California town conquered the fire with HDPE pipe
The reconstruction of the town of Paradise, California, which was destroyed by the Camp Fire, continues to focus on the rapid replacement of water supply lines.
"When we are finished, there will be approximately 315,000 feet of new HDPE service lines," said Paradise Town Manager Kevin Phillips.
Before the fire in 2018, the town had a population of 26,000. In the 17 days starting on November 8, 2018, the fire destroyed approximately 150,000 acres and nearly 19,000 houses and buildings were destroyed.
Paradise Irrigation Department is replacing all water supply lines that use high-density polyethylene (HDPE) PE 4710 pipes with a diameter of 1 to 2 inches. PolyFlex CTS drinking water service pipes from Advanced Drainage Systems Inc. (ADS) are corrosion-resistant, easy to install, and comply with industry regulations for drinking water.
"This SDR 9 PolyFlex pipe from ADS is produced in accordance with AWWA standard C901 and meets NSF 14 and 61 standards," Camille George Rubez, PE, F. ASCE, Co-Chair, HDPE Municipal Advisory Committee member and Senior Engineering The director said the head of the Municipal and Industrial Department of the Plastic Piping Institute (PPI). "This means that the pipe has passed the drinking water system certification because it meets or exceeds the requirements for the health effects of drinking water components, as well as the performance standards for plastic pipe components specified by the NSF."
Rubeiz said the compound is particularly suitable for trenchless and open-air installations, noting that the pipeline can also withstand surge events and fatigue.
"The ANSI/AWWA C906-15 standard includes PE 4710 up to 65 inches in size and recognizes that HDPE pressure pipes used in water systems have higher durability and reliability," he added.
After the fire broke out, someone accused the charred plastic pipe section found on the ground to produce benzene, which entered the heaven water supply system. The main North American trade association PPI conducted a survey.
"These statements are clearly wrong," said David Fink, the president of PPI. "There is no evidence that plastic pipes produce benzene or any other pollutants due to heating of pipes during campfires. It is clear that the pollution comes from millions of tons of fire-burned environments being sucked into the water system."
Phillips, the manager of Paradise Town, responded to Fink and PPI's statement.
"What the area sees is that the pollution caused by the fire has nothing to do with any particular pipe material, and even the underground galvanized pipes and copper pipes are polluted the same as polyethylene." He said. "The percentage of contaminated service pipes using other materials is similar to polyethylene. Therefore, we decided to continue using polyethylene because it is easy to use and cost is the best on the market. We think it will be the best choice to rebuild heaven. "
He added that heaven was built in decades. When it was first built, many pipelines, like many communities in the United States, were made of lead. During the population boom in the 1950s, galvanized steel became the preferred pipe material, but due to corrosion issues, the community switched to copper pipes that had become the industry standard at the time.
"Similarly, there are flexibility and corrosion issues, especially in acid soil conditions," Philips said of the copper pipe. "So, due to durability, the area eventually switched to polyethylene and made it our standard. We felt it would be underground for many, many years. Even after the fire, we found that the buried polyethylene was not damaged by direct contact with heat. The problem we found is that most of the service branch pipes that serve the combustion structure are contaminated. Regardless of the material type, we need to replace these service pipes."
He said the use of HDPE pipe also allows the community to have flexibility in pipe size. The utility company can expand the scale of service lines to support reconstruction work after the fire to meet customer and fire needs. In the face of seismic activity, the pipeline is also flexible and adopts trenchless technology to quickly install new pipelines.
"We believe that the best form of protection for our service branches is not the material itself, but just providing backflow protection to reduce the chance of pollutants entering the system during a decompression event," Phillips said. "Similarly, we believe that the occurrence of pollution has nothing to do with the material of the pipeline, but with the decompression, the pollutants being sucked into the system, and the length of time the system is disconnected to allow the pollutants to adsorb to the pipe wall."
Phillips estimates that it will take nearly 20 years for the new town of Paradise to rebuild back to where it was before the campfire.
"It takes a long time to build a house," he said. "We have obtained a large number of building permits in Paradise Town. Providing new water supply services for these new reconstruction projects is under tremendous pressure. Using polyethylene, it improves efficiency, so we can take one or two of them after receiving the request. Get there within an hour and get a service line."
The speed of installation combined with the ability to solve on-site challenges (such as rocks, other service lines, and roads) speeds up the process of smooth reconstruction.
Phillips said: "Compared with the steel or copper we have to drill holes, it makes the reconstruction process and restoring the water supply system easier." "PE is the standard for our progress and the entire reconstruction process."
In addition, several of Paradise’s rainwater drainage projects are using large-diameter N-12 corrugated HDPE pipes. These include Paradise Tennis Court and Paradise Softball Field.
After the devastating campfire in 2018, HDPE pipes played a key role in restoring the water infrastructure in Paradise, California.
Steve Cooper is a writer at SCA Communications. Cooper can be reached at [email protected].
The Water and Waste Digest staff invites industry professionals to nominate what they consider to be the most outstanding and innovative water and wastewater projects to be recognized in the annual reference guide question. All projects must be in the design or construction stage within the past 18 months.
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