Workers from IVGID work on a faulty section of the new effluent pipeline running from Incline Village to Carson City. Photo provided
The project to repair damaged pipeline that transports 1.3 million gallons of wastewater out of Incline Village and Crystal Bay everyday will open for public comment Dec. 21.
The 33-year-old line exports treated wastewater out of the Tahoe Basin and 21 miles down the hill to Carson Valley. The pipeline was mandated by the Tahoe Regional Planning Agency, which prohibits discharge of wastewater in the Lake Tahoe Basin.
The 16-inch pipe runs along state route 28, across Spooner Meadow and down Spooner Summit, a distance of about 21 miles, and an engineering feat unprecedented for a small community like Incline, according to IVGID Senior Engineer Joe Pomroy.
"It's an incredible achievement in both its scope and effectiveness," Pomroy said. "Not just the pipeline, but the pumping stations and the treatment plant showed a lot of foresight and engineering skill on the part of the district back then."
The system also includes a water treatment plant at Sweetwater Road, the Spooner Pump Station and a 9-mile gravity pipeline that travels east along Highway 50, down into the valley.
In the early 1980s, IVGID purchased 900 acres in the Carson Valley and rerouted the pipeline to that location to form a wetlands area.
"Piping the water to form the wetlands created a bird refuge and hunting preserve," IVGID Assistant General Manager Dan St. John said. "It's proven to be an effective way of re-using a resource and it is also a beautiful area."
IVGID began investigating potential corrosion to the line in August 2001 by drilling holes in the line and running a video camera through parts of the system.
"We always had small leaks here and there over the years, and this inspection that took place over about two years confirmed that there was damage to certain parts of the system," St. John said.
"When NDOT (Nevada Department of Transportation) would replace guard rails (along Highway 28) from time to time, the supports would hit the buried pipe," he said. "And while it would just dent the outer steel shell, it would crack the inner concrete lining and result in corrosion of the outer shell."
Other damage was found further down the line but this was caused by natural occurrences, according to St. John.
"What was found was that the soils that surrounded the pipe had several corrosive properties which caused the damage," he said.
Approximately 15 of the 21 miles of pipe remains in good condition. Improved surge control and corrosion protection measures will extend its life.
While repairs are needed for the 5 miles of line in the basin, there is only a mile of pipe in the Carson Valley in need of repair.
IVGID has been working with the U.S. Army Corps of Engineers, as well as partnering with Nevada State Parks, Nevada Division of State Lands, TRPA and NDOT.
To fund the project, IVGID is looking to the state's elected officials in Washington D.C.
"The federal government has authorized $100 million for these projects through the Army Corps," St. John said. "They've already authorized $51 million and have allocated $21 million to other projects throughout the state and Senators Ensign and Reid have made Tahoe a priority and are working on getting some of that money for the project."
While the $13.6 million project would be funded 75 percent by the government, IVGID would have to kick in the remaining 25 percent.
If the funding didn't happen, St. John said that the district would attempt every funding option possible.
"The fact is, the project is needed, but I would recommend that we investigate every funding option before we put it on the rate-payers," St. John said. "That is a possibility, although a little remote."
Though the Army Corps has held up construction, IVGID has started the planning and design process and hopes to have everything in place when the decision is handed down.
"Our goal is to have a camera-ready project in place, so that all we have to do is bid and build," St. John said. "But we'd like to start soon to stay ahead of the deterioration process in the pipeline."
Copies of the environmental assessment may be found online at www.trpa.org with hardcopies available for public viewing at Incline Village, Zephyr Cove and Carson City Libraries, Rainbow Printing in Incline and the IVGID Public Works and Administration Buildings.
