Trenchless Technology Roundtable: From the Owner’s Perspective
At Trenchless Technology magazine, one of the annual rites of spring is the Editorial Roundtable. These open-ended discussions involving leading trenchless professionals began back in 1993 with a panel at the San Jose No-Dig Show.
We continued this tradition on March 4 with our latest panel of experts, which was convened March 4 at the Sacramento Convention Center during this year’s No-Dig Show. We focused on owners, and we gathered a mix of sewer and water system professionals that represented Georgia, Ontario, Alaska, Oregon and California. Despite their disparate locales and geologies, many common themes emerged in trying to maintain the quality and integrity of our sewer and water systems in the face of budget constraints and regulatory requirements.
PARTICIPANTS:
Serge Terentieff — Senior Civil Engineer,
Pipeline Infrastructure Division,
East Bay Municipal Utility District, Oakland, Calif.
Marisa Boyce — Associate Civil Engineer:
East Bay Municipal Utility District, Oakland, Calif.
Deirdre Blackard — Linear Asset Manager,
Gwinnett County (Ga.) Department of Water Resources
Stephen Nuss, P.E. — Capital Program Manager,
Anchorage (Alaska) Water and Wastewater Utility
Ashley Rammeloo — Sewer Operations Engineer,
City of London, Ontario, Canada
Mark Hutchinson — Principal Engineer,
City of Portland (Ore.) Environmental Services
Jim Rush — Editor,
Trenchless Technology, Panel Moderator
Briefly describe your utility’s water/sewer system and its condition. What is unique about your system and/or the way it operates?
ST – The East Bay Municipal Utility District (EBMUD) has both a water and wastewater system. Our water distribution system serves about 1.3 million people in the San Francisco Bay area. Our distribution system includes about 4,100 miles of pipe with the average age being 53 years old. We also provide wastewater services to about 650,000 people and recycled water services for irrigation, commercial and industrial uses.
What is unique about our distribution system is that we have more than 120 different pressure zones because our elevation varies greatly from sea level to about 1,500 ft. Additionally, we are in the middle of an active seismic area — our distribution system is crossed by the Hayward fault — so we get a lot of ground movement from landslides and fault creep. EBMUD also does a majority of its main replacements in house, which is somewhat unique for water agencies. We have six pipeline crews, which replace about 8 to 10 miles of distribution mains per year.
SN – The Anchorage Water and Wastewater Utility (AWWU) has about 1,600 miles of total pipe, so it is a medium-size utility. It is pretty evenly split between the water and sewer side. On the water distribution side, we have pipes ranging from 1 to 72 in.; and on the sewer side from 4 to 120 in. We serve about 250,000 customers — about 80 percent of the population of Anchorage. Our infrastructure is reaching middle age. The average age of our infrastructure is about 32 years, so it is younger than some systems but older than others. We have quite a variation of different pipe materials, with 14 different pipe materials in our system. We still have some wood stave pipe left in our system, as well as some Orangeburg pipe left in some locations. One of the challenges that we face, which is similar to many northern tier utilities, is the depth of burial for freeze protection that adds significantly to our cost of rehab, replacement and emergency repair projects.
We have been implementing more condition assessment and we have found that in places where we thought our system was good, it could use a little more work; and where we thought it might be in jeopardy, it is better than we thought. It has been an eye-opener for us over the years as we have gotten more data as to where we need to focus our attention.
MH – The City of Portland system serves 615,000 ratepayers. We’ve got roughly 2,000 miles of pipe in the sanitary and storm sewer systems. The majority of our pipe system was built prior to 1930, so a lot of our pipes are brick and clay. In general, those pipes are doing pretty well but we are having some problems with concrete pipe that was put in during the Depression. We just finished doing a $1.5 billion combined sewer overflow program, and now we are switching gears and putting in an asset management framework. Right now there is a big push on condition assessment. We are just starting a $180 million rehab program on our sanitary lines to fix the worst of the worst. We have two crews that install spot liners and lateral liners; large mains and anything over 100 ft or so we contract out. We also have four dig crews for repairs that arise.
AR – The City of London system serves about 360,000 people. We have about 1,300 km of sanitary sewer with sizes ranging from about 200 mm diameter up to 1,650 mm, although we don’t have the really large interceptors because of how many treatment plants we have. The average age is about 40 years but the oldest sewer we have in the ground was built in 1852. A lot of that really old pipe is brick, egg-shaped sewer, especially in our downtown area. Often those brick sewers were originally combined sewers and we have a program in which we are steadily getting rid of the combined sewers and eliminating overflow structures. We are somewhat unique in the way that we operate in that we have in-house construction crews to do repairs; it is very rare that we would contract out emergency repairs to a contractor. That would be would a last-ditch effort if we absolutely just couldn’t get to it; and we benchmark ourselves, too to make sure our approach is economical. London looks after about 1,600 km of water main ranging from 6 in to 48 in. The average age of that system is 33 years with the oldest pipe in the ground being from 1878. We typically have less than 120 main breaks per year.
DB – Gwinnett County Department of Water Resources has about 3,400 miles of distribution mains from 2 to 72 in. in varying materials from cast iron, ductile iron, ACP and PCCP. On the sewer side, we have 2,800 miles of pipe and 230 pump stations, which is quite a challenge because we have different directions that we can pump. We have 250,000 customers. We’re lucky in that the majority of our system was put in during the 1980s. Recently, development has been down, so it gave us the opportunity to re-develop our asset management program. We’re looking at how we spend our money and making sure that it is done in the most effective way possible. We just completed a life-cycle cost projection project with WERF that was very beneficial for us because it helped us to automate our decision-making and where we route our work. We do in-house repairs for point repairs, but we do contract out some point repairs and all of our trenchless. We have a study that we just completed on alternative rehabilitation techniques. We used to do sliplining years ago and when our annual contract comes up for renewal we’re looking at bringing back sliplining as a new line item. We also do pipe bursting and CIPP on our rehab contract, but we’re also looking at mechanical seals and exploring grouting options, as well as CIPP for our distribution mains
What programs have been created to address challenges? What is the process for implementation and how do you get started with a new program?
DB – We have a large system of forcemains and we know we have corrosion. We dose to reduce corrosion, but we cannot confirm that we’re dosing in the correct areas. So, we have instituted a program of continual monitoring of our downstream manholes. It is as simple as having our crews do pH testing at the same time they are doing inspections. We also have loggers that we can deploy and set up to monitor hydrogen sulfide levels. We also have a large problem with I/I from private service laterals and our ordinance doesn’t support controlling that. We are now in the process of collecting data to support a business case to rehabilitate laterals to help control I/I.
Some of our new programs include a system wide flow monitoring program that we manage in-house through contracted maintenance with Woolpert instead of commissioning individual I/I studies. Two years ago we formed our Operations Technical Services group that reviews information and develops the programs and the means and methods for supporting these programs in-house.
MB – One of the main problems we are facing is the replacement of our distribution mains, many of which are nearing the end of their useful life. Right now, EBMUD replaces about 8 to 10 miles of our distribution mains per year, which represents only about 0.2 percent of our overall distribution system; so one of the challenges we face is to eventually increase that replacement rate to 20, 30 or even 40 miles per year. Another big challenge we face is with our asbestos cement (AC) pipe, which we are doing studies on right now. Finally, we also have a number of large diameter pipes that are nearing the end of their useful life, and we started up a new program to prioritize the replacement of these mains.
ST – EBMUD is working with the Water Research Foundation to assess our AC pipe. What we have found so far, contrary to our cast iron (CI) mains, is that age may be a significant factor in deciding when to replace AC mains. For example, some of our CI mains from the late 1800s are really thick walled and often perform better than CI mains from the 1950s; currently, our infrastructure renewal program is mostly based on leak rate, not age of pipe. Results of a study we conducted indicated that the calcium in the AC walls of the pipe leached out over time, and reduced the strength of the AC pipe; based on those initial results, we recently initiated another study that includes an extensive sample collection and lab testing program to identify the factors that impact the loss of strength and rate of deterioration of AC pipe, including water quality and its potential impact on leaching. We are also looking at acoustic testing systems to measure the remaining useful wall thickness. We need to get ahead of the AC curve because we have more than 1,000 miles of AC pipe in our system, and we can’t afford to replace all of that 1,000 miles at once.
As Marisa mentioned, we are currently only replacing about 10 out of 4,100 miles, which represents only about 0.2 percent of our system. We recognize that that rate of renewal can’t stay at those levels as our pipes age; 0.2 percent represents a replacement cycle of every 400 years, and we recognize that our pipes won’t last 400 years. We foresee a need to double or triple that rate in the not-too-distant-future and that is a tremendous challenge.
DB – We are focusing on our PCCP now. We were looking at condition assessment and magnetic flux leak detection, but we determined that it was cheaper for us in the long term to go ahead and replace everything then to do the condition assessment, schedule it for re-inspection, set up an acoustic fiber-optic monitoring program and so on. So, we have done a budget for 20 years out to do prioritized replacements based off their criticality/risk.
SN – For AWWU there are two kinds of programs that we have ongoing. One of them, in our Girdwood area, has been over a five-year time period of reducing I/I in our collection system. Girdwood is basically a ski resort community and there is a lot of snowmelt in summer time. There wasn’t a lot of enforcement when construction was taking place in the 1970s and 1980s and now we’re finding that we have a lot of inflow coming in. We are in Phase V of a program involving looking at the laterals, mains and manholes. We have implemented a program to spend about $500,000 a year to help reduce the amount of inflow in that area. We have had improvements, but what we’re finding is that on the manhole chimney seals and other things like that with the frost jacking we have you have to go back in and maintain it; so even though you go and install these things then you have to get the maintenance guys to go back in and maintain it and you’re adding work on top of what they have already have to do. Similarly, within our main Anchorage area as we performed did data collection and condition assessment on our sewer mains and found a lot of areas that have breaks and cracks that require spot repairs. We can’t put spot repairs on the capital program, so we are asking our O&M folks to go out and do more of these kinds of repairs. So we are assessing what our O&M crews can do, what they can’t do and how we get increased funding in the operational budget to be able to go do repairs. They only have equipment to do up to about 12-in. diameter pipe, so anything over 12 in. we need to potentially outsource. We’re looking at what is the best method to outsource and what is the best technology to use.
As we began our trenchless program more than 15 years ago, one of the hard parts for us was determining what technologies to use, getting our investigation done and finding who’s experienced in the area. We are finding that same thing on the operational side — what is the best technology to use, what can our crews effectively do, what are the long-term maintenance requirements of those different technologies? For anybody who is implementing a program, doing your homework and getting as much information as you can is a key step.
MH – We just finished our CSO program so we’ve got funding now and we’re going in and fixing the worst of our worst pipes, which we didn’t really have the funding to do for a while. We’re just starting about a $180 million program to do that. We’ve been looking at all the pipes and through our asset management system and taking a look at what needs to be fixed. We used to fix things by basin — you go in and fix all the pipes. We’re adjusting to just fixing some of them; we’ll fix a couple manhole runs here, a couple manhole runs there. We divided the city into big areas and we are packaging work within those areas to get our costs down.
We are also addressing I/I. For quite a while we thought we had capacity in our system and so we weren’t dealing with I/I and issues with property owners and replacing laterals. We are trying to figure out how to deal with it politically. Even though our rehab program is $30 million to $40 million a year, it only affects 2 percent of our pipeline.
We also have a large mains program that we need to work on to address capacity issues. We have basement flooding in a lot of areas in town and it is a challenge to get the resources to work on that. After doing tunnels for quite a while and a large treatment plant project, we’re finding that training is a big issue. We’re trying to get people up to speed. Things you assume everybody knows you find out that maybe they don’t know. As construction division manager, getting my construction managers and inspectors and everybody trained and set up so they can be successful is a big issue.
AR – We have similar challenges with the laterals. In our case, the property owners own the lateral right to the main, but we are the only entity that can replace the lateral on city property. We have the capability to pipe burst or line laterals in-house. We’re currently examining the business case to change ownership of those laterals so that the city would own the lateral to the property line. Right now if there is a failure in the lateral, the property owner has to pay to fix it.
That is a challenge for us because any time we are doing a replacement project or rehab project we want to be able to fix everything to ensure that we’re not coming back to fix a lateral. We do offer a discount when we are doing a replacement project, but it is very onerous on the administration side in dealing with the private property issues. It would be nice to be able to do some of the lining programs and take advantage of some of the technologies now that are out there such as lining the laterals from within the main while they are lining the pipe.
In our lining program, we don’t do a lot of lining specifically for I/I. Mainly we are lining for structural reasons. But when we are lining to address I/I, we want to address laterals as well because they are a big part of the problem.
One of the challenges with our old brick sewers is that once they start to fail, they fail very quickly. We have a six-year plan to reline the brick sewers and keep them in service because they are typically underneath downtown streets where open-cut is problematic. But then we are left with the manholes on that system and they tend to be small — 2 by 2 brick. With these manholes we are usually looking at a structural rehab too. We’ve done pilot manhole rehab projects in conjunction with some of our lining programs, and we are currently evaluating the different systems.
And then, of course, we always have the problem with funding and reaching sustainability. We do have an aging system, and we need to have money to spend to keep up with it. In 2011, for instance, we relined 8 km of sanitary sewer and we replaced 3 km of sanitary sewer, but we have 1,300 km — so it is a small percentage.
What technologies do you use and how do you select them? What improvements need to be be made to help you address the challenges facing your utility?
MB – For our infrastructure renewals, we piloted trenchless technologies. As a result of that pilot program, we determined that we are going to use HDD as an alternative installation method to open trench. We’re hoping that that is going to reduce our cost of replacement so that we’ll have additional funding to do more. We’re also hoping that the process might be more efficient so that we can increase our replacement rate.
We piloted both HDD and pipe bursting. Typically when we replace our mains, we replace them with open trench. We put in a parallel main and then we transfer our services over. HDD is very similar in that we install a new main and then we transfer the services over. We also experimented with pipe bursting but that requires installing a temporary line while the pipe was being burst. We are at the point where we are ready to design these jobs. We plan to use our own crews to manage the projects, including doing excavation and site work, but we’ll contract out the drilling portion.
ST – Prior to implementing the pilot that Marisa mentioned, we faced the challenge of getting our construction and maintenance staff trained and familiar with fusible pipe materials such as HDPE and Fusible PVC. We were not able to implement our pilot trenchless project until our pipeline crews were comfortable with using these new pipe materials and installation methods. Specifically, we had to develop new standards and provide training on the use of fusible pipe materials for water mains. For example, we had to develop new procedures for completing a mechanical repair for HDPE that could be used to repair a water main in an emergency in wet conditions, when the use of fusible couplings may not be feasible. These were issues that had to be worked through with our stakeholders, our construction and maintenance staff and to make sure everybody was on board with how that material was going to be handled and maintained. Once we got past that hurdle, our pilot went quite well.
We are planning to replace 1 to 2 miles of water mains per year with HDD. We are planning on using HDD mainly on flatter, residential areas where we encounter mostly straight pipe alignments and not a lot of utility conflicts. In the older parts of our system — downtown areas with high utility congestion — we’ll probably take another look at pipe bursting.
DB – That was an issue we had before we started our Operations Technical Services group. We used to have silo’ed information — no one communicated. You need to get your field crews vested into the entire process. We include engineering and operations in our programs because they will never be enjoined unless they understand what is going on. It has to be a cooperative effort to empower people to make decisions and get behind the vision of where you want to go. It has been one of our biggest challenges.
Another problem that we have encountered is that some of the trenchless technologies that are used in Europe are not widely available here. We are now looking at a grouting product called Sanipor that can provide a 75-year increase on the useful life of the pipe. A further problem is that some of these technologies are sole-sourced, and for us sole-sourcing is one of the most difficult things to get through purchasing — even on a pilot project. So if we could have more vendors or more certified contractors that could bid on these projects, it would help the government entities.
SN – AWWU has used a lot of different trenchless technologies — HDD, pilot tube microtunneling with modified HDD pullback, sliplining, CIPP, auger boring, pipe ramming. Getting buy-in from the public and elected officials has been relatively easy because of fewer impacts. It’s almost to the point now where we have to say: “We can’t do trenchless on this project. We have to open-cut it and this is the reason why.”
Some of the issues we face are related to contracting. Sometimes if you are using a particular technology you are essentially sole-sourcing it even though it may be put out to competitive bid. And, if you only have a few lining projects a year and they go to the same contractor, there is risk that you may not get all the work completed if there is a problem on one project. You also have your local excavation contractors who contend that they can do the work faster and cheaper. So you have to weigh what technologies are available and whether you can get the job done while achieving a savings or greater efficiency by doing it trenchless. You also need to analyze your risks and fallbacks options whenever you select an installation technology.
In our area we have a fairly limited contractor pool, so the question is whether the technologies are affordable enough to entice contractors to invest in them, and then whether we have work going forward to sustain them.
MH – You have to invest in your contractors and put out a steady stream of work. We tend to put out a lot of one type of work so we started packaging CIPP contracts and we found that our costs dropped 30 to 50 percent per foot and our relationship with the contractors got better because we were seeing them every month. Now that we are ramping up our rehab program, I have concerns about whether there is enough contractor capacity to do the work.
For us, we are to develop our people — getting them experience and having them weigh the different options and the risks. We also have the same thing with silos — our maintenance group is completely separate from our engineering group and it would be nice to have more sharing of information between the two.
DB – Part of what we do on each project, we have a contingency plan for each of the trenchless methods. It is part of the project initiation report that needs to be completed before a project can even start.
ST – For EBMUD’s pipe bursting pilot projects, we found that we have to do a very thorough search of our as-built records because we find that some pipe segments may have steel repairs clamps or sections of pipe have been replaced with steel that may require a cutting head in addition to a bursting head. So doing a good job upfront and identifying the risks and previous repairs has been a challenge.
In general, our water distribution mains are 50-plus years old and are at the end of their useful life, so we mainly considered structural replacement options, which is why we are currently focused on HDD and pipe bursting as an alternative to open trench construction. For our large diameter mains, on the other hand, we are developing a different replacement criteria and are considering the use of sliplining as a rehabilitation option, when the hydraulics allow for a reduction in pipe diameter. For the rehabilitation of our AC pipes, we will also be considering the use of in-situ spray lining technology or semi-structural liner to determine if these alternative technologies can be installed at a significantly lower cost than a fully structural replacement option.
AR – We do a lot of inspection and rehab. We haven’t done a lot of in-situ main line replacement, such as pipe bursting. We do new installation with trenchless when the situation calls for it, such as river and railway crossings. For rehab, we have done cement lining for the water mains where there were a few breaks, and in 2009 we started doing structural lining on mains with many breaks. We currently set out a structural lining budget for the water mains at $4.3 million annually. On our sewer lining we spend $2 million on an annual program that is packaged up and we do both sanitary and storm sewers under that contract. That includes typical felt liner, and this is the first year that we have a UV-cured liner in that contract. And I also run every year one or two specialty trunk sewer lining projects. That is typically CIPP and usually between $1 million to $2.5 million. We have also done a fair amount of inspection using CCTV for sewers and combined sonar and CCTV for our trunk sewers. On our water mains we have done several pilot projects using acoustic and electromagnetic testing. We are currently installing fiber optics for acoustic monitoring of our PCCP pipes.
ST – In adapting to trenchless, one of the things that has really helped us at EBMUD was to make the potholing of existing utilities during the design phase of the project painless. For us, whenever we have to hire an outside contractor it can be a lengthy process. So we have gone to our Board to obtain approval for a recurring potholing contract because we realize the importance of potholing, particularly when using trenchless technologies. We have found that if our pipeline designers and engineers can just pick up the phone and have a couple of vendors that can accurately locate existing utilities, we can include accurate utility information on our drawings; this improves safety and reduces construction costs and potential delays.
Asset management programs are becoming increasingly important for water and sewer operators. What is your experience with asset management and how is it impacting your utility?
DB – Gwinnett County established an asset management steering committee in 2008. There were only two asset managers and we essentially acted as an internal consulting group. Our early on progress was slow but steady. Now that we have groups dedicated to analyzing information, developing programs, setting processes and protocols and maintaining data; our progress has increased exponentially. Information is driving most of our decision-making today. We have standardized the decision-making methods that we go through for review of every CCTV inspection and determining replacement, repair and rehabilitation needs. We review each pipe for feasibility and for the most cost-effective solution. Without the Operations Technical Services group — the analysis division that has been in existence for two years — we wouldn’t have made the progress that we have to date. We have taken all of our asset classes and we have divided them into subclasses. For example, in sewer we have divided the pipeline assets into gravity mains, interceptors and forcemains because they all perform differently. They all have different risks, condition assessment means, and R/R options. We use these risk ratings and inspection results to review the associated costs for R/R to drive and prioritize our programs.
MH – We’ve put together a program and then one of the things we did was to send every engineer who was in a decision-making capacity to classes so that we had standardized nomenclature. The program has changed the way we have gone to replacing our pipes. We use triple-bottom line evaluating criteria and criticality ratings to determine where we need to focus our efforts. In the past, we would do a planning effort for a part of town and have projects where we replaced everything. One of the challenges is that it takes some time to get an asset management system running.
DB – We are doing less and less open-cut replacement and doing more trenchless. We have completed a life-cycle cost project where we found that on our 150-ft gravity runs where we would normally do a point repair, it is more cost-effective for us to do a CIPP repair. We added in that life-cycle cost analysis for every alternative and that has changed the direction that we pursue. The key for us has been opening up communication and empowering people to do their jobs.
We’re trying to completely move from a reactive to a proactive approach, so all of our proactive or preventative programs have grown incrementally. We have had substantial increases in funding in our preventative programs due to that. Originally we were probably 80-20 reactive-preventative; now we’re about 60-40. We’ll be happy when we can get to 40-60.
SN – At AWWU, we have about a $60 million per year capital program. When my staff does work, about every $10 million worth of plant that we put into operation is a rate increase to our residential customers of 75 to 90 cents a month, depending on the type of asset and its depreciation rate. So, on a yearly basis when the capital budgets get approved, the administration and assembly is essentially authorizing a $5/month increase to the rates — and our rates are already at $88/month for a typical residential family for both water and sewer. That’s gone up from $40-something 10 years ago, and we’re starting to get a lot of push back on it. As a result, we have really focused our efforts on spending money in the right places. Our historical method of replacing a water pipe was if there were three breaks within three years within the same three-block area, it would be replaced. It was assumed that that was what the public could withstand. It may not have mattered how many customers were served by that line. With our asset management plan that began about three years ago, we are looking to prioritize our rehab and make sure we are not just spending the money on just the problem children, but also the most critical assets. We had to shift our mindset. Gathering the data gathering has been the key thing that changed the way we as an organization function. A lot of condition assessment money was spent and we went through a big and painful process of how we were going to standardize coding so we can analysis data and tie that to GIS so that the information is accessible. That organizational shift has been really hard.
One of the things that we are evaluating in our strategic asset planning is our DI pipes. Instead of replacing them we’ve considering adding cathodic protection where it doesn’t exist. We didn’t really start putting cathodic protection on our pipes until the mid to late 1990s. What we’re being told now is that if we vacuum excavate down to the pipe and put in anodes every 20 to 30 ft, we can extend the life of that pipe. So what is the cost of doing that? Do we get a better cost-benefit ratio? That is what we are really looking at and asset management is driving the risk-based approach to maintaining our assets. As a result of our analysis, we were able to defer off about $50 million of water pipe replacement work over a five-year capital budget. Basically it was determined that it was not the right time to replace some of the pipes.
DB – We had a similar situation with our PVC and on our DI. For the PVC, we have actually extended our life expectancy out to 125 years now. We look at our strategic asset management plans as an executive summary — it is something for management to view. As operators, though, we needed something that was more hands-on and that defined exactly what the programs consisted of and what they set out to do. We needed a set of rules and the decision matrices outlined, so we developed what we call a tactical asset management plan for every asset class. It took forever but it has been invaluable. Everything is documented within this tactical asset management plan; from risk matrices, condition assessment protocols, re-inspection schedules, flushing schedules, standard operations, etc.
MH – The big challenge for us has been factoring criticality into our triple-bottom line analysis. Do you rate lines higher that are next to schools or police stations? But you have to test yourself and determine whether you really value that or whether you value it high because it sounds good. So we’ve got an algorithm that we developed to helps us rate our pipes, but we are finding that we needed to go back and adjust it based on our experience and who we are.
ST – We are facing similar challenges in our asset management program for pipeline replacement. We have had a GIS program in place for over 10 years, and our main criterion for deciding if a pipe should be replaced is a cost-benefit analysis of the cost of continuing to fix leaks on a segment of pipe, assuming a main continues leaking at the same rate, vs. the cost of replacing that pipe. The problem is that when we use that criteria, we come up with more than 80 miles of mains that qualify for replacement each year, but we currently only have budget to replace about 8 to 10 miles a year. So, we typically pick the mains with the highest ratio, which may not always take into account the consequence of failure. We currently don’t have a systematic way of considering the consequence of failure, as part of our selection process. To address this, we are considering a number of different software packages to replace our current in-house GIS program that would factor pipe criticality into our analysis.
AR – When anyone talks about asset management, my now retired director liked to say that we had been doing asset management for over 150 years. And he’s right, but we’ve only just begun to create an entire corporate asset management program. Asset management had been done by every department in its own way. We have an internal utility coordinating committee so that the capital projects are coordinated and that is always one of the big challenges — if you need to replace a sewer is it best to replace the water main while you’re there or leave it and know that we’ll be replacing the asphalt again at a later date. Trenchless technology has certainly helped with this because now often we will line the sewer — we’re very proactive in lining our sewers once they reach a certain point. We are also quite proactive with our inspection program and that has helped significantly. This aggressive approach to inspection and lining resulted in a reduction of the long list of sewers needing replacing, extending the lifespan of the system. One of the challenges with our asset management is with the inventory and knowledge of the history of an asset; many sections of London have been annexed over the years in different phases from smaller townships around the city, so you don’t always have the best information from those areas. We did go through an exercise to clean up a lot of the data, but it is still a challenge we face as we move into corporate asset management. We need to have all of the information link to the GIS and have the information as accurate as possible.
We have a fairly proactive CCTV program and we do trunk sewer inspection, as well. Through the CCTV program we identify the needs based on condition and then we apply risk factors to prioritize the list. This program has come a long way over the last eight years. Last year we inspected about 100 km of sanitary sewer, as well as a significant portion of the storm sewer.
ST – While our leak data is accurate, we have a leak reporting system, which for example does not capture whether a main break resulted in collateral damage like flooding somebody’s property. In terms of our pipeline replacement program, this means that all of our main breaks are therefore treated equally, until we do further analyses, but we know that they are not equal depending on the consequence of failure. So we plan on updating our leak reporting system to automate and further improve our selection process for pipeline replacements.
MH – We have a program that all the data goes into, including repair and maintenance costs. That allows us to analyze the risk of failure and the consequence of failure.
DB – One of our biggest challenges was auditing our data for accuracy. Quality assurance has been a huge issue for us but we are working through this issue by establishing contractor submittal standards and internal auditing procedures and have made huge progress.
AR – We are actually on the cusp of some big changes in how we manage things because not only are we developing the corporate asset management system, but also we’re about to implement a CMMS, which we haven’t had to date. Once that is in place our reports will be entered using tablets in the field and the database will be populated automatically. That will have a big impact on the decision-making.
DB – Our work order system is asset-based so we know the history of every asset. We started in 2006 with our SSES work and internally with Field Operations in 2010. It’s a beautiful thing, but has taken a long time to get there and we still have a long way to go.
Enterprise systems are the way to go and you have to have resources that are dedicated to managing that information. You have to embed quality management principles from data collection to auditing and enforcement. If you don’t, why collect it?
What have you learned from your experience with trenchless technologies? What impacts do you see for the future?
SN – For us, one of the most recent advances that has had an impact on us is the water CIPP lining capabilities. As there are more manufacturers and suppliers that get into the industry and more contractors that get certified, I think that will have a big impact for the rehab as the water infrastructure ages, especially in areas of highly corrosive soils. Things that are in development and technologies that help pinpoint leaks more. As that technology becomes more cost-effective, especially on smaller diameter pipes, it will help guide our asset management and our repair/replacement programs. Sometimes we find that we that we go in to replace a main, only 40 to 50 ft of the main may be in really bad condition and the other 300-ft section is just fine.
DB – Tools to analyze the remaining pipe wall thickness will help with that as well, not just on water but on forcemains. One of our biggest challenges right now is tracking corrosion.
SN – For anyone who is starting a trenchless program — do your homework. Start early on getting the buy-in from within your organization on the types of technologies that you want to use and the type of materials that you want to use. You also need to realize that it is a collaborative effort within your utility and with the contractors in the industry because we are all in it together to get the projects done and maintain the systems for the benefit of the customers. It really is all about the customers and providing service at rates they can afford. Trenchless is really helping keep the rate of rate increases manageable.
AR – For anyone starting out, having a business case and knowing what the comparable costs are is important. It is helpful to talk to municipalities in your area and what their experience with the contracting is like in that area. In southwestern Ontario, we can often rehab a sewer for 20 percent of the cost as open cutting it. Also, rolling jobs into annual programs helps reduce cost. One of the things that we’ve learned too is that you have to recognize what can be handled in a general contract and what needs to be on its own as a specialized project.
