SAK Construction has rehabilitated three sewage siphons that run beneath the Truckee River in Reno, Nev., as well as pipelines that serve the city’s main water treatment plant.
The siphons were built to channel sewage from collector lines to an interceptor trunk that opened in 1976 with a projected service life of 50 years. Inspections of the system earlier this decade revealed pipeline corrosion. Given that the Truckee River supplies Reno’s drinking water and is heavily used for recreation, the city sought an expedited solution to prevent a major pollution event. Minimizing the duration of any bypass, limiting traffic blockage and completing the work with minimal day-to-day disruption were other requisites.
O’Fallon, Mo.–based SAK relined 45,000 linear ft of pipe with diameters of 8 to 72 in. cured-in-place-pipe (CIPP). In addition, it rehabbed another 3,500 linear ft of 60-in. pipe and 3,500 linear ft of 72-in. pipe that fed directly into the treatment plant. It also refurbished two 48-in. siphons and a 24-in. siphon under the river.
To bypass the 60 million-gal-per-day system that ran beneath the river, SAK collaborated with subcontractor Munson Pump Services of Anderson, Calif., to detour around the under-river system and, at times, past the entire treatment plant for a span of almost six months. When bypassing was not an option, SAK performed CIPP relining in live flow conditions in junction structures next to the line.
“This was likely the most environmentally and logistically challenging CIPP project put out to bid by the city of Reno in the last 15 years,” said Thayne Loendorf, project manager at environmental engineering consultant Brown and Caldwell. “It was complicated by lining siphons under the Truckee River, proximity to a wastewater treatment plant, high ground water levels and the need to coordinate activities with an adjacent highway project and to bypass high volume sanitary sewer flows.”
Source: SAK Construction
