Storm drain system succeeds for mega-mall project in salt marsh

Problem: A new 182-acre mega-mall in British Columbia required a large stormwater management system that could provide corrosion resistance to the salt marsh on which is being built, and structural strength because of the poor deltaic soil conditions in this seismically active region of Canada. Portions of the system would be installed under public roads. The two projects on the peninsula jutting into Boundary Bay are Tsawwassen Mills, an enclosed shopping mall with approximately 1.2 million square feet of retail space, and Tsawwassen Commons, a retail outlet with 555,000 square feet of outdoor retail space. The project is expected to be completed in summer 2016 and will include 6,000 parking spaces.

Solution: For the stormwater drainage system, more than 4,920 feet of SaniTite HP from Advanced Drainage Systems was used in diameters from 12 to 60 inches. In addition, 12 risers were fabricated using the pipe, each with an access ladder. Cover over the pipe ranged from 18 inches to 7 1/2 feet, and the backfill used was Class 1 crushed 3/4-inch angular stone.  

Result: The pipe provided a quick, contractor-friendly installation. The high beam strength, in addition to the pipe’s light weight and simple bell-and-spigot joints, allowed the crew to install more than 197 feet per day. Installed on a 0 percent grade, the pipeline acts as a holding tank as well as a conveyance system, allowing water to enter nearby ditches and be used by local farmers for irrigation. 800/821-6710; www.ads-pipe.com.

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Knife gate valves used to restore salmon habitat

Problem: In the early 1900s, two dams were built on the Elwha River in the Olympic Peninsula, Washington — the Elwha Dam in 1914 and Glines Canyon Dam in 1927. In 1992, full restoration of the Elwha River ecosystem was mandated by Congress to restore migrating salmon habitat and dramatically change the watershed. Lake Aldwell, a reservoir made by Elwha Dam, needed draining before the dam was blasted; it was necessary to remove silt from the reservoir as it emptied.

Solution: Five knife gate valves, fabricated by Lined Valve Company, were placed near the dam wall. All were bonneted (to reduce packing leak) and metal seated. They included two 72-inch, two 48-inch, and one 36-inch valve. Each was built with a carbon steel body, yoke and bonnet, and stainless steel gate, packing gland, stem and wetted parts. The seats were also stainless steel but with a welded bronze overlay. The valves were designed to 25 psi CWP, with TLSP packing, and electric motor actuators. These knife gate valves ensured clean, sediment-free flowing water.

Result: The knife gate valves operated for a few years as the reservoir emptied. The salmon population is recovering, riverbanks and gravel bars are rebuilding, and estuary habitat is growing. 888/256-5779; www.linedvci.com.

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Gate valves used on infrastructure repair program

Problem: In fall 2014, Oscar Renda Contracting was in the midst of the $116 million “North Contract” — one of Biloxi, Mississippi’s largest municipal public works projects ever, representing the bulk of the city’s recovery projects from Hurricane Katrina. The company was contracted to replace water mains, sanitary sewer lines, storm drains and pump stations.

Solution: Consolidated Pipe & Supply provided over 1,300 of Mueller Co.’s A-2361 350 psi resilient wedge, ductile iron gate valves. In addition, over 400 Super Centurion 250 fire hydrants and 2,500 pieces of service brass were shipped to the project. Supplied in sizes ranging from 2 to 12 inches, the A-2361 has dual-purpose lifting lugs, a user-friendly T-head bolt retention design, and a pressure-assist wedge geometry. The dual-purpose lifting lugs provide stability and alignment for the valve box. Secondly, all valves with a mechanical joint connection contain a nesting area for T-head bolts to prevent rotation during pipe installation, improving site safety, speeding installation, and resulting in a watertight connection. The shape of the iron wedge casting and the elastomeric encapsulation are designed to provide positive stop without overstressing the elastomer or epoxy lining.

Result: The A-2361 gate valves have performed as advertised, without a problem. 800/423-1323; www.muellercompany.com.

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Expanders used to fit and seal odd-sized clean-outs and pipes   

Problem: A Midwest energy contractor inspecting municipal sewer laterals needed a dependable non-leaking expansion plug for odd-sized pipes and clean-outs where conventional expansion plug sizes of 3 inches were too small and 3 1/2 inches were too large to seal and fit the clean-out opening.

Solution: The contractor in-stalled 3 1/2-inch flexible neoprene Real-Tite Expansion Plug Expanders that adapt over the 3-inch Real-Tite Standard Sized Expansion Plugs.

Result: The expanders provided a larger range of expansion, creating a leak-free solution that fit the odd-sized opening. The expansion plugs and adapters are watertight, easily removable and can be reused for future inspections. 800/877-0610; www.real-titeplugs.com.

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University fights drought conditions with reclaimed water program

Problem: As a public research university, UC San Diego is aware of California’s ongoing water shortage and embarked on a plan to leverage the availability of reclaimed wastewater in the San Diego area to further reduce the reliance on imported water in San Diego County.

Solution: When planning its reclaimed water project, the university relied on its prior use of horizontal directional drilling with Fusible PVC pipe from Underground Solutions to design an extensive distribution network with minimal campus and environmental disturbance. The project not only provides reclaimed water for irrigation systems that maintain the landscape, but also supplies water for the campus cooling tower complex, significantly reducing the potable water load. The project included 4,800 feet of 12-inch fusible PVC pipe in eight different horizontal directional drills through the heart of the campus. HDD installation protected the natural environment of the campus and minimized both vehicle and pedestrian disruption. Several of the directional drill pullbacks were completed at night and on weekends to minimize impact. Construction costs were minimized by crossing underneath many of the existing utilities and roadways across the campus.

Result: “Underground Solutions continues to bring added value to our projects throughout San Diego County,” says the project’s engineer, Greg Kump of Nasland Engineering. “They provide technical assistance during design, supportive guidance to bidding contractors, and cooperative, professional teamwork on the job site. Their project design and construction support is unique as a pipe supplier.” 858/679-9551; www.undergroundsolutions.com.