Sinkhole due to non-standard piping

It took a small, wheeled robot to figure out how to handle the 50-foot sink hole on Bethel Avenue — and the results aren’t great.

After sending a wheeled-camera into a broken drainage pipe, the city’s Department of Public Works is blaming sinkhole on a non-standard pipe running along Bethel Avenue.

Agency Director Maher Abed worked with WestSound Engineering to examine the drainage pipe that gave out during the Dec. 3 rainstorm and determined it was once an open-air drainage ditch, which was converted into a pipe.

The remote camera found the roof of the drainage system eroding and damaged in a number of areas, and continuing to corrode from the weight of Bethel Avenue traffic and the significant depth of fill above it.

The pipe is a non-standard trapezoid shape, meant to drain water at a surface level, but was later fashioned into an underground pipe by laying a concrete ceiling over the top.

According to a report by WestSound Engineering, the non-standard piping deteriorated in the vicinity of the sinkhole.

Public Works plans to demolish the non-standard pipe and replace it with a minimum 36-inch pipe, preferably a 54-inch pipe, at a shallower depth.

The robotic, wheeled camera showed that the roof of the pipe is still deteriorating in parts, with exposed rusty re-bar.

“It tells me that this collapsed over time,” Abed said Wednesday.

But Abed is confident that the pipe is stable for the moment, and plans to have the area ready for demolition and construction around the end of the year, with an early estimated cost at around $400,000.

Sidebar: DEM counts millions in storm damage

The Kitsap County Department of Emergency Management (DEM) is reporting more than $30 million in damages across the county to the Federal Emergency Management Agency, which could mean monetary compensation for various groups in the area.

Public Information Officer Susan May said government and nonprofit entities reporting $18 million in damage, businesses reported $1.5 million and private property owners reported $12 million.

“Let me emphasize that this is self-reporting,” May said. “This is based on observations and not on someone who’s an expert in construction or structural engineering. Some are high and some are low.”

The figures help FEMA determine compensation eligibility, and May said the government and non-profit sector is already eligible for 75 percent compensation from the federal government and 12.5 percent from the state of Washington.

The other sectors, businesses and private property, are still being determined, but May suspects compensation could come after FEMA assesses the area.

This is the final tally reported by the DEM, but businesses and property owners are encouraged to report damages for compensation. These numbers merely determine whether the area is eligible.

Those still cleaning up from the floods can receive more assistance today and Sunday. Kitsap County Solid Waste will be accepting flood damaged carpet, furniture, mattresses, sheetrock, siding, clothing, and other personal property at no charge from 8 a.m. to 5 p.m. at the Olympic View Transfer Station at 9300 SW Barney White Road, across State Route 3 from the Bremerton Airport.

The station will not be accepting household hazardous waste.

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