Project Orange County Choppers headquarters, Newburgh, N.Y.

Civil engineer M. A. Day Engineering

Stormwater system contractor Ultimate Land Developer, Inc.

Product application A CULTEC underground stormwater retention chamber system addresses site-specific challenges of land constraint, high water table, and zero discharge restrictions.

Underground stormwater retention system provides an eco-friendly solution on a small site.

Basking in the success of their "American Chopper" television show, Paul Teutul Sr., and sons Paul Jr. and Mikey decided to build a new Orange County Choppers (OCC) corporate world headquarters in Newburgh, N.Y., about 60 miles north of New York City. In 2007, ground was broken for a facility that includes OCC’s manufacturing and assembly area, a service center, a retail sales department, a merchandise store, offices, a display area, and the television filming and production area for the American Chopper series.

The 92,800-square-foot headquarters was designed as an environmentally friendly building. Engineers from M. A. Day Engineering specified recycled and locally processed building materials, high-efficiency storefront and curtain wall glazing with greater insulation and shading properties, as well as the use of energy-efficient equipment and construction waste recycling. Upon its completion, the $13 million building was also LEED-certified.

Addressing stormwater management was another important step in the design of this green building. To prevent pollution of local waterways, the stormwater solution needed to comply with the Phase II regulations of the Environmental Protection Agency’s Clean Water Act, which requires that a certain amount of stormwater be treated on site and that best management practices (BMPs) are used as precautionary measures.

When the owners of the popular TV show "American Chopper" decided to build their new Orange County Choppers corporate world headquarters in Newburgh, N.Y., CULTEC underground plastic chambers were selected as the best management practice for controlling stormwater.

Engineers conducted a hydrologic study to determine the amount of pre-development stormwater discharge to ensure that post-development runoff would be less than or equal to this amount, as required by New York State Department of Environmental Conservation. In addition, engineers wanted to ensure that the stormwater system would minimize land disturbance in the eco-friendly development and use captured stormwater for on-site irrigation.

The proposed building and 274 parking spaces were to be located on a 3.3-acre development site. The site’s size posed a challenge in terms of a stormwater system design. While M. A. Day Engineering previously had relied on stone-filled trenches and above-ground detention ponds when working in Newburgh, the space constraints at this site made above-ground solutions less desirable.

In addition to the lack of available land, engineers met with other onsite challenges. A protected stream was located at the northern part of the property, so they needed to plan for a smaller stormwater system footprint to keep a 50-foot distance between the stream and the system while also having adequate clearance from the building. The property also had a high water table, which restricted the potential system’s depth. The site was sanctioned as a zero-discharge area, so all of the runoff had to be contained and treated on site without being released into nearby waters. To address all of these challenges, the engineers selected CULTEC underground plastic chambers as the site’s BMP for controlling stormwater runoff.

"When an open detention pond is used to control stormwater runoff, the site loses acreage," said Larry Ruscitti, site supervisor at Ultimate Land Developers, Inc., the project’s installing subcontractor. "The OCC development needed to use a smaller footprint because there was a water stream at the back of the property. The CULTEC system allowed for some extra space that an above-ground system would not have permitted. That space was later used to add to a parking lot and create a grassy area."

Made of high-density polyethylene (HDPE), CULTEC chambers are capable of capturing high-volume runoff and can be used both to retain and detain stormwater on site. In retention systems, stormwater is stored without subsequent surface discharge, where the chambers capture, filter, and hold the stormwater until it is infiltrated back into the ground. In detention systems, runoff is only temporarily stored until it is cast out to an off-site area, such as a storm drain, pond, or wetland. A detention system is usually implemented if local regulations or concerns for watershed pollution prohibit infiltration practices at a commercial building site.

The Recharger V8 chamber has an internal manifold feature. Two side portals located on each chamber allow manifolds at any point within the system, eliminating the need to build external manifolds, thereby condensing the system by decreasing the required footprint.

CULTEC’s dome-shaped, open-bottom chambers feature built-in endwalls for strength throughout the system and a patented, overlapping rib connection, which facilitates installation and provides a stronger connection between chambers. The corrosion-resistant HDPE material is resistant to damage that can be caused by typical parking lot runoff.

The OCC site featured ground cover consisting of a brush/weeds/grass mixture in a moderate hydrologic condition with percolation rates from 3.7 to 5.3 minutes per inch. The stormwater system was designed with approximately 50,000 cubic feet of storage capacity to withstand a 100-year storm event. According to Day Engineering’s Dennis Lynch, the firm used Intellisolve’s Hydraflow stormwater modeling software for pond routing and to calculate the required storage capacity in post-development conditions.

Because part of the system would be located beneath the parking area, the stormwater chambers had to have enough cover to withstand vehicular traffic loads while also being 13 feet above the water table to prevent groundwater from impacting the system’s storage capacity.

CULTEC’s sales and technical staff helped engineers select a type of chamber that would provide the maximum storage capacity given the site’s parameters and restrictions. The Recharger V8, currently CULTEC’s largest-capacity stormwater chamber, was deemed best for this facility. This chamber is 34 inches high, 54 inches wide, and has a chamber storage capacity of 8.933 cubic feet per linear foot, with each chamber holding approximately 500 gallons of runoff. The heavy-duty construction of the V8 model makes it especially well suited for high-traffic applications.

Engineers also worked with CULTEC’s technical staff to determine the footprint and configure the system as an L-shaped bed on the northern portion of the site and along the east parking area.

To calculate the system’s width and configuration, CULTEC used Recharger V8 parameters, along with the site’s workable depth, desired bed area, and required storage volume, considering that the system would be used for retention. CULTEC also incorporated the storage of the backfill stone porosity at 40 percent, a 20-inch-thick stone foundation as requested by the engineers, and typical 6-inch chamber spacing. Usually, a minimum 6-inch-thick stone foundation is required, but the engineers chose a thicker stone base to maximize the system’s storage capacity by utilizing the stone void volume.

CULTEC determined that 480 chambers would be required and installed in a 15,900-square-foot stormwater bed. The storage volume provided per installed chamber was 15.36 cubic feet/foot when using a 20-inch stone base, installing the chambers 60 inches on center, and placing an additional 6 inches of stone above the chambers. The company also provided the engineers with bed width and length measurements, excavation volume, minimum bed depth, and the amount of stone that would be required for the installation. Once the proposed design was approved, CULTEC provided drawings and details for the engineers to use on their blueprints.

Underground storage chambers helped solve a number of stormwater management issues on site, including the lack of available land, a high water table, and zero-discharge restriction. It also helped minimize land disturbance in an eco-friendly development.

At the OCC facility, the CULTEC system collects stormwater in catch basins from a basin inlet structure. The runoff then enters an internal manifold system that conveys it throughout the bed of stormwater chambers. A conventional manifold consists of a pipe and fitting configuration. The Recharger V8, however, has an internal manifold feature. Two side portals located on each chamber allow manifolds at any point within the system, eliminating the need to build external manifolds, thereby condensing the system by decreasing the required footprint. High-Volume Low-Velocity (HVLV) F-110 Feed Connectors, open on both endwalls, are inserted into the side portals to construct the manifold.

Specific to the OCC system’s design, the chambers retain stormwater until it infiltrates into the ground. That satisfies the zero-discharge requirement that all stormwater runoff be captured, treated, and stored on site to preserve water quality of the local waterways.

The OCC installation began with excavating a bed, laying CULTEC non-woven polypropylene filter fabric along the sides and the bottom of this bed, and then adding a layer of crushed stone. The chambers were arranged in the bed and fed using the internal manifold feature. After the chambers were in place and covered with 6 inches of crushed stone and a layer of filter fabric, the site was prepared for asphalt. The entire system was installed in a about 10 days, with the excavation process taking most of that time.

"The CULTEC system was installed very quickly, with only half a day needed to install the chambers," said Dennis Lynch, field engineer at Day Engineering. "It was the first time we ever used an underground system, and CULTEC walked us through every step of its design, layout, and configuration."

At OCC headquarters, the CULTEC underground system is capable of capturing, retaining, and treating a large amount of stormwater runoff in a relatively small footprint. The system became an ideal solution to the site-specific challenges of land constraint, high water table, and zero-discharge restriction, as well as federal and state requirements. Employing an underground system also helped engineers maximize the size of the building and the number of parking spaces, while freeing up land for grassy areas that otherwise would have been taken up by above-ground stormwater solutions.


Fred Dotson is vice president of CULTEC, Inc. He can be contacted at custservice@cultec.com.