Major project begins to replace pipes buried 12andndash;14 feet under street
Construction crews have finally started work on a major project to replace the sewer main on Second Street that has been delayed for months.
Workers with the Eureka company Mercer-Fraser on Tuesday began drilling de-watering wells that will allow them to dig underneath the street without running into groundwater, said Crescent City Public Works Director Eric Wier. They will replace the 18-inch clay sewer pipe with a 24-inch pipe made of high density polyethylene and polyvinyl chloride.
Meanwhile, Second Street between B and F streets will be closed to traffic, Wier said. Only residents and business owners on that street will have access. Mercer-Fraser must complete the project within 40 business days, but could suspend the project during a major storm, he said.
"Talking with this contractor, it is their intent to work right through the rains," Wier said. "If it's a big storm they may stop for a few days, but their intent is to pick up right where they left off as soon as the storm lessens."
The project is being funded through a $1.28 million Community Development Block Grant. It was expected to start in July, but was delayed and revised when one of only two contractors who responded requested to withdraw its bid due to a clerical error.
Mercer-Fraser will replace the main using a "cut and cover" method, Wier said. This involves digging up the street to replace the pipe. The existing line would be used as a sewer bypass while the new pipe is being installed.
The sewer main underneath Second Street was installed following the 1964 tsunami and is one of two major collection lines that serve the Crescent City area, according to Wier. All the pipes that go down the city's letter streets feed into the Second Street pipe, which connects to another pipe under B Street and winds up at the wastewater treatment plant, he said.
"The further down the system you go, the deeper (the pipes) have to be so it's still able to flow by gravity to the treatment plant," Wier said. "That pipe ranges in depths from 14 feet to 12 feet below the surface."
Groundwater is also an issue when installing a new sewer pipe, Wier said. In Crescent City, groundwater can be just below the surface during the winter and five to six feet below the surface in the summer, he said.
Mercer-Fraser will install a well roughly every 50 feet to pump out and store the groundwater, Wier said. When the project is complete, the contractor will remove the wells and the water table will be restored, he said.
"They're going to be installing the pipe at 12 to 14 feet deep," he said.
The revised project includes five components starting with the base portion to replace the mainline laterals from B to F streets. The other four components would extend the new line to K Street, but the city would need additional funding to complete that project, Wier said.
The City Council was poised to select local company Hemmingsen Contracting in September, but awarded the project to Mercer-Fraser after that contractor filed a bid protest. Mercer-Fraser's bid protest contended that because Hemmingsen did not provide prices for all five components of the project, and therefore did not comply with the city's instructions.
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