Municipal water systems that installed ductile iron pipe (DIP) 20 or more years ago are failing at an alarming rate. Cities like Duluth, Minnesota have been forced to address water main breaks and leaks with costly repairs to the DIP. And despite the financial investment, not to mention the time and inconvenience, these repairs are like putting a bandage on a proverbial compound fracture.
As municipal leaders continue to lean on their old friends and old ways (read DIP), it is time to try some new medicine.
After all, some of the early municipal water systems utilized hollowed out elm and cypress logs to transport water – we somehow found the wisdom to move on from that.
While there are a few choices that can work, there is only one solution that does more than spray some Bactine on the municipal wound and wrap it in gauze.
Benefits of HDPE Piping in Municipal Water Systems
High density polyethylene (HDPE) piping systems have proven to check all of the boxes when it comes to installing a new water or sewer system.
While legacy pipe like ductile iron and PVC can have leak rates of 30 percent, HDPE has a failure rating of one in ten million. If installed correctly – HDPE pipe provides a leak-free solution that requires little or no maintenance.
In other words, you would have a better chance of winning a gold medal in the Olympics than a properly installed HDPE system failing.
Potential leak points can occur at every joint (10–20 feet) in a traditional PVC or DIP system. For some perspective – a city of 100,000 residents using PVC for their potable water supply would lose around 14 percent to leakage—over 12 million gallons yearly. That doesn’t even consider the cumbersome, expensive, unreliable and time-consuming welds that have to be performed when joining ductile iron, or the messy and less-than environmentally friendly solvents and primers used with PVC.
HDPE is linked pipe to pipe utilizing a technology called butt fusion. The would-be joints are fused, or welded together end-to-end, creating a monolithic connection that is as strong or stronger than the pipe itself. No fittings, no solvents, just two pieces of pipe and heat.
You eliminate not only leaks, but the need to repair or replace the piping in 20 years. Financially it’s pretty simple math to see the numerous benefits.
If your concern jumps to the likelihood of improper installation, it certainly does exist – but not when you utilize ISCO for your HDPE solutions. Certified training programs for every client and partner eliminates these risks. In addition to the training, ISCO can rent or sell the fusion equipment your job requires. ISCO is so much more than just pipe.
Another benefit of HDPE is that it is less expensive and easier to install than most other potable piping systems.
Unlike legacy pipe systems, HDPE pipe can be fused at the surface and lowered into the existing trench -or- installed with trenchless technologies like directional drilling, pipe bursting, slip lining, and compression fit lining. Trenchless technology typically costs 50 to 75 percent less than open-cut installations.
HDPE pipe installation is safer, more efficient, less environmentally disruptive, and no as physically demanding – increasing worker safety, reducing trench excavation, and simplifying the process.
In addition to the reduced time and cost of installation, positive impacts on the environment occur at the genesis of the HDPE production, as it requires less energy to produce than legacy pipe. Due to its weight it reduces vehicular emissions for transporting the pipe and is therefore less expensive to ship than DIP.
HDPE is more resistant to surge and fatigue than any other material used in potable water piping systems. HDPE pipe can handle occasional surges up to two times its working pressure rating and recurring surges up to one-and-a-half times its pressure rating with no risk of stress damage to the pipe.
The ductile polyethylene material also absorbs energy created during a surge event and dissipates the wave quickly when compared to legacy materials. Rigid PVC and DIP pipe amplify the wave, leading to downstream surge impacts. Areas that are conducive to shifting soils or seismic activity will negatively impact legacy systems, but due to its flexibility HDPE can absorb the changes without being compromised.
Unlike brittle PVC and ductile iron, HDPE has an average bend radius of 25 times the outside diameter, and you can form a radius without using fittings for directional changes. Unless you have a superhero or magician on your installation crew, ductile iron and PVC will not take kindly to bending.
Sometimes ductile iron failure is due to corrosion or tuberculation that compromises the integrity of the pipe. Not only is HDPE completely resistant to both corrosion and tuberculation, but it is resistant to acids, bases, reducing agents and gentle oxidants, and the material mitigates the risk of leaching, ensuring that chemicals do not reach hazardous levels.
When you consider that HDPE has a service life of well over 100-years, does not leak, is durable, flexible, fully restrained, can offer less-expensive installation methods with minimal environmental disruption and limits costs at every turn, it is no wonder that the cure for your failing and outdated municipal water system is HDPE.
Make an appointment with ISCO to discuss your municipal water solution.
The Doctor is in.