January 2021 Vol. 76 No. 1
Features
Rebuilding of Paradise Counts on HDPE Pipe
The rebuilding of this California town that was destroyed by the infamous Camp Fire continues with a focus on the rapid replacement of water service lines.
“When we’re done, there will be about 315,000 feet of new HDPE service lines,” stated Kevin Phillips, town manager for the Town of Paradise.
Prior to the 2018 fire, the town had a population of 26,000. During 17 days starting on Nov. 8, 2018, the fire destroyed some 150,000 acres and nearly 19,000 homes and buildings.
The Paradise Irrigation Department is replacing all water service lines using high-density polyethylene (HDPE) PE 4710 pipe in diameters of one to two inches. The pipe, PolyFlex CTS potable water service tubing from Advanced Drainage Systems Inc. (ADS) is resistant to rot and corrosion, can be easily installed and is consistent with industry specifications for potable water.
Plastic pipe cleared
After the fire, accusations were made that sections of burnt plastic pipe found above ground created benzene, which found its way into the Paradise water system. PPI, a major North American trade association, investigated.
“These claims are patently false,” stated David Fink, PPI president. “There has been no evidence that plastic pipes are responsible for the production of benzene or any other contaminant due to the heating of the pipes during the Camp Fire. It’s clear that the contamination was from the millions of tons of the fire-ravaged environment that got sucked into the water system.”
According to Phillips, “What the district saw was that the contamination from the fire was not associated with any particular pipe material and that even the galvanized and copper pipes that were in the ground saw the same amount of contamination as the polyethylene. There was a similar percentage of contaminated service laterals with those other materials, as there was with polyethylene.
“So, we decided to continue to use polyethylene because of the ease of use and the cost being the best on the market. We felt it would be the best choice for the rebuilding of Paradise,” Phillips said.
That’s been the decision-making approach over the many decades of the town’s history. The first pipes that went into the ground were lead, and then galvanized steel was used during the boom in the 1950s. Due to corrosion issues, the district moved to copper pipe, which was the industry standard at the time. Continuing and additional issues, related to flexibility and corrosion – especially with the acidic soil conditions – then led to making polyethylene the standard, because of its durability.
“We felt it would be in the ground for many, many years,” Phillips recalled.
And it was. “Even after the fires, we found the buried polyethylene was undamaged from direct contact with heat,” he said.
The district did find contamination in the majority of laterals servicing the burned structures – regardless of material type. HDPE pipe emerged as the best product for replacing those service lines, allowing them to be upsized, as necessary, to support the rebuild and meet customers’ meter and fire service needs.
“Seismically, it’s flexible and can handle the movement up here,” Phillips noted.
Protection options
Rather than the material being the issue, the district believed the contamination was drawn into the system by the depressurization and allowed to absorb into the pipe walls during the length of time the system was disconnected.
“We felt the best form of protection for our service laterals was … just putting in backflow protection to reduce the chance of contamination entering the system during a depressurization event,” he explained.
Phillips estimates the Town of Paradise will take nearly 20 years to be back to where it was prior to the Camp Fire.
“It takes a long time to build homes,” he said. “We have had a huge surge of building permits issued in the Town of Paradise. There is a ton of pressure on getting new water service to those new rebuilds.”
In addition to residential water service, HDPE from ADS – large-diameter N-12 corrugated pipe – is being used on several stormwater drainage projects in Paradise. These include the town’s tennis courts and the softball field. •
FOR MORE INFORMATION:
PPI, plasticpipe.org
Advanced Drainage Systems Inc., (419) 424-8275, ads-pipe.com
Specifics on Pipe Used in Paradise
“This SDR 9 PolyFlex tubing from ADS is produced in accordance with AWWA Standard C901, and meets NSF 14 and 61 standards,” explained Camille George Rubeiz, P.E., F. ASCE, co-chair of the HDPE Municipal Advisory Board and senior director of engineering for the Municipal and Industrial Division of the Plastics Pipe Institute Inc. (PPI).
“This means that the pipe is certified for potable water systems because it meets or exceeds the requirements for health effects in drinking water components and, also, the performance criteria of plastic piping components as stipulated by NSF. PE 4710 compounds offer an excellent level of performance for trenchless and open-cut installations.
“The PE 4710 HDPE pipe can be used with increased flow capacities plus increased resistance to surge events and fatigue. The ANSI/AWWA C906-15 standard includes PE 4710 for sizes up to 65 inches and recognizes the increased durability and reliability of HDPE pressure pipe used in water systems,” Rubeiz added.
Kevin Phillips, town manager, Town of Paradise, “It is clear that the contamination was from the burned-out environment that got sucked into pipes. Pipes of all materials were found to be contaminated.”
The Paradise Irrigation District will eventually replace 315,000 feet of water service lines using high-density polyethylene (HDPE) tubing.
Displaced and new residents are part of the rebuilding of Paradise.
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