Case Studies: Inspection

Case Studies: Inspection

Plugs and sleeves from Real-Tite Plugs seal damaged clean-outs

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City seeks solution to eliminate data capture errors

Problem: In 2008, the city of Toronto sought to create and facilitate access to a complete asset inventory that would virtually eliminate all errors during the inspection data capture.

Solution: By choosing CTSPEC, the city became aware of the complete inventory of sewer assets, including pipe and manhole conditions. The solution was rapidly adopted by the contractor responsible for the sewer asset inspections, ensuring continuity and accuracy throughout the chain of information — from the field data collection to its processing by city analysts and engineers. A single system — covering asset inspection all the way through to report preparation — made it possible to provide a consistent, comprehensive approach to information management.

Result: All of the city’s teams were able to increase their productivity because of the automated update of infrastructure conditions, the production of thematic maps and the improvement of information sharing. Information was highly reliable, allowing analysts to focus their efforts on asset management and operational priorities. It is easy to produce specific reports on the condition of sewer systems and the need for inspection, maintenance and repair operations. 888-965-8987;

Acoustic inspection approved as part of cleaning mandate

Problem: New Castle County, Delaware, serves a population of over 550,000 that generates 50 mgd of wastewater, which is conveyed using 1,700 miles of underground sanitary sewer pipes. As part of a mandate from the Delaware Department of Natural Resources and Environmental Control, they are required to clean 500 miles per year, which roughly equates to a three-year cleaning frequency for the entire system.

Solution: InfoSense’s Sewer Line Rapid Assessment Tool, or SL-RAT technology was developed for rapidly identifying sewer line blockage conditions. It is based on measuring an acoustic signal transmitted between manholes in an active sewer line segment. As part of the initial pilot study, 56,000 linear feet were evaluated in mid-2014. An average of seven line segments (1,450 linear feet) per hour was achieved.

Result: Results showed that less than 10 percent of the inspected pipes needed immediate cleaning, which created an opportunity to better allocate resources to pipes that actually needed attention. Pilot studies have continued, and to date, over 1,450 inspections have been performed (320,000 linear feet). On average, over 55 percent of the pipes received a “Good” score (7-10) and only 11.4 percent needed immediate cleaning (acoustic score of 0-3). Use of the SL-RAT has been approved by the Department of Natural Resources and Environmental Control and the Environmental Protection Agency to count toward the annual 500-mile cleaning requirement. There are no immediate plans to reduce cleaning. Instead, they’ll use the preliminary acoustic inspection data to focus cleaning efforts on the pipes that actually need it. 877-747-3245;

Plugs and sleeves from Real-Tite Plugs seal damaged clean-outs

Problem: A Midwest city inspector doing video inspections of homes with possible inflow and infiltration breeches needed a dependable, nonleaking expansion clean-out plug to seal clean-out openings where the inside diameter of pipes were increased due to corrosion; odd-sized pipe; or fouled, damaged threads.

Solution: The city inspector installed Real-Tite expansion clean-out plugs fitted with Real-Tite expansion sleeves in place of the old, worn brass clean-out plugs.

Result: The Real-Tite plugs, gaskets and expansion sleeves fit the expanded openings by seating behind and over the damaged threads, providing dependable leak-free seals. 800-877-0610;

Program allows city to scan 3,000 feet of pipe quickly

Problem: The city of Muscatine, Iowa, experiences high-flow conditions in its sanitary sewer interceptors that run through flood control levees on the Mississippi River. As a designated critical sewer, the Army Corps of Engineers ordered the city to inspect its interceptors on a regular basis. However, bypassing and dewatering high-flow pipes so they can be taken offline to accommodate CCTV inspection can be an expensive and time-consuming process, often with mixed results.

Solution: The city chose instead to use low-voltage conductivity to test its large-diameter mains. By turning off the pump station and allowing a temporary buildup in effluent flow, Electro Scan, in partnership with Municipal Pipe Tool, was able to inspect all 3,000 feet (12 segments) of 24- and 27-inch, CIPP-lined RCP in less than a day and a half. Additionally, defects often not seen on CCTV were located and quantified in gallons per minute. All work was done in accordance with ASTM F2550 and newly issued 7th Edition, Volume 1 of the Operations and Maintenance of Wastewater Collection Systems.

Result: While nine of 12 pipes had little to no defects, two segments had multiple defects. In fact, combined defect flows for the two pipes accounted for nearly 80 percent of the infiltration flows for the 3,000-foot project. The city was happy with the speed and efficiency of the project and the level of data provided. 800-975-6149;

Video nozzle saves on inspection costs

Problem: The city of Denton, Texas, was looking for a way to increase CCTV footage to document successful cleaning and to decrease the cost of operation of their conventional CCTV mainline camera truck.

Solution: The city purchased an Envirosight Jetscan video nozzle, distributed by Green Equipment. The nozzle is an easy way to see what is being jetted. The video nozzle is affordable, yet quickly captures valuable, high-definition footage of pipe that can be viewed moments later on a PC or tablet. “We can identify the cause of any kind of stoppage that we have (roots, grease, bore through),” says Drew Huffman, Denton field services supervisor. “With this information, the combo truck operators can clean the line more efficiently by being able to choose the right kind of nozzle for the kind of problem that is found in the line.”

Result: The city has been able to increase overall CCTV footage while reducing cost and improving productivity. They’ve been able to keep the CCTV crew on plan, with the ability to not waste time on good lines that don’t require full PACP review. The city also found that the cost of operating the Jetscan came in at a cost of 19 cents per foot of operation, versus a cost of 83 cents for a conventional CCTV camera truck, saving $181,674 for 283,866 feet of sewer line inspection. 800-391-7612;

Town leverages inspection technology to meet goals

Problem: In 2013, the city of Warsaw, Indiana, knew they had problems. Like many other similar-sized towns, the city desperately needed to assess the condition of their storm and sanitary sewers in order to develop an improvement plan. Substantial portions of their system dated back to 1899 and had never received a visual inspection.

Solution: The management team undertook an extensive refit of their existing equipment, starting with new combination cleaning trucks and new RapidView IBAK North America camera inspection system. The management team set the ambitious goal of inspecting the entire sanitary system within 3 years. With over 86 miles of pipelines, this would equate to over 450,000 linear feet, or 150,000 linear feet a year. They immediately began to see success and leveraged the information they received from their new camera system to make better rehabilitation and maintenance decisions. As the project progressed, they understood the need for a faster, more proactive inspection tool and chose to add a PANORAMO 2 system to their fleet. This system not only put them on a path to meet their inspection goals, but provided data that engineering and management staff used to make critical decisions and prioritize rehabilitation efforts.

Result: Although they faced some unforeseen delays due to flooding and emergencies, within four years they had completed their goal of inspecting their entire sanitary system. As a result of this effort, the city recently approved $10 million in rehabilitation efforts. 800-656-4225; 

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