Paula Wallis, Reporter

The owner had hoped construction would begin this summer on a mega sewer outfall project in the Las Vegas region. But like the City of Detroit, which is suffering dramatic drops in ratepayer revenues for its public works projects, funding sources for the massive SCOP project for the Clean Water Coalition (CWC) in Nevada have dried up.

"We've got things ready to go. Half of the project is bid ready," CWC's former General Manager Doug Karafa was quoted in February. "We've slowed down because of the economy."

Fig 1. Alignment of the SCOP wastewater conveyance project

At an estimated cost of $860 million (in 2009 dollars), the System Conveyance Operation Program (SCOP) project includes a 9.3 miles long, x 120in minimum diameter (15km x 3m) tunnel through the River Mountains to a new wastewater outlet at the bottom of Lake Mead (Fig 1).

Two thirds of the project's cost was expected to come from connection fees driven by new residential and commercial construction, but those revenues have evaporated.

''That's why we've adopted a slight wait and see attitude,'' said John Brumley, Financial Manager for the CWC. ''Revenue from new connections totaled roughly $29 million in 2008, but the agency anticipates receiving less than half that, or about $14 million in 2009, and even less next year.''

Brumley also says the project won't receive much from the US federal government's economic stimulus bill. The American Recovery and Reinvestment Act allocates nearly $3.9 billion to wastewater projects nationwide and Nevada's share is about $19 million. Of that, only a few million is expected to trickle down to the CWC.

Table 1. SCOP cost summary in year of expenditure dollars

The CWC is also hoping $50 million in federal funding will be released from the Army Corps of Engineers. The money was authorized for the project as part of a 2007 water bill, but has yet to be appropriated.

''We will take anything we can get,'' said Brumley, ''but it won't be enough to start the project.''

Nevada and half a dozen other states received the minimum amount allocated for water projects from the stimulus package, with the largest sum, $437 million, going to New York, followed by California at $283 million, and Ohio with $223 million.

While the CWC financial team in Nevada scrambles to secure funding, the SCOP design team has revisited some of the priorities of the project and investigated value-engineering options to make the most of every dollar.

''In late February we held a two day workshop with our consulting engineers and primary designer, Black & Veatch, to take another look at where we could save,'' said Jim Devlin, CWC's Engineering Manager. ''By the end of the two days we had come up with $60 million in value engineering savings.

The wastewater conveyance project is broken into five reaches, with the major tunnel drives coming in Reaches 3 and 4 (Fig 1). Reach 3 includes a 5,280ft x 120in diameter (1.6km x 3m) tunnel that crosses under the Las Vegas Wash and connects to the 44,000ft long x 120in minimum diameter (13.5km x 3m) River Mountains Tunnel No. 3. The east shaft location connects to a pressure reducing/power generation station located on the east side of River Mountains. ''During the workshop we discussed combining the Reach 3 and 4 contracts,'' said Devlin. ''That would save time, cut some redundancies, and take advantage of economies of scale.''

The panel also recommended applying for a permit from the State to discharge ground water from the tunneling works directly into the Las Vegas Wash instead of evaporating it on site or feeding it into rapid infiltration basins.

Project purpose, scope and design

''That saves a lot of money because the intermediate lining system can be less robust,'' said Devlin. ''If we had to deal with the water we're talking about segmented liners and without the water we can use a less watertight, less costly intermediate lining.''

The tunnel alignment is also under review to achieve a more direct drive to Lake Mead. But given the geology, Devlin was not optimistic that the investigation of six to eight weeks would yield any significant changes or savings.

The CWC had hoped to advertise the two tunnel contracts in the fall of last year, but the schedule has been revised. If Reaches 3 and 4 are combined, which Devlin says is very likely, that larger, mostly tunneling contract will bid in January 2010 at the earliest.

CWC officials are disappointed that the work is on hold just when the region could use the jobs and the costs of raw materials are way down. Oil, that was at more than $150 a barrel 10 months ago, is now down to around $50 a barrel and steel has dropped below $300 a tonne from a high of $1,200 a tonne a year ago. The sewer outfall project is also expected to create more than 1,400 jobs over a five-year period.

''The timing is unfortunate, but we do anticipate going forward with construction and I would imagine we would start advertising some of the other non-tunneling contracts by summer or fall of this year,'' said Brumley. ''But we're definitely working towards living within our means.''

SCOP is designed to pipe about 400 million gallons of wastewater, treated to near drinking water standards, from the valley's sewage treatment plants to a pipeline discharge at the bottom of Lake Mead some three miles off shore. Right now, about half that amount is treated and released into the Las Vegas Wash to flow downstream to Lake Mead.

The new conveyance system will secure the region's own drinking water supply. Nevada earns return-flow credits for every gallon of wastewater injected into the lake, allowing it to almost double its annual potable water share of the mighty Colorado River. Without the credits, the state's river allotment would not be enough to meet Southern Nevada's water demand.

The Clark County Water Reclamation District and the cities of Las Vegas and Henderson, the three agencies that make up the CWC coalition, are developing SCOP.

References

Detroit's Upper Rouge River CSO tunnel project -TunnelTalk, Apr 2009

Water project allocations from the US stimulus package