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Sewer system failures
[Steve Willie provided] the most comprehensive listing of causes of system failure that we have read in over 60 years of messing with sewers, both sanitary and storm (Letters, April 2007, page 10). We heartily agree that age has very little to do with system durability. The many hex- and octo-shaped water mains that still turn up, laid in God knows when, attest to this.
There are two contributing factors that we were surprised he didn’t include: slope [less than] self-cleaning velocity (design error usually, construction goof sometime) and sloppy backfill/bedding procedures (construction and inspection share the blame for this one).
Both over and under compaction, in our opinion, carry a large responsibility for poor performance and short life. The hoop strength in pipe is astonishing, if bedded right. Witness the numerous tin whistles in rural areas made shiny by the vehicle tires passing over and directly upon them.
Total disregard for other underground utilities, like the water main running through the sanitary manhole, also play a part. There was big rush after World War II to provide homes for the guys who had been fighting for their country, and a lot of underground construction was "anything goes," and "get it done quick." Many of these lines are still surprisingly in use; failures waiting to happen.
Inspection has always been important, as has pride in workmanship. I have been lucky to work with people who were fiercely proud of their craft.
Henry J. Boesch, Jr., P.E.
[The] letter from Steve Willie (April 2007, page 10) argued that most sewer infrastructure problems are construction related and not age related. They can be age related because of old technology, but new installations are being screwed up all the time. I was in the pipe industry for many years and visited many problem installations and saw many videotaped sewers. I agree with most of Willie’s comments and further, I strongly recommend that every city engineer/public works director in the United States make Willie’s comments the subject of a management meeting, especially with his or her construction/inspection manager. I would add a few more comments:
Much of Willie’s comments can be applied to stormwater installations too, especially with all the underground detention/retention pipe systems being installed these days.
The agency’s standard specifications should require that all new stormwater and sanitary sewer installations be videoed prior to acceptance. If this is too odious to the local developers, a good alternative is to require a minimum of 20 percent of the lines be videoed. The agency’s engineer gets to pick which runs to video and does not reveal to the contractor which ones until after the complete system in installed. It is amazing how the quality of construction improves if such a specification is enforced.
When water-tight joints are required, all types of pipe, rigid and flexible, should be required to pass the same air test for joints prior to acceptance. Why should one type be held to a lower standard than another?
Modern flexible pipes, such as PVC and CPEP, are wonderful improvements in structural, material durability, and joint performance when compared with older pipe types, but just because they are easier to install does not mean their installation should be treated casually. I have been called to many jobsites because "the pipe failed." All too often, the "failure" was not the pipe, but rather caused by the contractor’s and the agency inspector’s lack of knowledge about proper pipe bedding and backfilling, compaction level/methods.
One example I never forget is a 60-inch plastic pipe with an outside diameter of approximately 66 inches being installed in a trench 72 inches wide with 3-inch-minus crushed rock backfill. Both the contractor and the inspector assured me the backfill material was "a high-quality backfill." When I asked them how they were going to get enough of this material around the pipe when there was only 3 inches on each side of the trench, they assured me it would be fine (the pipe was ultimately going to have 40 feet of cover). Only when I threatened to call the city engineer and ask him to shut the project down did I get an agreement to widen the trench. Obviously, training in proper installation of pipe should be a requirement for inspectors, but I’ve seldom encountered any such formal courses for contractors.
Most of the pipe is sold to contractors through distributors. Distributors usually have very little technical expertise, and even when supplied with "how-to-install" brochures from the pipe manufacturers, [they] seldom pass them along to their customers. I suggest that Standard Specifications require some sort of "Certificate of Pipe Installation Training" be provided by the contractor. These courses are available online from some members of the underground pipe industry.
Mike Whaley
Riprap retaining walls
In reference to your Product Guide regarding retaining walls (April 2007, page 38), I have used two of the retaining walls described and found them an excellent design. I live on the Central Oregon Pacific Ocean coastline [where] oceanfront properties suffer severe erosion from the strong storm tides. The erosion is stopped and controlled by construction of riprap rock retaining walls, a design that is not included in your article. The riprap rock retaining seawalls have the definite beneficial feature that the slope construction promotes accumulation of beach sand and growth of dune grass, a benefit [not] provided by vertical concrete or sheet piling retaining walls for beachfront properties.
Lester E. Fultz, P.E.
| The following letters are in response to the Insider’s View column published in Civil Connection, an electronic newsletter from the publisher of CE News. In late February and March, Jason Burke, P.E., wrote about "Comparison of professional standards." In early March, Cathy Bazán-Arias, Ph.D., P.E., wrote about "Communicating risk and risk understanding." Both columns are available on the Civil Connection website under "Article Archive." |
Comparison of professional standards
I think there is a more basic reason, than ethical standards, that explains why medical doctors and lawyers enjoy a higher public opinion than engineers. It is simply that both of those fields require a graduate degree, with four extra years of college. Engineers get their degrees, and though there is a four- to five-year period before they can take the P.E. exam to become Professional Engineers, they do not have the title "Dr." before their names. Ask yourself why college professors are so much more highly regarded than our primary and secondary teachers and the same reason holds—they have doctorates. As a society, we hold in high regard the perceived intelligence that is required to get these higher degrees. We respect these people, not for the ethical standards to which their profession holds them, but for the intellect and effort that are required to receive their degrees.
Most everyone is aware of the selective and competitive process to which applicants to medical and law schools are subjected. You have to be one of the best and brightest to get into these programs. Is it that difficult to get into engineering programs? Most of the public is not aware of the ethical standards of any of these professions, so I do not believe that is where the difference in respect arises.
Interestingly, at the turn of the last century, engineering was among the highest paid professions in our society. Medical schools were separate from our university system and often sub-par. Over the past century, the American Medical Association (AMA) has done a great job of marketing the medical profession and improving the educational system for its practitioners. They have turned the tables on engineers, financially, one-hundred fold. If engineers want to garner this type of respect (or is it income?), we have to create one engineering society (not one for each type of engineer), work together to elevate educational standards for engineers, and then market our profession so that people perceive that they cannot live without us.
Linda J. Madigan, MSCE
Indeed, we do have at least one society for all engineers, the National Society of Professional Engineers. Whether or not it is as effective at promotion and marketing as the AMA is debatable, but it is still one of the primary sources of our ethical code. Nevertheless, I agree that an ethical code by itself does not automatically deserve respect and recognition; it is how that code is applied by its practitioners that will determine its status in society. That being said, we can easily observe that even with a code, there will still be "lawyer jokes" based on dishonesty or unethical behavior. But yet, how many television programs are there based on the "glamour" of law and medicine compared with that of engineering? It is not that we lack the intellectual respect of society, it is that non-engineers often simply do not appreciate the time and effort that is required of a degree and the public trust that is put into our designs. Outsiders understand that engineers are necessary, but there is a perception that doctors and lawyers have a much more personal and passionate interest in their clients’ well-being.
Jason Burke, P.E.
[A] basic difference between lawyers, doctors, and engineers is that as a society and as individuals, we seek to establish a long-term relationship with a doctor and lawyer. We do not casually make changes in these relationships. Society does not set out to establish a similar relationship with engineers. There are no life experiences that regularly expose society to our professional services. Additionally, the majority of our society may never have need for an engineer’s direct services. We as engineers need to focus on how and why our profession is justifiably different. We need to become cheerleaders for our profession and strive to be recognized for the differences in our service to society.
We must be objective in our practice because we serve the public, not just an individual. We must evaluate and judge what solution is best for everyone. However, like lawyers, we must recognize that conflicts exist and serve to find answers that are in our client’s best interest, while serving the public’s interest.
So, while the other professions serve focused individuals, we as engineers serve everyone. Our responsibility is much broader and deeper, and accordingly should have a much different direction for our practice. I certainly agree that we need to educate society to better understand the services engineers provide. But I would like for our profession to spend time focusing on why we are different, and to promote those unique differences. An engineer’s services are as important as those obtained from a doctor or lawyer.
Kevin N. Clemo, P.E.
[Jason] Burke is trying to find a philosophical (i.e., high-minded) reason for our decrepit state of affairs. In doing this, he fundamentally ignores the economic market for engineers. Supply [is] out-of-whack with demand. [There are] too many engineers to create significant, sustained income growth. If and when there is a shortage [of engineers], the government responds by simply opening the immigration floodgate to depress cost and, in effect, income. Unlike the AMA, and to some extent the American Bar Association, the American Society of Civil Engineers (ASCE) is unable to control the supply of engineers through program accreditation. [There is] a lack of universal demand for engineers (even the average person requires the services of a doctor or lawyer on a periodic or routine basis) and a low cost of entry into the engineering profession, where only a four year degree is required, unlike medicine and law. Not unlike many other people in our field, Burke tries to take the principled high road in explaining the situation, but the reality of the problem is simply about economics and market structure, [which is] another reason why engineers could be accused of being bad business people: We can’t even recognize the root causes of our problem.
John Gobieski, P.E.
One effort being undertaken by ASCE is development of new standards for engineering licensure in the 21st century. However, until such standards are implemented, and for a significant time thereafter, the existing experience standards will be a fact of life. If we cannot substantially change the supply of engineers in the short term though, we would be well-advised to increase demand if we feel that our services are a commodity subject to simple supply and demand laws. The only way to accomplish this is through education, outreach, and community service that highlights the benefits and ubiquity of engineering and the passion that engineers should have for their work if they are to be considered true professionals. Far from being decrepit, engineers have a continuing opportunity and obligation to shape the future for all.
Jason Burke, P.E.
Communicating risk
Thank you for your column urging engineers to get out and explain the risk to our fellow citizens. Just as we expect medical doctors to sit down and explain complex health issues in terms patients can understand, engineers must explain the impacts of our work to the public. We should consider educating our clients and the public an essential part of the services we provide. When we fail to do this, architects and politicians step in and often miscommunicate or omit essential information.
I recently published a column in the ASCE Louisiana Section journal on the topic of the risks of designing flood protection to the 1-percent annual exceedence benchmark—a benchmark established not by engineers or policymakers, but by insurance adjusters. The New Orleans newspaper, The Times-Picayune, asked me to rewrite the column for a more general audience. It was printed March 3 and can be read online here.
The response to my column has been very positive. The public not only needs to know, they want to know about the risks and about what they can do to reduce the risks. Engineers should not be holding back or letting others speak for us.
Timothy M. Ruppert, P.E., M.ASCE
I’m not sure your article is asking the right questions. Those individuals, businesses, and agencies that directly interact with the lay public who may purchase dwellings or establish businesses in these high-risk locations are faced with conflicting interests, primarily verity versus monetary. The risks are known and recognizable from FEMA flood maps and other public information. The requirements to reinforce a deficient flood management system and reorganize its equally deficient management structure were also well documented and communicated by engineers to public policy officials. While there may be avenues that engineers could pursue to further improve communication with the public, those already tasked with communicating the requisite available information to the public need to be held accountable for their actions and omissions.
Steven Kaufman, P.E.
The pure idea of communicating risk to residents is blaming the victim too much. This seems to come up whenever natural disaster strikes and insurance or government funds are needed to help with the cleanup or repair. In the case of Hurricane Katrina, most of the residents of the hardest hit areas had little economic choice as to where to live. This same sentiment comes across in the direction to fill up your car with gas, buy supplies, and head out of the hurricane zone. Those with the means to do so probably did. Those without the means had to rely on the government and its engineers to help evacuate. Your mission to educate is laudable, but it is also wholly inadequate. Our mission as engineers and professionals who make decisions on infrastructure planning should simply be to do our jobs of providing adequate life safety in the built environment.
Todd Rusche, P.E., Esq.
The design professions have nurtured a performance-based design basis for some time now with perhaps not a complete understanding of the risk communication responsibilities. This new way of balancing the economic and risk factors for projects works only when the job of education is well done. We embrace the idea that more safety can be achieved when the decision makers (owners/owners’ representatives) can share in the knowledge of probabilities of a likely event affecting properties, yet struggle with making sure they "get it."
Some do a better job than others when constructing the mental pictures necessary to grasp the nature of floods, earthquakes, and wind storms, yet it is a necessary task and one we should actively embrace as a profession charged with protecting public safety. Allowing owners and public officials to minimize the need to fully understand the temperament of natural events is a disservice to the public who live and work in a fragile landscape of man-made structures.
Being advocates for safety means not only communicating the risk but also looking continually for solutions to a "do nothing because it costs too much" mentality. A single-stage improvement can often be broken into component parts and done over time, therefore affording increased safety incrementally.
I concur with Cathy Bazan-Arias that our best tools are face-to-face communication with those affected by natural disasters and those in charge of protecting the public. Finding opportunities to interject professional opinions at appropriate venues is our responsibility, for it will be better after a disaster not to be asked, "How come you didn’t tell me?"
Barry H. Welliver
