low profile.”
A HEAVY-DUTY SOLUTION
CULTEC’s Contactor 100HD heavy-duty subsurface plastic chambers were chosen for the job as they maximized the storage capacity while maintaining a low profile. Distributed by John Hoadley and Sons, Inc. from Rockland, Massachusetts, the Contactor 100HD is one of CULTEC’s lowest profile chambers with of height 12.5 inches (318 millimeters). The chamber holds 112 gallons (422.7 liters) and stores a minimum of 28.81 cubic feet (0.82 cubic meters) of storage per unit when surrounded with stone. The chambers have repeating support panels to add strength and features the patented side portal to allow for internal lateral manifolding of the system. A small chamber—the HVLV™ SFCx2 Feed Connector—is inserted into the side portal of the Contactor 100HD to create the internal manifold. The internal manifold eliminates the need for an external custom pipe and fitting header system, which would take up additional space and is costly to fabricate.
Because of its low profile, the Contactor 100HD is ideal for projects with restrictive depth parameters caused by high water tables, ledge, etc. In addition, CULTEC has an even lower profile unit, the Contactor® Field Drain C-4 which is only 8.5 inches (216 millimeters) high for applications with extreme depth restrictions.
HOW IT WORKS
Four separate beds were arranged within the site to comply with the local Conservation Commission’s requirement that the system also treat the runoff from the new parking area. The existing lot did not previously utilize any type of formal treatment—runoff simply flowed off the site onto the grass athletic fields. This often compromised the fields’ playability and made maintenance difficult.
The new system consists of nearly 950 CULTEC Contactor 100HD chambers and is located beneath the fields and parking lot. The system also utilizes CULTEC’s Separator Row™ and deep sump catch basins, which flow into the Separator Row, as a method of double-duty pre-treatment. The Separator Row acts as a water quality row preventing suspended solids from intruding into the chamber bed and stone. It captures any silt or fine particles prior to runoff overflowing into the rest of the basin and sump. To help maintain the stormwater system, any debris can be pushed toward the catch basin and sump using a water jet, and vacuumed out.
Deep sump catch basins are storm drain inlets that typically include a grate or curb inlet and a sump to capture trash, debris, and other sediment, oil and grease. Stormwater runoff enters the catch basin via an inlet pipe located at the top of the basin. The basin outlet pipe is located below the inlet and can be equipped with a hood (i.e., an inverted pipe). Floatables such as trash, oil and grease are trapped on the permanent pool of water, while coarse sediment settles to the bottom of the basin sump.
ON THE STARTING LINE
“The entire installation process went even faster than we had imagined—which was great because the fields and parking area had to be complete by the start of the school year,” says Rob Delmonico, President of R.A.D. Sports.
“Everyone was working on a really tight schedule,” he adds, “so the constant support from CULTEC representatives helped keep this a very seamless operation.” Students have been using the new turf fields since the start of the fall 2013 school year. ■
For More Information
CULTEC’S technical staff offers free design assistance including preliminary calculations and job-specific CAD details. For more information about CULTEC stormwater management chambers and other products, call 203.775.4416 or visit www.cultec.com.