When it comes to infrastructure management, information drives utility decision making. But more specifically, accurate information allows for better decision making.
The American Society of Civil Engineers estimates that utilities in the United States will need to spend approximately $300 billion over the next 20 years in wastewater infrastructure, with pipeline replacement and rehabilitation representing the majority of that work. Thus, municipalities are continually looking at improvement programs that account for performing necessary water and sewer upgrades while also maintaining budgets.?
One of the first steps to managing underground assets is having a proactive pipeline condition assessment program ? essentially, an effective system by which a utility goes about inspecting its pipelines. New technologies are constantly reinventing the way pipeline inspection is approached. While this is not a brand new trend, these technological advancements are ever-evolving, and with many cities? budgets for infrastructure work stretched thin, utilities are looking for ways to save money and implement the proper condition assessment initiatives before rehab or replacement is discussed.
The Evolution of Pipeline Inspection
Pipeline inspection equipment is one of many prime examples of technological growth in the utility industry. In addition to knowing which pipelines need to be repaired or replaced, utilities must also be aware of which pipelines are in working order. In the September issue of Trenchless Technology magazine, Marc Bracken, vice president and general manager of acoustic detection technology manufacturer, Echologics, emphasized this point.
According to Bracken, when it comes to water systems, life expectancy and age alone are not accurate indications of pipe integrity. Many pipes have been found to have significant remaining service life even after the end of their theoretical design life. Basing pipe replacement strictly on age can result in the unnecessary removal of healthy pipe, thus wasting money, Bracken said.
Various acoustic technologies to complement CCTV as well as modern capabilities with CCTV itself are a couple technological trends in this area. As an example, the SewerBatt system, developed by the recently formed Acoustic Sensing Technology, Ltd., based in the United Kingdom, is one piece of innovative technology that can be included in this trend.
The SewerBatt
Acoustic technology has been making headway in the utility industry in recent years. Not only does it present another tool for utilities in addition to CCTV inspection, but it can also be used to complement CCTV. The SewerBatt is one piece of inspection technology gaining traction in the industry. The history of its development also presents a fascinating example of technology born out of academia that is now making its way into the commercial market.
The idea of the SewerBatt was conceived about 10 years ago in the United Kingdom, when civil engineer Richard Long was looking into possible ways to perform a quicker inspection of sewer pipes, and wondered if it would be possible to do it using sound. His concept was based on the idea of sonar (only in this case, not in water).
Long enlisted the help of two professors ? Simon Tait and Kirill Horoshenkov ? working at the University of Bradford at the time, who he worked with for several years to perfect the technology. The SewerBatt uses acoustic signals to quickly and accurately determine if a pipe system contains breaks, blockages or structural defects. The system comprises an acoustic sensor that can be inserted into a manhole, with cables connecting the sensor to software that is viewed on a ruggedized electronic module.
In 2009, the SewerBatt was entered into The Royal Society, the prominent British learning society that funds research fellowships and scientific start-up companies and was awarded the Brian Mercer Award for Innovation, designed for scientists who wish to develop a proven concept or prototype into a near-market product ready for commercial exploitation. Soon after, Nick Hawkins, a corporate lawyer and businessman, heard about the SewerBatt at an investment conference. Hawkins, who was familiar with the prestige of The Royal Society, recognized the potential in the SewerBatt and became interested in working with Richard Long to further establish the technology.
Hawkins, now chief executive of Acoustic Sensing Technology, described one of the obstacles of this process as moving the product out of the academic world and into the commercial world. For nearly two years, Hawkins worked to bring investors to the table and eventually secured an investment to fund the company start-up. In February 2013, Acoustic Sensing Technology was founded and up until now has conducted successful trials of the SewerBatt with various utilities in the United Kingdom, Australia and the United States. Richard Long now serves as director of technology while professors Simon Tait and Kirill Horoshenkov, now with the University of Sheffield, maintain their roles as consultants to the company.
Hawkins said the idea of a system like SewerBatt is not to replace CCTV but rather to complement it as a first-step assessment ? the idea being that a quick acoustic assessment can accurately determine if a pipe has a certain amount of blockage or damage and if it needs to be inspected further.?
?The algorithms in the software analyze the acoustic responses that come back and it can tell you if there are breaks in the pipe or blockages, and it can tell you what it is ? if it?s fats, oils and grease, or tree roots, which is what a utility or the contractors doing the inspection want to know,? he said.
?It can also tell you, extremely accurately, where that problem is. Because you are measuring the time that it takes [for the acoustic responses to come back to the receiver] and we know as an absolute what the speed of sound is, the distance and the time of the signal can be plotted very accurately.? Hawkins also said the data is also stored so that the user can come back several months later and measure a rate of deterioration.
?It?s very important for companies to know when they have to dig up a road, for example, to replace a pipe,? Hawkins said. ?Or alternatively, if a pipe is found to be completely clean, then you don?t need to spend a huge amount of time using closed-circuit television on pipes that may be absolutely fine. What we can say to customers and potential customers is that you can use your CCTV much more effectively by only using it when you have to.?
Based on a trial with a utility in Australia, it was estimated that SewerBatt could be used to inspect about 2.5 miles of sewer pipe in less than three days. In April, the SewerBatt team performed trials for the U.S. EPA in Cincinnati, Ohio, at the Metropolitan Sewer District of Greater Cincinnati ? one of the few tests the team has conducted in the United States. According to Hawkins, trials have been successful and the SewerBatt is providing utilities with a practicable tool to perform condition assessment.
Sewer Line Rapid Assessment Tools
Also new in the area of acoustics is the Sewer Line Rapid Assessment Tool (SL-RAT), manufactured by InfoSense, Inc., based in Charlotte, N.C. The development of the SL-RAT somewhat parallels that of the SewerBatt in the United Kingdom.
In 2005, the Charlotte-Mecklenburg Utilities Division (CMUD), partnered with the University of North Carolina at Charlotte in an effort to develop new technologies for pipe inspection. After two years of research, a partnership was formed between CMUD and InfoSense to commercialize the university?s patented acoustic inspection technology.
The SL-RAT consists of a transmitter and a receiver, of which the transmitter is placed in an open manhole and transmits a sequence of tones through the air gap within the pipe. The receiver is placed in an adjacent manhole and listens for degradation in the tones it hears, compared to the tones it should hear in a clean pipe.
Essentially, the SL-RAT is based on the idea that sound and water flow similarly through the free space within a pipe. Hence, if a known sound signal transmitted through a pipe segment is degraded, the sophisticated signal processing algorithms within the SL-RAT are able to analyze the result in less than three minutes and provide a simple assessment of blockage within the pipe on a scale of zero to 10. Since 2005, the SL-RAT has been used to inspect more than 1 million ft of pipe. In 2012, the SL-RAT was named a winner of the WEF Innovative Technology Award.
The Modernization of CCTV
When looking at how some of these emerging technologies in acoustic inspection are changing the ways cities approach condition assessment, it?s important to remember that CCTV remains the staple in this area. Video inspection or the use of CCTV has long been the standard in pipeline condition assessment and has provided utility owners with accurate details on the state of underground infrastructure. However, there are some noteworthy developments that have taken place in this area as well.
One recent development in the area of inspection cameras has been the introduction of high definition (HD) capability. These cameras can have a dramatic effect on the accuracy of pipeline assessment as they can offer a higher resolution image, improved image size, quality and enhanced zoom capability. These enhancements can result in an assessment that is much more accurate and useful to those responsible for making decisions on pipeline repair.
Another development in CCTV has been the introduction of side scanning technology. These systems can be driven through the pipeline without stopping while taking a picture four frames per second coordinated with a flashing strobe light.
?It?s a departure from traditional inspection equipment,? said Paul Stenzler, vice president of sales at CUES, Inc., a manufacturer of inspection equipment with digital side scanning capability. ?It speeds up the process of inspection and condition assessment of the pipeline system because it can produce digital video where you can immediately skip to an area of interest and rapidly complete the condition assessment.?
These cameras are often equipped with a sort of digital processing software that stitches the pictures together in a high resolution, panoramic view that can be several times the traditional resolution of a conventional sewer inspection camera. The user can immediately access an unfolded flat view of the entire pipe section, and jump from one area of interest to another so that particular areas can be quickly viewed.
?With conventional video, if the operator forgets to pan or tilt, a critical observation can be missed, resulting in a potential major error of omission for the asset on record,? Stenzler said. ?This camera doesn?t miss a thing, so you can go back and review all details of the video at any time.?
More Tools in the Toolbox
Information drives decision making in utility construction, and with several of these new developments in inspection technology emerging, access to more accurate information is available. At the same time, developments in inspection cameras can be complemented with new technology, such as acoustics, that can make for a more efficient assessment.
As Nick Hawkins noted, acoustic technology such as the SewerBatt ultimately presents another tool to maximize the potential of condition assessment.
?In the U.K., specifically, there?s a lot of concern about water pipes and leaks,? he said. ?Water companies are in a situation where they want to do things better, provide better customer service and at the same time, save money. Our answer as the suppliers is that we can help. We can enable you to provide more surveys for the same money, survey more of your network, and in every possible way, provide better customer service.?? ?
Andrew Farr is assistant editor of UIM.?
