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Maine Moves Ahead On CSO Projects
Lewiston's Most Difficult Job Faced Multiple Problems
The SaniTite pipe used was 15 and 18-inch diameter sanitary sewer, 42 and 48-inch diameter for the storm drainage along with another 400-feet of 48-inch for the sanitary sewer sliplining of the old RCP pipe. Additionally, the project used 12, 15 and 18-inch diameter ADS N-12 corrugated HDPE pipe for storm drainage collector piping. The company also helped with the design of the T-Base manholes that included pre-manufactured tees. "It was a doghouse structure with a six-foot diameter manhole around it and encased in concrete that worked out really well," stated Beaule.
Angles and manhole
After all the connections were made, the trenches were backfilled with regular sand and gravel and rock that was brought back.
"We put in an 8-foot by 12-foot concrete manhole in the middle of one of the busiest streets in Lewiston," Gendron continued. "They had to actually close down the street to make the connections – we had many different angles and turns. We had 90-degree and 45-degree connections and even 22-degree bends. We had to have pipe made so we could come up at a 45-degree angle and back at a 45-deree angle. It was like a big slide in the hole and how we did it was very intricate."
"The CSO project was very challenging and very time consuming. When Todd and his crew got near an old 60-inch concrete transmission sewer main, they found the joints were leaking. They ended up having to install 400-feet of the 48-inch pipe to segmentally slipline and rehabilitate the sewer pipe," explained Beaule.
"As the crew was digging alongside that old concrete pipe, the effluent was just pouring out of all the joints because there were no gaskets in the concrete pipe – it was a 50-year-old RCP pipe. With the effluent pouring out into the trench it was decided that we needed to do something quickly and sliplining seemed to be the best option since we already had a big hole opened. Matt Timberlake of the Ted Berry Company headed up that operation. Gendron helped them out with the excavation that was needed. Since we were installing a second storm drain for the CSO, we didn't need the full 60-inch capacity of the old sewer, so the 48-inch pipe that we already had onsite worked perfectly. They just slipped it right through and it worked out great."