HDPE pipe solves swamp problem for airport expansion
Problem: Building the 3,300-foot-long, east-west runway at Grand Forks International Airport in North Dakota required that swampland around it be properly drained because it could not support any load.
Solution: Ulteig Engineers designed the drainage system using 18- to 60-inch-diameter pipe connected in a herringbone pattern in cover ranging from 4 to 5 feet. More than 3.5 miles of MEGA GREEN corrugated high-density polyethylene pipe made with a minimum of 40 percent recycled content was specified. The pipe from Advanced Drainage Systems has a pre-drilled perforation pattern that allows groundwater to enter the system and be conveyed away. The pipe is available with a soil-tight or watertight joint in diameters from 12 to 60 inches for gravity-flow drainage systems. Its structural strength will support H-25 live loads and meets ASTM F2648 standard specifications.
Result: At the start of construction the land itself was the problem. “Bulldozers were getting stuck two to three times a day,” says Ryan Jones of Ulteig. “The land around Grand Forks is extremely flat, and the infield is actually below the rest of the grade. It was a bog that didn’t have any structural stability. This had to be corrected, and we did it by using the HDPE pipe. And so far it’s been working beautifully.” 800/821-6710; www.ads-pipe.com.
Stormwater chambers installed under space-constricted parking area
Problem: The Crossroads at Firestone Boulevard shopping center in South Gate, California, required a stormwater management plan that would direct stormwater runoff according to zoning regulations and work effectively in a limited space under the future parking lot of the new plaza. Regulations require that stormwater be held back on site to prevent entering the public water systems. The best option was a subsurface stormwater management system; however, soil at the job site was silty and sandy, making stability difficult.
Solution: Plastic underground stormwater chambers from CULTEC were chosen due to their reputation, ease of installation and widespread product availability. Delta Pipeline installed the Recharger 330XLHD, a 30.5-inch-tall, high-capacity stormwater chamber that allowed for a condensed installation area. The company installed 392 chambers amongst five areas, and provided 34,969 cubic feet of storage within 17,542 square feet. The units measure 8.5 feet long by 52 inches wide. Per the design, each chamber was able to store and infiltrate over 667 gallons of stormwater, localizing the runoff to the plaza’s location.
Result: “The real issue was the sandy soil,” says Marco Leon, site foreman with Delta Pipeline. “With the CULTEC chamber, install was perfect: no problems off-loading or installing the system with difficult soil conditions. We needed few additional materials to increase the system’s stability.” Over the two-week installation, the team had no complications. 800/428-5832; www.cultec.com.
Epoxy and PVC adhesive used in transition between T-Lock and concrete manhole
Problem: Nine wet wells required coating of floors with a reliable connection to a previously installed PVC T-Lock liner at the Maui County Wastewater District in Hawaii.
Solution: Neopoxy International recommended using a combination of solvent-free PVC adhesives and epoxy resins for this project. Coating Works Hawaii applied a 1-inch-wide strip of PVC adhesive on the low edge of the T-Lock sheet. The next day the floor was coated with highly corrosion-resistant NPR-5305 epoxy overlapping the PVC adhesive strip. The epoxy coating bridged the PVC material with the concrete wet well floor.
Result: The combination of PVC adhesive and NPR-5305 epoxy resin created a reliable transition between PVC material and concrete structure. 510/782-1290; www.neopoxy.us.
Combination of products used to decrease infiltration
Problem: The city of American Fork, Utah, recently completed a trenchless wastewater rehabilitation project primarily aimed at diminishing infiltration in a busy and growing business center that is home to a number of tech businesses in the area.
Solution: The city and its engineer selected a combination of UV-cured CIPP lining, lateral lining, as well as manhole rehabilitation using high-performance epoxy and chemical grouting. Manhole products included Sewer Shield Composite 150, a 100 percent solids high-build epoxy, C-120 build-back mortar, and hydrophobic chemical grout, all manufactured by Environmental Coatings.
Result: Despite the small project size, the results of using this comprehensive, multi-technology trenchless rehabilitation approach to reduce infiltration and control corrosion in the system were dramatic. The manhole coating and lining system performed superbly, and combined with the UV-cured CIPP pipe and lateral lining technologies, the city realized an infiltration reduction of approximately 100 gpm, resulting in significant long-term savings in treatment costs. 480/830-9537; www.sewershield.com.