Case Studies - Summer 2020

Case Studies - Summer 2020

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INTERNAL JOINT SEAL USED TO REPAIR AGING WATER MAIN

PROBLEM: 

An aging cast iron water main’s deteriorating joints were threatening water quality and experiencing exfiltration in a Southwestern U.S. city. Previous repair methods had been employed, but a more permanent solution was required to make the water supply system more efficient, reliable and clean. Trench repair would have disturbed the museums, galleries, cultural centers, community organizations and trees that are above the water main. Most of the water main was 30 or 36 inches, but there was a point where a 24-inch pipe intersected the water main. This intersection required 24-inch seals, and an abandoned 12-inch connection had to be blocked with a seal. Multiple unused service taps had to be covered with seals as well.

SOLUTION: 

The mechanical HydraTite internal joint seal from HydraTech Engineered Products was selected for the many needs of the water main. Seals of different diameters and thicknesses were employed for this project. Backing plates were used with the seals to cover the abandoned connecting 12-inch pipe and service taps. The pipe had a low section that required dewatering. More than 800 seals were installed throughout the entire water main. These were used to seal joints, unused service taps and abandoned connecting pipes. 

Result: The seals eliminated infiltration at all joints. They enabled a trenchless repair at a fraction of the cost of alternatives. None of the aboveground trees or facilities were affected by the water main rehabilitation. The seals proved to be an economical in situ repair solution, making the operation of the water main pipe more cost-effective. 

513-827-9169; www.hydratechllc.com


THRUST BORING MACHINE PROVIDES COST-EFFECTIVE ALTERNATIVE

PROBLEM: 

Aware of aging and deteriorating infrastructure, Military Ocean Terminal Sunny Point in North Carolina employed Ellixson and Sons to inspect its sanitary sewer system. Upon investigation, they noticed several of the 8-inch terra cotta sewer mains were cracked and had root intrusion at the joints. To make matters worse, the damaged areas were in high-traffic areas where open trenching would have been costly and socially disruptive.

SOLUTION: 

Ellixson and Sons used the PD-6 thrust boring machine from Pow-R Mole Trenchless Solutions. This multifaceted machine with its 85,000 pounds of force can either be used for directional thrust boring or pipe bursting. On this particular project, Ellixson and Sons were able to burst 8-inch terra cotta pipe while installing 8-inch HDPE pipe. Most of the damaged sewer mains were replaced from manhole to manhole in 340-foot sections.

Result: The PD-6’s power and small footprint enabled Ellixson and Sons to complete six sections of sewer main in 10 days. This allowed one of the largest military terminals in the world to have a cost-effective solution with limited social disruption. 

800-344-6653; www.powrmole.com


INSIDE MANHOLE DROPS REPLACE FAILED OUTSIDE DROPS

PROBLEM:

Aging outside drops in Saugus, Massachusetts, had proven difficult to access for inspection, cleaning and maintenance. Many of the drops were deteriorating, leaking or clogged. The community sought a replacement.

SOLUTION:

National Water Main Cleaning, using design documents developed by CDM Smith, was contracted to fill in the outside drops and install new inside drops from RELINER/Duran. The base of the outside drop is plugged with concrete prior to the drop being filled with pea stone, flowable fill or sand. A hydraulic cement cap is placed on top and smoothed out with the mainline pipe invert. The mainline pipe is then CIPP-lined, followed by rehabilitation of the manhole. After the installation of a cementitious liner in the manhole, the Inside Drop System is installed. The system consists of a fiberglass drop bowl that is bolted to the manhole wall just beneath the high-level inflow pipe, and stainless steel pipe support brackets are used to attach the drop pipe to the wall. A flexible coupler is used to connect the drop pipe to the drop bowl, and a bend is installed at the pipe base in the manhole invert. The system is easy to install and allows the drop to be cleaned and inspected from above. The system is available to accommodate internal drops ranging from 4 to 24 inches in diameter.

Result: The system eliminated the maintenance problems associated with failing outside drops.  

800-508-6001; www.reliner.com


REMOTE CANAL MONITORING SYSTEM IMPROVES OVERFLOW RESPONSE TIME

PROBLEM:

Lake Worth Drainage District operates approximately 500 miles of canals and 20 major water control structures across more than 200 miles in southwest Florida. The district was hampered by an outdated operational philosophy and lacked a systemwide integration with weather and tidal data. Operators found themselves continuously struggling to react quick enough to protect their customers from overflows.

SOLUTION: 

The district deployed SmartCover to remotely monitor its canals while integrating local radar and tidal data with National Oceanic and Atmospheric Administration rainfall information along with the SCADA and remote-control gate operation. 

Result: This revolutionized the district’s response time. “Before SmartCover, we would drive out to check conditions, call the office, make our operational decisions, drive to the gate, operate the gate. ... It was a two-hour exercise. With SmartCover, we’ve reduced response time to minutes,” says Tommy Stroud, the district’s executive director and district engineer. The SmartCover system was put to the test by Hurricane Irma in September 2017. Canal level visibility, in addition to rainfall intensity and duration, enabled the district to monitor flow, predict peak stages and manage its infrastructure during this historic storm event. The system allowed them to minimize the impact of flooding and to operate with no service interruptions before, during or after Irma. 

760-291-1980; www.smartcoversystems.com


MANHOLE RISERS ARE A FIT FOR PICTURESQUE TOWN

PROBLEM: 

New Philadelphia, Ohio, population 17,000, is the county seat of Tuscarawas County. Keeping this old, picturesque town in tiptop shape is partly the responsibility of Brian Myers, wastewater superintendent. One of Myers’ responsibilities is the raising of city manholes to grade after roads are repaved or when manholes fail and need to be rebuilt or repaired.

SOLUTION: 

Myers employed the pivoted turnbuckle. American Highway Products manhole risers are open, flexible rings of high-quality, galvanized steel with a turnbuckle that can be expanded or contracted with a screwdriver to fit snugly into original utility rims. They’re available in precisely sized increments to match any manhole rim diameter and any paving lift thickness needed to bring manholes exactly to new paving surface grades. The adjustable risers make it possible to raise dozens of manholes in a day, all while avoiding extensive traffic closures. They can take as little as 10 minutes to install, with no excavation or hot patching required.

Result: In 2019, the town installed 35 of the pivoted turnbuckle risers, including 25 on a single resurfacing project carried out by the state on New Philadelphia’s South Broadway Street. 

888-272-2397; www.ahp1.com


CRAWLER CAMERA HELPS CITY INCREASE PRODUCTIVITY

PROBLEM:

 The Roanoke River, which meanders through Roanoke, Virginia’s residential and industrial neighborhoods, serves as one of the main water sources for the city. To protect the water quality for years to come, the city formed the Roanoke Stormwater Utility. To achieve its goals, the utility needed a reliable, efficient inspection system.

SOLUTION: 

Envirosight’s ROVVER X inspection platform provided the efficiency the utility needed to assess its system for defects and allowed it to find any infiltration and exfiltration that came with that damage. It can be transported in built-out inspection trucks or vans, on the back of a pickup truck or out of an all-terrain vehicle. The crawler is also agile and maneuverable, with a short wheelbase and 0-degree turning radius that makes it easy to overcome any obstacle. The system has the power to tackle long runs, as it features 1,000 feet of lightweight, buoyant cable. It can crawl upstream or down, tackling offsets and inclines with ease.

Result: The Roanoke Stormwater Utility improved from inspecting 17,000 feet of pipe in one year to inspecting more than 100,000 feet of pipe in five months. This increase in inspection capacity dramatically improved its ability to identify line defects and ultimately reduce inflow and infiltration. Additionally, the team discovered nearly 200 miles of storm line that had been forgotten and neglected. The city now understands its collections system and can identify sources of stormwater pollution and infiltration and continue working toward its water-quality goals. 

866-936-8476; www.envirosight.com


MOBILE DEVICE ENABLES WATER LEAK DETECTION IN CHALLENGING PVC PIPING 

PROBLEM: 

The Florida Keys Aqueduct Authority is the sole provider of potable water for all of the residents of the Florida Keys and presently serves more than 44,000 customers within Monroe County. A history of leaks and several suspected active leaks were a good reason to target Simonton Street, where most of the pipes are PVC in the length of 6,963 feet. This area contains high water loss rates at 1,000 gph.

SOLUTION: 

In January 2019, the authority initiated a pilot with Aquarius Spectrum to examine the suitability of its technology. The pilot was carried out by the nonrevenue water department in the authority in collaboration with Aquarius Spectrum and Trimble Water. Aquarius Spectrum installed seven hydrophone sensors to cover half of the selected pipeline. The sensors were installed 450 to 700 feet apart on aboveground hydrants and empty meter boxes. These sensors are part of the AQS-SYS continuous monitoring system. It provides a daily picture of the underground hidden leaks from an initial stage of their development. The sensors are equipped with radio frequency technology for optimal synchronization and transmit data to the Aquarius Spectrum cloud-based software via 3G/4G communication.

Result: After a couple of days, the AQS-SYS system detected two points of interest. In order to finalize and pinpoint the exact locations of those POIs, Aquarius Spectrum used its iQuarius iQ300 mobile leak detection device. The actual leaks were around 50 feet from the alert location on the system. These leaks were identified by two hydrophones 518 feet apart. Thanks to the good results, the authority expanded its search territory from a single street to the entire south side of Key West. 

www.aquarius-spectrum.com


GRADE ADJUSTMENT SYSTEM STOPS SEVERE INFILTRATION

PROBLEM: 

In late 2009, a southcentral Wisconsin municipality identified a manhole with a severe infiltration problem needing repair. The water was coming from an extremely high groundwater table due to an underground aquifer, and water was leaking through the joint between the concrete rings and precast manhole cone. This single manhole was contributing an estimated 20,000 gallons of clearwater every day, year-round.

SOLUTION: 

Cretex Specialty Products had just introduced PRO-RING, a lightweight manhole grade adjustment system made from expanded polypropylene, and it was chosen for this repair as a trial. EPP is a high-strength, lightweight plastic, making it a suitable material to replace traditional construction methods using masonry materials. This system is watertight, fast, safe and cost-effective, with one man being able to complete an entire adjustment in minutes. On the day of the repair, the temperature was 15 degrees F, so everyone knew this would be a challenging repair, especially for trying to control the groundwater. The manhole was excavated, and the frame and existing 20 inches of precast concrete grade rings were removed, exposing the top of the manhole cone. Two pumps were required to keep the water level down to allow the necessary surface preparation and the installation of PRO-RING to be completed. The total time required from the start of the excavation to PRO-RING installation and completed backfill was approximately 90 minutes.

Result: Since the installation was completed more than 10 years ago, this manhole has remained watertight, saving the municipality more than $150,000 in treatment costs. 

800-345-3764; www.cretexseals.com  



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