When you think of construction safety, what comes to mind first? It’s a question that arises every year during Construction Safety Week. For many, it’s proper-fitting PPE. For others, it’s about the proper protocols for working at heights or other dangerous environments. Recently, mental health has emerged as an inextricable part of the construction safety landscape. If you go to Google Images and type in “construction safety,” you’ll likely find pictures that reflect many of those things.
What you probably won’t find, though, is a picture of someone working in a trench or calling 811 before starting a project that involves digging.
While trench safety has found its way into the hot seat in recent years to do spikes in trench collapses and subsequent fatalities, the issue of utility damage prevention has largely flown under the ground-penetrating radar, especially at the residential level. A recent national survey for the Common Ground Alliance found that 68% of Americans plan to take on a do-it-yourself project involving digging within the next year. However, 27.2 million of them will not contact 811 beforehand, which puts themselves, their neighbors and essential utility services at risk.
As CGA emphasized in an April press release for Safe Digging Month, planning projects and digging without knowing the location of underground utilities can lead to serious injuries, service outages and expensive repairs. Accidentally striking gas, electric, communications, water or sewer lines can cause significant disruptions to homes and businesses.
“What is under the ground is very difficult to understand,” said Bill Kiger, president and CEO of Pennsylvania 811. “And you don’t know where an underground line is when you’re looking at grass, concrete or asphalt. Underground lines are often ‘out of sight, out of mind,’ which can pose a risk to excavators and homeowners. It’s very important that you call 811.”
The one call system is a solution that streamlines the communications between project owners, designers, excavators and facility owners. In Pennsylvania, 811 serves as the central hub for transmitting relevant information provided by those digging to the member underground facility owners within the municipality where the excavation is taking place. By doing so, it ensures that the affected facility owners are notified before the excavation begins.
“A facility owner provides the approximate position of their underground lines at the excavation site within eighteen inches horizontally from the outside edge of a line or facility,” Kiger said. “Within the tolerance zone an excavator employs prudent techniques which may involve hand-dug test holes until the utility line is exposed, or use of vacuum excavation. If an excavator damages a line even with a spoon, they’re not using prudent techniques.”
Ed DeNeale, director of safety at the National Utility Contractors Association, says that for nonresidential utility construction, labor shortages and increased construction activity have worsened the problem, creating significant downtime and financial risks for contractors when utilities are unmarked or mismarked.
“There’s no avenue for a contractor to go back to the utility owner and say ‘Hey, I just had … three hours of downtime. I need to back charge you,” DeNeale says. “So what incentive does a utility owner or a locator that’s contracted that utility owner … to start to remedy some of these issues that we’re seeing over and over and over again? Nothing.”
NUCA is tackling issues like this through its damage information reporting tool (DIRT). It is an enhanced data collection system developed in partnership with the Common Ground Alliance. Unlike the standard CGA DIRT program, NUCA’s version collects more comprehensive data about utility damages. DeNeale says the NUCA DIRT program collects utility owner names, helps identify root causes of damages (e.g., mismarked utilities, unmarked facilities), track damages by state, county and specific utility, and provide detailed analytics on utility damage incidents. The primary purpose is to gather granular data that can be used for advocacy and legislative efforts. As DeNeale explains, they can now precisely break down damage information, showing exactly how many damages occurred, in which counties, the utilities involved, and what caused them. The goal is to use this detailed data to demonstrate specific problems in utility locating, support legislative changes, improve safety standards and provide good evidence when advocating for industry improvements.
At the state and local level, DeNeale says that in Maryland and Washington, D.C, contractors, utility owners and locators meet monthly for 811 meetings to collaboratively develop legislative changes, ensuring all parties have input and buy-in before presenting proposals to state legislators. A concrete example of their collaborative approach is a new law requiring locators to run a tracer wire from the house to the main utility line, which was developed through consensus among all stakeholders.
What about bigger projects?
Avoiding utility damage is hard enough for smaller residential and commercial projects, but it gets infinitely more complicated when you’re importing a huge tunnel boring machine from Germany to create a overflow tunnel. At last month’s Associated General Contractors of America convention in Columbus, Ohio, Granite Construction’s power couple David and Maria Chaska explained the challenges of working with a massive TBM for the Lower Olentangy Tunnel project—a $265 million effort to bore a 3.5-mile tunnel that will help prevent combined sewer overflows by providing underground storage for stormwater during heavy rain events. Now approximately 90% complete, the tunnel is expected to drastically reduce the frequency of sewer overflow events.
Using a $16 million Earth Pressure Balance tunnel boring machine, the crew advances through soft ground at a rate of 60 feet per day while simultaneously installing concrete tunnel segments. The work is highly technical and runs almost constantly. Due to space constraints in Columbus, the TBM was launched twice: first driven one mile south, then retrieved and relaunched to complete the remaining stretch northward. The tunnel runs just 40 to 60 feet below the surface, often in densely developed areas with unpredictable underground conditions.
A key approach to utility damage prevention has been route selection. Rather than cutting through private property or sensitive areas, the project team chose to align the tunnel underneath existing public roadways whenever possible.
“We had to drive it under a road which seems kind of productive, especially with the ideas of sinkholes, but we stayed under a road almost the entire way, because they owned it,” explained David.
In areas where underground alignment had to shift, the team took additional precautions. One such case was near the Stephanie Spielman Breast Cancer Center. “Instead of taking the true alignment, which would have been straight under the Breast Cancer Center, we had to wing out the road and take a real hard curve right off the bat, which was not fun,” said David.
The TBM also helps prevent surface settlement and utility disruptions.
“We live and die by that pressure bubble that we’re producing, so if anything is interrupting that, we stop and hold the bubble and fix whatever we have to fix,” noted Maria.
This constant monitoring and rapid-response capability reduce the risk of unintentional ground movement that could affect nearby infrastructure. Ground-penetrating radar and borehole data inform the team’s excavation strategy and soil conditioning techniques. These tools allow them to detect potential voids or unexpected materials that could compromise tunnel stability or risk damaging existing utilities.
“We’ve used ground penetrating radar on this job … to try to see if there are void spaces between where we’re going to be and the surface,” said Maria.
Safety on site extends beyond engineering controls. Granite’s safety culture emphasizes daily briefings, hazard recognition and worker empowerment. The project team has implemented an immediate, personal recognition system to reinforce a culture where safety is shared responsibility.
“Every person on our job knows at any point in time… they can, on the spot, get a $25, $50, $100 gift card just for doing [safety] right,” said David.
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