Engineer recommends maintenance to keep things flowing in sewers

Warwick — Park Lane residents, who have had to deal with sewage overflows over the past few years, may soon be free of the foul and unsightly problem. After studying the flow through a large section of the village’s sewer system — most everything east of Main Street - there was both good news and not so good news. The good news, according to village engineer Michael Murphy of HDR/LMS Engineering, is that there is no major infiltration from ground water and therefore no major reconstruction project looming over the village. The pipes that were monitored throughout September and October - 10 miles of sewer mains and 20 miles of sewer connection lines in total — are in good shape. The inside of the pipes were structurally sound. Only one 70 foot area along Forester Avenue should be replaced because of a rock protruding into it. The bad news, Murphy said, is they haven’t found the problem that is causing the overflow on Park Lane, which only occurred after major rainstorms. Murphy said he believes the problem is caused by sediment in many of the pipes. Some of the pipes were 75 percent filled with sediment. Another problem throughout the system is the slope of the pipes. “Some pipes are dead level,” said Murphy in his presentation to the Village Board. “It is hard to flow through level pipes.” And it is not possible to pitch the pipes on a better slant to get the sewage moving better. That is restricted by the terrain in the village. And it would also be a major undertaking. The pipes meet the minimum slope required by the Department of Environmental Conservation. Instead, Murphy suggested that the village put together a year-long program of pipe cleaning. “Cleaning the pipes is a good first step,” said Murphy. “It may cost tens of thousands of dollars instead of hundreds of thousands of dollars to replace them.” How it will be done will be with high pressure jets that are inserted to push the sediment to the next manhole where it is suctioned up. “Is there a risk to the system with power washing them?” asked Trustee Eileen Patterson. “If the pipes are in bad shape, yes,” said Murphy. “But you have to get the sediment out of there.” And from the testing of the system, the pipes were deemed sound. Last May the DEC sent a consent order to the village to determine what was happening to cause the overflow on Park Lane and to repair it. The village engineer set up five flow meters throughout the system during September and October. With no major infiltration found, Murphy said, the survey of sewer mains for slopes was more telling that the flow monitoring. His complete report will be done by Jan. 31.