Pipelines and Infrastructure

Pipelines and Infrastructure
Polypropylene pipe stops unwelcome stormwater infiltration

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Polypropylene pipe stops unwelcome stormwater infiltration

Problem
To prevent stormwater from infiltrating into its sewer system, the City of Moberly, Mo., decided to replace the crumbling 80-year-old brick and mortar tunnel serving as a combined stormwater and sanitary pipeline. The Reed Street Combined Sewer Overflow (CSO) replacement project used more than 3,000 feet of new pipe to connect to the Taylor Street CSO as a way to reduce inflow and infiltration by replacing the old brick sewer with a larger diameter pipe. 

Solution
The 60-inch diameter pipe selected was SaniTite HP pipe from Advanced Drainage Systems (ADS). According to Mike McCarty, P.E., of Jacobs Engineering Group Inc. in St. Louis, “In designing the new pipeline, we tried to match or exceed what the capacity of the brick arch was, which yielded the combination of pipe sizes ­— 60-inch RCP and 54-inch PVC. After consideration of constructability, cost and hydraulic issues, the decision was made to eliminate RCP and PVC and construct the project with polypropylene pipe.”

Result
The new pipeline was installed successfully, and has significantly cut infiltration. “Another benefit we got from the polypropylene pipe was that we were able to increase capacity for the entire run,” says McCarty. 800/821-6710; www.ads-pipe.com.

Corrosion-resistant manholes needed for quick install

Problem
A new residential development in North Las Vegas, Nev., required corrosion-protected manholes that could be quickly installed. Ease of installation was tremendously important for the project contractor and the small crew of laborers.

Solution
Working with a local contractor, HD Supply Waterworks selected Geneva Polymer’s noncorrosive Armorock Manholes for the project. They are made of sand and aggregate, with resin as the binder in lieu of traditional cement. They also offer half the wall thickness of a traditional concrete manhole, with strength to surpass the load requirements of a concrete manhole.

Result
The manholes bypass the need for many of the inspections and tests required for other manholes, as there is no welding or coating involved. On the job site, the manholes arrived noncorrosive, speeding up installation and avoiding some of the pitfalls of field applications going awry. A significant amount of installation time was saved, and the contractor delivered on time. 262/844-2923; www.hdswaterworks.com.

Sound-attenuated pumps enable nondisruptive sewer work following hurricane 

Problem
Following Hurricane Ike, the City of Galveston, Texas, needed to keep its sewer system operational. Sixteen lift stations needed portable pumps with auto start/stop capability, along with the hose and fittings to tie into existing piping. Several of these stations were in the shadow of expensive beachfront homes, apartments and local businesses. The residents needed to continue their daily lives despite the issues caused by Ike. 

Solution
National Pump & Compressor wanted to help accomplish sewer improvement jobs without intruding into residents’ space or causing excess noise that usually accompanies running diesel engines. They utilized a mix of 4-, 6- and 8-inch Pioneer Prime dBA Silencer sound-attenuated pump packages at 12 locations throughout the city. The package emits only 68 dBA at 25 feet.  

Result
The packages have been on site for several years while the City awaits funding to repair the lift stations. “We have not received a single noise complaint with the placement of the silent packs,” says Cynthia Diaz, Galveston Waste Water Superintendent. It will see continued use in the City of Galveston for the foreseeable future. 888/840-5886; www.npcrents.com.

Fitting fabricated for emergency transmission pipeline repair

Problem
Dekalb County, Ga., maintenance crews responded to a leak on Buford Highway. They excavated a failed 48-inch pipe connection buried more than 12 feet below that was deflected 5 1/2 degrees beyond what it was designed for. Conditions prevented straightening the joint, adding to the list of complications. The large number of customers dependent on this pipeline for water service meant shutdown would be an absolute last resort.

Solution
Smith-Blair Inc. was chosen to design and fabricate a solution for this project. The solution would involve installing a specially designed fitting under pressure, without interrupting service. First, personnel were deployed to the job site to collect information critical to ensuring the fitting became reality. Then the company’s internal design team developed shop drawings. The factory produced a complex, corrosion-resistant fitting designed specifically for the application. It displayed a blue Flexi-Coat system, a series of specially bonded fusion powder coatings.

Result
Along with county personnel, Smith-Blair installed and tested the fitting in the field, assuring a proper installation completed in a timely manner. 800/643-9705; www.smith-blair.com.

Multiphase engineered bypasses aid in sewer system upgrades

Problem
The city of Atlanta, Ga., serving nearly 2 million customers, had outgrown their existing wastewater treatment plant and pipeline. The city needed to replace their pipeline with a larger-diameter pipe and build a new high-capacity tunnel for water collection prior to going into the treatment facility. The plan was also to eliminate sanitary sewer overflows to a nearby river, separating their Combined Sewer Overflow (CSO) system as part of the expansion. The 20 mgd project included installation of 26,000 feet of sewer line, requiring more than 30 bypasses over the course of the project.

Solution
Rain for Rent was directly involved in the engineering, planning and deployment to coordinate with the various contractors to ensure a seamless operation. During the multiphase bypass, the company provided 30 pumps, more than two miles of 12- and 18-inch HDPE pipe, fittings, valves, alarm monitoring and spill containment. The bypasses ran through neighborhoods, wetlands and creeks. Sound attenuated pumps were installed to mitigate noise concerns in the neighborhoods.

Result
As part of best management practices on the project, the company hydrotested the HDPE pipe with clean water to ensure a leak-free system once the bypass was underway. The new sewer system was installed without any complications or spills. 800/742-7246; www.rainforrent.com.

Vertical lift pumps solve clogging issues caused by flushables

Problem
Wastewater pump clogging caused by flushables (wet wipes and other consumer products marketed safe for flushing) are pervasive issues in collection systems across the nation. Steve Peterson, lead foreman for Sanders Construction in Salt Lake City, began seeking solutions to this problem when he experienced clogging issues at a pump station he maintained for area mobile home parks that serviced approximately 300 residential units. Peterson experienced issues roughly twice a month. Every time the pumps clogged, he spent at least $500 sending two service employees to perform maintenance.

Solution
Peterson utilized a solution for vertical dry-pit lift station pumps that requires a fairly simple change in the rotating assembly. The station’s duplex pumps were retrofitted with X-PELLER impellers from Smith & Loveless featuring a clog-busting design. Because of the vertical construction, impeller replacement was quick and easy. Its mono-port design creates a single flow path through the impeller, negating the buildup of fibrous material in multi-vane pump impellers. It counterbalances the hydraulic forces at play inside the pump volute to maintain balance during operation.

Result
Since installation over a year ago, Peterson has been pleased with the results. Pump clogs have been eliminated. “We’ve already recouped the cost in less than a year,” Peterson says. “Looking five years down the road, that will be a big, big thing for us.” 800/898-9122; www.smithandloveless.com.

Fusible PVC utilized in challenging water line installation

Problem
Faced with significant rate increases from one of their largest wholesale water suppliers, the Bucks County (Pa.) Water & Sewer Authority (BCWSA), along with other neighboring authorities, began a search for an alternative water supply. The most direct and cost-effective route for the new line followed heavily traveled County Line Road and required a crossing of the Pennsylvania Turnpike (Rt. 276). The most difficult section of the entire transmission line project, the crossing would require either a horizontal directional drill (HDD) under the County Line Road bridge abutments and road surface, or a difficult jack and bore installation that would require the line to be rerouted away from the bridge crossing.

Solution
Ultimately, the utility chose the most direct alignment and elected to complete the 800 LF HDD with Fusible PVC pipe. Underground Solutions Inc. contracted with Aaron Enterprises Inc. to provide 800 LF of 30-inch DR 21 Fusible C-905 pipe and fusion services. In order to achieve the required 25-foot minimum vertical clearance from the road surface, the HDD alignment required an elevation change close to 55 feet within the 800 LF span. This is a very tight radius for an HDD operation that utilized 30-foot steel drill rods to complete the reaming passes and final pipe pull-in.

Result
The strength and flexibility of Fusible PVC pipe makes it a strong material that can withstand the long-term vertical loading required of a pipeline installed 25 feet below a major highway, and allows the end user to use standard ductile iron fittings for connections. “As a critical part of an overall $100 million dollar water project, the method of horizontal directional drilling [HDD] with Fusible PVC pipe was chosen based on cost-effectiveness and reliability of the pipe material in this extreme situation,” says Benjamin Jones, BCWSA CEO. 858/679-9551; www.undergroundsolutions.com.



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