The war of the water tank

By Sarah Pridgeon

 

Sundance's troubled Cole water tank.

There is light at the end of the tunnel for the Public Works Department, which for the past two years has quietly toiled to keep the Cole Water Storage Tank in service. While most of us have been taking our faucets for granted, a constant battle has waged behind the scenes.

“The number one priority in our job is to supply safe drinking water,” says Public Works Director Larry Schommer, praising his team for its dedication to that task. “But our other mission is to do it, and to get through all these projects, without anybody ever noticing.”

Achieving that second goal has been no mean feat; with one water tank slowly sliding down its hill and work ongoing to install a chlorinator at Well 6, the department has been at war for the past two years with both the elements and time itself.

The hope is to perform a smooth transition before the Cole tank finally gives in to gravity, moving it from one site to the other without a moment’s interruption in water flow. Meanwhile, the current site grows more unstable by the day and requires vigilant monitoring.

“We’ve been limping along with that tank for going on two years,” says Schommer. “The fact that it’s still usable at the old site is very, very fortunate – we’ve essentially been gambling for two years.”

How long it can remain in place is anybody’s guess. Its stability relies largely on the weather.

“It all depends on the moisture we get,” Schommer explains. “In a normal year it would already be unusable. The drought has been bad for many people and I’m certainly not discounting the hardship it’s caused elsewhere, but it has been fortunate for us.”

It would cost the city upwards of $45,000 to properly establish the tank’s current stability. Instead, the team keep watch on it themselves, using a SCADA control that monitors the water level and alerts them if it drops below a certain figure.

“We try to keep the minimum amount of water in it, from one to ten feet,” says Schommer. “The alarm is pretty sensitive – it can go off if there’s a sudden change in temperature or if there’s a hiccup in the tank talking to the wells.”

It can go off, and it does go off – often in the middle of the night. For two years, the team’s nightly rest has been at the whim of the alarm; each time it triggers, someone must drive to the office, check the monitors and, if necessary, head to the tank itself to be sure that all is well.

Even so, you won’t hear a complaint from within the department; to the team, it’s all part of the job. Quickly dismissing the question of how one would ever get a proper night’s sleep, Schommer moves on to what would happen if the tank took a tumble.

“Looking at it, and the way it’s progressively getting worse, in my estimation it will break a transmission line before it goes all the way down the hill. It’s doing a natural slide, trying to kick out at the bottom and rotate.”

The team has not neglected to make a contingency plan, should the worst happen. Again, it’s an operation that few residents would be aware of.

“We’ve done several drills to work out what we would do,” Schommer explains. “We can have the tank offline in a matter of minutes if the problem can’t be fixed. There would be a fluctuation in water pressure on the Orr Subdivision and for somewhere between 15 and 20 residents on the east side of town, but that would be the only immediate effect.”

Meanwhile, one hitch after another has beset the change of site; rock drilling will now be performed up to 30 feet under the new site to identify the best choice of foundation. Although geologists maintain that the site is stable enough for there to be no need to drill, Engineering America is uncomfortable with the complex construction of a concrete foundation.

“So we’re going to drill to simplify that foundation,” Schommer explains. “We won’t know until we drill what will be needed, we’ll design it from the geotechnical report.”

Drilling will clarify whether rock anchors are needed, whether blasting can be used during construction and how the slope will affect what can be excavated and to what depth. Winter has also taken a toll on the process, slowing progress by denying access to the site.

“The weather hasn’t helped, no,” agrees Schommer. “It’s difficult to get up there in winter, even on a tracked rig. With the recent thaw, though, we’re getting close to where we can get up there.”

If the move can be made before the tank’s situation becomes too critical, the best case scenario will be for Engineering America to take it down from the old site and move it immediately to the new one. The engineering firm remains on standby, ready and willing to move the tank when the time comes.

“One mobilization would be highly preferred by everyone, but we’re really on the edge with the current site, every day is a gamble,” says Schommer.

In the meantime, the tank remains in place to keep the water flowing smoothly. “The only reason it’s still in use is that otherwise we get a tremendous water hammer. We’re going to install a check valve to minimize that. It’s in the final stages of engineering design and then the Department of Environmental Quality permit will take around 45 days.”

With a check valve installed, the department will feel a lot more comfortable about taking the tank offline. “But it’s not hurting anything now to have it online, it’s not progressing the slide. It’s going to do what it’s going to do, whether we’re using it or not,” Schommer adds.

Although Well 6 is offline for construction, it can be brought back online within hours should there be a catastrophic failure on the east side and could supply the town during the winter months, when water demand is at its lowest. Not so in the summer, however.

“It’s important that we get this finished in time for that higher demand,” says Schommer. “There are a lot of things going on behind the scenes, timing wise – we hope for the best, but we plan for the worst.”

The team is aiming to complete Well 6, along with the check valve, before the Cole tank comes offline. Such complicated juggling of project timings is intended, as always, to minimize the impact in town.

“Nobody should be out of water,” Schommer confirms. “The worst case will be some pressure fluctuation.”

For the past two years, the Public Works Department has been on call 24 hours a day to nurture each project to completion and make sure the city never loses access to its fresh, clean water. Though it’s a task that must surely take a toll, the team takes pride in how well their work has remained hidden; “If nobody ever knows what we were doing, then we did our job adequately,” says Schommer.