Much of the evidence of expensive site work for a new Rhode Island middle school is buried, including a sprawling system of pipes for capturing hundreds of thousands of gallons of stormwater.

About $5 million of the $31-million cost of the North Smithfield Middle School, being built under a design-build contract by Gilbane Building Company, is earmarked for site work by Fleet Construction. The Cumberland, R.I.-based site contractor is putting in such visible elements as roads, parking lots and playing fields, as well as such out-of-sight structures as holding tanks for water, grease, acid waste, propane, fuel oil, and six underground stormwater detention systems.

Providence-headquartered Gilbane broke ground late in May 2007 for the 106,000-square-foot school, with RGB Architects, also of Providence, providing the design of the structure. RGB is also responsible for the design of all civil and plumbing construction.

Gilbane's project manager, Charlie Roberts, explained the need for the extensive earthmoving:

"The site work share of the total cost is disproportionately high for a project of this size because of the rural location of the school," he said. Roberts said there aren't any town utilities such as water or sewerage that they can tap into, even though the new school is near an existing high school. Consequently the middle school needs its own water well, wastewater pretreatment system and a storage system for storm water.

Crews drilled a 450-foot-deep well into bedrock to supply enough drinking water for the school, while a package station provided by California company Advantex will pre-treat sanitary wastewater before it is pumped into a large, standard leeching field.

But capturing stormwater was a significant challenge.

"The specs require zero discharge of stormwater," said Roberts. Based on the size of the impermeable area of surface structures — school and related buildings, parking lots and roads that rainwater simply rolls off — engineers calculated the approximate volume of runoff that could not be allowed to leave the site. Traditionally, designers would call for the construction of detention ponds that would hold this amount of runoff for a specified period of time to protect surrounding watercourses and real estate from flooding.

However, there is not enough space at the job site to accommodate large ponds, said Roberts, so designers opted for underground detention. This technique is often used where space is at a premium, or where open ponds could attract birds that present a pollution problem or even pose a hazard to flight operations at a nearby airport.

At the North Smithfield site, Fleet is installing six underground detention systems. All of the overlying land is to be utilized. The largest system, measuring 360 feet by 160 feet, will be covered by a soccer and football field. Remaining systems are to lay under five paved parking lots.

Detention systems are comprised of 36-inch-diameter, black, corrugated high-density polythylene pipe (HDPE), manufactured by Lane Enterprises of Ballston Spa, N.Y., and supplied locally by Vellano Bros. of Cranston, R.I. They are placed with the help of a Cat 345B excavator in a manifold arrangement. Approximately 9,500 linear feet of pipe was supplied for these systems, enough to store nearly 78,000 cubic feet or about 580,000 gallons of stormwater. Some of the pipe is perforated and bedded on stone to allow water to leech into the soil.

Other buried objects are a 55,000-gallon water storage tank for fire protection, a grease trap/tank fed by the school cafeteria and an acid waste tank serving the science lab. Tanks are made of non-corroding, fiber reinforced polyethylene.

Fleet is also relocating a softball field and an outdoor paved basketball court, and constructing the multipurpose playing field. The latter is covered with synthetic turf and includes a running track, also covered with a synthetic surface. As mentioned previously, this field overlies the biggest underground detention system. In addition, the site contractor leveled the adjacent high school's 500-foot by 250-foot sloping parking lot, filling in areas up to 8 feet deep.

By late July much of the site work was finished, and construction was under way on building walls and foundations.

As designed by RGB Architects, the three-story school is framed of steel, with some load-bearing masonry walls. Building Resources Inc. of Burrillville, R.I., is erecting steel that is supplied by Canadian fabricator CANATAL, while Costa Bros. of Fairhaven, Mass., is building the masonry walls. Other major subcontractors are: Marguerite Construction, Holliston, Mass., concrete; Delta Mechanical, Warwick, R.I., plumbing; and Wayne J. Griffin, Hopkinton, Mass., electrical.

Planned for many years, the project represents the beginning of a program to upgrade and expand North Smithfield schools. The new middle school fits within the existing high school campus, and will accommodate 550 students in grades 6, 7 and 8. Its design will allow connection with the high school. Housed in the building in addition to classrooms will be library and media center, a full-size gymnasium, and multipurpose cafeteria.

In keeping with the latest "sustainable design" concepts, the new facility will include such "green" building elements as high-performance window systems, solar shades to redirect natural light, a high-efficiency heating system, and the latest type of classroom lighting.

(Key personnel for the project include: for Gilbane Building Co., Ron Fargnoli, project executive, Charlie Roberts, project manager, Pat Walsh, project superintendent, and Matteo Alibrio, project engineer; for RGB Architects, David DeQuattro, principal in charge; and for Fleet Construction, Fred Sarmento, project manager.)