Project Case Study: Severe-service storm sewer

April 2006 » Feature Articles
Usually, watertight seals are specified for storm sewer projects to keep water in a pipeline. But for a recent New Jersey Department of Transportation (NJDOT) installation completed in December 2004, exfiltration wasn't the problem. The challenge was to keep pollutants in the surrounding soil from entering the system.

HDPE pipe and midnight custom fabrication aid installation of a new storm sewer line beneath narrow roads and through toxic waste and hidden utility traps.

BY STEVE COOPER

Project
Stormwater sewer installation, Port Newark, N.J.

Civil Engineer
Louis Berger Associates, East Orange, N.J.

Product application
Soil and groundwater pollution in a heavily developed industrial area required use of chemical-resistant stormwater pipe and seals in custom-fabricated sizes to protect stormwater and receiving waters from contamination.

Usually, watertight seals are specified for storm sewer projects to keep water in a pipeline. But for a recent New Jersey Department of Transportation (NJDOT) installation completed in December 2004, exfiltration wasn't the problem. The challenge was to keep pollutants in the surrounding soil from entering the system. Carbro Construction of Hillsborough, N.J., also found some unexpected surprises once the digging began. Doremus Avenue, the major street serving the dock areas of Port Newark, was reconstructed to widen lanes and shoulders, and to install about 9,500 feet of new storm sewer lines that would safely discharge into the Passaic River.

During the late 1800s, the area was a world-renowned manufacturing center. Producing carriages, shoes, hats, and saddle hardware, it was called the Ironbound because crisscrossing railroad tracks bounded the area. By World War I, Newark expanded the Ironbound by building Doremus Avenue, soon to be known as Chemical Row because of all the refineries and smelters constructed there. Doremus Avenue was built on a salt marsh filled in with industrial slag from local manufacturing operations and garbage from New York City. The Ironbound, like other urban areas, has had a long history of industrial use that has continued to the present time.

According to the U.S. Environmental Protection Agency (EPA), the waters and sediments of the Lower Passaic River watershed are contaminated with hazardous substances, including dioxin, PCBs, DDT, heavy metals, and hydrocarbons, which stay in the soil. Long a heavily industrialized area along the Passaic River in Newark, Doremus Avenue now has nearly 400 large industrial plants dominated by electroplaters, metal finishers, pharmaceutical manufacturers, textile dyers, hospitals, electronic products manufacturers, newsprint recycling mills, scrap metal yards, oil tank farms, refinery operations, and chemical plants.

Pollution also comes from residual oil and gas from the thousands of trucks daily using the road.

While industry provided the pollutants, the low-lying area, much of it below sea level, trapped the residue in its soft, mucky soil, making it a prime concern for the New Jersey Department of Environmental Protection (NJDEP), the NJDOT, and the new stormwater system's design consultant, Louis Berger Associates of East Orange, N.J.

“The only way to prevent polluted groundwater from getting into the new storm drain system was to use pipe that could provide the flow characteristics, stand up to the harsh environment, and have a gasket that would securely seal the pipe joints,” said John Kurdziel, Advanced Drainage Systems (ADS) director of technical services. “The project managers knew from the beginning that concrete pipe could not be used in this environment because of the corrosive nature of the soil and the joint performance requirements in these soil conditions. That's why corrugated, [high density] polyethylene (HDPE) pipe was selected. This project needed pipe that wasn't vulnerable to anything that was in the soil. Plus, we knew they'd need custom lengths, as few joints as possible, and a product that was easy to handle and wouldn't require a lot of makeready room, which wasn't available. We recommended our N-12 WT pipe because of its watertight joint capacity.” Because of the toxic severity of the soil, specifications and performance data of the materials were double checked. “We went through a list provided by the NJDOT that identified chemicals in the soil to make sure the pipe and gasket would be acceptable in this concoction of chemicals,” Kurdziel stated.

The company provided documentation showing that its pipe would not be affected; however, the high concentration of petroleum- based contaminants could affect the standard polyisoprene rubber gasket. A nitrile gasket was proposed and approved by the NJDOT and Berger. For the watertight manhole adapter, the precaster used an A-LOK gasket also manufactured using nitrile rubber.

Additionally, the pipe, connections, and seals had to stand up to some pretty heavy loads, such as truck traffic, and even heavy storage as the area is part of the Port of Newark, where shipping containers are sometimes stacked nearly as high as an eight-story building, and weighing just as much.

But this wasn't a typical cut-and-fill operation. The project also required close tolerances for a storm sewer project-so tight that exact lengths of the HDPE pipe were manufactured the night before to fit the next day's installation.

“The traditional field cut and connecting from manhole structure to manhole structure had to be eliminated because of the type of joining system that had to be used,” explained Kurdziel.

The big surprises came from underground utilities and structures that weren't identified on the plan or not well noted. After all, this area had been built, rebuilt, dug up, changed, and added to for more than 100 years. The site is filled with an uncharted maze of petroleum pipelines, high-pressure gas lines, and water and sanitary sewer mains. There also are high-voltage electrical feeds that carry power for New Jersey Transit PATH trains and Amtrak. Because of this, there were a lot of “on-the-fly” changes to the storm sewer design.

This challenge fell to Carbro Construction, which found a simple but very uncommon solution. “We just had the ADS plant work all night,” said a smiling Tom Tomasulo, supervisor for Carbro.

Tomasulo's crew would uncover and measure. ADS would manufacture the piece and adaptor overnight and deliver it early the following morning to keep the project rolling.

“We had to do a lot of in-field designing, and the system worked like a charm,” Tomasulo said. “The specifications for the closure-usually a bell and spigot-and pipe lengths were given to ADS, and they custom made what we needed and delivered it to us onsite by 7 a.m. the next day.” In total, there were 206 custom-made lengths of N-12 WT pipe in diameters ranging from 15 inches to 60 inches.

The convenience of the ADS plant in Muncy, Pa., within a three-hour drive to Newark, made overnight manufacture possible.

ADS has 24 manufacturing plants in the United States and 28 company-owned distribution centers to provide local supplies.

“Corrugated HDPE pipe is the ideal storm sewer pipe for this job,” said Pino Carlomagno, vice president of Carbro. “It is significantly more resistant to corrosion, chemical attack, and abrasion than reinforced concrete pipe, which is critical as the soil is flagged by the EPA as ID27, meaning dry, industrial solid waste. The way ADS worked with us provided joints that are superior and watertight to sanitary sewer standards. Over the 8,200-foot project, we used an assortment of diameters and they all fit perfectly.” ADS N-12 WT pipe is made from engineered grades of HDPE.

Designed with a corrugated exterior and smooth interior, the ADS pipe provides both strength and maximum flow for water. Named for its Manning's “n” rating of 0.012, the N-12 WT pipe was designed in 1987 by ADS specifically for storm sewers, and for use under highways, railroads, airports, and other engineered construction.

Because the ADS N-12 pipe meets the requirements for Type S pipe under AASHTO M 252 and M 294, it can be specified for culverts, cross drains, storm sewers, underground stormwater detention systems, and other new and rehab construction.

As a flexible conduit, HDPE pipe withstands vertical pressure by transferring virtually the entire load to the surrounding soil. N- 12 WT pipe will support H-25 highway live loads with 12-inch minimum cover, and E-80 railroad loads under 24 inches of cover.

According to ADS, the N-12 pipe has performed well in controlled tests at fill heights of more than 100 feet.

Because Doremus Avenue is the major truck route, traffic could not be shut down or detoured. This meant that the Carbro crew had another challenge to overcome. “We did the job in two phases,” Tomasulo said. “The first phase required the storm sewer inlets and cross pipes to be constructed on the upstream side of the road. The cross pipes were constructed to the centerline of the road.

The second phase installed the trunk line down the middle of the northbound lane and the continuation of the cross pipes to connect to the trunk line. This required the manufacturing of nonstandard lengths of pipe.” “Overall, we're very pleased with the project, especially the pipe and the way ADS helped us with this unique situation,” said Carbro's Tomasulo. “The N-12 WT pipe was what we needed-chemical resistance, excellent joint performance, and custom fabrication.”

Steve Cooper is president of SCA Communications, Baldwin, N.Y. He can be contacted at 516-623-7615 or via e-mail at steve@scacommunications.com.


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