Despite an incident that could have set back construction of Water Treatment Plant 4, the plant will be operational in spring 2014 as planned, said Greg Meszaros, director of Austin Water Utility.

In August, Austin City Council directed city staff to examine the cost of delaying completion of the plant by five years or 10 years. Staff concluded a delay could cost between $138 million and $206 million, on top of the $508 million price tag, so council voted against halting construction.

"That was a strong statement," Meszaros said of the vote.

In another incident, media reports in December claimed that workers drilling near the intersection at RM 620 and RR 2222—at what is known as the Four Points shaft—noticed water seeping into the shaft area. However, Meszaros said the seepage was minimal, about 1 to 2 gallons per minute, and that some seepage had been anticipated. Meszaros said the seepage now amounts to one-one hundredth of an inch per day.

Austin Water is funding construction of the treatment plant. Initially, WTP4 will treat 50 million gallons of water daily; at full capacity, it could treat up to 300 million gallons per day.

The Jollyville Transmission Main

Construction of the Jollyville Transmission Main, which will be located 100 to 340 feet underground and will carry treated water from the plant at Lake Travis to the Jollyville Reservoir started in October.

Workers are using four open shafts, or 50- to 80-foot-wide vertical tunnels, to excavate material and install the underground water main. The shafts are located at the plant off RM 620 at Bullick Hollow Road; in the Four Points area; at the intersection of Spicewood Springs Road and Old Lampasas Trail; and at the Jollyville Reservoir.

The Four Points shaft, for which tunneling began in October, is in the most environmentally sensitive area, Meszaros said. Much of the structure is surrounded by water-bearing or porous limestone in the Edwards Aquifer.

"It's the riskier part of construction. The odds of [seepage] happening again is much less likely to occur, but you just can't say for sure," Meszaros said.

Shaft construction

Meszaros said about 85 percent to 90 percent of the work at the plant—including construction of the underwater intake structure at Lake Travis and the treatment buildings—had been bid upon and awarded to contractors.

Austin Water plans to begin work on the Spicewood Springs shaft in February. Many residents who live near the shaft site had initially protested the amount of truck traffic that would occur along Spicewood Springs Road as a result of construction, but Austin Water staff came to an agreement with residents in spring 2011 to control dust and limit work hours.

"We significantly changed the truck traffic down to just a few hundred truckloads of traffic over the next few years," Meszaros said.

Austin Water will host neighborhood meetings with residents who live near this shaft site to explain the work that will be done and what they can expect when construction begins.

"There's still some neighbors who flat out don't want this," Meszaros said. "By and large, we are doing our best to make sure these relationships are good."