Sewer project provides underground history lesson

Two men protected by an orange trench box work at a depth of 20 feet to replace a sewer line under 100 West near Center Street. City of Moab Engineer Chuck Williams said this section was the deepest encountered along the 1,900-foot project. Photo courtesy of City of Moab

A fairly simple public works project turned into a frustrating and fascinating archaeological dig of sorts for the men and women who worked on the City of Moab’s 100 West Infrastructure Project, resulting in a nearly five-month delay at a cost overrun that has not yet been tabulated.

The primary goal of the project that began late last summer was to replace 1,900 feet of failed 18-inch sewer line from just north of Walnut Lane, south on 100 West, under Mill Creek and almost to 200 South.

That and other key work – such as a new shared use path for pedestrians and bicyclists – is nearly finished five months after a December completion date came and went.

A very wet and cold winter contributed to frequent delays or work slowdowns, but the real culprit, according to Moab City Engineer Chuck Williams, lurked underground, where decades of utility installations vexed employees of Nelco, the Price-based contractor that was awarded the contract last August.

“We encountered storm drains and waterlines buried 14 feet underground,” said Williams. “We found abandoned gas, irrigation and fiber optics. This slowed us down because we have to treat them as ‘alive,’ or functional.” And they kept encountering them, some going back perhaps as far as eight decades. “I’m pretty sure one of the waterlines was from the World War II era,” said Williams.

They found an active storm drain that was corroded. “All of this was down there and nobody knows for how long,” he said. “So, the question became, ‘Do we blow by or do we repair or replace?’ My point is, this added to the scope of the project.”

Did it ever. Williams said that among the unexpected fixes were the replacement of four waterlines and the associated valves totaling roughly 300 feet, as well as another 350 feet of storm drains.

The problems were not entirely unforeseen. “Going into it we anticipated having to deal with the unknown,” he said. Williams noted the sewer pipes that were replaced carry a load that comes from as far away as Spanish Valley on its way to the city’s wastewater plant at 1070 West and 400 North.

While sewer lines are usually buried deeper than other utilities, such as water or gas, Williams said some waterlines and storm drains were 14 feet deep. Interestingly, most of them were not installed at that depth. Williams said it was the road being built up over the years that created the problem – in some cases as much as 10 feet. For whatever reason, some of the utilities encountered were indeed buried that deep. Leaky waterlines were repaired, as were active but corroded storm drains.

Along the way, Nelco engineers went under Mill Creek and at several junctures crews had to dig across the street to make replacements or repairs.

The jumble of still-used and long abandoned utilities below the ground on 100 West – the fourth busiest street in Moab – is undoubtedly a problem elsewhere in the downtown area.

“There is no doubt Moab has some old and aging infrastructure,” said Williams. “I would like residents to know we now have GIS [Geographic Information System mapping technology].”

Public Works engineers map out where the utilities are so people in the future have a better understanding of where we are.”

The city has been using GIS for more than five years, but records were not diligently kept in the past so problems like those encountered on 100 West could surely recur in the downtown area as other projects are addressed.

Williams pegged a ballpark estimate of the cost overrun at between 10 and 20 percent – or between $236,000 and $472,000. Money was saved, however, when the city entered into a “time and materials” deal with the contractor that allowed city crews to replace water pipes that weren’t part of the contract using Nelco’s heavy equipment, some that the city doesn’t have in its fleet.

“We took advantage,” said Williams. The city implemented a five-year moratorium on pavement cuts for utilities in the project area. Dominion Energy was able to replace about 200 feet of gas line. The moratorium is in effect from Main Street and 100 South to just north of Walnut Lane on 100 West.

What’s next?

The next big plan for the city is the North Sewer Trunk Line Project, which calls for the installation of 3,500 feet of 15-inch sewer line from Highways 191 and 128 south to just past Slickrock Campground.

This will result in two campgrounds – Sun Moab Valley is the other one – that will be taken off of a septic system and hooked into city sewer. Williams said all of the business on that stretch of road – including two hotels that use maintenance-heavy lift stations to pump sewage to the city’s lines – will transition to sewer.

“We expect to go to bid within three months,” said Williams. He said he doesn’t anticipate running into the multi-generational maze of utilities found beneath 100 West, but that doesn’t mean there won’t be issues. The groundwater is shallow and will have to be pumped as the lines are installed.

Williams said the community was generally gracious while the work on 100 West continued for months after it was supposed to be finished, but motorists mostly complied with traffic laws. The only down moments came from business owners who were upset when the project required water to be unexpectedly shut off, sometimes for half of the day. “Especially when it happened a second time,” he said. “We just couldn’t help it.”

Moab is far from the only community in the nation with aging infrastructure. It’s a problem throughout the country, something Williams knows better than most, saying, “You know how presidential candidates always talk about infrastructure and how it’s a problem that needs to be fixed? This is what they’re talking about.”