Next round of Sandy Lane sewer work slated to take 2 days

The Warwick Sewer Authority is going to “sock it” to more detours on Sandy Lane.

Yes, it is a sock that the authority plans to use to avert additional pipe collapses like that which occurred on Nov. 21, resulting in the diversion of Sandy Lane traffic until Jan. 5 when the replacement of 154 feet of sewer line 25 feet below ground was completed. In making that repair, cameras were sent into the line extending in both directions from the break.

What was discovered is a disaster waiting to happen. The concrete pipe installed in 1978-79 under a federally financed program was so badly deteriorated from the corrosive effects of hydrogen sulfide gas – it smells like rotten eggs – that there are holes in places and the wire frame is all that remains. Another collapse is certain to happen. The only question is when.

Hopefully that won’t happen before the sock arrives.

Last week, a police cruiser diverted traffic from the middle of Sandy Lane as a crew from Green Mountain took measurements for a “sock” (the technical term is CIPP or “cured in place pipe”) to be fitted into more than 700 feet of the 24-inch pipe. Made of fiberglass, the sock will be impregnated with resin and then filled with water to conform to the walls of the existing pipe. The resin will harden overnight and the following day the line will be drained and a robot sent into the newly reinforced pipe to cut openings for collecting pipes, explained Scott Goodinson, WSA superintendent.

“If we didn’t do this we’re looking at another collapse,” Goodinson said following his presentation Thursday night to the Warwick Sewer Authority. Unlike the pipe replacement that detoured traffic around Mickey Stevens Sports Complex and on to Cedar Swamp Road for weeks, the “sock project” should be completed in two days in mid-February.

There’s more to it than the inconvenience of a detour on one of the city’s major thoroughfares.

Apart from being rapidly completed, the preventive measure is a fraction of the cost of replacing the existing pipe. The contract with Green Mountain is $107,000 to line more than 700 feet of the Oakland Beach interceptor that starts near the fire station on West Shore Road, cuts over by Vets Middle School to Armory Lane and then Down Sandy Lane to Cedar Swamp Road. As it cost $550,000 to replace the 154 feet of collapsed pipe, unearthing and replacing an additional 700 feet could cost at least an additional $1 million.

In October the authority contracted with Green Mountain for an additional 700 feet of CIPP to the Oakland Beach interceptor that cuts across Vets Middle School to Armory Street. That is a 20-inch pipe and will cost $73,700 and will be done as soon as possible after completion of the 24-inch pipe, said WSA director Janine Burke-Wells.

Hit twice by a surprise pipe collapse in the area – the first was last August when the line feeding the Cedar Swamp pumping station ruptured – the authority isn’t taking any chances. At Thursday’s meeting the authority acted to keep near the site two rental pumps that were used for the Sandy Lane bypass during repairs. In addition, the authority has installed monitoring devices at two of the Sandy Lane manholes that are programmed to send an alert to the cell phones of key personnel when water levels within the pipe either increase or drop to preset levels. When they significantly divert from those levels, a sign of a blockage, they send an alarm. This allows the authority to respond with a truck to pump out the line as the blockage is located and before there are backups into residences and businesses.

Of the 300 miles of pipes in the city’s sewer system, Burke-Wells estimates about 80 miles are concrete pipes with the newer and corrosion-resistant PVC pipe making up the difference. She explained that not all concrete pipe is the same and that the pre-stressed concrete cylinder (PCC) used for Sandy Lane was designed for a forced main. She can’t answer why the proper pipe was not used at that time.

She said the authority’s other “no-dip” options are being explored to address the aging system. Slip lining, as was done to the main interceptor running under Route 95, is another option.

Thankfully, she said, the authority has the funds in its renewal and replacement account to cover the cost of the work being done to the Oakland Beach interceptor.