Pennsylvania facility’s storm water management installation addresses topographic challenges
CubeSmart, the fourth-largest owner and operator of self-storage facilities in the country according to the 2011 Self Storage Almanac, is a self-administered and self-managed real estate company focused on the ownership, operation, acquisition and development of self-storage facilities in the United States. The company owns or manages 479 self-storage facilities across the country and operates the CubeSmart Network, which consists of approximately 850 additional self-storage facilities. These facilities are designed to offer affordable, easily accessible, secure and, in most locations, climate-controlled storage space for residential and commercial customers, as well as boat storage and mini storage.
Recently, the organization chose to expand its presence in Pennsylvania by opening a location in East Whiteland. Originally, the town envisioned that the site would consist entirely of office space, but when CubeSmart chose to purchase the space, the company decided to relocate its corporate headquarters there and use the other half for storage. The space includes Class-A offices for 160 employees formerly operating out of the Wayne, Pa., office, as well as self-storage facilities.
Engineers from Nave Newell Inc.—based in King of Prussia, Pa.—were tasked with designing the new location, which would include the installation of a storm water management system. The engineering team from Nave Newell collaborated with contractors at Lyons & Hohl Site Contractors to develop the new layout for the site, and they were faced with a number of onsite challenges when designing the storm water management system. The engineers had to overcome a 60-ft topographic grade in order to establish the building pad and parking area. Also, the site is the last piece of land to be developed at a prominent intersection and is located at the top of a steep bluff. Because of this, engineers were under close scrutiny by township, county and state regulators and stakeholders, and they had to be mindful of the quality of the receiving watershed.
Nave Newel engineers selected the CULTEC storm water system to detain (or temporarily store) excess storm water onsite and allow for infiltration in accordance with both township and state regulations. Since the site is located atop a steep bluff, engineers had to be very careful in establishing the discharge location. Runoff could not be discharged directly over the side of the bluff for fear of erosion down the slope.
“We knew that any consistent flow of runoff going over the side of the bluff would eventually cause it to erode and set other potential dangers in motion,” said Alex Tweedie, Nave Newell design engineer. “In order to prevent any chance of erosion, a pipe was extended outside of the area to create a discharge site that would be able to adequately receive the runoff.”
Since only half of the site was dedicated to office space, the demand for parking was greatly reduced. Still, engineers had to optimize the grading to create enough level pads for the parking and reserve parking areas. The most efficient solution was to install a subsurface storm water system. A grass field for reserve parking was placed on top of the storm water system, leaving space for approximately 100 additional parking spots.
Given the constraints of the site terrain and the storage requirement of 93,397 cu ft, Nave Newell engineers chose to install CULTEC’s Recharger 330XL model for the system. With a capacity of over 400 gal, this CULTEC chamber is one of the largest available. It maximizes storage while using a small footprint, and it best satisfied the requirements of the CubeSmart site. The unit is 52 in. wide by 30.5 in. high, and it has an installed length of 7.5 ft with a bare chamber capacity of 7.5 cu ft per linear ft. Because of its size, the chamber can help save land space and offer design flexibility. In all, the subsurface CULTEC system provided 94,319 cu ft of storage.
“We prefer to install an open chamber system over a pipe system because you get a much better overall footprint,” said John Hogan, Nave Newell design engineer. “The Recharger 330XL is a very efficient chamber that has a lower volume in the early stages of a storm.”
Representatives of Lyons & Hohl Site Contractors, which specializes in residential and commercial turnkey site work projects, installed the subsurface system in less than three weeks. The extensive bed included more than 700 chambers placed in 45 rows. Moreover, CULTEC’s No. 410 filter fabric encases the entire bed. The fabric prevents soil intrusion into the chamber bed. The system occupies 33,088 sq ft. It also required 7,264 tons of stone, which provided a 40% void for the water. The void spaces between the stone add to the storage provided while also assisting in alleviating the load above the system.
“CULTEC’s chambers are created out of lightweight polyethylene, making the installation fast and efficient,” said Mike Hohl, project manager at Lyons & Hohl Site Contractors. “The entire system was installed with only a handful of workers. The chambers are durable and corrosion-resistant, and their interlocking connections help facilitate a fast and foolproof operation.”
Town regulations required a cost-effective yet environmentally friendly solution for the storm water management system designed for CubeSmart’s East Whiteland, Pa., corporate headquarters. The subsurface system solved the challenges of the extensive topography while maximizing the space above for reserve parking.