Case Studies - Spring 2021

Case Studies - Spring 2021

Sanitary district finds cause of I&I issues 

Problem:

The Klamath Falls South Suburban Sanitary District in Oregon includes roughly 10 square miles and serves a population of approximately 25,000 people. It owns and maintains more than 100 miles of sewer pipe and more than 1,000 manholes. Most of the sewer mains were installed in the 1960s and 1970s and consist of asbestos cement pipe. Excessive I&I was causing overflows and unnecessarily increasing the treatment plant processing costs. They had been using flowmeters, but these were hard to install, hard to move around and were expensive.

Solution:

The district turned to the use of SmartCover sewer monitoring because the deployment was less invasive, as there is no confined space entry for installation. Also, based on calibration against other flow systems, it delivered accuracy, trend analysis and modeling to home in on specific I&I issues, especially for a sub-basin.

Result: For the relatively small staff, the SmartCover units helped with better targeting of available resources on addressing real issues of concern regarding I&I. By leveraging them, the district has been able to expand monitoring and enhance the granularity and detail of flow information that it receives. “Monitoring remote locations with SmartCover is key in our efforts to identify and combat I&I,” says Mike Fritschi, manager of the Klamath Falls South Suburban Sanitary District. 760-291-1980; www.smartcoversystems.com


Mechanical point repair sleeve used in sewer preventive maintenance program

Problem:

 The Franklin Township Sewer Authority in New Jersey has a preventive maintenance program that had prioritized identifying and addressing defects to reduce I&I. But the repair process had become a bottleneck: Staff engineers spent too much time planning how to tackle each defect, and the contractor bidding process was slow. In the meantime, groundwater infiltration would continue to fill the pipe. They needed an option that was easier and more efficient.

Solution:

Quick-Lock point repair sleeves from Pipeline Renewal Technologies provide infiltration abatement and structural repair, and they can be installed by just two people in under 30 minutes. Made of a heavy-gauge 316L stainless steel cuff and an EPDM rubber gasket, a sleeve can restore strength and stop infiltration immediately. Users position and prepare the sleeve with a standard inspection crawler, and the device is then expanded pneumatically to seal out infiltration. With no contaminating resins or prolonged cure time, this mechanical solution requires neither wet-outs nor bypass pumping. And it can be installed directly over gushers to eliminate high-volume sources of I&I. 

Result: With the addition of Quick-Lock to its repair options, the authority is now able to identify a defect, determine if it is a candidate and make the repair immediately. After just two months of utilizing Quick-Lock on an as-needed basis, they had installed seven sleeves and were saving over $6,500 per month. 866-936-8476; www.pipelinert.com


Sewer manhole leak fixed by grout injection

Problem:

 Colchester, Vermont’s wastewater system processes more than 100 million gallons of wastewater per year. When a significant groundwater leak was discovered at the joint between manhole pipe sections, IP&C Industrial Services was invited to evaluate the situation.

Solution:

 IP&C Industrial Services determined that the most cost-effective solution would be to apply a chemical grout-injection system from AmTech Tank Lining & Repair. The crew drilled an injection path into the center of the crack. Flexible packing was wedged into the joint to slow the inflow. Fast-setting grout was pressure injected throughout the crack and voids created by groundwater outside the manhole pipe.

Result: Once the grout set, the leak and outside voids were completely sealed off. The town of Colchester realized significant savings compared with curtain grouting or replacement of the manhole pipes. 888-839-0373; www.amtechtanklining.com


CIPP point repairs provide no-dig solution for localized damage

Problem:

 An 8-inch PVC sewer main located beneath newly laid asphalt in an upscale residential neighborhood in Utah was damaged when an HDD contractor accidentally bored through it. Fortunately, the contractor realized their mistake before pullback, but the cross bore left large holes in the PVC sewer main.

Solution:

 While opencut replacement was an option, it was not ideal, as it would require cutting into the new asphalt and cause a significant inconvenience to area residents, so the city opted for a trenchless alternative. Cured-in-place sectional point repairs from HammerHead Trenchless provide a permanent, structural solution to repair localized damage. Point repairs can be installed in a wide range of host pipe materials, 3 to 60 inches in diameter. A point repair utilizes a fiberglass-reinforced mat saturated with resin in 2- or 4-foot lengths installed using an inflatable packer.

Result: The experienced underground contractor first had to prepare the pipe and deal with debris entering the pipe from the large holes from the cross bore, which they removed with a reverse jet nozzle. The fiberglass mat and resin come pre-measured and packaged so the crew had everything necessary to prepare the mat and packer on site and install the 2-foot point repair, entering the pipe through a manhole. Once the repair was in place, it took around 2.5 hours to fully cure and the pipe was successfully repaired without any excavation. 800-331-6653; www.hammerheadtrenchless.com


Dismantling joint helps create customized piping solution

Problem:

 The water utility in Queen Creek, Arizona, had a range of solid steel piping that was connected on one side of a booster pump for water suction and on the other side for water discharge. After 20 years of use, the piping needed to be replaced, as it was rusting. The problem was that each of these connecting pipes was custom-made and varied in length. To replace each pipe, a new customized pipe would need to be constructed on site, with high associated costs in terms of money, time and effort. The utility was looking for a more cost-effective solution to replace the rusted sections without using tailored pipes for each repair.

Solution:

HYMAX, a Mueller brand, developed an eccentric dismantling joint with flange connectors on either end that could be telescoped to be anywhere between 10 to 14 inches in length. Instead of fabricating each connection on site, a costly and work intensive process, the product could be adjusted exactly to match the length between the booster pumps and the discharge piping and installed by just one person in about 30 minutes.

Result: Without each pipe needing to be customized on site, repair cost, time and effort were greatly minimized. The new dismantling joint also helped increase water flow by approximately 40 to 60 gpm. The design enabled better hydraulic flow, as the old pipe was rough on the inside due to rusting. 855-457-2879; www.krauszusa.com


Utility upgrades outdated lift station

Problem:

 The Terrace Street Lift Station is the main lift station for the village of Millersport, Ohio. Two surface pumps handled daily operation. During rainstorms, two 30 hp submersible pumps took over. By 2017, the surface pumps had reached their end-of-life. Flow went through the surface pump wet well first and overflowed into the submersible pump wet well. But debris settled in the wet well and plugged the surface pumps during rain events. Frequent unclogging decreased pump efficiency and increased maintenance costs. Additionally, the village didn’t grow as expected, and the 30 hp submersible pumps were oversized, causing inflow to the facility. That resulted in increased treatment costs and added capacity to the collections system.

Solution:

 The village engaged Xylem to engineer a complete design/build solution. Working with Stutske Construction, they designed a turnkey solution for the lift station upgrade. Stutske found flow issues on Terrace Street and the nearby canal. Because all sewage flows toward the Terrace Street Lift Station, the infiltration caused backflow issues during heavy rains. The upgrade included installing two 10 hp Flygt N-Technology submersible pumps in the existing wet well. The pumps are controlled by two Aquavar IPC variable-frequency drives, water level control float sensors and a MultiSmart controller.

Result: Since completion, pump clogging has ceased, and energy consumption has dropped. In addition, with the installation of Flygt Cloud SCADA, they can remotely control the pumps to eliminate wastewater spills. 855-995-4261; www.xylem.com/pumping


High-build epoxy coating a solution for lift station

Problem:

 A Florida utility needed to coat a concrete lift station/wet well. The structure measured 21 by 21 feet and contained two tanks. The city was searching for a solution to line and protect the structures effectively before the typical 30-day concrete cure time.

Solution:

 Universal Painting was able to deliver the desired solution using Epoxytec products. Mortartec Ceramico was applied at 1/4-inch- minimum thickness. The product was kept under humid conditions while curing and away from direct sunlight to avoid dry-out conditions. CPP Sprayliner was applied as a protective topcoat.

Result: The application qualities of Epoxytec allowed the project to be completed on time. “It has been the easiest plural application we have ever had,” says John Aldrich, president/CEO of Universal Painting. “We absolutely love the surfacer. We are planning on submitting the product for some thin-film systems whose manufacturer doesn’t have an equal.” 877-463-7699; www.epoxytec.com


Manhole inserts assist in controlling sewer odor emissions

Problem:

 For more than a year, New York’s Saratoga County Sewer District was faced with complaints from residents regarding odors being emitted from manholes. Historically, the sewer district would handle these complaints by chemically treating the pump stations closest to the odor problem. However, this only proved to be partially effective, as some of the communities within the treatment plant’s jurisdiction were simply too far away for the treatment to reach. 

Solution:

 Dan Rourke, executive director of Saratoga County Sewer District, took his research online and found the Parson Environmental Products Odoreater Manhole Insert. This specially designed manhole insert, with the addition of a canister containing 20 pounds of activated carbon or non-impregnated activated catalytic carbon, works to trap and store unpleasant hydrogen sulfide and methyl mercaptan odors. The filtered and odor-free air is then ventilated into the atmosphere through the canister lid. 

Result: The inserts were installed in manholes throughout the county. “The simplicity is the best feature,” Rourke says. “They work really well in remote areas, but are still heavily used by the public, such as walking and biking trails, public parks or utility easements in rural neighborhoods.” The insert requires minimal maintenance and is as easy as replacing the carbon materials (also available from Parson) when necessary. 800-356-9023; www.parsonenvironmental.com


Lining system used to fix root-infested sewer pipe

Problem:

 Mr. Rooter of Western Washington was called to help fix a root-infested sewer pipe on a nearly 100-year-old, two-family home in Seattle. The root infestation caused breaks in the lateral pipe and sewer backups in the basement. The multidiameter lateral, consisting of 4-inch cast iron for the first one-third of the pipe and 6-inch clay for the remainder, was approximately 85 feet from the basement clean-out to the city sewer main.

Solution:

 A tailored, 4- to 6-inch polyester Transition Scrim Liner from Paramount Pipe Lining Products was used because it creates a smooth, seamless transition in pipes with multiple diameters. The five-step process involved removing roots from the pipe, mixing the epoxy, wetting out the liner, using air pressure to insert the liner into the pipe, and using a hot-water curing process. The liner was cured in less than two hours using the Hornet hot-water curing system.

Result: The entire sewer line from the basement out to the city sewer was effectively relined, forming a watertight barrier impenetrable by root intrusions. In less than two hours, the cracked and defective pipes were like new and 100% flow capacity was restored. “It’s important for homeowners to understand they have options to tearing up their landscape when it comes to fixing their deteriorated pipes,” says Vinnie Sposari, owner of Mr. Rooter of Western Washington. 833-663-2477; www.paramountcipp.com



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