REBUTTAL: HDPE Pipe – A Progressive Step

 
 

I read the article that was published by Mr. Walt Drabinski (WB) in the September 6 issue of Key West, The Newspaper.

I appreciate the opportunity to have The Newspaper publish a rebuttal to address some of the misinformation that was included in the article about High Density Polyethylene (HDPE).  I selected 6 statements from the article and provided a brief response and links to supporting documents as listed below-

1.      WB –   An Environmental Nightmare?

Response: this is incorrect- the article did not provide the relevant facts to justify this title; to the contrary, the mayor of the city of Livonia, MI (and many other utilities in Florida and around the country) are using HDPE ‘to be  environmentally progressive’ and ‘to save infrastructure in tough economic times’ as was documented in the ‘Best Practices’ section of the US Mayor magazine http://plasticpipe.org/pdf/livonia-mi-pe-pipe-replacement.pdf; Mayor Jack Kirksey concluded  “The use of HDPE pipe is a progressive step that all other cities should consider to reduce costs and disruption of daily life during the project, and to improve their water infrastructure with a long-life product.”

Other cities in Florida that have or are using HDPE for water and sewer include:

2.      WB- It will be under pressures of 15psi to 60psi

Response: HDPE is commonly designed and installed to support gravity and pressure applications; for example, PE 4710 DR 21 has a pressure rating of 100 psi and DR 9  is rated at 250psi per ASTM F714 http://www.astm.org/Standards/F714.htm

3.      WB- Could it be an environmental disaster in the future due to pipe failures? Or perhaps a financial disaster if the piping needs replacement in a few years?

Response: the answer to both questions is No; CSIRO concluded ‘polyethylene networks show significantly lower costs throughout their lifetime, and the combined benefits of low failure (rate) and low water loss rates can potentially result in long term cost savings.” Pls refer to the full paper for additional details http://www.pepipe.org/uploads/pdfs/Life_Cycle_Cost_Study.pdf.  Also, see response # 4.

4.      WB- has a tendency to become brittle and crack over time.  It is inevitable that failures will occur at some time in the future.

Response: All materials will fail at some time in the future; however, properly specified, designed, installed and inspected HDPE sewer pipe will not crack or become brittle during its design life which can exceed 100 years.  http://plasticpipe.org/pdf/mid-fatigue-plastic-water-pipe-01-12-12.pdf    http://plasticpipe.org/pdf/evaluating-disinfectants-on-pe-pipe-nana-awwa.pdf

The Water Research Foundation concluded that the ‘failure rates of PE pipes under normal operating conditions are extremely low.”  Also, the PE materials have significantly improved resistance to cracking and has a ‘very low predicted future failure rate” as summarized in here: http://www.waterrf.org/ExecutiveSummaryLibrary/91194_2975_profile.pdf

5.      WB- A leak in a pressurized system 

Response: Properly fused HDPE pipe has zero leakage per AWWA M55 http://www.awwa.org/store/productdetail.aspx?ProductId=6743; other gasketed pipe materials allow leakage per their respective AWWA manuals and the owners’ specifications.

6.      WB- there is an excellent web site

Response: this is incorrect- The author of the “excellent web site” does withhold his identity and commercial interests from the public.

For long service life of HDPE pipe, the owner, design engineer, installer and inspector have to follow the design and installation methods as required in multiple sources such as:

In conclusion, properly specified, designed, installed and inspected HDPE Pipelines will provide the County with a piping system that has a long service life.   As Mayor Kirksey concluded,  “The use of HDPE pipe is a progressive step that all other cities should consider to reduce costs and disruption of daily life during the project, and to improve their water infrastructure with a long-life product.”

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Camille George Rubeiz is the Director of Engineering (M&I) for the Plastics Pipe Institute. Mr. Rubeiz holds a BS and MS in Civil Engineering from the University of Tennessee and Rensselaer Polytechnic Institute.  He is also a registered professional engineer in the State of New York.   Mr. Rubeiz serves as the Secretary of the American Water Works Association (AWWA) Standards Committee on Polyolefin (HDPE) Pressure Pipe and Fittings and is a member of the Florid section of AWWA; in addition, Mr. Rubeiz is an Associate Editor of the American Society of Civil Engineers’ Journal of Pipeline Systems Engineering and Practice and is the Co-Chair of the HDPE Municipal Advisory Board.

Contact:  Camille George Rubeiz, PE, Director of Engineering (M&I), Plastics Pipe Institute, 469-499-1050, [email protected]

  One Response to “REBUTTAL: HDPE Pipe – A Progressive Step”

  1. halloween says:
    March 21, 2015 at 5:21 am

    It’s an old article, but I just found it. Since it is so old, I won’t bother countering each criticism of the article that it challenges. It might even suffice to point out that it comes from the sales promotional organization for HDPE pipe! Of course they say it is great- that’s the job of a salesman.
    I have worked at both a private and a public utility elsewhere in Florida that have banned HDPE. The public utility found that HDPE water service lines developed pinhole leaks over time.
    Test procedures for HDPE allow for expansion of the pipe to cause a drop in pressure, but that is indistinguishable from a leak. A savvy contractor can stretch the pipe with overpressure so that the elasticity can compensate for any leaks. That elasticity vanishes in time due to leaching and offgassing of the chemical that makes it flexible. HDPE products of all kinds get brittle in time, and faster in the Keys than anywhere I know. That HDPE garbage can that seemed indestructible when new will crack or have chunks fall off upon impact later in lifespan- which is lots shorter than you want your sewer pipe to last. I had a Rubbermaid storage container well sheltered from sun in an enclosure under my house. While it would have bounced without harm if dropped from the roof when new, it shattered when I picked it up after about 12 years of just sitting in the dark. FKAA had HDPE water services in Marathon that were leaking, and when they tried to repair them, the pipes snapped like dry twigs. To see it new, it is hard to imagine that HDPE has a crystalline molecular structure. A tiny scar on a piece of pipe can be like a score on a piece of glass or a tile where you intend to break it cleanly. It gets scarred easily during installation because it is so soft and so heavy compared to other pipe. Butt welded sections above ground as is typical or on long rolls prior to installation creates very awkward handling where scars are likely.
    Notice the claim in this article that the new resin in PE 4710 solves the old problems. Actually, it’ not really old enough to know it’s not worse in the long term.
    HDPE pipe in larger sizes is very difficult and expensive to repair. Its change in length with any temperature change is so extreme that restraint is difficult to keep it from pulling itself apart. Any welded repair takes perfectly dry conditions, and a skilled operator to achieve a weld that will last. HDPE has a characteristic called “creep” that causes it to ooze away from a point of compression such as the bands on a mechanical joint. Various schemes have been developed to compensate for creep, but all have issues with time and damp buried exposure.
    The flexibility of HDPE when being installed results in curves instead of fittings when changing direction. A curved piece of HDPE is pretty well unrepairable, and that is just where you may expect to put a hole in it with your sign post auger.