If you’re working on a project that involves going under the surface, you’re going to want to avoid striking utilities, keeping your distance as far as possible from existing lines. What do you do if you suspect there are utilities at your site? How close can you get to existing structures before they become a problem? Luckily, there’s a handful of ways you can be mindful and keep clearance for underground structures to prevent damages.
An important first step is to call 811 and verify the existence of public lines. Public lines are connected to existing infrastructure owned by other utilities, usually connecting to public services such as water, gas, electric, cable, or sewers (although there are some varying rules around sewer lateral ownership depending on where you are). The best way to consider this is to imagine utilities entering from outside of a property from the street or sidewalk. It’s important to do this step because it’s the law to call 811 at the minimum. Not all lines will be marked by 811, however, and it’s important to understand private utilities may fall within the same area as public ones.
Second would be to perform utility locating or hiring a professional private locator. On top of locating private lines, private utility locators can reverify public lines made by 811 to make sure there aren’t inaccuracies. There are a number of different ways to locate underground utilities. The most common locating method is through radio detection: using a digital locator and a combination of passive and active scans to examine existing structures. Passive scans are sweeps of an area to pick up a natural utility signal and tracing the signal to surface features. Active scans involve connecting to a utility, sending a signal from a radio transmitter to detect a specific radio wavelength. It’s kind of like tuning your car’s radio until you find a song you really enjoy, except that song is a utility you don’t want to hit. Another method is ground penetrating radar, or GPR, using electromagnetic waves to examine the potential for structures by reflecting radiowaves through the ground and reflecting off of structures. Underground utilities, structures and other anomalies are picked up in this data through spikes and dips along the wavelike data.
Now that you have marks and plans for all of your utility lines, you’ll want to keep clearance of existing marks. The common recommendation is within a foot and a half of each side of the utility marking. This makes room for any slight marking errors and acknowledges that utility lines can vary in size. You’ll also want to be especially careful working around utility surface features, such as electrical boxes and manholes. Being spatially aware on a job site is a safety tip that extends beyond protecting utilities, and that extends to what can’t be seen from the surface. Communicating this information to others working on your project is important as well. It’s not unheard of that someone may completely ignore these spraypainted marks and pull out utility flags, hitting a utility line in the process of excavating.
What if utilities fall within an area with a lot of congested utility infrastructure? It’s not uncommon for utilities to run parallel or perpendicular, sometimes even boring through other utilities. When these situations happen, vacuum excavation comes in handy. By performing soft dig test hole investigations, you’ll get an accurate idea of the exact depth, size, and direction of your utility lines. This will give you a clear picture of the clearance you need to keep your distance from hitting utilities at your site.If you need professional utility locating services for your project, our team at Trinity Subsurface can help you locate and safely excavate around utilities, helping you stay away from damages, injuries and project delays. Visit our website to find out more about the full suite of utility services we can offer for your next project.
